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list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0705.1698 | Joel Kamnitzer | Joel Kamnitzer | Hives and the fibres of the convolution morphism | 11 pages | null | null | AIM 2007 - 24 | math.AG math.RT | null | By the geometric Satake correspondence, the number of components of certain
fibres of the affine Grassmannian convolution morphism equals the tensor
product multiplicity for representations of the Langlands dual group. On the
other hand, in the case of GL_n, combinatorial objects called hives also count
tensor product multiplicities. The purpose of this paper is to give a simple
bijection between hives and the components of these fibres. In particular, we
give a description of the individual components. We also describe a conjectural
generalization involving the octahedron recurrence.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 17:22:49 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Aug 2007 17:05:00 GMT"
}
] | 2007-08-23T00:00:00 | [
[
"Kamnitzer",
"Joel",
""
]
] |
0705.1699 | Charles Epstein | Charles L. Epstein | Subelliptic Spin_C Dirac operators, II Basic Estimates | To appear Annals of Math. 57 pages. Wrong file uploaded on previous
attempt. The second revision fills a gap in the proof of Proposition 16 | null | null | null | math.AP math.SG | null | We assume that the manifold with boundary, X, has a Spin_C-structure with
spinor bundle S. Along the boundary, this structure agrees with the structure
defined by an infinite order integrable almost complex structure and the metric
is Kahler. The induced CR-structure on bX is integrable and either strictly
pseudoconvex or strictly pseudoconcave. We assume that E->X is a complex vector
bundle, which has an infinite order integrable complex structure along bX,
compatible with that defined along bX. In this paper use boundary layer methods
to prove subelliptic estimates for the twisted Spin_C- Dirac operator acting on
sections on S\otimes E. We use boundary conditions that are modifications of
the classical dbar-Neumann condition. These results are proved by using the
extended Heisenberg calculus.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 17:30:33 GMT"
},
{
"version": "v2",
"created": "Mon, 14 May 2007 10:50:56 GMT"
},
{
"version": "v3",
"created": "Fri, 2 Nov 2007 13:52:32 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Epstein",
"Charles L.",
""
]
] |
0705.1700 | Richard J. Mathar | Richard J. Mathar | Synthesis of Taylor Phase Screens with Karhunen-Loeve Basis Functions | 19 pages, 1 Figure, RevTeX4. Table in Appendix C corrected | null | null | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Phase screens above a telescope pupil represent the variation of the phase of
the electromagnetic field induced by atmospheric turbulence. Instances drawn
from such statistics are represented by a vector of random phase amplitudes
which are coefficients of a linear superposition of two-dimensional basis
functions across the pupil. This work shortly reviews Fried's analysis of this
modal decomposition for the case of Kolmogorov statistics of the phase
covariance as a function of separation in the pupil plane.
We focus on the numerical synthesis of phase screens. The statistically
independent modes are transformed into the eigen-modes of a gradient matrix as
time-dependence is introduced such that on short time scales the instances of
the phase screens are rigidly shifted into a direction imposed by some wind
velocity - known as the Taylor frozen screen approximation. This simple
technique factorizes spatial and temporal variables and aims at binding the
time dependence of the phase screens to the few expansion coefficients of the
basis functions that obey a stochastic time-dependent differential equation.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 17:33:53 GMT"
},
{
"version": "v2",
"created": "Fri, 23 Nov 2007 16:11:53 GMT"
},
{
"version": "v3",
"created": "Fri, 29 Feb 2008 15:19:57 GMT"
},
{
"version": "v4",
"created": "Fri, 23 Oct 2009 14:21:10 GMT"
}
] | 2009-10-23T00:00:00 | [
[
"Mathar",
"Richard J.",
""
]
] |
0705.1701 | P\'ech\'e Sandrine | Sandrine Peche | Universality results for largest eigenvalues of some sample covariance
matrix ensembles | 3 figures 47 pages Simulations have been included, a mistake in the
computation of the variance has been corrected (Section 2.5) | null | null | null | math.PR math.ST stat.TH | null | For sample covariance matrices with iid entries with sub-Gaussian tails, when
both the number of samples and the number of variables become large and the
ratio approaches to one, it is a well-known result of A. Soshnikov that the
limiting distribution of the largest eigenvalue is same as the of Gaussian
samples. In this paper, we extend this result to two cases. The first case is
when the ratio approaches to an arbitrary finite value. The second case is when
the ratio becomes infinity or arbitrarily small.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 18:06:10 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Jun 2007 03:35:36 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Peche",
"Sandrine",
""
]
] |
0705.1702 | Charles Epstein | Charles L. Epstein | Cobordism, Relative Indices and Stein Fillings | null | null | null | null | math.AP math.CV | null | In this paper we build on the framework developed in "Subelliptic Boundary
Value Problems for the Spin_C Dirac Operator, I, II, III" to obtain a more
complete understanding of the gluing properties for indices of boundary value
problems for the SpinC-Dirac operator with sub-elliptic boundary conditions. We
extend our analytic results for sub-elliptic boundary value problems for the
SpinC-Dirac operator, and gluing results for the indices of these boundary
problems to SpinC-manifolds with several pseudoconvex (pseudoconcave) boundary
components. These results are applied to study Stein fillability for compact,
3-dimensional, contact manifolds.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 17:49:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Epstein",
"Charles L.",
""
]
] |
0705.1703 | Garret Lau | G. C. Lau, B.G. Ueland, M. L. Dahlberg, R.S. Freitas, Q. Huang, H. W.
Zandbergen, P. Schiffer and R. J. Cava | Structural Disorder and Properties of the Stuffed Pyrochlore Ho2TiO5 | submitted to Phys. Rev. B | null | 10.1103/PhysRevB.76.054430 | null | cond-mat.mtrl-sci | null | We report a structural and thermodynamic study of the "stuffed spin ice"
material Ho2TiO5 (i.e., Ho2(Ti1.33Ho0.67)O6.67), comparing samples synthesized
through two different routes. Neutron powder diffraction and electron
diffraction reveal that the previously reported defect fluorite phase has
short-range pyrochlore ordering, in that there are domains in which the Ho and
Ho/Ti sublattices are distinct. By contrast, a sample prepared through a
floating zone method has long range ordering of these sublattices. Despite the
differences in crystal structures, the two versions of Ho2TiO5 display similar
magnetic susceptibilities. Field dependent magnetization and measured recovered
entropies, however, show a difference between the two forms, suggesting that
the magnetic properties of the stuffed pyrochlores depend on the local
structure.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 17:58:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lau",
"G. C.",
""
],
[
"Ueland",
"B. G.",
""
],
[
"Dahlberg",
"M. L.",
""
],
[
"Freitas",
"R. S.",
""
],
[
"Huang",
"Q.",
""
],
[
"Zandbergen",
"H. W.",
""
],
[
"Schiffer",
"P.",
""
],
[
"Cava",
"R. J.",
""
]
] |
0705.1704 | Yaroslav Kartashov | Eugene Smirnov, Christian E. Ruter, Detlef Kip, Yaroslav V. Kartashov,
Lluis Torner | Observation of higher-order solitons in defocusing waveguide arrays | 13 pages, 3 figures, to appear in Optics Letters | Optics Letters 32, 1950 (2007) | 10.1364/OL.32.001950 | null | physics.optics nlin.PS | null | We observe experimentally higher-order solitons in waveguide arrays with
defocusing saturable nonlinearity. Such solitons can comprise several in-phase
bright spots and are stable above a critical power threshold. We elucidate the
impact of the nonlinearity saturation on the domains of existence and stability
of the observed complex soliton states.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 17:55:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Smirnov",
"Eugene",
""
],
[
"Ruter",
"Christian E.",
""
],
[
"Kip",
"Detlef",
""
],
[
"Kartashov",
"Yaroslav V.",
""
],
[
"Torner",
"Lluis",
""
]
] |
0705.1705 | Andrew Levan | A.J. Levan, N.R. Tanvir, P. Jakobsson, R. Chapman, J. Hjorth, R.S.
Priddey, J.P.U. Fynbo, K. Hurley, B.L. Jensen, R. Johnson, J. Gorosabel, A.J.
Castro-Tirado, M. Jarvis, D. Watson, K. Wiersema | On the nature of the short duration GRB 050906 | 8 pages, 5 figures, accepted for publication in MNRAS | Mon.Not.Roy.Astron.Soc. 384 (2008) 541-547 | 10.1111/j.1365-2966.2007.11953.x | null | astro-ph | null | We present deep optical and infrared observations of the short duration GRB
050906. Although no X-ray or optical/IR afterglow was discovered to deep
limits, the error circle of the GRB (as derived from the Swift BAT) is unusual
incontaining the relatively local starburst galaxy IC328. This makes GRB 050906
a candidate burst from a soft-gamma repeater, similar to the giant flare from
SGR 1806-20. The probability of chance alignment of a given BAT position with
such a galaxy is small (<1%), although the size of the error circle (2.6
arcminute radius) is such that a higher-z origin can't be ruled out. Indeed,
the error circle also includes a moderately rich galaxy cluster at z=0.43,
which is a plausible location for the burst given the apparent preference that
short GRBs have for regions of high mass density. No residual optical or
infrared emission has been observed, either in the form of an afterglow or
later time emission from any associated supernova-like event. We discuss the
constraints these limits place on the progenitor of GRB 050906 based on the
expected optical signatures from both SGRs and merging compact object systems.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 18:09:33 GMT"
}
] | 2008-04-13T00:00:00 | [
[
"Levan",
"A. J.",
""
],
[
"Tanvir",
"N. R.",
""
],
[
"Jakobsson",
"P.",
""
],
[
"Chapman",
"R.",
""
],
[
"Hjorth",
"J.",
""
],
[
"Priddey",
"R. S.",
""
],
[
"Fynbo",
"J. P. U.",
""
],
[
"Hurley",
"K.",
""
],
[
"Jensen",
"B. L.",
""
],
[
"Johnson",
"R.",
""
],
[
"Gorosabel",
"J.",
""
],
[
"Castro-Tirado",
"A. J.",
""
],
[
"Jarvis",
"M.",
""
],
[
"Watson",
"D.",
""
],
[
"Wiersema",
"K.",
""
]
] |
0705.1706 | Richard Kent IV | David Dumas, Richard P. Kent IV | Slicing, skinning, and grafting | 11 pages, 1 figure, to appear in American Journal of Mathematics | null | null | null | math.GT math.DG | null | We prove that a Bers slice is never algebraic, meaning that its Zariski
closure in the character variety has strictly larger dimension. A corollary is
that skinning maps are never constant.
The proof uses grafting and the theory of complex projective structures.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 18:19:41 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Mar 2008 13:15:21 GMT"
}
] | 2008-03-18T00:00:00 | [
[
"Dumas",
"David",
""
],
[
"Kent",
"Richard P.",
"IV"
]
] |
0705.1707 | Peter Hislop | Peter D. Hislop and Peter M\"uller | A lower bound for the density of states of the lattice Anderson model | 7 pages, typos corrected in v2, to appear in Proc. Amer. Math. Soc | Proc. Amer. Math. Soc. 136, 2887 - 2893 (2008) | 10.1090/S0002-9939-08-09361-1 | null | math-ph math.MP math.SP | null | We consider the Anderson model on the multi-dimensional cubic lattice and
prove a positive lower bound on the density of states under certain conditions.
For example, if the random variables are independently and identically
distributed and the probability measure has a bounded Lebesgue density with
compact support, and if this density is essentially bounded away from zero on
its support, then we prove that the density of states is strictly positive for
Lebesgue-almost every energy in the deterministic spectrum.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 18:42:57 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Oct 2007 13:19:40 GMT"
}
] | 2013-02-27T00:00:00 | [
[
"Hislop",
"Peter D.",
""
],
[
"Müller",
"Peter",
""
]
] |
0705.1708 | Kerry Soileau | Kerry M. Soileau | A homotopy method for finding eigenvalues and eigenvectors | Minor formatting change | null | null | null | math.FA math.SP | null | Suppose we want to find the eigenvalues and eigenvectors for the linear
operator L, and suppose that we have solved this problem for some other
"nearby" operator K. In this paper we show how to represent the eigenvalues and
eigenvectors of L in terms of the corresponding properties of K.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 18:59:26 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Aug 2007 20:36:22 GMT"
},
{
"version": "v3",
"created": "Fri, 7 Sep 2007 18:00:33 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Soileau",
"Kerry M.",
""
]
] |
0705.1709 | Giovanni Felder | Giovanni Felder, Carlo A. Rossi (ETH Zurich) | Differential operators on toric varieties and Fourier transform | 13 pages, 1 figure. Added results on higher cohomologies. Reference
added in version 3 | null | null | null | math.AG math.RT | null | We show that Fourier transforms on the Weyl algebras have a geometric
counterpart in the framework of toric varieties, namely they induce
isomorphisms between twisted rings of differential operators on regular toric
varieties, whose fans are related to each other by reflections of
one-dimensional cones. The simplest class of examples is provided by the toric
varieties related by such reflections to projective spaces. It includes the
blow-up at a point in affine space and resolution of singularities of varieties
appearing in the study of the minimal orbit of sl(n+1).
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:32:57 GMT"
},
{
"version": "v2",
"created": "Wed, 30 May 2007 12:58:44 GMT"
},
{
"version": "v3",
"created": "Fri, 1 Jun 2007 12:24:34 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Felder",
"Giovanni",
"",
"ETH Zurich"
],
[
"Rossi",
"Carlo A.",
"",
"ETH Zurich"
]
] |
0705.1710 | Beat R\"othlisberger | Beat R\"othlisberger, J\"org Lehmann, D. S. Saraga, Philipp Traber,
and Daniel Loss | Highly Entangled Ground States in Tripartite Qubit Systems | 4 pages, 2 figures | Phys. Rev. Lett. 100, 100502 (2008). | 10.1103/PhysRevLett.100.100502 | null | quant-ph cond-mat.mes-hall | null | We investigate the creation of highly entangled ground states in a system of
three exchange-coupled qubits arranged in a ring geometry. Suitable magnetic
field configurations yielding approximate GHZ and exact W ground states are
identified. The entanglement in the system is studied at finite temperature in
terms of the mixed-state tangle tau. By adapting a steepest-descent
optimization algorithm we demonstrate that tau can be evaluated efficiently and
with high precision. We identify the parameter regime for which the equilibrium
entanglement of the tripartite system reaches its maximum.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:08:57 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Feb 2008 16:36:52 GMT"
}
] | 2008-03-19T00:00:00 | [
[
"Röthlisberger",
"Beat",
""
],
[
"Lehmann",
"Jörg",
""
],
[
"Saraga",
"D. S.",
""
],
[
"Traber",
"Philipp",
""
],
[
"Loss",
"Daniel",
""
]
] |
0705.1711 | Takao Sakaguchi | Takao Sakaguchi (for the PHENIX Collaboration) | Measurement of electro-magnetic radiation at PHENIX | 8 pages, 8 figures, Proceedings of the 23rd Winter Workshop on
Nuclear Dynamics, held at Big Sky, Montana, February 11-18, 2007 | null | null | null | nucl-ex | null | Recent results on direct photons and dileptons from the PHENIX xperiment
opened up a possibility of landscaping electro-magnetic radiation over various
kinetic energies in heavy ion collisions. A detail discussion is given based on
a review of the results.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:36:56 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Sakaguchi",
"Takao",
"",
"for the PHENIX Collaboration"
]
] |
0705.1712 | James L. Nagle | J.L. Nagle (for the PHENIX Collaboration) | Heaviness of Heavy Quarkonia in Heavy Ion Collisions | Proceedings for the 23rd Winter Workshop on Nuclear Dynamics, Big
Sky, Montana, USA, February 11-18, 2007, 8 pages, 5 figures | null | null | null | nucl-ex | null | High energy heavy ion collisions at the Relativistic Heavy Ion Collider
(RHIC) produce a novel medium characterized by an initial energy density over
an order of magnitude above the expected phase transformation value and that
then evolves as a nearly inviscid liquid. Probing the medium with
auto-generated particles is a key methodology to quantitatively determine the
medium properties. Pairs of heavy quarks are an excellent probe since their
spatial separation to form various quarkonia states spans the relevant range of
color screening lengths in the medium. In this proceedings, we describe results
from the PHENIX experiment on $J/\psi$ production and discuss initial physics
implications of the measurements.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:24:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Nagle",
"J. L.",
"",
"for the PHENIX Collaboration"
]
] |
0705.1713 | Michael Lublinsky | Alex Kovner, Michael Lublinsky and Urs Wiedemann | From bubbles to foam: dilute to dense evolution of hadronic wave
function at high energy | 30 pages | JHEP 0706:075,2007 | 10.1088/1126-6708/2007/06/075 | null | hep-ph hep-th | null | We derive the evolution of a hadronic light cone wave function with energy at
weak coupling. Our derivation is valid both in the high and the low partonic
density limit, and thus encompasses both the JIMWLK and the KLWMIJ evolution.
The hadronic wave function is shown to evolve by the action of the
Bogoliubov-type operator, which diagonalizes on the soft gluon sector the
light-cone hamiltonian in the presence of an arbitrary valence charge density.
We find explicitly the action of this operator on the soft as well as the
valence degrees of freedom of the theory.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:27:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kovner",
"Alex",
""
],
[
"Lublinsky",
"Michael",
""
],
[
"Wiedemann",
"Urs",
""
]
] |
0705.1714 | Ariel Sanchez | Ariel Sanchez and Juan-Luis Vazquez | Selfsimilar Equivalence of Porous Medium and p-Laplacian Flows | 6 pages | null | null | null | math.AP | null | We demonstrate the equivalence between the two popular models of nonlinear
diffusion, the porous medium equation and the p-Laplacian equation. The
equivalence is shown at the level of selfsimilar solutions.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:32:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Sanchez",
"Ariel",
""
],
[
"Vazquez",
"Juan-Luis",
""
]
] |
0705.1715 | Youssef Alaoui rd | Youssef Alaoui | Holomorphic fiber bundle with Stein base and Stein fibers | null | null | null | null | math.CV | null | In this article, we prove that if $\Pi: X\to \Omega$ is a surjective
holomorphic map, with $\Omega$ a Stein space and $X$ a complex manifold of
dimension $n\geq 3,$ and if, for every $x\in \Omega$ there exists an open
neighborhood $U$ such that $\Pi^{-1}(U)$ is Stein, then $X$ is Stein
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:34:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Alaoui",
"Youssef",
""
]
] |
0705.1716 | Enrico Rodrigo | Enrico Rodrigo | Wormholes, Void Bubbles and Vacuum Energy Suppression | Accepted by Classical and Quantum Gravity | Class.Quant.Grav.24:3221-3234,2007 | 10.1088/0264-9381/24/13/006 | null | gr-qc | null | The gargantuan discrepancy between the value of the observed cosmological
constant and that expected from the zero-point energy of known matter fields
can be eliminated by supposing that on macroscopic scales the overwhelming
majority of any volume of spacetime is literal nothingness. This nothingness or
void results from the proliferative nucleation of tiny void bubbles (a.k.a.
"bubbles of nothing" or "semi wormholes") that expand until their surfaces,
presumed to be 2-branes, collide. This process results in a dense packing of
void bubbles of various sizes that leaves only the vanishing interstitial
regions between bubbles for spacetime to occupy. This vast reduction in the
amount of actual space contained within any apparent volume, reduces
correspondingly the effective zero-point energy density. Unlike previous
wormhole-based attempts at vacuum energy suppression, the current approach is
entirely Lorentzian and results in a nonzero value for the cosmological
constant.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:40:10 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Rodrigo",
"Enrico",
""
]
] |
0705.1717 | Andreas Hesselmann | Andreas Goerling, Andreas Hesselmann, Martin Jones and Mel Levy | Relation between exchange-only optimized potential and Kohn-Sham methods
with finite basis sets; solution of a paradox | null | null | null | null | physics.chem-ph | null | Arguments showing that exchange-only optimized effective potential (xOEP)
methods, with finite basis sets, cannot in general yield the Hartree-Fock (HF)
ground state energy, but a higher one, are given. While the orbital products of
a complete basis are linearly dependent, the HF ground state energy can only be
obtained via a basis set xOEP scheme in the special case that all products of
occupied and unoccupied orbitals emerging from the employed orbital basis set
are linearly independent from each other. In this case, however, exchange
potentials leading to the HF ground state energy exhibit unphysical
oscillations and do not represent a Kohn-Sham (KS) exchange potential. These
findings solve the seemingly paradoxical results of Staroverov, Scuseria and
Davidson that certain finite basis set xOEP calculations lead to the HF ground
state energy despite the fact that within a real space (or complete basis)
representation the xOEP ground state energy is always higher than the HF
energy. Moreover, whether or not the occupied and unoccupied orbital products
are linearly independent, it is shown that basis set xOEP methods only
represent exact exchange-only (EXX) KS methods, i.e., proper density-functional
methods, if the orbital basis set and the auxiliary basis set representing the
exchange potential are balanced to each other, i.e., if the orbital basis is
comprehensive enough for a given auxiliary basis. Otherwise xOEP methods do not
represent EXX KS methods and yield unphysical exchange potentials.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:46:01 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Goerling",
"Andreas",
""
],
[
"Hesselmann",
"Andreas",
""
],
[
"Jones",
"Martin",
""
],
[
"Levy",
"Mel",
""
]
] |
0705.1718 | Christopher Gordon | Christopher Gordon, Kate Land, Anze Slosar | Cosmological Constraints from Type Ia Supernovae Peculiar Velocity
Measurements | 5 pages, 4 figures. V2: references added. V3: clarifying comments
added in response to referee reports. V4: typo in eq. 6 corrected. V5: error
in Fig. 1 corrected | Phys.Rev.Lett.99:081301,2007 | 10.1103/PhysRevLett.99.081301 | null | astro-ph gr-qc hep-ph hep-th | null | We detect the correlated peculiar velocities of nearby type Ia supernovae
(SNe), while highlighting an error in some of the literature. We find
sigma_8=0.79 +/- 0.22 from SNe, and examine the potential of this method to
constrain cosmological parameters in the future. We demonstrate that a survey
of 300 low-z SNe (such as the nearby SNfactory) will underestimate the errors
on w by about 35% if the coherent peculiar velocities are not included.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 19:53:53 GMT"
},
{
"version": "v2",
"created": "Wed, 16 May 2007 13:07:26 GMT"
},
{
"version": "v3",
"created": "Fri, 13 Jul 2007 09:33:13 GMT"
},
{
"version": "v4",
"created": "Mon, 16 Jul 2007 19:19:46 GMT"
},
{
"version": "v5",
"created": "Fri, 7 Sep 2007 14:00:14 GMT"
}
] | 2009-11-16T00:00:00 | [
[
"Gordon",
"Christopher",
""
],
[
"Land",
"Kate",
""
],
[
"Slosar",
"Anze",
""
]
] |
0705.1719 | Frank Tackmann | Christian W. Bauer and Frank J. Tackmann | Gaining analytic control of parton showers | 12 pages, 6 figures, v2: final journal version | Phys.Rev.D76:114017,2007 | 10.1103/PhysRevD.76.114017 | null | hep-ph | null | Parton showers are widely used to generate fully exclusive final states
needed to compare theoretical models to experimental observations. While, in
general, parton showers give a good description of the experimental data, the
precise functional form of the probability distribution underlying the event
generation is generally not known. The reason is that realistic parton showers
are required to conserve four-momentum at each vertex. In this paper we
investigate in detail how four-momentum conservation is enforced in a standard
parton shower and why this destroys the analytic control of the probability
distribution. We show how to modify a parton shower algorithm such that it
conserves four-momentum at each vertex, but for which the full analytic form of
the probability distribution is known. We then comment how this analytic
control can be used to match matrix element calculations with parton showers,
and to estimate effects of power corrections and other uncertainties in parton
showers.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 19:50:45 GMT"
},
{
"version": "v2",
"created": "Sat, 9 Feb 2008 03:12:17 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bauer",
"Christian W.",
""
],
[
"Tackmann",
"Frank J.",
""
]
] |
0705.1720 | Simon Dye | Simon Dye (Cardiff), Ian Smail (ICC, Durham), A. M. Swinbank (ICC), H.
Ebeling (IfA, Honolulu), A. C. Edge (ICC) | Separation of the visible and dark matter in the Einstein ring LBG
J213512.73-010143 | Accepted by MNRAS. 14 pages and 4 figures | Mon.Not.Roy.Astron.Soc.379:308-316,2007 | 10.1111/j.1365-2966.2007.11960.x | null | astro-ph | null | We model the mass distribution in the recently discovered Einstein ring LBG
J213512.73-010143 (the `Cosmic Eye') using archival Hubble Space Telescope
imaging. We reconstruct the mass density profile of the z=0.73 lens and the
surface brightness distribution of the z=3.07 source and find that the observed
ring is best fit with a dual-component lens model consisting of a baryonic
Sersic component nested within a dark matter halo. The dark matter halo has an
inner slope of 1.42+/-0.23, consistent with CDM simulations after allowing for
baryon contraction. The baryonic component has a B-band mass-to-light ratio of
1.71+0.28-0.38 (solar units) which when evolved to the present day is in
agreement with local ellipticals. Within the Einstein radius of 0.77'' (5.6
kpc), the baryons account for (46+/-11)% of the total lens mass. External shear
from a nearby foreground cluster is accurately predicted by the model. The
reconstructed surface brightness distribution in the source plane clearly shows
two peaks. Through a generalisation of our lens inversion method, we conclude
that the redshifts of both peaks are consistent with each other, suggesting
that we are seeing structure within a single galaxy.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:00:41 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Dye",
"Simon",
"",
"Cardiff"
],
[
"Smail",
"Ian",
"",
"ICC, Durham"
],
[
"Swinbank",
"A. M.",
"",
"ICC"
],
[
"Ebeling",
"H.",
"",
"IfA, Honolulu"
],
[
"Edge",
"A. C.",
"",
"ICC"
]
] |
0705.1721 | Kristen Coppin Dr. | K.E.K. Coppin (1), A.M. Swinbank (1), R. Neri (2), P. Cox (2), Ian
Smail (1), R.S. Ellis (3), J.E. Geach (1), B. Siana (4), H. Teplitz (4), S.
Dye (5), J.-P. Kneib (6), A.C. Edge (1), J. Richard (3) ((1) Durham, (2)
IRAM, (3) Caltech, (4) Spitzer Science Center, (5) Cardiff, (6) Marseille) | A Detailed Study of Gas and Star Formation in a Highly Magnified Lyman
Break Galaxy at z=3.07 | 8 pages, 3 figures, accepted for publication in ApJ | Astrophys.J.665:936-943,2007 | 10.1086/519789 | null | astro-ph | null | We report the detection of CO(3-2) emission from a bright, gravitationally
lensed Lyman Break Galaxy, LBGJ213512.73-010143 (the 'Cosmic Eye'), at z=3.07
using the Plateau de Bure Interferometer. This is only the second detection of
molecular gas emission from an LBG and yields an intrinsic molecular gas mass
of (2.4+/-0.4)x10^9 Mo. The lens reconstruction of the UV morphology of the LBG
indicates that it comprises two components separated by ~2 kpc. The CO emission
is unresolved, and appears to be centered on the intrinsically fainter (and
also less highly magnified) of the two UV components. The width of the CO line
indicates a dynamical mass of (8+/-2)x10^9csc(i)^2 Mo within the central 2 kpc.
Employing mid-infrared observations from Spitzer we derive a stellar mass of
~(6+/-2)x10^9 Mo and a star-formation rate of ~60 Mo/yr, indicating that the
molecular gas will be consumed in ~40 Myr. The gas fractions, star-formation
efficiencies and line widths suggests that LBGJ213512 is a high-redshift,
gas-rich analog of a local luminous infrared galaxy. This galaxy has a similar
gas-to-dynamical mass fraction as observed in the submillimeter-selected
population, although the gas surface density and star-formation efficiency is a
factor of 3x less, suggesting less vigorous activity. We discuss the
uncertainties in our conclusions arising from adopting a CO-to-H2 conversion
factor appropriate for either the Milky Way or local luminous infrared
galaxies. These observations demonstrate that current facilities, when aided by
fortuitous gravitational magnification, can study 'ordinary' galaxies at
high-redshift and so act as pathfinders for ALMA.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:35:17 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Coppin",
"K. E. K.",
""
],
[
"Swinbank",
"A. M.",
""
],
[
"Neri",
"R.",
""
],
[
"Cox",
"P.",
""
],
[
"Smail",
"Ian",
""
],
[
"Ellis",
"R. S.",
""
],
[
"Geach",
"J. E.",
""
],
[
"Siana",
"B.",
""
],
[
"Teplitz",
"H.",
""
],
[
"Dye",
"S.",
""
],
[
"Kneib",
"J. -P.",
""
],
[
"Edge",
"A. C.",
""
],
[
"Richard",
"J.",
""
]
] |
0705.1722 | Shai Kaspi | Shai Kaspi | Advances in Reverberation Mapping | 10 pages, 4 figures, Conference proceedings to appear in "The Central
Engine of Active Galactic Nuclei", ed. L. C. Ho and J.-M. Wang (San
Francisco: ASP) | null | null | null | astro-ph | null | This contribution briefly reviews the reverberation mapping technique which
leads to determination of black hole masses. I focus on the emerging relation
between the broad-line region size and the active galactic nucleus (AGN)
luminosity, and on an overview of recent results of reverberation mapping
studies which are starting to cover the full AGN luminosity range. Preliminary
results and time lag determination from a reverberation mapping program of
high-luminosity quasars are also presented.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:04:13 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kaspi",
"Shai",
""
]
] |
0705.1723 | Edward Stoeffhaas | Francis Halzen and Aongus O'Murchadha | Neutrinos from Cosmic Ray Accelerators in the Cygnus Region of the
Galaxy | Latex, 16 pages, uses pdproc.sty (included), 7 postscript figures.
Talk presented at the XII International Workshop on Neutrino Telescopes,
Istituto Veneto di Scienze, Lettere ed Arti, Venice, Italy, March 6-9, 2007.
Version with added text and references | Phys.Rev.D76:123003,2007 | 10.1103/PhysRevD.76.123003 | null | astro-ph hep-ex hep-ph | null | While supernova remnants have been identified as the most likely sources of
the galactic cosmic rays, no conclusive observational evidence for this
association exists. We show here that IceCube has the possibility of producing
incontrovertible evidence by detecting neutrinos produced by the cosmic ray
beam interacting with the hydrogen in the vicinity of the supernova shock
expanding into the interstellar medium. We show that the observational
information on gamma ray fluxes from the Cygnus region, although limited, is
sufficient to pinpoint the expected event rate of the neutrinos associated with
a single source of 0.5 Crab at the TeV level to within a factor of two, between
2 and 3.8 neutrinos per year. Finally, we note that recent gamma-ray
observations reveal the presence of at least three and possibly up to eight
such sources, raising the possibility of seeing more than 10 neutrinos per year
from these sources alone.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:14:39 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 18:41:58 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Halzen",
"Francis",
""
],
[
"O'Murchadha",
"Aongus",
""
]
] |
0705.1724 | Elbert E. M. Chia | Elbert E. M. Chia, Jian-Xin Zhu, D. Talbayev, R. D. Averitt, Kyu-Hwan
Oh, In-Sun Jo, S.-I. Lee, and A. J. Taylor | Observation of Competing Order in a High-$T_{c}$ Superconductor with
Femtosecond Optical Pulses | 5 pages, 3 figures | Phys. Rev. Lett. 99, 147008 (2007) | 10.1103/PhysRevLett.99.147008 | null | cond-mat.supr-con cond-mat.str-el | null | We present studies of the photoexcited quasiparticle dynamics in
Tl$_{2}$Ba$_{2}$Ca$_{2}$Cu$_{3}$O$_{y}$ (Tl-2223) using femtosecond optical
techniques. Deep into the superconducting state (below 40 K), a dramatic change
occurs in the temporal dynamics associated with photoexcited quasiparticles
rejoining the condensate. This is suggestive of entry into a coexistence phase
which, as our analysis reveals, opens a gap in the density of states (in
addition to the superconducting gap), and furthermore, competes with
superconductivity resulting in a depression of the superconducting gap.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:22:34 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Chia",
"Elbert E. M.",
""
],
[
"Zhu",
"Jian-Xin",
""
],
[
"Talbayev",
"D.",
""
],
[
"Averitt",
"R. D.",
""
],
[
"Oh",
"Kyu-Hwan",
""
],
[
"Jo",
"In-Sun",
""
],
[
"Lee",
"S. -I.",
""
],
[
"Taylor",
"A. J.",
""
]
] |
0705.1725 | Andrei Gruzinov | A. Gruzinov | Kerr quasinormal modes and Hod's time-temperature bound | 5 pages | null | null | null | gr-qc | null | We give an explicit expression for the frequencies of slowly damped
quasinormal modes of near-extreme Kerr black holes. It follows from this
expression that the near-extreme Kerr holes obey the Hod's bound: in the limit
of maximal rotation, $\lim \sup \omega_{IS}/T\leq \pi / \hbar$, where $\omega
_{IS}$ is the decay rate of the slowest decaying quasinormal mode, $T$ is the
black hole temperature. On the other hand, the bound is not saturated in the
sense that $\lim \inf \omega_{IS}/T< \pi /\hbar$ is a strict inequality. {\it
It remains unclear} whether the bound is saturated in the sense that $\lim \sup
\omega_{IS}/T= \pi /\hbar$.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:27:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gruzinov",
"A.",
""
]
] |
0705.1726 | Anthony H. Gonzalez | Anthony H. Gonzalez (University of Florida), Dennis Zaritsky
(University of Arizona), and Ann I. Zabludoff (University of Arizona) | A Census of Baryons in Galaxy Clusters and Groups | 10 pages, 5 figures, accepted to ApJ | Astrophys.J.666:147-155,2007 | 10.1086/519729 | null | astro-ph | null | We determine the contribution of stars in galaxies, intracluster stars, and
the intracluster medium to the total baryon budget in nearby galaxy clusters
and groups. We find that the baryon mass fraction (f_b) within r500 is constant
for systems with M500 between 6e13 and 1e15 Msun. Although f_b is lower than
the WMAP value, the shortfall is on the order of both the observational
systematic uncertainties and the depletion of baryons within r500 that is
predicted by simulations. The data therefore provide no compelling evidence for
undetected baryonic components, particularly any that vary in importance with
cluster mass. A unique feature of the current analysis is direct inclusion of
the contribution of intracluster light (ICL) in the baryon budget. The increase
in X-ray gas mass fraction with increasing total mass is entirely accounted for
by a decrease in the total stellar mass fraction, supporting the argument that
the behavior of both the stellar and X-ray gas components is dominated by a
decrease in star formation efficiency in more massive environments. Within just
the stellar component, the fraction of the total stellar luminosity in the BCG
and ICL decreases as velocity dispersion increases, suggesting that the BCG+ICL
component, and in particular the dominant ICL component, grows less efficiently
in higher mass environments. The degree to which this behavior arises from our
sample selection, which favored systems with central, giant elliptical
galaxies, remains unclear. A more robust result is the identification of low
mass groups with large BCG+ICL components, demonstrating that the creation of
intracluster stars does not require a massive cluster environment. Within r500
and r200, the BCG+ICL contributes on average 40% and 33% of the total stellar
light, respectively.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:46:53 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Gonzalez",
"Anthony H.",
"",
"University of Florida"
],
[
"Zaritsky",
"Dennis",
"",
"University of Arizona"
],
[
"Zabludoff",
"Ann I.",
"",
"University of Arizona"
]
] |
0705.1727 | Xi Chen | Xi Chen | On Vojta's $1+\epsilon$ Conjecture | 30 pages in total | null | null | null | math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I gave a geometric proof of Vojta's 1 + epsilon conjecture.
Some gaps in the published paper were spotted and kindly pointed out to me by
Paul Vojta. These were addressed in "Erratum".
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:45:06 GMT"
},
{
"version": "v2",
"created": "Fri, 1 Jun 2012 20:55:20 GMT"
}
] | 2012-06-05T00:00:00 | [
[
"Chen",
"Xi",
""
]
] |
0705.1728 | David Vitali | Claudiu Genes, David Vitali, Paolo Tombesi, Sylvain Gigan, Markus
Aspelmeyer | Ground-state cooling of a micromechanical oscillator: generalized
framework for cold damping and cavity-assisted cooling schemes | 10 pages, 4 figures. Erratum of the published version included | Phys. Rev. A 77, 033804 (2008); Phys. Rev. A 79, 039903(E) (2009) | 10.1103/PhysRevA.77.033804 | null | quant-ph cond-mat.mes-hall gr-qc physics.optics | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We provide a general framework to describe cooling of a micromechanical
oscillator to its quantum ground state by means of radiation-pressure coupling
with a driven optical cavity. We apply it to two experimentally realized
schemes, back-action cooling via a detuned cavity and cold-damping
quantum-feedback cooling, and we determine the ultimate quantum limits of both
schemes for the full parameter range of a stable cavity. While both allow to
reach the oscillator's quantum ground state, we find that back-action cooling
is more efficient in the good cavity limit, i.e. when the cavity bandwidth is
smaller than the mechanical frequency, while cold damping is more suitable for
the bad cavity limit. The results of previous treatments are recovered as
limiting cases of specific parameter regimes.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:45:07 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Aug 2007 14:30:12 GMT"
},
{
"version": "v3",
"created": "Wed, 7 Nov 2007 17:19:24 GMT"
},
{
"version": "v4",
"created": "Sat, 26 Jan 2008 19:23:57 GMT"
},
{
"version": "v5",
"created": "Mon, 9 Feb 2009 12:21:11 GMT"
},
{
"version": "v6",
"created": "Sun, 12 Jul 2009 20:41:39 GMT"
}
] | 2009-07-12T00:00:00 | [
[
"Genes",
"Claudiu",
""
],
[
"Vitali",
"David",
""
],
[
"Tombesi",
"Paolo",
""
],
[
"Gigan",
"Sylvain",
""
],
[
"Aspelmeyer",
"Markus",
""
]
] |
0705.1729 | Dmitry Gorbunov | Dmitry Gorbunov, Mikhail Shaposhnikov | How to find neutral leptons of the nuMSM? | 45 pages, 17 figures; v2: references added, journal version | JHEP0710:015,2007 | 10.1088/1126-6708/2007/10/015 | null | hep-ph | null | An extension of the Standard Model by three singlet fermions with masses
smaller than the electroweak scale allows to explain simultaneously neutrino
oscillations, dark matter and baryon asymmetry of the Universe. We discuss the
properties of neutral leptons in this model and the ways they can be searched
for in particle physics experiments. We establish, in particular, a lower and
an upper bound on the strength of interaction of neutral leptons coming from
cosmological considerations and from the data on neutrino oscillations. We
analyse the production of neutral leptons in the decays of different mesons and
in $pp$ collisions. We study in detail decays of neutral leptons and establish
a lower bound on their mass coming from existing experimental data and Big Bang
Nucleosynthesis. We argue that the search for a specific missing energy signal
in kaon decays would allow to strengthen considerably the bounds on neutral
fermion couplings and to find or definitely exclude them below the kaon
threshold. To enter into cosmologically interesting parameter range for masses
above kaon mass the dedicated searches similar to CERN PS191 experiment would
be needed with the use of intensive proton beams. We argue that the use of
CNGS, NuMI, T2K or NuTeV beams could allow to search for singlet leptons below
charm in a large portion of the parameter space of the nuMSM. The search of
singlet fermions in the mass interval 2-5 GeV would require a considerable
increase of the intensity of proton accelerators or the detailed analysis of
kinematics of more than 10^{10} B-meson decays.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:51:19 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Oct 2007 17:42:58 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gorbunov",
"Dmitry",
""
],
[
"Shaposhnikov",
"Mikhail",
""
]
] |
0705.1730 | Markus Aschwanden | Virginia Trimble, Markus J. Aschwanden, Carl J. Hansen | Astrophysics in 2006 | 244 pages, no figures | null | 10.1007/s11214-007-9224-0 | null | astro-ph | null | The fastest pulsar and the slowest nova; the oldest galaxies and the youngest
stars; the weirdest life forms and the commonest dwarfs; the highest energy
particles and the lowest energy photons. These were some of the extremes of
Astrophysics 2006. We attempt also to bring you updates on things of which
there is currently only one (habitable planets, the Sun, and the universe) and
others of which there are always many, like meteors and molecules, black holes
and binaries.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 20:56:11 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Trimble",
"Virginia",
""
],
[
"Aschwanden",
"Markus J.",
""
],
[
"Hansen",
"Carl J.",
""
]
] |
0705.1731 | Michael Boyer | M. C. Boyer, W. D. Wise, Kamalesh Chatterjee, Ming Yi, Takeshi Kondo,
T. Takeuchi, H. Ikuta, E. W. Hudson | Imaging the Two Gaps of the High-TC Superconductor Pb-Bi2Sr2CuO6+x | 6 pages | null | 10.1038/nphys725 | null | cond-mat.supr-con cond-mat.str-el | null | The nature of the pseudogap state, observed above the superconducting
transition temperature TC in many high temperature superconductors, is the
center of much debate. Recently, this discussion has focused on the number of
energy gaps in these materials. Some experiments indicate a single energy gap,
implying that the pseudogap is a precursor state. Others indicate two,
suggesting that it is a competing or coexisting phase. Here we report on
temperature dependent scanning tunneling spectroscopy of Pb-Bi2Sr2CuO6+x. We
have found a new, narrow, homogeneous gap that vanishes near TC, superimposed
on the typically observed, inhomogeneous, broad gap, which is only weakly
temperature dependent. These results not only support the two gap picture, but
also explain previously troubling differences between scanning tunneling
microscopy and other experimental measurements.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 16:55:04 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Boyer",
"M. C.",
""
],
[
"Wise",
"W. D.",
""
],
[
"Chatterjee",
"Kamalesh",
""
],
[
"Yi",
"Ming",
""
],
[
"Kondo",
"Takeshi",
""
],
[
"Takeuchi",
"T.",
""
],
[
"Ikuta",
"H.",
""
],
[
"Hudson",
"E. W.",
""
]
] |
0705.1732 | Sam Payne | Sam Payne | Fibers of tropicalization | 11 pages. v2: added footnote explaining gap in earlier proofs of
surjectivity of tropicalization, other minor changes. To appear in Math. Z | Math. Z. 262 (2009), no. 2, 301--311. | null | null | math.AG | null | We use functoriality of tropicalization and the geometry of projections of
subvarieties of tori to show that the fibers of the tropicalization map are
dense in the Zariski topology. For subvarieties of tori over fields of
generalized power series, points in each tropical fiber are obtained
"constructively" using Kedlaya's transfinite version of Newton's method.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 17:53:05 GMT"
},
{
"version": "v2",
"created": "Sat, 10 May 2008 15:34:52 GMT"
}
] | 2009-04-25T00:00:00 | [
[
"Payne",
"Sam",
""
]
] |
0705.1733 | Tina Kahniashvili | Grigol Gogoberidze, Tina Kahniashvili and Arthur Kosowsky | The Spectrum of Gravitational Radiation from Primordial Turbulence | typos corrected, the form of Eq. 37 is modified, Results and
conclusions unchanged | Phys.Rev.D76:083002,2007 | 10.1103/PhysRevD.76.083002 | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Energy injection into the early universe can induce turbulent motions of the
primordial plasma, which in turn act as a source for gravitational radiation.
Earlier work computed the amplitude and characteristic frequency of the relic
gravitational wave background, as a function of the total energy injected and
the stirring scale of the turbulence. This paper computes the frequency
spectrum of relic gravitational radiation from a turbulent source of the
stationary Kolmogoroff form which acts for a given duration, making no other
approximations. We also show that the limit of long source wavelengths,
commonly employed in aeroacoustic problems, is an excellent approximation. The
gravitational waves from cosmological turbulence around the electroweak energy
scale will be detectable by future space-based laser interferometers for a
substantial range of turbulence parameters.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 21:40:08 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Sep 2007 04:14:13 GMT"
},
{
"version": "v3",
"created": "Wed, 29 Apr 2009 01:35:21 GMT"
}
] | 2009-04-29T00:00:00 | [
[
"Gogoberidze",
"Grigol",
""
],
[
"Kahniashvili",
"Tina",
""
],
[
"Kosowsky",
"Arthur",
""
]
] |
0705.1734 | Shin-ichi Fujimori | Shin-ichi Fujimori, Yuji Saitoh, Tetsuo Okane, Atsushi Fujimori,
Hiroshi Yamagami, Yoshinori Haga, Etsuji Yamamoto, and Yoshichika Onuki | Itinerant to localized transition of f electrons in antiferromagnetic
superconductor UPd2Al3 | 16 pages, 4 figures, the revised manuscript was accepted to Nature
Physics | Nature Physics 3, 618 (2007) | 10.1038/nphys651 | null | cond-mat.str-el | null | Electrons in solids have been conventionally classified as either band-like
itinerant ones or atomic-like localized ones depending on their properties. For
heavy Fermion (HF) compounds, however, the f electrons show both itinerant and
localized behaviours depending on temperature. Above the characteristic
temperature T*, which is typically of the order of few K to few tens K, their
magnetic properties are well described by the ionic f-electron models,
suggesting that the f-electrons behave as 'localized' electrons. On the other
hand, well below T*, their Fermi surfaces (FS's) have been observed by
magneto-oscillatory techniques, and generally they can be explained well by the
'itinerant' f-electron model. These two models assume totally different natures
of felectrons, and how they transform between localized and itinerant state as
a function of temperatures has never been understood on the level of their
electronic structures. Here we have studied the band structure of the HF
antiferromagnetic superconductor UPd2Al3 well below and above T* by
angle-resolved photoelectron spectroscopy (ARPES), and revealed the temperature
dependence of the electronic structure. We have found that the f-bands, which
form the FS's at low temperatures are excluded from FS's at high temperatures.
The present results demonstrate how the same f-electrons show both itinerant
and localized behaviours on the level of electronic structure, and provide an
important information for the unified description of the localized and
itinerant nature of HF compounds.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 21:52:03 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Fujimori",
"Shin-ichi",
""
],
[
"Saitoh",
"Yuji",
""
],
[
"Okane",
"Tetsuo",
""
],
[
"Fujimori",
"Atsushi",
""
],
[
"Yamagami",
"Hiroshi",
""
],
[
"Haga",
"Yoshinori",
""
],
[
"Yamamoto",
"Etsuji",
""
],
[
"Onuki",
"Yoshichika",
""
]
] |
0705.1735 | Gabriel T\'ellez | Alejandro Ferrero and Gabriel Tellez (Universidad de los Andes,
Bogota, Colombia) | Two-dimensional two-component plasma with adsorbing impurities | null | J. Stat. Phys. 129, 759 (2007) | 10.1007/s10955-007-9401-2 | null | cond-mat.stat-mech | null | We study the behavior of the two-dimensional two-component plasma in the
presence of some adsorbing impurities. Using a solvable model, we find analytic
expressions for the thermodynamic properties of the plasma such as the $n$-body
densities, the grand potential, and the pressure. We specialize in the case
where there are one or two adsorbing point impurities in the plasma, and in the
case where there are one or two parallel adsorbing lines. In the former case we
study the effective interaction between the impurities, due to the charge
redistribution around them. The latter case is a model for electrodes with
adsorbing sticky sites on their surface.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 22:08:53 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Ferrero",
"Alejandro",
"",
"Universidad de los Andes,\n Bogota, Colombia"
],
[
"Tellez",
"Gabriel",
"",
"Universidad de los Andes,\n Bogota, Colombia"
]
] |
0705.1736 | Bob Holdom | B. Holdom | The heavy quark search at the LHC | 12 pages, 7 figures | JHEP 0708:069,2007 | 10.1088/1126-6708/2007/08/069 | null | hep-ph | null | We explore further the discovery potential for heavy quarks at the LHC, with
emphasis on the $t'$ and $b'$ of a sequential fourth family associated with
electroweak symmetry breaking. We consider QCD multijets, $t\bar{t}+\rm{jets}$,
$W+\rm{jets}$ and single $t$ backgrounds using event generation based on
improved matrix elements and low sensitivity to the modeling of initial state
radiation. We exploit a jet mass technique for the identification of
hadronically decaying $W$'s and $t$'s, to be used in the reconstruction of the
$t'$ or $b'$ mass. This along with other aspects of event selection can reduce
backgrounds to very manageable levels. It even allows a search for both $t'$
and $b'$ in the absence of $b$-tagging, of interest for the early running of
the LHC. A heavy quark mass of order 600 GeV is motivated by the connection to
electroweak symmetry breaking, but our analysis is relevant for any new heavy
quarks with weak decay modes.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 18:49:34 GMT"
}
] | 2009-04-22T00:00:00 | [
[
"Holdom",
"B.",
""
]
] |
0705.1737 | Seong-Gon Kim | Amitava Moitra, Sungho Kim, J. Houze, B. Jelinek, Seong-Jin Park,
Randall M. German, M. F. Horstemeyer, and Seong-Gon Kim | Melting tungsten nanoparticles: a molecular dynamics study | 7 pages, 4 figures | null | 10.1088/0022-3727/41/18/185406 | null | cond-mat.mtrl-sci | null | We report a molecular dynamics simulation of melting of tungsten (W)
nanoparticles. The modified embedded atom method (MEAM) interatomic potentials
are used to describe the interaction between tungsten atoms. The melting
temperature of unsupported tungsten nanoparticles of different sizes are found
to decrease as the size of the particles decreases. The melting temperature
obtained in the present study is approximately a decreasing function of inverse
radius, in a good agreement with the predictions of thermodynamic models. We
also observed that the melting of a W nanoparticle is preceded by the
premelting of its outer skin at a temperature lower than its melting
temperature.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 22:47:37 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Moitra",
"Amitava",
""
],
[
"Kim",
"Sungho",
""
],
[
"Houze",
"J.",
""
],
[
"Jelinek",
"B.",
""
],
[
"Park",
"Seong-Jin",
""
],
[
"German",
"Randall M.",
""
],
[
"Horstemeyer",
"M. F.",
""
],
[
"Kim",
"Seong-Gon",
""
]
] |
0705.1738 | Wei-Zhou Jiang | Wei-Zhou Jiang, Bao-An Li and Lie-Wen Chen | Equation of state of isospin-asymmetric nuclear matter in relativistic
mean-field models with chiral limits | 14 pages, 3 figures | Phys.Lett.B653:184-189,2007 | 10.1016/j.physletb.2007.08.004 | null | nucl-th nucl-ex | null | Using in-medium hadron properties according to the Brown-Rho scaling due to
the chiral symmetry restoration at high densities and considering naturalness
of the coupling constants, we have newly constructed several relativistic
mean-field Lagrangians with chiral limits. The model parameters are adjusted
such that the symmetric part of the resulting equation of state at supra-normal
densities is consistent with that required by the collective flow data from
high energy heavy-ion reactions, while the resulting density dependence of the
symmetry energy at sub-saturation densities agrees with that extracted from the
recent isospin diffusion data from intermediate energy heavy-ion reactions. The
resulting equations of state have the special feature of being soft at
intermediate densities but stiff at high densities naturally. With these
constrained equations of state, it is found that the radius of a 1.4$M_\odot$
canonical neutron star is in the range of 11.9 km$\leq$R$\leq$13.1 km, and the
maximum neutron star mass is around 2.0$M_\odot$ close to the recent
observations.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 22:46:39 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Jiang",
"Wei-Zhou",
""
],
[
"Li",
"Bao-An",
""
],
[
"Chen",
"Lie-Wen",
""
]
] |
0705.1739 | Surya Ramana D | Gyan Prakash and D.S. Ramana | The Large Sieve Inequality for Quadratic Polynomial Amplitudes | 7 pages comments welcome | null | null | null | math.NT math.CA | null | We provide here a modest improvement upon a large sieve inequality for
quadratic polynomial amplitudes orginally due to Liangyi Zhao.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 23:09:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Prakash",
"Gyan",
""
],
[
"Ramana",
"D. S.",
""
]
] |
0705.1740 | Diederik Aerts | Diederik Aerts | General Quantum Modeling of Combining Concepts: A Quantum Field Model in
Fock Space | 51 pages, 7 figures, submitted for publication | null | null | null | physics.gen-ph quant-ph | null | We extend a quantum model in Hilbert space developed in Aerts (2007a) into a
quantum field theoric model in Fock space for the modeling of the combination
of concepts. Items and concepts are represented by vectors in Fock space and
membership weights of items are modeled by quantum probabilities. We apply this
theory to model the disjunction of concepts and show that the predictions of
our theory for the membership weights of items regarding the disjunction of
concepts match with great accuracy the complete set of results of an experiment
conducted by Hampton (1988b). It are the quantum effects of interference and
superposition of that are at the origin of the effects of overextension and
underextension observed by Hampton as deviations from a classical use of the
disjunction. It is essential for the perfect matches we obtain between the
predictions of the quantum field model and Hampton's experimental data that
items can be in superpositions of `different numbers states' which proves that
the genuine structure of quantum field theory is needed to match predictions
with experimental data.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 23:09:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Aerts",
"Diederik",
""
]
] |
0705.1741 | U. Zuelicke | U. Zuelicke (Massey U), J. Bolte (U Ulm), R. Winkler (NIU) | Magnetic focusing of charge carriers from spin-split bands: Semiclassics
of a Zitterbewegung effect | 14 pages, 2 figures, IOP style, v2: minor changes, to appear in NJP
Focus Issue on Spintronics | New J. Phys. 9, 355 (2007) | 10.1088/1367-2630/9/9/355 | null | cond-mat.mes-hall | null | We present a theoretical study of the interplay between cyclotron motion and
spin splitting of charge carriers in solids. While many of our results apply
more generally, we focus especially on discussing the Rashba model describing
electrons in the conduction band of asymmetric semiconductor heterostructures.
Appropriate semiclassical limits are distinguished that describe various
situations of experimental interest. Our analytical fomulae, which take full
account of Zeeman splitting, are used to analyse recent magnetic-focusing data.
Surprisingly, it turns out that the Rashba effect can dominate the splitting of
cyclotron orbits even when the Rashba and Zeeman spin-splitting energies are of
the same order. We also find that the origin of spin-dependent cyclotron motion
can be traced back to Zitterbewegung-like oscillatory dynamics of charge
carriers from spin-split bands. The relation between the two phenomena is
discussed, and we estimate the effect of Zitterbewegung-related corrections to
the charge carriers' canonical position.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 23:31:11 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Aug 2007 18:58:52 GMT"
}
] | 2007-09-30T00:00:00 | [
[
"Zuelicke",
"U.",
"",
"Massey U"
],
[
"Bolte",
"J.",
"",
"U Ulm"
],
[
"Winkler",
"R.",
"",
"NIU"
]
] |
0705.1742 | Niccolo' Bucciantini | N. Bucciantini (1), E. Quataert (1), J. Arons (1), B.D. Metzger (1),
Todd A. Thompson (2) ((1)Astronomy Department, UC Berkeley, (2)Department of
Astrophysical Sciences, Princeton) | Magnetar Driven Bubbles and the Origin of Collimated Outflows in
Gamma-ray Bursts | 14 pages, 8 figures, accepted for publication in MNRAS | null | 10.1111/j.1365-2966.2007.12164.x | null | astro-ph | null | We model the interaction between the wind from a newly formed rapidly
rotating magnetar and the surrounding supernova shock and host star. The
dynamics is modeled using the two-dimensional, axisymmetric thin-shell
equations. In the first ~10-100 seconds after core collapse the magnetar
inflates a bubble of plasma and magnetic fields behind the supernova shock. The
bubble expands asymmetrically because of the pinching effect of the toroidal
magnetic field, just as in the analogous problem of the evolution of pulsar
wind nebulae. The degree of asymmetry depends on E_mag/E_tot. The correct value
of E_mag/E_tot is uncertain because of uncertainties in the conversion of
magnetic energy into kinetic energy at large radii in relativistic winds; we
argue, however, that bubbles inflated by newly formed magnetars are likely to
be significantly more magnetized than their pulsar counterparts. We show that
for a ratio of magnetic to total power supplied by the central magnetar
L_mag/L_tot ~ 0.1 the bubble expands relatively spherically. For L_mag/L_tot ~
0.3, however, most of the pressure in the bubble is exerted close to the
rotation axis, driving a collimated outflow out through the host star. This can
account for the collimation inferred from observations of long-duration
gamma-ray bursts (GRBs). Outflows from magnetars become increasingly
magnetically dominated at late times, due to the decrease in neutrino-driven
mass loss as the young neutron star cools. We thus suggest that the
magnetar-driven bubble initially expands relatively spherically, enhancing the
energy of the associated supernova, while at late times it becomes
progressively more collimated, producing the GRB.
| [
{
"version": "v1",
"created": "Fri, 11 May 2007 23:31:30 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Jul 2007 23:05:48 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bucciantini",
"N.",
""
],
[
"Quataert",
"E.",
""
],
[
"Arons",
"J.",
""
],
[
"Metzger",
"B. D.",
""
],
[
"Thompson",
"Todd A.",
""
]
] |
0705.1743 | Zhen-Hua Zhao | Zhen-Hua Zhao, Yu-Xiao Liu, Xi-Guo Li | Gravitational Corrections to the Energy-Levels of a Hydrogen Atom | 7 pages | Commun.Theor.Phys.47:658-662,2007 | 10.1088/0253-6102/47/4/018 | null | gr-qc | null | The first order perturbations of the energy levels of a hydrogen atom in
central internal gravitational field are investigated. The internal
gravitational field is produced by the mass of the atomic nucleus. The energy
shifts are calculated for the relativistic 1S, 2S, 2P, 3S, 3P, 3D, 4S and 4P
levels with Schwarzschild metric. The calculated results show that the
gravitational corrections are sensitive to the total angular momentum quantum
number.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 00:47:33 GMT"
}
] | 2009-03-19T00:00:00 | [
[
"Zhao",
"Zhen-Hua",
""
],
[
"Liu",
"Yu-Xiao",
""
],
[
"Li",
"Xi-Guo",
""
]
] |
0705.1744 | Gabriel Perez | Gabriel Perez | Statistics of jamming in the discharge of a 2-D Silo | 5 pages, 4 figures | null | null | null | cond-mat.soft | null | Jamming and avalanche statistics are studied in a simulation of the discharge
of a polydisperse ensemble of disks from a 2-D silo. Exponential distributions
are found for the avalanche sizes for all sizes of the exit opening, in
agreement with reported experiments. The average avalanche size grows quite
fast with the size of the exit opening. Data for this growth agree better with
a critical divergence with a large critical exponent, as reported for 3-D
experiments, than with the exponential growth reported for 2-D experiments.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 00:53:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Perez",
"Gabriel",
""
]
] |
0705.1745 | Kaige Wang | Lu Gao, Jun Xiong, Lu-Fang Lin, Wei Wang, Su-Heng Zhang, and Kaige
Wang | Nonlocal Double-Slit Interference with Pseudothermal Light | 2 pages, 2 figures | null | null | null | quant-ph | null | We perform a nonlocal double-slit interference experiment with pseudothermal
light. The experimental result exhibits a typical double-slit interference
fringe in the intensity correlation measurement, in agreement with the
theoretical analysis by means of the property of the second-order spatial
correlation of field.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 02:39:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gao",
"Lu",
""
],
[
"Xiong",
"Jun",
""
],
[
"Lin",
"Lu-Fang",
""
],
[
"Wang",
"Wei",
""
],
[
"Zhang",
"Su-Heng",
""
],
[
"Wang",
"Kaige",
""
]
] |
0705.1746 | Fu-Guo Deng | Chun-Yan Li, Hong-Yu Zhou, Yan Wang, Fu-Guo Deng | Secure quantum key distribution network with Bell states and local
unitary operations | 5 pages, 2 figures. The decoy-photon technique is presented in a
clear way for preventing a potentially dishonest server on a network from
eavesdropping quantum communication freely. This technique may be useful in
quantum secret sharing (of classical information or quantum information),
controlled teleportation, and so on | Chinese Physics Letters 22, 1049-1052 (2005) | 10.1088/0256-307X/22/5/006 | null | quant-ph | null | We propose a theoretical scheme for secure quantum key distribution network
following the ideas in quantum dense coding. In this scheme, the server of the
network provides the service for preparing and measuring the Bell states, and
the users encodes the states with local unitary operations. For preventing the
server from eavesdropping, we design a decoy when the particle is transmitted
between the users. It has high capacity as one particle carries two bits of
information and its efficiency for qubits approaches 100%. Moreover, it is not
necessary for the users to store the quantum states, which makes this scheme
more convenient for application than others.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 02:57:13 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Li",
"Chun-Yan",
""
],
[
"Zhou",
"Hong-Yu",
""
],
[
"Wang",
"Yan",
""
],
[
"Deng",
"Fu-Guo",
""
]
] |
0705.1747 | Yancy L. Shirley | Yancy L. Shirley (Bart J. Bok Fellow, Univ. of Arizona), Mark J.
Claussen (NRAO), Tyler M. Bourke (CfA), Chadwick H. Young (Nicholls State
Univ.), Geoffrey A. Blake (Caltech) | The Detection and Characterization of cm Radio Continuum Emission from
the Low-mass Protostar L1014-IRS | 14 pages. Accepted for publication in ApJ | Astrophys.J.667:329-339,2007 | 10.1086/520570 | null | astro-ph | null | Observations by the Cores to Disk Legacy Team with the Spitzer Space
Telescope have identified a low luminosity, mid-infrared source within the
dense core, Lynds 1014, which was previously thought to harbor no internal
source. Followup near-infrared and submillimeter interferometric observations
have confirmed the protostellar nature of this source by detecting scattered
light from an outflow cavity and a weak molecular outflow. In this paper, we
report the detection of cm continuum emission with the VLA. The emission is
characterized by a quiescent, unresolved 90 uJy 6 cm source within 0.2" of the
Spitzer source. The spectral index of the quiescent component is $\alpha =
0.37\pm 0.34$ between 6 cm and 3.6 cm. A factor of two increase in 6 cm
emission was detected during one epoch and circular polarization was marginally
detected at the $5\sigma$ level with Stokes {V/I} $= 48 \pm 16$% . We have
searched for 22 GHz H2O maser emission toward L1014-IRS, but no masers were
detected during 7 epochs of observations between June 2004 and December 2006.
L1014-IRS appears to be a low-mass, accreting protostar which exhibits cm
emission from a thermal jet or a wind, with a variable non-thermal emission
component. The quiescent cm radio emission is noticeably above the correlation
of 3.6 cm and 6 cm luminosity versus bolometric luminosity, indicating more
radio emission than expected. We characterize the cm continuum emission in
terms of observations of other low-mass protostars, including updated
correlations of centimeter continuum emission with bolometric luminosity and
outflow force, and discuss the implications of recent larger distance estimates
on the physical attributes of the protostar and dense molecular core.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 02:58:57 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Shirley",
"Yancy L.",
"",
"Bart J. Bok Fellow, Univ. of Arizona"
],
[
"Claussen",
"Mark J.",
"",
"NRAO"
],
[
"Bourke",
"Tyler M.",
"",
"CfA"
],
[
"Young",
"Chadwick H.",
"",
"Nicholls State\n Univ."
],
[
"Blake",
"Geoffrey A.",
"",
"Caltech"
]
] |
0705.1748 | Fu-Guo Deng | Chun-Yan Li, Xi-Han Li, Fu-Guo Deng, Ping Zhou, Yu-Jie Liang, Hong-Yu
Zhou | Efficient quantum cryptography network without entanglement and quantum
memory | 4 pages, 1 figures. It also presented a way for preparing decoy
photons without a sinigle-photon source | Chinese Physics Letters 23, 2896-2899 (2006) | 10.1088/0256-307X/23/11/004 | null | quant-ph | null | An efficient quantum cryptography network protocol is proposed with
d-dimension polarized photons, without resorting to entanglement and quantum
memory. A server on the network, say Alice, provides the service for preparing
and measuring single photons whose initial state are |0>. The users code the
information on the single photons with some unitary operations. For preventing
the untrustworthy server Alice from eavesdropping the quantum lines, a
nonorthogonal-coding technique (decoy-photon technique) is used in the process
that the quantum signal is transmitted between the users. This protocol does
not require the servers and the users to store the quantum state and almost all
of the single photons can be used for carrying the information, which makes it
more convenient for application than others with present technology. We also
discuss the case with a faint laser pulse.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 03:12:13 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Li",
"Chun-Yan",
""
],
[
"Li",
"Xi-Han",
""
],
[
"Deng",
"Fu-Guo",
""
],
[
"Zhou",
"Ping",
""
],
[
"Liang",
"Yu-Jie",
""
],
[
"Zhou",
"Hong-Yu",
""
]
] |
0705.1749 | Kenji Kadota | Tony Gherghetta, Kenji Kadota and Masahide Yamaguchi | Warped Leptogenesis with Dirac Neutrino Masses | Typos corrected | Phys.Rev.D76:023516,2007 | 10.1103/PhysRevD.76.023516 | UMN-TH-2540-07, FTPI-MINN-07-07 | hep-ph astro-ph hep-th | null | We show how leptogenesis can occur at the TeV scale with neutrinos that
possess almost purely Dirac masses and negligible Majorana mass contributions
as a consequence of the small wavefunction overlap in a warped fifth dimension.
Lepton number violation at the Planck scale is introduced via a Majorana mass
term on the Planck brane. Such a Majorana mass operator leads to the small mass
splitting of otherwise degenerate Kaluza-Klein excited states on the TeV brane.
This tiny mass splitting can compensate for the small Yukawa couplings to give
a CP asymmetry large enough to produce the sufficient baryon asymmetry from the
decay of the nearly degenerate neutrino Kaluza-Klein states. In this way the
standard baryogenesis via leptogenesis scenario can naturally occur at the TeV
scale without the need for a high mass scale.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 03:14:22 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Aug 2007 06:35:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gherghetta",
"Tony",
""
],
[
"Kadota",
"Kenji",
""
],
[
"Yamaguchi",
"Masahide",
""
]
] |
0705.1750 | Peng Cui | Peng Cui | A Tighter Analysis of Setcover Greedy Algorithm for Test Set | 12 pages, 3 figures, Revised version | null | null | null | cs.DS | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Setcover greedy algorithm is a natural approximation algorithm for test set
problem. This paper gives a precise and tighter analysis of performance
guarantee of this algorithm. The author improves the performance guarantee
$2\ln n$ which derives from set cover problem to $1.1354\ln n$ by applying the
potential function technique. In addition, the author gives a nontrivial lower
bound $1.0004609\ln n$ of performance guarantee of this algorithm. This lower
bound, together with the matching bound of information content heuristic,
confirms the fact information content heuristic is slightly better than
setcover greedy algorithm in worst case.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 04:18:36 GMT"
},
{
"version": "v2",
"created": "Thu, 17 May 2007 09:32:21 GMT"
},
{
"version": "v3",
"created": "Sun, 29 Mar 2009 02:58:29 GMT"
},
{
"version": "v4",
"created": "Sat, 4 Apr 2009 02:46:12 GMT"
},
{
"version": "v5",
"created": "Sat, 29 Jan 2011 04:49:11 GMT"
},
{
"version": "v6",
"created": "Sat, 5 Mar 2011 00:17:44 GMT"
}
] | 2011-03-08T00:00:00 | [
[
"Cui",
"Peng",
""
]
] |
0705.1751 | Francois Rodier | Eric F\'erard (UPF), Fran\c{c}ois Rodier (IML) | Nonlinarity of Boolean functions and hyperelliptic curves | null | null | null | null | math.NT | null | We study the nonlinearity of functions defined on a finite field with 2^m
elements which are the trace of a polynomial of degree 7 or more general
polynomials. We show that for m odd such functions have rather good
nonlinearity properties. We use for that recent results of Maisner and Nart
about zeta functions of supersingular curves of genus 2. We give some criterion
for a vectorial function not to be almost perfect nonlinear.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 06:48:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Férard",
"Eric",
"",
"UPF"
],
[
"Rodier",
"François",
"",
"IML"
]
] |
0705.1752 | Sujatha N V Dr. | N. V. Sujatha (1), Jayant Murthy (1), P. Shalima (1) and Richard Conn
Henry (2) ((1) Indian Institute of Astrophysics, Koramangala, Bangalore,
India, (2) The Johns Hopkins University, Baltimore) | Measurement of Dust Optical Properties in Coalsack | Total 19 pages, Figures 9, Accepted for publication in Astrophysical
Journal | Astrophys.J.665:363-368,2007 | 10.1086/519439 | null | astro-ph | null | We have used FUSE and Voyager observations of dust scattered starlight in the
neighborhood of the Coalsack Nebula to derive the optical constants of the dust
grains. The albedo is consistent with a value of $0.28 \pm 0.04$ and the phase
function asymmetry factor with a value of $0.61 \pm 0.07$ throughout the
spectral range from 900 -- 1200 \AA, in agreement with previous determinations
as well as theoretical predictions. We have now observed two regions (Ophiuchus
and Coalsack) with intense diffuse background radiation and in both cases have
found that the emission is due to light from nearby hot stars scattered by a
relatively thin foreground cloud, with negligible contribution from the
background molecular cloud.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 07:25:06 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Sujatha",
"N. V.",
""
],
[
"Murthy",
"Jayant",
""
],
[
"Shalima",
"P.",
""
],
[
"Henry",
"Richard Conn",
""
]
] |
0705.1753 | Julien Gibelin | J. Gibelin (IPNO, Rikkyo University), D. Beaumel (IPNO), T.
Motobayashi (Riken), N. Aoi (Riken), H. Baba (Riken), Y. Blumenfeld (IPNO),
Z. Elekes (ATOMKI), S. Fortier (IPNO), N. Frascaria (IPNO), N. Fukuda
(Riken), T. Gomi (Riken), K. Ishikawa (Tokyo Institute of Technology), Y.
Kondo (Tokyo Institute of Technology), T. Kubo (Riken), V. Lima (IPNO), T.
Nakamura (Tokyo Institute of Technology), A. Saito (CNS), Y. Satou (Tokyo
Institute of Technology), E. Takeshita (Rikkyo University), S. Takeuchi
(Riken), T. Teranishi (CNS), Y. Togano (Rikkyo University), A.M. Vinodkumar
(Tokyo Institute of Technology), Y. Yanagisawa (Riken), K. Yoshida (Riken) | Search for low lying dipole strength in the neutron rich nucleus
$^{26}$Ne | null | 2nd International Conference on Collective Motion in Nuclei under
Extreme Conditions - COMEX 2, Sankt Goar (2007) 153-158 | 10.1016/j.nuclphysa.2007.01.076 | null | nucl-ex | null | Coulomb excitation of the exotic neutron-rich nucleus $^{26}$Ne on a
$^{nat}$Pb target was measured at 58 A.MeV in order to search for low-lying E1
strength above the neutron emission threshold. Data were also taken on an
$^{nat}$Al target to estimate the nuclear contribution. The radioactive beam
was produced by fragmentation of a 95 A.MeV $^{40}$Ar beam delivered by the
RIKEN Research Facility. The set-up included a NaI gamma-ray array, a charged
fragment hodoscope and a neutron wall. Using the invariant mass method in the
$^{25}$Ne+n channel, we observe a sizable amount of E1 strength between 6 and
10 MeV. The reconstructed $^{26}$Ne angular distribution confirms its E1
nature. A reduced dipole transition probability of B(E1)=0.49$\pm$0.16
$e^2fm^2$ is deduced. For the first time, the decay pattern of low-lying
strength in a neutron-rich nucleus is obtained. The results are discussed in
terms of a pygmy resonance centered around 9 MeV.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 09:28:53 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gibelin",
"J.",
"",
"IPNO, Rikkyo University"
],
[
"Beaumel",
"D.",
"",
"IPNO"
],
[
"Motobayashi",
"T.",
"",
"Riken"
],
[
"Aoi",
"N.",
"",
"Riken"
],
[
"Baba",
"H.",
"",
"Riken"
],
[
"Blumenfeld",
"Y.",
"",
"IPNO"
],
[
"Elekes",
"Z.",
"",
"ATOMKI"
],
[
"Fortier",
"S.",
"",
"IPNO"
],
[
"Frascaria",
"N.",
"",
"IPNO"
],
[
"Fukuda",
"N.",
"",
"Riken"
],
[
"Gomi",
"T.",
"",
"Riken"
],
[
"Ishikawa",
"K.",
"",
"Tokyo Institute of Technology"
],
[
"Kondo",
"Y.",
"",
"Tokyo Institute of Technology"
],
[
"Kubo",
"T.",
"",
"Riken"
],
[
"Lima",
"V.",
"",
"IPNO"
],
[
"Nakamura",
"T.",
"",
"Tokyo Institute of Technology"
],
[
"Saito",
"A.",
"",
"CNS"
],
[
"Satou",
"Y.",
"",
"Tokyo\n Institute of Technology"
],
[
"Takeshita",
"E.",
"",
"Rikkyo University"
],
[
"Takeuchi",
"S.",
"",
"Riken"
],
[
"Teranishi",
"T.",
"",
"CNS"
],
[
"Togano",
"Y.",
"",
"Rikkyo University"
],
[
"Vinodkumar",
"A. M.",
"",
"Tokyo Institute of Technology"
],
[
"Yanagisawa",
"Y.",
"",
"Riken"
],
[
"Yoshida",
"K.",
"",
"Riken"
]
] |
0705.1754 | Jurgen Knodlseder | J\"urgen Kn\"Odlseder (CESR) | GRI: The Gamma-Ray Imager mission | 8 pages | Adv.Space Res.40:1263-1267,2007 | 10.1016/j.asr.2007.07.036 | GRI-2007 | astro-ph | null | With the INTEGRAL observatory, ESA has provided a unique tool to the
astronomical community revealing hundreds of sources, new classes of objects,
extraordinary views of antimatter annihilation in our Galaxy, and fingerprints
of recent nucleosynthesis processes. While INTEGRAL provides the global
overview over the soft gamma-ray sky, there is a growing need to perform
deeper, more focused investigations of gamma-ray sources. In soft X-rays a
comparable step was taken going from the Einstein and the EXOSAT satellites to
the Chandra and XMM/Newton observatories. Technological advances in the past
years in the domain of gamma-ray focusing using Laue diffraction have paved the
way towards a new gamma-ray mission, providing major improvements regarding
sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow
studies of particle acceleration processes and explosion physics in
unprecedented detail, providing essential clues on the innermost nature of the
most violent and most energetic processes in the Universe.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 09:42:06 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"KnÖdlseder",
"Jürgen",
"",
"CESR"
]
] |
0705.1755 | G. J. Savonije | G.J. Savonije | Non-radial oscillations of the rapidly rotating Be star HD 163868 | 7 pages, 7 figures; accepted by A&A | null | 10.1051/0004-6361:20077377 | null | astro-ph | null | We study the pulsational stability of the rapidly rotating Be star HD 163868
using a newly developed 2D oscillation code which takes the Coriolis force
fully into account and compare our results with observations (MOST) and recent
other stability analyses of this ~ 6 Msun star. We find both prograde and
retrograde overstable modes (although more prograde than retrograde modes) and
confirm the existence of low degree odd r-modes destabilised by the
kappa-mechanism. The ultra-low frequency modes that could not be explained in a
previous analysis are interpreted as high degree, retrograde m=1 modes. A
reasonably good fit to the observed oscillation spectrum is possible if we
assume that only even modes are observed. This requires a nearly equator-on
view of the observed star, consistent with the measured high v sin i value of
250 km/s.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 09:51:26 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Savonije",
"G. J.",
""
]
] |
0705.1756 | Christian Boehmer | C. G. Boehmer, T. Harko | On Einstein clusters as galactic dark matter halos | MNRAS LaTeX, 7 pages, accepted by MNRAS; reference added | Mon.Not.Roy.Astron.Soc.379:393-398,2007 | 10.1111/j.1365-2966.2007.11977.x | null | gr-qc astro-ph | null | We consider global and gravitational lensing properties of the recently
suggested Einstein clusters of WIMPs as galactic dark matter halos. Being
tangential pressure dominated, Einstein clusters are strongly anisotropic
systems which can describe any galactic rotation curve by specifying the
anisotropy. Due to this property, Einstein clusters may be considered as dark
matter candidates. We analyse the stability of the Einstein clusters against
both radial and non-radial pulsations, and we show that the Einstein clusters
are dynamically stable. With the use of the Buchdahl type inequalities for
anisotropic bodies, we derive upper limits on the velocity of the particles
defining the cluster. These limits are consistent with those obtained from
stability considerations. The study of light deflection shows that the
gravitational lensing effect is slightly smaller for the Einstein clusters, as
compared to the singular isothermal density sphere model for dark matter.
Therefore lensing observations may discriminate, at least in principle, between
Einstein cluster and other dark matter models.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 09:55:12 GMT"
},
{
"version": "v2",
"created": "Thu, 24 May 2007 22:16:12 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Boehmer",
"C. G.",
""
],
[
"Harko",
"T.",
""
]
] |
0705.1757 | Tshilidzi Marwala | T. Marwala, P. De Wilde, L. Correia, P. Mariano, R. Ribeiro, V.
Abramov, N. Szirbik, J.Goossenaerts | Scalability and Optimisation of a Committee of Agents Using Genetic
Algorithm | 6 pages, In Proceedings of the 2001 International Symposia on Soft
Computing and Intelligent Systems for Industry, Scotland | null | null | null | cs.MA | null | A population of committees of agents that learn by using neural networks is
implemented to simulate the stock market. Each committee of agents, which is
regarded as a player in a game, is optimised by continually adapting the
architecture of the agents using genetic algorithms. The committees of agents
buy and sell stocks by following this procedure: (1) obtain the current price
of stocks; (2) predict the future price of stocks; (3) and for a given price
trade until all the players are mutually satisfied. The trading of stocks is
conducted by following these rules: (1) if a player expects an increase in
price then it tries to buy the stock; (2) else if it expects a drop in the
price, it sells the stock; (3)and the order in which a player participates in
the game is random. The proposed procedure is implemented to simulate trading
of three stocks, namely, the Dow Jones, the Nasdaq and the S&P 500. A linear
relationship between the number of players and agents versus the computational
time to run the complete simulation is observed. It is also found that no
player has a monopolistic advantage.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 10:11:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Marwala",
"T.",
""
],
[
"De Wilde",
"P.",
""
],
[
"Correia",
"L.",
""
],
[
"Mariano",
"P.",
""
],
[
"Ribeiro",
"R.",
""
],
[
"Abramov",
"V.",
""
],
[
"Szirbik",
"N.",
""
],
[
"Goossenaerts",
"J.",
""
]
] |
0705.1758 | Nina Nowak | N. Nowak, R.P. Saglia, J. Thomas, R. Bender, M. Pannella, K. Gebhardt,
R.I. Davies | The supermassive black hole in NGC4486a detected with SINFONI at the VLT | 7 pages, 7 figures. Accepted by MNRAS | Mon.Not.Roy.Astron.Soc.379:909-914,2007 | 10.1111/j.1365-2966.2007.11949.x | null | astro-ph | null | The near-infrared integral field spectrograph SINFONI at the ESO VLT opens a
new window for the study of central supermassive black holes. With a near-IR
spatial resolution similar to HST optical and the ability to penetrate dust it
provides the possibility to explore the low-mass end of the M-sigma relation
(sigma<120km/s) where so far very few black hole masses were measured with
stellar dynamics. With SINFONI we observed the central region of the
low-luminosity elliptical galaxy NGC4486a at a spatial resolution of ~0.1arcsec
in the K band. The stellar kinematics was measured with a maximum penalised
likelihood method considering the region around the CO absorption band heads.
We determined a black hole mass of M_BH=1.25^{+0.75}_{-0.79} x 10^7 M_sun (90%
C.L.) using the Schwarzschild orbit superposition method including the full
2-dimensional spatial information. This mass agrees with the predictions of the
M-sigma relation, strengthening its validity at the lower sigma end.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 10:24:43 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Nowak",
"N.",
""
],
[
"Saglia",
"R. P.",
""
],
[
"Thomas",
"J.",
""
],
[
"Bender",
"R.",
""
],
[
"Pannella",
"M.",
""
],
[
"Gebhardt",
"K.",
""
],
[
"Davies",
"R. I.",
""
]
] |
0705.1759 | Tshilidzi Marwala | Tshilidzi Marwala | Finite Element Model Updating Using Response Surface Method | 9 pages | null | null | null | cs.CE | null | This paper proposes the response surface method for finite element model
updating. The response surface method is implemented by approximating the
finite element model surface response equation by a multi-layer perceptron. The
updated parameters of the finite element model were calculated using genetic
algorithm by optimizing the surface response equation. The proposed method was
compared to the existing methods that use simulated annealing or genetic
algorithm together with a full finite element model for finite element model
updating. The proposed method was tested on an unsymmetri-cal H-shaped
structure. It was observed that the proposed method gave the updated natural
frequen-cies and mode shapes that were of the same order of accuracy as those
given by simulated annealing and genetic algorithm. Furthermore, it was
observed that the response surface method achieved these results at a
computational speed that was more than 2.5 times as fast as the genetic
algorithm and a full finite element model and 24 times faster than the
simulated annealing.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 10:25:22 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Marwala",
"Tshilidzi",
""
]
] |
0705.1760 | Tshilidzi Marwala | Tshilidzi Marwala | Dynamic Model Updating Using Particle Swarm Optimization Method | 6 pages | null | null | null | cs.CE cs.NE | null | This paper proposes the use of particle swarm optimization method (PSO) for
finite element (FE) model updating. The PSO method is compared to the existing
methods that use simulated annealing (SA) or genetic algorithms (GA) for FE
model for model updating. The proposed method is tested on an unsymmetrical
H-shaped structure. It is observed that the proposed method gives updated
natural frequencies the most accurate and followed by those given by an updated
model that was obtained using the GA and a full FE model. It is also observed
that the proposed method gives updated mode shapes that are best correlated to
the measured ones, followed by those given by an updated model that was
obtained using the SA and a full FE model. Furthermore, it is observed that the
PSO achieves this accuracy at a computational speed that is faster than that by
the GA and a full FE model which is faster than the SA and a full FE model.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 10:27:07 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Marwala",
"Tshilidzi",
""
]
] |
0705.1761 | Tshilidzi Marwala | Tshilidzi Marwala and Monica Lagazio | Modeling and Controlling Interstate Conflict | 6 pages | null | null | null | cs.CY | null | Bayesian neural networks were used to model the relationship between input
parameters, Democracy, Allies, Contingency, Distance, Capability, Dependency
and Major Power, and the output parameter which is either peace or conflict.
The automatic relevance determination was used to rank the importance of input
variables. Control theory approach was used to identify input variables that
would give a peaceful outcome. It was found that using all four controllable
variables Democracy, Allies, Capability and Dependency; or using only
Dependency or only Capabilities avoids all the predicted conflicts.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 10:34:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Marwala",
"Tshilidzi",
""
],
[
"Lagazio",
"Monica",
""
]
] |
0705.1762 | F. Cecconi | Umberto Marini-Bettolo-Marconi, Pedro Tarazona, Fabio Cecconi | Theory of thermostatted inhomogeneous granular fluids: a self-consistent
density functional description | RevTeX4, 18 pages, 9 eps-figures | J. Chem. Phys. vol. 126, 164904 (2007) | 10.1063/1.2723744 | null | cond-mat.mtrl-sci cond-mat.stat-mech | null | The authors present a study of the non equilibrium statistical properties of
a one dimensional hard-rod fluid dissipating energy via inelastic collisions
and subject to the action of a Gaussian heat bath, simulating an external
driving mechanism. They show that the description of the fluid based on the
one-particle phase-space reduced distribution function, in principle necessary
because of the presence of velocity dependent collisional dissipation, can be
contracted to a simpler description in configurational space. Indeed, by means
of a multiple-time scale method the authors derive a self-consistent governing
equation for the particle density distribution function. This equation is
similar to the dynamic density functional equation employed in the study of
colloids, but contains additional terms taking into account the inelastic
nature of the fluid. Such terms cannot be derived from a Liapunov generating
functional and contribute not only to the relaxational properties, but also to
the non equilibrium steady state properties. A validation of the theory against
molecular dynamics simulations is presented in a series of cases, and good
agreement is found.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 10:44:27 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Marini-Bettolo-Marconi",
"Umberto",
""
],
[
"Tarazona",
"Pedro",
""
],
[
"Cecconi",
"Fabio",
""
]
] |
0705.1763 | Allal Ghanmi | Allal Ghanmi and Ahmed Intissar | Landau (\Gamma,\chi)-automorphic functions on \mathbb{C}^n of magnitude
\nu | 20 pages. Minor corrections. Scheduled to appear in issue 8 (2008) of
"Journal of Mathematical Physics" | null | 10.1063/1.2958090 | null | math.SP math-ph math.CV math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the spectral theory of the invariant Landau Hamiltonian
$\La^\nu$ acting on the space ${\mathcal{F}}^\nu_{\Gamma,\chi}$ of
$(\Gamma,\chi)$-automotphic functions on $\C^n$, for given real number $\nu>0$,
lattice $\Gamma$ of $\C^n$ and a map $\chi:\Gamma\to U(1)$ such that the
triplet $(\nu,\Gamma,\chi)$ satisfies a Riemann-Dirac quantization type
condition. More precisely, we show that the eigenspace $
{\mathcal{E}}^\nu_{\Gamma,\chi}(\lambda)=\set{f\in
{\mathcal{F}}^\nu_{\Gamma,\chi}; \La^\nu f = \nu(2\lambda+n) f}$;
$\lambda\in\C,$ is non trivial if and only if $\lambda=l=0,1,2, ...$. In such
case, ${\mathcal{E}}^\nu_{\Gamma,\chi}(l)$ is a finite dimensional vector space
whose the dimension is given explicitly. We show also that the eigenspace
${\mathcal{E}}^\nu_{\Gamma,\chi}(0)$ associated to the lowest Landau level of
$\La^\nu$ is isomorphic to the space, ${\mathcal{O}}^\nu_{\Gamma,\chi}(\C^n)$,
of holomorphic functions on $\C^n$ satisfying $$ g(z+\gamma) = \chi(\gamma)
e^{\frac \nu 2 |\gamma|^2+\nu\scal{z,\gamma}}g(z), \eqno{(*)} $$ that we can
realize also as the null space of the differential operator
$\sum\limits_{j=1}\limits^n(\frac{-\partial^2}{\partial z_j\partial \bar z_j} +
\nu \bar z_j \frac{\partial}{\partial \bar z_j})$ acting on $\mathcal C^\infty$
functions on $\C^n$ satisfying $(*)$.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 16:00:05 GMT"
},
{
"version": "v2",
"created": "Sun, 19 Aug 2007 13:54:45 GMT"
},
{
"version": "v3",
"created": "Sat, 20 Oct 2007 18:21:53 GMT"
},
{
"version": "v4",
"created": "Thu, 7 Aug 2008 12:12:21 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ghanmi",
"Allal",
""
],
[
"Intissar",
"Ahmed",
""
]
] |
0705.1764 | Paolo Gensini | P.M. Gensini (Univ & INFN Perugia), R. Hurtado (Univ Nac Colombia),
Y.N. Srivastava (Univ & INFN Perugia) and G. Violini (Univ Calabria & INFN
Cosenza) | Is the Pentaquark the Only Justification for Research on KN Physics ? | Plain TeX 12+1 pages with 3 tables in the text, 3 .eps figures.
Presented by G.V. at "EURIDICE: The Final Meeting", Kazimierz, Poland, August
24 -- 27, 2006; v2: minor (one word!) editing by referee; v3: final version
to appear in Acta Physica Polonica B 38, n.9 (2007), with further minor
corrections | Acta Phys.Polon.B38:2911-2922,2007 | null | DFUPG-06-PG-01 | nucl-th hep-ex hep-ph nucl-ex | null | The talk is intended to motivate the use of DA$\Phi$NE--2 running at the
$\phi$ peak as an intense, clean source of low--momentum charged and neutral
kaons. It covers a few open problems still unsolved after more than
twenty--five years and the physics (some of it still novel) that could be
learned only in this way. And, of course, the answer to the above question is
{\sl NO}.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 07:31:59 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 11:53:11 GMT"
},
{
"version": "v3",
"created": "Thu, 16 Aug 2007 20:43:49 GMT"
}
] | 2009-04-22T00:00:00 | [
[
"Gensini",
"P. M.",
"",
"Univ & INFN Perugia"
],
[
"Hurtado",
"R.",
"",
"Univ Nac Colombia"
],
[
"Srivastava",
"Y. N.",
"",
"Univ & INFN Perugia"
],
[
"Violini",
"G.",
"",
"Univ Calabria & INFN\n Cosenza"
]
] |
0705.1765 | Dr. Anirudh Pradhan | Anirudh Pradhan, Mukesh Kumar Mishra and Anil Kumar Yadav | A New Class of String Cosmological Models in Cylindrically Symmetric
Inhomogeneous Universe | 14 pages. arXiv admin note: substantial text overlap with
arXiv:0705.0904 | Rom. J. Phys. 54:747-762,2009 | null | null | gr-qc | null | A new class of cylindrically symmetric inhomogeneous string cosmological
models is investigated. To get the deterministic solution, it has been assumed
that the expansion ($\theta$) in the model is proportional to the eigen value
$\sigma^{1}_{1}$ of the shear tensor $\sigma^{i}_{j}$. The physical and
geometric aspects of the model are also discussed.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 11:08:33 GMT"
},
{
"version": "v2",
"created": "Tue, 24 Jul 2007 13:48:34 GMT"
}
] | 2018-07-10T00:00:00 | [
[
"Pradhan",
"Anirudh",
""
],
[
"Mishra",
"Mukesh Kumar",
""
],
[
"Yadav",
"Anil Kumar",
""
]
] |
0705.1766 | Teo Sharia | Teo Sharia | Recursive Parameter Estimation: Convergence | 25 pages with 1 postscript figure | null | null | null | math.ST stat.TH | null | We consider estimation procedures which are recursive in the sense that each
successive estimator is obtained from the previous one by a simple adjustment.
We propose a wide class of recursive estimation procedures for the general
statistical model and study convergence.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 11:38:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Sharia",
"Teo",
""
]
] |
0705.1767 | Teo Sharia | Teo Sharia | Rate of Convergence in Recursive Parameter Estimation procedures | 21 pages | null | null | null | math.ST stat.TH | null | We consider estimation procedures which are recursive in the sense that each
successive estimator is obtained from the previous one by a simple adjustment.
We study rate of convergence of recursive estimation procedures for the general
statistical model.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 11:51:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Sharia",
"Teo",
""
]
] |
0705.1768 | Alexandre Zagoskin | A.N. Omelyanchouk, S.N. Shevchenko, A.M. Zagoskin, E. Il'ichev, Franco
Nori | Pseudo-Rabi oscillations in superconducting flux qubits in the classical
regime | null | Phys. Rev. B 78 (2008) 054512 | 10.1103/PhysRevB.78.054512 | null | cond-mat.supr-con cond-mat.mes-hall | null | Nonlinear effects in mesoscopic devices can have both quantum and classical
origins. We show that a three-Josephson-junction (3JJ) flux qubit in the
_classical_ regime can produce low-frequency oscillations in the presence of an
external field in resonance with the (high-frequency) harmonic mode of the
system, $\omega$. Like in the case of_quantum_ Rabi oscillations, the frequency
of these pseudo-Rabi oscillations is much smaller than $\omega$ and scales
approximately linearly with the amplitude of the external field. This classical
effect can be reliably distinguished from its quantum counterpart because it
can be produced by the external perturbation not only at the resonance
frequency $\omega$ and its subharmonics ($\omega/n$), but also at its
overtones, $n\omega$.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 12:01:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Omelyanchouk",
"A. N.",
""
],
[
"Shevchenko",
"S. N.",
""
],
[
"Zagoskin",
"A. M.",
""
],
[
"Il'ichev",
"E.",
""
],
[
"Nori",
"Franco",
""
]
] |
0705.1769 | Rahmede Christoph | Alessandro Codello, Roberto Percacci, Christoph Rahmede | Ultraviolet properties of f(R)-Gravity | 4 pages | Int.J.Mod.Phys.A23:143-150,2008 | 10.1142/S0217751X08038135 | null | hep-th gr-qc | null | We discuss the existence and properties of a nontrivial fixed point in
f(R)-gravity, where f is a polynomial of order up to six. Within this
seven-parameter class of theories, the fixed point has three
ultraviolet-attractive and four ultraviolet-repulsive directions; this brings
further support to the hypothesis that gravity is nonperturbatively
renormalizabile.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 13:25:08 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Codello",
"Alessandro",
""
],
[
"Percacci",
"Roberto",
""
],
[
"Rahmede",
"Christoph",
""
]
] |
0705.1770 | Kari J. Eskola | K.J. Eskola, H. Honkanen, H. Niemi, P.V. Ruuskanen and S.S. Rasanen | Hadron multiplicities, pT-spectra and net-baryon number in central Pb+Pb
collisions at the LHC | 2 pages, 2 figures, to be presented at the workshop "Heavy Ion
Collisions at the LHC: Last Call for Predictions" at CERN 29 May - 2 June | null | null | null | hep-ph | null | We compute the initial energy density and net baryon number density in 5%
most central Pb+Pb collisions at $\sqrt s=5.5$ TeV from pQCD + (final state)
saturation, and describe the evolution of the produced system with
boost-invariant transversely expanding hydrodynamics. In addition to the total
multiplicity at midrapidity, we give predictions for the multiplicity of
charged hadrons, pions, kaons and (anti)protons, for the total transverse
energy and net-baryon number, as well as for the $p_T$-spectrum of charged
hadrons, pions and kaons. We also predict the region of applicability of
hydrodynamics by comparing these results with high-$p_T$ hadron spectra
computed from pQCD and energy losses.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 12:38:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Eskola",
"K. J.",
""
],
[
"Honkanen",
"H.",
""
],
[
"Niemi",
"H.",
""
],
[
"Ruuskanen",
"P. V.",
""
],
[
"Rasanen",
"S. S.",
""
]
] |
0705.1771 | Hiroshi Nakajima | H. Nakajima, H. Yamaguchi, H. Matsumoto, T. G. Tsuru, K. Koyama, H.
Tsunemi, K. Hayashida, K. Torii, M. Namiki, S. Katsuda, M. Shoji, D.
Matsuura, T. Miyauchi, T. Dotani, M. Ozaki, H. Murakami, M. W. Bautz, S. E.
Kissel, B. LaMarr, G. Y. Prigozhin | Performance of the Charge Injection Capability of Suzaku XIS | Paper contains 18 figures and 15 tables. Accepted for publication in
PASJ | null | 10.1093/pasj/60.sp1.S1 | null | astro-ph | null | A charge injection technique is applied to the X-ray CCD camera, XIS (X-ray
Imaging Spectrometer) onboard Suzaku. The charge transfer inefficiency (CTI) in
each CCD column (vertical transfer channel) is measured by the injection of
charge packets into a transfer channel and subsequent readout. This paper
reports the performances of the charge injection capability based on the ground
experiments using a radiation damaged device, and in-orbit measurements of the
XIS. The ground experiments show that charges are stably injected with the
dispersion of 91eV in FWHM in a specific column for the charges equivalent to
the X-ray energy of 5.1keV. This dispersion width is significantly smaller than
that of the X-ray events of 113eV (FWHM) at approximately the same energy. The
amount of charge loss during transfer in a specific column, which is measured
with the charge injection capability, is consistent with that measured with the
calibration source. These results indicate that the charge injection technique
can accurately measure column-dependent charge losses rather than the
calibration sources. The column-to-column CTI correction to the calibration
source spectra significantly reduces the line widths compared to those with a
column-averaged CTI correction (from 193eV to 173eV in FWHM on an average at
the time of one year after the launch). In addition, this method significantly
reduces the low energy tail in the line profile of the calibration source
spectrum.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 13:38:35 GMT"
}
] | 2017-01-18T00:00:00 | [
[
"Nakajima",
"H.",
""
],
[
"Yamaguchi",
"H.",
""
],
[
"Matsumoto",
"H.",
""
],
[
"Tsuru",
"T. G.",
""
],
[
"Koyama",
"K.",
""
],
[
"Tsunemi",
"H.",
""
],
[
"Hayashida",
"K.",
""
],
[
"Torii",
"K.",
""
],
[
"Namiki",
"M.",
""
],
[
"Katsuda",
"S.",
""
],
[
"Shoji",
"M.",
""
],
[
"Matsuura",
"D.",
""
],
[
"Miyauchi",
"T.",
""
],
[
"Dotani",
"T.",
""
],
[
"Ozaki",
"M.",
""
],
[
"Murakami",
"H.",
""
],
[
"Bautz",
"M. W.",
""
],
[
"Kissel",
"S. E.",
""
],
[
"LaMarr",
"B.",
""
],
[
"Prigozhin",
"G. Y.",
""
]
] |
0705.1772 | Marek Szydlowski | Marek Szydlowski and Wlodzimierz Godlowski | Acceleration of the Universe driven by the Casimir force | RevTeX4, 17 pages, 9 figures | Int.J.Mod.Phys.D17:343-366,2008 | 10.1142/S021827180801205X | null | gr-qc | null | We investigate an evolutional scenario of the FRW universe with the Casimir
energy scaling like $(-)(1+z)^4$. The Casimir effect is used to explain the
vacuum energy differences (its value measured from astrophysics is so small
compared to value obtained from quantum field theory calculations). The
dynamics of the FRW model is represented in terms of a two-dimensional
dynamical system to show all evolutional paths of this model in the phase space
for all admissible initial conditions. We find also an exact solution for non
flat evolutional paths of Universe driven by the Casimir effect. The main
difference between the FRW model with the Casimir force and the $\Lambda$CDM
model is that their generic solutions are a set of evolutional paths with a
bounce solution and an initial singularity, respectively. The evolutional
scenario are tested by using the SNIa data, FRIIb radiogalaxies, baryon
oscillation peak and CMB observation. We compare the power of explanation of
the model considered and the $\Lambda$CDM model using the Bayesian information
criterion and Bayesian factor. Our investigation of the information criteria of
model selection showed the preference of the $\Lambda$CDM model over the model
considered. However the presence of negative like the radiation term can remove
a tension between the theoretical and observed primordial ${}^4$He and D
abundance.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 13:45:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Szydlowski",
"Marek",
""
],
[
"Godlowski",
"Wlodzimierz",
""
]
] |
0705.1773 | Georgiy Shevchenko | Yuliya Mishura and Georgiy Shevchenko | The rate of convergence of Euler approximations for solutions of
stochastic differential equations driven by fractional Brownian motion | 21 pages, (incorrect) weak convergence result removed, to appear in
Stochastics | Stochastics An International Journal of Probability and Stochastic
Processes 80 (2008), 489-511 | 10.1080/17442500802024892 | null | math.PR | null | The paper focuses on discrete-type approximations of solutions to
non-homogeneous stochastic differential equations (SDEs) involving fractional
Brownian motion (fBm). We prove that the rate of convergence for Euler
approximations of solutions of pathwise SDEs driven by fBm with Hurst index
$H>1/2$ can be estimated by $O(\delta^{2H-1})$ ($\delta$ is the diameter of
partition). For discrete-time approximations of Skorohod-type quasilinear
equation driven by fBm we prove that the rate of convergence is $O(\delta^H)$.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 13:53:21 GMT"
},
{
"version": "v2",
"created": "Thu, 14 Feb 2008 18:26:20 GMT"
}
] | 2012-06-18T00:00:00 | [
[
"Mishura",
"Yuliya",
""
],
[
"Shevchenko",
"Georgiy",
""
]
] |
0705.1774 | E. V. Ferapontov | E.V. Ferapontov, L. Hadjikos, K.R. Khusnutdinova | Integrable equations of the dispersionless Hirota type and hypersurfaces
in the Lagrangian Grassmannian | 32 pages | null | null | null | math.DG | null | We investigate integrable second order equations of the form
F(u_{xx}, u_{xy}, u_{yy}, u_{xt}, u_{yt}, u_{tt})=0.
Familiar examples include the Boyer-Finley equation, the potential form of
the dispersionless Kadomtsev-Petviashvili equation, the dispersionless Hirota
equation, etc. The integrability is understood as the existence of infinitely
many hydrodynamic reductions. We demonstrate that the natural equivalence group
of the problem is isomorphic to Sp(6), revealing a remarkable correspondence
between differential equations of the above type and hypersurfaces of the
Lagrangian Grassmannian. We prove that the moduli space of integrable equations
of the dispersionless Hirota type is 21-dimensional, and the action of the
equivalence group Sp(6) on the moduli space has an open orbit.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 14:16:01 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ferapontov",
"E. V.",
""
],
[
"Hadjikos",
"L.",
""
],
[
"Khusnutdinova",
"K. R.",
""
]
] |
0705.1775 | Stephane Dorbolo | S. Dorbolo, A. Merlen, M. Creyssels, N. Vandewalle, B. Castaing, and
E. Falcon | Effects of electromagnetic waves on the electrical properties of
contacts between grains | 4 pages, 5 figures | null | 10.1209/0295-5075/79/54001 | null | cond-mat.soft | null | A DC electrical current is injected through a chain of metallic beads. The
electrical resistances of each bead-bead contacts are measured. At low current,
the distribution of these resistances is large and log-normal. At high enough
current, the resistance distribution becomes sharp and Gaussian due to the
creation of microweldings between some beads. The action of nearby
electromagnetic waves (sparks) on the electrical conductivity of the chain is
also studied. The spark effect is to lower the resistance values of the more
resistive contacts, the best conductive ones remaining unaffected by the spark
production. The spark is able to induce through the chain a current enough to
create microweldings between some beads. This explains why the electrical
resistance of a granular medium is so sensitive to the electromagnetic waves
produced in its vicinity.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 14:35:12 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Jul 2007 09:16:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dorbolo",
"S.",
""
],
[
"Merlen",
"A.",
""
],
[
"Creyssels",
"M.",
""
],
[
"Vandewalle",
"N.",
""
],
[
"Castaing",
"B.",
""
],
[
"Falcon",
"E.",
""
]
] |
0705.1776 | Eric Josef Ribeiro Parteli | Eric J. R. Parteli and Hans J. Herrmann | Saltation transport on Mars | 4 pages, 3 figures | Physical Review Letters 98, 198001 (2007) | 10.1103/PhysRevLett.98.198001 | null | cond-mat.other | null | We present the first calculation of saltation transport and dune formation on
Mars and compare it to real dunes. We find that the rate at which grains are
entrained into saltation on Mars is one order of magnitude higher than on
Earth. With this fundamental novel ingredient, we reproduce the size and
different shapes of Mars dunes, and give an estimate for the wind velocity on
Mars.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 15:01:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Parteli",
"Eric J. R.",
""
],
[
"Herrmann",
"Hans J.",
""
]
] |
0705.1777 | Alexandre Fournier | Alexandre Fournier, C\'eline Eymin and Thierry Alboussi\`ere | A case for variational geomagnetic data assimilation: insights from a
one-dimensional, nonlinear, and sparsely observed MHD system | null | Nonlinear processes in Geophysics, Vol. 14, pp 163-180, 2007 | 10.5194/npg-14-163-2007 | null | physics.geo-ph | null | Secular variations of the geomagnetic field have been measured with a
continuously improving accuracy during the last few hundred years, culminating
nowadays with satellite data. It is however well known that the dynamics of the
magnetic field is linked to that of the velocity field in the core and any
attempt to model secular variations will involve a coupled dynamical system for
magnetic field and core velocity. Unfortunately, there is no direct observation
of the velocity. Independently of the exact nature of the above-mentioned
coupled system -- some version being currently under construction -- the
question is debated in this paper whether good knowledge of the magnetic field
can be translated into good knowledge of core dynamics. Furthermore, what will
be the impact of the most recent and precise geomagnetic data on our knowledge
of the geomagnetic field of the past and future? These questions are cast into
the language of variational data assimilation, while the dynamical system
considered in this paper consists in a set of two oversimplified
one-dimensional equations for magnetic and velocity fields. This toy model
retains important features inherited from the induction and Navier-Stokes
equations: non-linear magnetic and momentum terms are present and its linear
response to small disturbances contains Alfv\'en waves. It is concluded that
variational data assimilation is indeed appropriate in principle, even though
the velocity field remains hidden at all times; it allows us to recover the
entire evolution of both fields from partial and irregularly distributed
information on the magnetic field. This work constitutes a first step on the
way toward the reassimilation of historical geomagnetic data and geomagnetic
forecast.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 14:57:50 GMT"
}
] | 2015-10-28T00:00:00 | [
[
"Fournier",
"Alexandre",
""
],
[
"Eymin",
"Céline",
""
],
[
"Alboussière",
"Thierry",
""
]
] |
0705.1778 | Eric Josef Ribeiro Parteli | Eric J. R. Parteli, Orencio Duran and Hans J. Herrmann | Minimal size of a barchan dune | 11 pages, 10 figures | Physical Review E 75, 011301 (2007) | 10.1103/PhysRevE.75.011301 | null | cond-mat.other | null | Barchans are dunes of high mobility which have a crescent shape and propagate
under conditions of unidirectional wind. However, sand dunes only appear above
a critical size, which scales with the saturation distance of the sand flux [P.
Hersen, S. Douady, and B. Andreotti, Phys. Rev. Lett. {\bf{89,}} 264301 (2002);
B. Andreotti, P. Claudin, and S. Douady, Eur. Phys. J. B {\bf{28,}} 321 (2002);
G. Sauermann, K. Kroy, and H. J. Herrmann, Phys. Rev. E {\bf{64,}} 31305
(2001)]. It has been suggested by P. Hersen, S. Douady, and B. Andreotti, Phys.
Rev. Lett. {\bf{89,}} 264301 (2002) that this flux fetch distance is itself
constant. Indeed, this could not explain the proto size of barchan dunes, which
often occur in coastal areas of high litoral drift, and the scale of dunes on
Mars. In the present work, we show from three dimensional calculations of sand
transport that the size and the shape of the minimal barchan dune depend on the
wind friction speed and the sand flux on the area between dunes in a field. Our
results explain the common appearance of barchans a few tens of centimeter high
which are observed along coasts. Furthermore, we find that the rate at which
grains enter saltation on Mars is one order of magnitude higher than on Earth,
and is relevant to correctly obtain the minimal dune size on Mars.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 14:16:00 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Parteli",
"Eric J. R.",
""
],
[
"Duran",
"Orencio",
""
],
[
"Herrmann",
"Hans J.",
""
]
] |
0705.1779 | Anthony Bloch | Fred Adams and Anthony Bloch | Hill's Equation with Random Forcing Terms | null | null | null | null | math-ph astro-ph math.MP | null | Motivated by a class of orbit problems in astrophysics, this paper considers
solutions to Hill's equation with forcing strength parameters that vary from
cycle to cycle. The results are generalized to include period variations from
cycle to cycle. The development of the solutions to the differential equation
is governed by a discrete map. For the general case of Hill's equation in the
unstable limit, we consider separately the case of purely positive matrix
elements and those with mixed signs; we then find exact expressions, bounds,
and working estimates for the growth rates. We also find exact expressions,
estimates, and bounds for the infinite products of several $2 \times 2$
matrices with random variables in the matrix elements. In the limit of sharply
spiked forcing terms (the delta function limit), we find analytic solutions for
each cycle and for the discrete map that matches solutions from cycle to cycle;
for this case we find the growth rates and the condition for instability in the
limit of large forcing strength, as well as the widths of the stable/unstable
zones.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 15:48:27 GMT"
},
{
"version": "v2",
"created": "Mon, 8 Oct 2007 16:38:56 GMT"
}
] | 2007-10-08T00:00:00 | [
[
"Adams",
"Fred",
""
],
[
"Bloch",
"Anthony",
""
]
] |
0705.1780 | Brynmor Haskell | B. Haskell, L. Samuelsson, K. Glampedakis, N. Andersson | Modelling magnetically deformed neutron stars | null | Mon.Not.Roy.Astron.Soc.385:531-542,2008 | 10.1111/j.1365-2966.2008.12861.x | null | astro-ph | null | Rotating deformed neutron stars are important potential sources for
groundbased gravitational-wave interferometers such as LIGO, GE0600 and VIRGO.
One mechanism that may lead to significant non-asymmetries is the internal
magnetic field. It is well known that a magnetic star will not be spherical
and, if the magnetic axis is not aligned with the spin axis, the deformation
will lead to the emission of gravitational waves. The aim of this paper is to
develop a formalism that would allow us to model magnetically deformed stars,
using both realistic equations of state and field configurations. As a first
step, we consider a set of simplified model problems. Focusing on dipolar
fields, we determine the internal magnetic field which is consistent with a
given neutron star model. We then calculate the associated deformation. We
conclude by discussing the relevance of our results for current
gravitational-wave detectors and future prospects.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 15:56:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Haskell",
"B.",
""
],
[
"Samuelsson",
"L.",
""
],
[
"Glampedakis",
"K.",
""
],
[
"Andersson",
"N.",
""
]
] |
0705.1781 | John Pretz | The IceCube Collaboration: A. Achterberg, et al | Detection of Atmospheric Muon Neutrinos with the IceCube 9-String
Detector | null | Phys.Rev.D76:027101,2007 | 10.1103/PhysRevD.76.027101 | null | astro-ph | null | The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino
detector under construction at the geographic South Pole. The dominant
population of neutrinos detected in IceCube is due to meson decay in cosmic-ray
air showers. These atmospheric neutrinos are relatively well-understood and
serve as a calibration and verification tool for the new detector. In 2006, the
detector was approximately 10% completed, and we report on data acquired from
the detector in this configuration. We observe an atmospheric neutrino signal
consistent with expectations, demonstrating that the IceCube detector is
capable of identifying neutrino events. In the first 137.4 days of livetime,
234 neutrino candidates were selected with an expectation of 211 +/-
76.1(syst.) +/- 14.5(stat.) events from atmospheric neutrinos.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 19:40:39 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"The IceCube Collaboration",
"",
""
],
[
"Achterberg",
"A.",
""
]
] |
0705.1782 | Cai-Dian Lu | C.D. Lu (IHEP, Beijing) | The study of charmless hadronic $B_s$ decays | 4 pages, 1 figure, talk given at 4th International workshop on the
CKM unitarity triangle, Dec. 12-16,2006, Nagoya, Japan and The IVIIth
Rencontres de Moriond: QCD and High Energy Hadronic Interactions, March 2007,
La Thuile, Italy | null | null | null | hep-ph | null | The perturbative QCD approach has achieved great success in the study of
hadronic B decays. Utilizing the constrained parameters in these well measured
decay channels, we study most of the possible charmless $B_s \to PP$, $PV$ and
$VV$ decay channels in the perturbative QCD approach. In addition to the
branching ratios and CP asymmetries, we also give predictions to the
polarization fractions of the vector meson final states. The size of SU(3)
breaking effect is also discussed. All of these predictions can be tested by
the future LHCb experiment.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 16:36:06 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lu",
"C. D.",
"",
"IHEP, Beijing"
]
] |
0705.1783 | Teo Sharia | Teo Sharia | Recursive Parameter Estimation: Asymptotic expansion | 30 pages with 1 postscript figure | null | null | null | math.ST stat.TH | null | We consider estimation procedures which are recursive in the sense that each
successive estimator is obtained from the previous one by a simple adjustment.
The model considered in the paper is very general as we do not impose any
preliminary restrictions on the probabilistic nature of the observation process
and cover a wide class of nonlinear recursive procedures. In this paper we
study asymptotic behaviour of the recursive estimators. The results of the
paper can be used to determine the form of a recursive procedure which is
expected to have the same asymptotic properties as the corresponding
non-recursive one defined as a solution of the corresponding estimating
equation.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 17:02:42 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Sharia",
"Teo",
""
]
] |
0705.1784 | Andrei Galiautdinov | Andrei Galiautdinov | Single-step controlled-NOT logic from any exchange interaction | 12 pages + 7 figures; revised version; title changed | J. Math. Phys. 48, 112105 (2007) | 10.1063/1.2806489 | null | quant-ph | null | A self-contained approach to studying the unitary evolution of coupled qubits
is introduced, capable of addressing a variety of physical systems described by
exchange Hamiltonians containing Rabi terms. The method automatically
determines both the Weyl chamber steering trajectory and the accompanying local
rotations. Particular attention is paid to the case of anisotropic exchange
with tracking controls, which is solved analytically. It is shown that, if
computational subspace is well isolated, any exchange interaction can always
generate high-fidelity, single-step controlled-NOT (CNOT) logic, provided that
both qubits can be individually manipulated. The results are then applied to
superconducting qubit architectures, for which several CNOT gate
implementations are identified. The paper concludes with consideration of two
CNOT gate designs having high efficiency and operating with no significant
leakage to higher-lying non-computational states.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 11:51:40 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Nov 2007 00:40:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Galiautdinov",
"Andrei",
""
]
] |
0705.1785 | Allen Stern | A. Pinzul and A. Stern | Gauge Theory of the Star Product | 16 pages | Nucl.Phys.B791:284-297,2008 | 10.1016/j.nuclphysb.2007.09.012 | null | hep-th math-ph math.MP | null | The choice of a star product realization for noncommutative field theory can
be regarded as a gauge choice in the space of all equivalent star products.
With the goal of having a gauge invariant treatment, we develop tools, such as
integration measures and covariant derivatives on this space. The covariant
derivative can be expressed in terms of connections in the usual way giving
rise to new degrees of freedom for noncommutative theories.
| [
{
"version": "v1",
"created": "Sun, 13 May 2007 05:36:36 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Sep 2007 17:58:57 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Pinzul",
"A.",
""
],
[
"Stern",
"A.",
""
]
] |
0705.1786 | Ali Chamseddine | Ali H. Chamseddine and Alain Connes | Quantum Gravity Boundary Terms from Spectral Action of Noncommutative
Space | "Noncommutative Space" was added to end of title. Minor changes.
Content that appeared in print | Phys.Rev.Lett.99:071302,2007 | 10.1103/PhysRevLett.99.071302 | null | hep-th gr-qc | null | We study the boundary terms of the spectral action of the noncommutative
space, defined by the spectral triple dictated by the physical spectrum of the
standard model, unifying gravity with all other fundamental interactions. We
prove that the spectral action predicts uniquely the gravitational boundary
term required for consistency of quantum gravity with the correct sign and
coefficient. This is a remarkable result given the lack of freedom in the
spectral action to tune this term.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 17:58:35 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Sep 2007 12:57:17 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chamseddine",
"Ali H.",
""
],
[
"Connes",
"Alain",
""
]
] |
0705.1787 | Farhad Meshkati | Farhad Meshkati, H. Vincent Poor and Stuart C. Schwartz | Energy-Efficient Resource Allocation in Wireless Networks: An Overview
of Game-Theoretic Approaches | To appear in the IEEE Signal Processing Magazine: Special Issue on
Resource-Constrained Signal Processing, Communications and Networking, May
2007 | null | 10.1109/MSP.2007.361602 | null | cs.IT cs.GT math.IT | null | An overview of game-theoretic approaches to energy-efficient resource
allocation in wireless networks is presented. Focusing on multiple-access
networks, it is demonstrated that game theory can be used as an effective tool
to study resource allocation in wireless networks with quality-of-service (QoS)
constraints. A family of non-cooperative (distributed) games is presented in
which each user seeks to choose a strategy that maximizes its own utility while
satisfying its QoS requirements. The utility function considered here measures
the number of reliable bits that are transmitted per joule of energy consumed
and, hence, is particulary suitable for energy-constrained networks. The
actions available to each user in trying to maximize its own utility are at
least the choice of the transmit power and, depending on the situation, the
user may also be able to choose its transmission rate, modulation, packet size,
multiuser receiver, multi-antenna processing algorithm, or carrier allocation
strategy. The best-response strategy and Nash equilibrium for each game is
presented. Using this game-theoretic framework, the effects of power control,
rate control, modulation, temporal and spatial signal processing, carrier
allocation strategy and delay QoS constraints on energy efficiency and network
capacity are quantified.
| [
{
"version": "v1",
"created": "Sun, 13 May 2007 17:22:29 GMT"
}
] | 2016-11-18T00:00:00 | [
[
"Meshkati",
"Farhad",
""
],
[
"Poor",
"H. Vincent",
""
],
[
"Schwartz",
"Stuart C.",
""
]
] |
0705.1788 | Farhad Meshkati | Farhad Meshkati, Andrea J. Goldsmith, H. Vincent Poor and Stuart C.
Schwartz | A Game-Theoretic Approach to Energy-Efficient Modulation in CDMA
Networks with Delay QoS Constraints | To appear in the IEEE Journal on Selected Areas in Communications
(JSAC): Special Issue on Non-Cooperative Behavior in Networking, August 2007 | null | 10.1109/JSAC.2007.070802 | null | cs.IT cs.GT math.IT | null | A game-theoretic framework is used to study the effect of constellation size
on the energy efficiency of wireless networks for M-QAM modulation. A
non-cooperative game is proposed in which each user seeks to choose its
transmit power (and possibly transmit symbol rate) as well as the constellation
size in order to maximize its own utility while satisfying its delay
quality-of-service (QoS) constraint. The utility function used here measures
the number of reliable bits transmitted per joule of energy consumed, and is
particularly suitable for energy-constrained networks. The best-response
strategies and Nash equilibrium solution for the proposed game are derived. It
is shown that in order to maximize its utility (in bits per joule), a user must
choose the lowest constellation size that can accommodate the user's delay
constraint. This strategy is different from one that would maximize spectral
efficiency. Using this framework, the tradeoffs among energy efficiency, delay,
throughput and constellation size are also studied and quantified. In addition,
the effect of trellis-coded modulation on energy efficiency is discussed.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 22:39:27 GMT"
}
] | 2016-11-18T00:00:00 | [
[
"Meshkati",
"Farhad",
""
],
[
"Goldsmith",
"Andrea J.",
""
],
[
"Poor",
"H. Vincent",
""
],
[
"Schwartz",
"Stuart C.",
""
]
] |
0705.1789 | Lu\'isa Lima | Lu\'isa Lima and Muriel M\'edard and Jo\~ao Barros | Random Linear Network Coding: A free cipher? | 5 pages, 2 figures, Accepted for the IEEE International Symposium on
Information Theory, Nice, France, June, 2007 | null | null | null | cs.IT cs.CR math.IT | null | We consider the level of information security provided by random linear
network coding in network scenarios in which all nodes comply with the
communication protocols yet are assumed to be potential eavesdroppers (i.e.
"nice but curious"). For this setup, which differs from wiretapping scenarios
considered previously, we develop a natural algebraic security criterion, and
prove several of its key properties. A preliminary analysis of the impact of
network topology on the overall network coding security, in particular for
complete directed acyclic graphs, is also included.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 18:11:48 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Lima",
"Luísa",
""
],
[
"Médard",
"Muriel",
""
],
[
"Barros",
"João",
""
]
] |
0705.1790 | Satoshi Okamoto | Satoshi Okamoto | Nonequilibrium transport and optical properties of model
metal--Mott-insulator--metal heterostructures | 11 pages, 11 figures, published version | Phys. Rev. B 76, 035105 (2007) | 10.1103/PhysRevB.76.035105 | null | cond-mat.str-el | null | Electronic properties of heterostructures in which a finite number of
Mott-insulator layers are sandwiched by semi-infinite metallic leads are
investigated by using the dynamical-mean-field method combined with the Keldysh
Green's function technique to account for the finite bias voltage between the
leads. Current across the junction is computed as a function of bias voltage.
Electron spectral functions in the interacting region are shown to evolve by an
applied bias voltage. This effect is measurable by photoemission spectroscopy
and scanning tunneling microscopy. Further predictions are made for the optical
conductivity under a bias voltage as a possible tool to detect a deformed
density of states. A general discussion of correlated-electron based
heterostructures and future prospect is given.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 20:39:58 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 13:44:10 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Okamoto",
"Satoshi",
""
]
] |
0705.1791 | Jorma Louko | K. Kajantie, Jorma Louko, T. Tahkokallio | Gravity dual of 1+1 dimensional Bjorken expansion | 21 pages, 2 igures. v4: Typos corrected. Published version | Phys.Rev.D76:106006,2007 | 10.1103/PhysRevD.76.106006 | HIP-2007-27/TH | hep-th hep-ph | null | We study the application of AdS/CFT duality to longitudinal boost invariant
Bjorken expansion of QCD matter produced in ultrarelativistic heavy ion
collisions. As the exact (1+4)-dimensional bulk solutions for the
(1+3)-dimensional boundary theory are not known, we investigate in detail the
(1+1)-dimensional boundary theory, where the bulk is AdS_3 gravity. We find an
exact bulk solution, show that this solution describes part of the spinless
Banados-Teitelboim-Zanelli (BTZ) black hole with the angular dimension
unwrapped, and use the thermodynamics of the BTZ hole to recover the
time-dependent temperature and entropy density on the boundary. After
separating from the holographic energy-momentum tensor a vacuum contribution,
given by the extremal black hole limit in the bulk, we find that the boundary
fluid is an ideal gas in local thermal equilibrium. Including angular momentum
in the bulk gives a boundary flow that is boost invariant but has a nonzero
longitudinal velocity with respect to the Bjorken expansion.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 18:44:38 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 08:53:04 GMT"
},
{
"version": "v3",
"created": "Sat, 8 Sep 2007 16:50:38 GMT"
},
{
"version": "v4",
"created": "Thu, 8 Nov 2007 20:53:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kajantie",
"K.",
""
],
[
"Louko",
"Jorma",
""
],
[
"Tahkokallio",
"T.",
""
]
] |
0705.1792 | Gabriele Mondello | Gabriele Mondello | Riemann surfaces, ribbon graphs and combinatorial classes | LaTeX 2(e), 69 pages, 18 figures | "Handbook of Teichm\"uller theory II", EMS (2009), pp. 151-216 | null | Roma01.Math.AG - Roma01.Math.DG | math.AG math.DG | null | This survey paper begins with the description of the duality between arc
systems and ribbon graphs embedded in a punctured surface. Then we explain how
to cellularize the moduli space of curves in two different ways: using
Jenkins-Strebel differentials and using hyperbolic geometry. We also briefly
discuss how these two methods are related. Next, we recall the definition of
Witten cycles and we illustrate their connection with tautological classes and
Weil-Petersson geometry. Finally, we exhibit a simple direct argument to prove
that Witten classes are stable.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 19:01:02 GMT"
}
] | 2016-02-01T00:00:00 | [
[
"Mondello",
"Gabriele",
""
]
] |
0705.1793 | Nicolas Le Bihan | Salem Said and Nicolas Le Bihan | Higher Order Statistsics of Stokes Parameters in a Random Birefringent
Medium | null | Waves in Random and Complex Media, Volume 18, No. 2, pp. 275-292,
2008 | 10.1080/17455030701762636 | null | physics.optics physics.data-an | null | We present a new model for the propagation of polarized light in a random
birefringent medium. This model is based on a decomposition of the higher order
statistics of the reduced Stokes parameters along the irreducible
representations of the rotation group. We show how this model allows a detailed
description of the propagation, giving analytical expressions for the
probability densities of the Mueller matrix and the Stokes vector throughout
the propagation. It also allows an exact description of the evolution of
averaged quantities, such as the degree of polarization. We will also discuss
how this model allows a generalization of the concepts of reduced Stokes
parameters and degree of polarization to higher order statistics. We give some
notes on how it can be extended to more general random media.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 14:04:46 GMT"
},
{
"version": "v2",
"created": "Mon, 18 Jun 2007 12:17:17 GMT"
}
] | 2012-02-06T00:00:00 | [
[
"Said",
"Salem",
""
],
[
"Bihan",
"Nicolas Le",
""
]
] |
0705.1794 | Teo Sharia | N. Lazrieva, T. Sharia and T. Toronjadze | Semimartingale Stochastic Approximation Procedures and Recursive
Estimation | 62 pages, no figures | null | null | null | math.PR math.ST stat.TH | null | The semimartingale stochastic approximation procedure, namely, the
Robbins-Monro type SDE is introduced which naturally includes both generalized
stochastic approximation algorithms with martingale noises and recursive
parameter estimation procedures for statistical models associated with
semimartingales. General results concerning the asymptotic behaviour of the
solution are presented. In particular, the conditions ensuring the convergence,
rate of convergence and asymptotic expansion are established. The results
concerning the Polyak weighted averaging procedure are also presented.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 19:47:15 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lazrieva",
"N.",
""
],
[
"Sharia",
"T.",
""
],
[
"Toronjadze",
"T.",
""
]
] |
0705.1795 | Francis O'Donovan | Francis T. O'Donovan, David Charbonneau | TrES Exoplanets and False Positives: Finding the Needle in the Haystack | v1. 6 pages, 5 figures. To appear in the ASP Conference Series:
"Transiting Extrasolar Planets Workshop", MPIA Heidelberg Germany, 25-28
September 2006. Eds: Cristina Afonso, David Weldrake & Thomas Henning | null | null | null | astro-ph | null | Our incomplete understanding of the formation of gas giants and of their
mass-radius relationship has motivated ground-based, wide-field surveys for new
transiting extrasolar giant planets. Yet, astrophysical false positives have
dominated the yield from these campaigns. Astronomical systems where the light
from a faint eclipsing binary and a bright star is blended, producing a
transit-like light curve, are particularly difficult to eliminate. As part of
the Trans-atlantic Exoplanet Survey, we have encountered numerous false
positives and have developed a procedure to reject them. We present examples of
these false positives, including the blended system GSC 03885-00829 which we
showed to be a K dwarf binary system superimposed on a late F dwarf star. This
transit candidate in particular demonstrates the careful analysis required to
identify astrophysical false positives in a transit survey. From amongst these
impostors, we have found two transiting planets. We discuss our follow-up
observations of TrES-2, the first transiting planet in the Kepler field.
| [
{
"version": "v1",
"created": "Mon, 14 May 2007 19:19:00 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"O'Donovan",
"Francis T.",
""
],
[
"Charbonneau",
"David",
""
]
] |
0705.1796 | Sheng-Miao Wu | Sheng-Miao Wu and Ting-Gui Wang | Iron line profiles and self-shadowing from relativistic thick accretion
discs | 11 pages, 11 figures, some typographical errors are corrected | Mon.Not.Roy.Astron.Soc.378:841-851,2007 | 10.1111/j.1365-2966.2007.11855.x | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present Fe Kalpha line profiles from and images of relativistic discs with
finite thickness around a rotating black hole using a novel code. The line is
thought to be produced by iron fluorescence of a relatively cold X-ray
illuminated material in the innermost parts of the accretion disc and provides
an excellent diagnostic of accretion flows in the vicinity of black holes.
Previous studies have concentrated on the case of a thin, Keplerian accretion
disc. This disc must become thicker and sub-Keplerian with increasing accretion
rates. These can affect the line profiles and in turn can influence the
estimation of the accretion disc and black hole parameters from the observed
line profiles. We here embark on, for the first time, a fully relativistic
computation which offers key insights into the effects of geometrical thickness
and the sub-Keplerian orbital velocity on the line profiles. We include all
relativistic effects such as frame-dragging, Doppler boost, time dilation,
gravitational redshift and light bending. We find that the separation and the
relative height between the blue and red peaks of the line profile diminish as
the thickness of the disc increases. This code is also well-suited to produce
accretion disc images. We calculate the redshift and flux images of the
accretion disc and find that the observed image of the disc strongly depends on
the inclination angle. The self-shadowing effect appears remarkable for a high
inclination angle, and leads to the black hole shadow being completely hidden
by the disc itself.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 19:30:49 GMT"
},
{
"version": "v2",
"created": "Fri, 11 Jul 2008 08:26:12 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Wu",
"Sheng-Miao",
""
],
[
"Wang",
"Ting-Gui",
""
]
] |
0705.1797 | Anne Kinney | A. L. Kinney | National Scientific Facilities and Their Science Impact on
Non-Biomedical Research | 22 pages, 7 figures | null | 10.1073/pnas.0704416104 | null | physics.soc-ph physics.gen-ph | null | H-index, proposed by Hirsch is a good indicator of the impact of a
scientist's research. When evaluating departments, institutions or labs, the
importance of h-index can be further enhanced when properly calibrated for
size. Particularly acute is the issue of federally funded facilities whose
number of actively publishing scientists frequently dwarfs that of academic
departments. Recently Molinari and Molinari developed a methodology that shows
the h-index has a universal growth rate for large numbers of papers, allowing
for meaningful comparisons between institutions.
An additional challenge when comparing large institutions is that fields have
distinct internal cultures, with different typical rates of publication and
citation; biology is more highly cited than physics, which is more highly cited
than engineering. For this reason, this study has focused on the physical
sciences, engineering, and technology, and has excluded bio-medical research.
Comparisons between individual disciplines are reported here to provide
contextual framework. Generally, it was found that the universal growth rate of
Molinari and Molinari holds well across all the categories considered,
testifying to the robustness of both their growth law and our results.
The overall goal here is to set the highest standard of comparison for
federal investment in science; comparisons are made with the nations preeminent
private and public institutions. We find that many among the national
facilities compare favorably in research impact with the nations leading
universities.
| [
{
"version": "v1",
"created": "Sat, 12 May 2007 20:46:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kinney",
"A. L.",
""
]
] |
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