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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0707.1430 | Jaiyeola Temitope Gbolahan | Temitope Gbolahan Jaiyeola and John Olushola Adeniran | On the Derivatives of Central Loops | null | Advances in Theoretical and Applied Mathematics, Vol. 1, No. 3
(2006), pp. 233-244 | null | null | math.GM | null | The right(left) derivative, $a^{-1},e-$ and $e,a^{-1}-$ isotopes of a C-loop
are shown to be C-loops. Furthermore, for a central loop $(L,F)$, it is shown
that $\big\{F,F^{a^{-1}},F_{a^{-1},e}\big\}$ and
$\big\{F,F_{a^{-1}},F_{e,a^{-1}}\big\}$ are systems of isotopic C-loops that
obey a form of generalized distributive law. Quasigroup isotopes $(L,\otimes)$
and $(L,\ominus)$ of a loop $(L,\theta)$ and its parastrophe $(L,\theta ^*)$
respectively are proved to be isotopic if either $(L,\otimes)$ or $(L,\ominus
)$ is commutative. If $(L,\theta)$ is a C-loop, then it is shown that
$\big\{(L,\theta),(L,\theta ^*),(L,\otimes),(L,\oplus)\big\}$ is a system of
isotopic C-quasigroup under the above mentioned condition. It is shown that
C-loops are isotopic to some finite indecomposable groups of the classes ${\cal
D}_i,i=1,2,3,4,5$ and that the center of such C-loops have a rank of 1,2 or 3.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 12:48:54 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
],
[
"Adeniran",
"John Olushola",
""
]
] |
0707.1431 | Merab Gogberashvili Dr | Merab Gogberashvili | Gravitational Field of Spherical Branes | Minor corrections, 8 pages, the version accepted by Mod. Phys. Lett.
A | Mod.Phys.Lett.A23:2979-2986,2008 | 10.1142/S0217732308028405 | null | gr-qc astro-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The warped solution of Einstein's equations corresponding to the spherical
brane in five-dimensional AdS is considered. This metric represents interiors
of black holes on both sides of the brane and can provide gravitational
trapping of physical fields on the shell. It is found the analytic form of the
coordinate transformations from the Schwartschild to co-moving frame that
exists only in five dimensions. It is shown that in the static coordinates
active gravitational mass of the spherical brane, in agreement with Tolman's
formula, is negative, i.e. such objects are gravitationally repulsive.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 12:50:25 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 11:39:48 GMT"
},
{
"version": "v3",
"created": "Thu, 30 Oct 2008 21:47:29 GMT"
}
] | 2008-12-25T00:00:00 | [
[
"Gogberashvili",
"Merab",
""
]
] |
0707.1432 | Jean-Guillaume Dumas | Jean-Guillaume Dumas (LJK), Dominique Duval (LJK), Jean-Claude Reynaud
(RC) | Sequential products in effect categories | null | null | null | null | math.CT cs.PL | null | A new categorical framework is provided for dealing with multiple arguments
in a programming language with effects, for example in a language with
imperative features. Like related frameworks (Monads, Arrows, Freyd
categories), we distinguish two kinds of functions. In addition, we also
distinguish two kinds of equations. Then, we are able to define a kind of
product, that generalizes the usual categorical product. This yields a powerful
tool for deriving many results about languages with effects.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 12:50:35 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Dumas",
"Jean-Guillaume",
"",
"LJK"
],
[
"Duval",
"Dominique",
"",
"LJK"
],
[
"Reynaud",
"Jean-Claude",
"",
"RC"
]
] |
0707.1433 | Luca Tornatore | L. Tornatore, A. Ferrara, R. Schneider | Population III stars: hidden or disappeared ? | to appear in MNRAS | null | 10.1111/j.1365-2966.2007.12215.x | null | astro-ph | null | A PopIII/Pop II transition from massive to normal stars is predicted to occur
when the metallicity of the star forming gas crosses the critical range Z_cr =
10^(-5 +/- 1) Z_sun. To investigate the cosmic implications of such process we
use numerical simulations which follow the evolution, metal enrichment and
energy deposition of both Pop III and Pop II stars. We find that: (i) due to
inefficient heavy element transport by outflows and slow "genetic" transmission
during hierarchical growth, large fluctuations around the average metallicity
arise; as a result Pop III star formation continues down to z=2.5, but at a low
peak rate of 10^-5 M_sun yr^-1 Mpc^-3 occurring at z~6 (about 10^-4 of the
PopII one); (ii) Pop III star formation proceeds in a "inside-out" mode in
which formation sites are progressively confined at the periphery of collapsed
structures, where the low gas density and correspondingly long free-fall
timescales result in a very inefficient astration. These conclusions strongly
encourage deep searches for pristine star formation sites at moderate (2<z<5)
redshifts where metal free stars are likely to be hidden.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 12:51:33 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Tornatore",
"L.",
""
],
[
"Ferrara",
"A.",
""
],
[
"Schneider",
"R.",
""
]
] |
0707.1434 | Angel Garcia-Adeva | Angel J. Garcia-Adeva | Spectroscopy, upconversion dynamics, and applications of Er3+-doped
low-phonon materials | 8 pages, 7 figures. This is an extended version of another manuscript
I wrote with occasion of the Michael D. Sturge prize 2007
(http://www.dpc07.org/). The shorter version of this paper will appear in an
especial issue of Journal Luminescence | null | null | null | cond-mat.other cond-mat.mtrl-sci | null | In this work I summarize some of the recent work carried out by our group on
the upconversion dynamics of Er3+-doped potassium lead halide crystals, which
possess very small phonons and present very efficient blue and green
upconversion. Furthermore, a non-conventional application of these RE-doped
low-phonon materials in optical refrigeration of luminescent solids is also
discussed, paying especial attention to new pathways for optical cooling that
include infrared-to-visible upconversion. Finally, I conclude with some hints
of what I think it is the next step into improving the luminescence efficiency
of solids: the use of RE-doped nanoscale photonic heterostructures for
controlling the density of photonic states.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 12:58:14 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Garcia-Adeva",
"Angel J.",
""
]
] |
0707.1435 | Jaiyeola Temitope Gbolahan | Temitope Gbolahan Jaiyeola and John Olushola Adeniran | On Isotopic Characterization of Central Loops | 8 pages, submitted | Creative Mathematics and Informatics, Vol. 18, No. 1 (2009),
39-45. | null | null | math.GM | null | The representation sets of central loops are investigated and the results
obtained are used to construct a finite C-loop. It is shown that for certain
types of isotopisms, the central identities are isotopic invariant.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 12:59:48 GMT"
}
] | 2010-03-10T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
],
[
"Adeniran",
"John Olushola",
""
]
] |
0707.1436 | Prabhu R. Nott | Vishwajeet Mehandia and Prabhu R. Nott | The collective dynamics of self-propelled particles | 25 pages, 19 figures, under review in J. Fluid. Mech | null | 10.1017/S0022112007009184 | null | cond-mat.soft cond-mat.stat-mech | null | We have proposed a method for the dynamic simulation of a collection of
self-propelled particles in a viscous Newtonian fluid. We restrict attention to
particles whose size and velocity are small enough that the fluid motion is in
the creeping flow regime. We have proposed a simple model for a self-propelled
particle, and extended the Stokesian Dynamics method to conduct dynamic
simulations of a collection of such particles. In our description, each
particle is treated as a sphere with an orientation vector $\te{p}$, whose
locomotion is driven by the action of a force dipole at a point slightly
displaced from its centre. In isolation, a self-propelled particle moves at a
constant speed in the direction of $\te{p}$. When it coexists with many such
particles, its hydrodynamic interaction with the other particles alters its
velocity and, more importantly, its orientation. As a result, the motion of the
particle is chaotic. Our simulations are not restricted to low particle
concentration, as we implement the full hydrodynamic interactions between the
particles, but we restrict the motion of particles to two dimensions to reduce
computation. We report the statistical properties of a suspension of
self-propelled particles, such as the distribution of particle velocity, the
pair correlation function and the orientation correlation function, for a range
of the particle concentration.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:16:38 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Mehandia",
"Vishwajeet",
""
],
[
"Nott",
"Prabhu R.",
""
]
] |
0707.1437 | Vasile Morariu | V. V. Morariu, L. Buimaga-Iarinca, C. Vamos, S. Soltuz | Detrended Fluctuation Analysis of Autoregressive Processes | 7 pages, 6 figures, submitted to Fluctuation and Noise Letters | null | null | null | physics.bio-ph physics.data-an | null | Autoregressive processes (AR) have typical short-range memory. Detrended
Fluctuation Analysis (DFA) was basically designed to reveal long range
correlation in non stationary processes. However DFA can also be regarded as a
suitable method to investigate both long-range and short range correlation in
non-stationary and stationary systems. Applying DFA to AR processes can help
understanding the non uniform correlation structure of such processes. We
systematically investigated a first order autoregressive model AR(1) by DFA and
established the relationship between the interaction constant of AR(1) and the
DFA correlation exponent. The higher the interaction constant the higher is the
short range correlation exponent. They are exponentially related. The
investigation was extended to AR(2) processes. The presence of a distant
positive interaction in addition to a near by interaction will increase the
correlation exponent and the range of correlation while the effect of a distant
negative interaction will decrease significantly only the range of interaction.
This analysis demonstrate the possibility to identify and AR(1) model in an
unknown DFA plot or to distinguish among AR(1) and AR(2) models. The analysis
was performed on medium long series of 1000 terms.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:02:42 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Morariu",
"V. V.",
""
],
[
"Buimaga-Iarinca",
"L.",
""
],
[
"Vamos",
"C.",
""
],
[
"Soltuz",
"S.",
""
]
] |
0707.1438 | Jaiyeola Temitope Gbolahan | Temitope Gbolahan Jaiyeola and John Olushola Adeniran | On Some Autotopisms Of Non-Steiner Central Loops | 12 pages, submitted | Journal Of Nigerian Mathematical Society, Vol. 27(2008), 53-68 | null | null | math.GM | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An algebraic process for the construction of an autotopism for a non-Steiner
C-loop is described and this is demonstrated with an example using a known
finite C-loop. In every C-loop, two of its parastrophes are not
equivalent(equal) it, if and only if both the first and second components of
the constructed autotopism and its inverse autotopism are not equal to the
identity map. Hence, none of the other three parastrophes is equivalent(equal)
to the C-loop. It is proved that the set of autotopisms that prevent a C-loop
from being a Steiner loop forms a Steiner triple system.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:05:19 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jun 2008 09:31:23 GMT"
}
] | 2008-06-05T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
],
[
"Adeniran",
"John Olushola",
""
]
] |
0707.1439 | Gil Benk\"o | Gil Benk\"o and Henrik Jeldtoft Jensen | Using a phase space cross section to study large complex systems | 10 pages, 7 figures | null | null | null | cond-mat.stat-mech math.DS | null | For large coupled nonlinear systems, it is difficult to visualize the
high-dimensional phase space, which has been thoroughly studied in smaller
systems with regards to phenomena such as riddled basins. Here we propose a
method to reduce the phase space by defining a phase space cross section. The
method is applied to a system of dynamically coupled maps introduced by Ito &
Kaneko (Phys. Rev. Lett., 88, 028701, 2001 & Phys. Rev. E, 67, 046226, 2003).
We show that the transitions between phases of different synchronization
behaviour are not always sharp but can be characterized by fractal boundaries
in both phase and parameter space.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:07:47 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Benkö",
"Gil",
""
],
[
"Jensen",
"Henrik Jeldtoft",
""
]
] |
0707.1440 | Wolfgang Lucha | Wolfgang Lucha, F. Schoberl | Stability of Salpeter Solutions | 6 pages, 2 figures, to appear in the Proceedings of "QCD @ Work
2007", International Workshop on Quantum ChromoDynamics - Theory and
Experiment, Martina Franca, Italy, 16 - 20 June 2007 | AIPConf.Proc.964:318-323,2007 | 10.1063/1.2823870 | HEPHY-PUB 844/07 | hep-ph | null | In the framework of instantaneous approximations to the Bethe-Salpeter
formalism for the description of bound states within quantum field theories,
depending on the Lorentz structure of the Bethe-Salpeter interaction kernel the
solutions of the full Salpeter equation with some confining interaction may
exhibit certain instabilities, which are possibly related to the Klein paradox
and signal the decay of states assumed to be bound by the confining
interactions. They are observed in numerical (variational) studies of the
Salpeter equation. The presumably simplest scenario allowing for the fully
analytic investigation of this problem is set by the reduced Salpeter equation
with harmonic-oscillator interaction. In this case, Salpeter's integral
equation simplifies to either an algebraic relation or a second-order
homogeneous linear ordinary differential equation, immediately accessible to
standard techniques. There one may hope to be able to decide unambiguously
whether this setting poses a well-defined eigenvalue problem the solutions of
which correspond to stable bound states associated to real energy eigenvalues
bounded from below. By analytical spectral analysis the bound-state solutions
of this "harmonic-oscillator reduced Salpeter equation" can be shown to be free
of such instabilities.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:10:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lucha",
"Wolfgang",
""
],
[
"Schoberl",
"F.",
""
]
] |
0707.1441 | Jaiyeola Temitope Gbolahan | Temitope Gbolahan Jaiyeola and John Olushola Adeniran | On central loops and the central square property | 10 pages | Quasigroups And Related Systems, Vol. 15, No. 2 (2007), pp.
191-200 | null | null | math.GM | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The representation sets of a central square C-loop are investigated. Isotopes
of central square C-loops of exponent 4 are shown to be both C-loops and
A-loops.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:37:09 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jun 2008 09:27:58 GMT"
}
] | 2008-06-05T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
],
[
"Adeniran",
"John Olushola",
""
]
] |
0707.1442 | Phuong Mai Dinh | F. Fehrer, P. M. Dinh, P.-G. Reinhard, and E. Suraud | Embedded metal cluster in strong laser fields | 13 pages, 4 figures, Comp. Mat. Sci. (in press) | Comp. Mat. Sci. 42 (2008) 203 | null | null | cond-mat.other | null | We discuss microscopic mechanisms of the violent dynamics following strong
laser excitation of a metal cluster embedded in a rare gas matrix, taking as
test case Na$_8$@Ar$_434$. This covers at least two aspects : first, it
represents the typical experimental situation of metal clusters handled in
raregas matrices or a finite drop of surrounding raregas material, and second,
it serves as a generic test case for highly excited chromophores in inert
surroundings addressing questions of energy transport and perturbation of the
medium. We simulate the process up to 10 ps using a mixed quantum mechanical
(for the electrons) and classical (ions and atoms) approach and analyze the
emerging dynamics with respect to all basic constituents : cluster electrons,
cluster ions, and matrix atoms. We find several stages of relaxation taking
place with time scales from a few fs to over a few ps and much slower processes
remaining for long after the simulation. A particularly interesting aspect is
that the surrounding raregas material stabilizes a highly charged metal cluster
which would otherwise explode without delay.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:15:52 GMT"
}
] | 2008-09-03T00:00:00 | [
[
"Fehrer",
"F.",
""
],
[
"Dinh",
"P. M.",
""
],
[
"Reinhard",
"P. -G.",
""
],
[
"Suraud",
"E.",
""
]
] |
0707.1443 | James Dunlop | J.C. Dunlop | Jet Tomography at RHIC | 6 pages, invited talk at HCP06 | null | null | null | nucl-ex | null | The status of the use of hard probes in heavy ion collisions at RHIC is
reviewed. The discovery of strong jet quenching at RHIC is a major success.
However, in order to make full use of this new phenomenon for full jet emission
tomography of the properties of the collision zone further development is
needed, both experimentally and theoretically.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:16:55 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Dunlop",
"J. C.",
""
]
] |
0707.1444 | Jaiyeola Temitope Gbolahan | Temitope Gbolahan Jaiyeola and John Olushola Adeniran | Algebraic properties of some varieties of central loops | 20 pages | Quasigroups And Related Systems, 2008, Vol. 16, No. 1, 37-54 | null | null | math.GM | null | Isotopes of C-loops with unique non-identity squares are shown to be both
C-loops and A-loops. The relationship between C-loops and Steiner loops is
further studied. Central loops with the weak and cross inverse properties are
also investigated. C-loops are found to be Osborn loops if every element in
them are squares.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:35:52 GMT"
},
{
"version": "v2",
"created": "Mon, 5 May 2008 19:22:42 GMT"
}
] | 2008-05-05T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
],
[
"Adeniran",
"John Olushola",
""
]
] |
0707.1445 | Nicolas Burq | N. Burq and N. Tzvetkov | Invariant measure for a three dimensional nonlinear wave equation | null | null | null | null | math.AP math.DS | null | We study the long time behavior of the subcritical (subcubic) defocussing
nonlinear wave equation on the three dimensional ball, for random data of low
regularity. We prove that for a large set of radial initial data in
$\cap_{s<1/2} H^s(B(0,1))$ the equation is (globally in time) well posed and we
construct an invariant measure.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:20:51 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Burq",
"N.",
""
],
[
"Tzvetkov",
"N.",
""
]
] |
0707.1446 | Michiel Wouters | M. Wouters and I. Carusotto | Excitations and superfluidity in non-equilibrium Bose-Einstein
condensates of exciton-polaritons | 4 pages, 2 figures | null | 10.1016/j.spmi.2007.07.024 | null | cond-mat.mes-hall | null | We present a generic model for the description of non-equilibrium
Bose-Einstein condensates, suited for the modelling of non-resonantly pumped
polariton condensates in a semiconductor microcavity. The excitation spectrum
and scattering of the non-equilibrium condensate with a defect are discussed.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:21:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wouters",
"M.",
""
],
[
"Carusotto",
"I.",
""
]
] |
0707.1447 | Nicolas Burq | N. Burq and N. Tzvetkov | Random data Cauchy theory for supercritical wave equations I: Local
theory | null | null | 10.1007/s00222-008-0124-z | null | math.AP | null | We study the local existence of strong solutions for the cubic nonlinear wave
equation with data in $H^s(M)$, $s<1/2$, where $M$ is a three dimensional
compact riemannian manifold. This problem is supercritical and can be shown to
be strongly ill-posed (in the Hadamard sense). However, after a suitable
randomization, we are able to construct local strong solution for a large set
of initial data in $H^s(M)$, where $s\geq 1/4$ in the case of a boundary less
manifold and $s\geq 8/21$ in the case of a manifold with boundary.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:47:05 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Burq",
"N.",
""
],
[
"Tzvetkov",
"N.",
""
]
] |
0707.1448 | Nicolas Burq | N. Burq and N. Tzvetkov | Random data Cauchy theory for supercritical wave equations II : A global
existence result | null | null | 10.1007/s00222-008-0123-0 | null | math.AP | null | We prove that the subquartic wave equation on the three dimensional ball
$\Theta$, with Dirichlet boundary conditions admits global strong solutions for
a large set of random supercritical initial data in $\cap_{s<1/2} H^s(\Theta)$.
We obtain this result as a consequence of a general random data Cauchy theory
for supercritical wave equations developed in our previous work \cite{BT2} and
invariant measure considerations which allow us to obtain also precise large
time dynamical informations on our solutions.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:36:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Burq",
"N.",
""
],
[
"Tzvetkov",
"N.",
""
]
] |
0707.1449 | Philippe Gaucher | Philippe Gaucher | Abstract homotopical methods for theoretical computer science | 16 pages; LaTeX2e; chapter of book | null | null | null | math.AT math.CT | null | The purpose of this paper is to collect the homotopical methods used in the
development of the theory of flows initialized by author's paper ``A model
category for the homotopy theory of concurrency''. It is presented
generalizations of the classical Whitehead theorem inverting weak homotopy
equivalences between CW-complexes using weak factorization systems. It is also
presented methods of calculation of homotopy limits and homotopy colimits using
Quillen adjunctions and Reedy categories.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:38:42 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Gaucher",
"Philippe",
""
]
] |
0707.1450 | Florian Greil | Florian Greil, Barbara Drossel, Joost Sattler | Critical Kauffman networks under deterministic asynchronous update | 8 pages, 3 figures, submitted to a journal | New Journal of Physics 9 (2007) 373 | 10.1088/1367-2630/9/10/373 | null | cond-mat.dis-nn cond-mat.stat-mech | null | We investigate the influence of a deterministic but non-synchronous update on
Random Boolean Networks, with a focus on critical networks. Knowing that
``relevant components'' determine the number and length of attractors, we focus
on such relevant components and calculate how the length and number of
attractors on these components are modified by delays at one or more nodes. The
main findings are that attractors decrease in number when there are more
delays, and that periods may become very long when delays are not integer
multiples of the basic update step.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:46:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Greil",
"Florian",
""
],
[
"Drossel",
"Barbara",
""
],
[
"Sattler",
"Joost",
""
]
] |
0707.1451 | Kazuaki Ohnishi | Kazuaki Ohnishi and Su Houng Lee | BFKL equation at finite temperature | 10 pages, no figure | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the Color Glass Condensate (CGC) at finite temperature, which
would be relevant to the initial condition of relativistic heavy ion collisions
and the energy loss of energetic partons in the quark-gluon plasma. In the weak
source approximation, we derive the thermal BFKL equation. We find that the
thermal effect shows up as a Bose enhancement of the soft gluon emission if the
temperature is high enough to match the light-cone energy of the soft gluons.
This suggests that the saturation regime could be reached sooner than in the
vacuum.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:46:33 GMT"
},
{
"version": "v2",
"created": "Fri, 19 Oct 2007 04:38:40 GMT"
},
{
"version": "v3",
"created": "Wed, 21 May 2008 05:10:16 GMT"
},
{
"version": "v4",
"created": "Sat, 26 Jul 2008 09:28:48 GMT"
}
] | 2008-07-26T00:00:00 | [
[
"Ohnishi",
"Kazuaki",
""
],
[
"Lee",
"Su Houng",
""
]
] |
0707.1452 | Xavier Polanco | Xavier Polanco (INIST) | Clusters, Graphs, and Networks for Analysing Internet-Web-Supported
Communication within a Virtual Community | null | Advances in Knowledge Organization (2002) 364-371 | null | null | cs.AI cs.LG | null | The proposal is to use clusters, graphs and networks as models in order to
analyse the Web structure. Clusters, graphs and networks provide knowledge
representation and organization. Clusters were generated by co-site analysis.
The sample is a set of academic Web sites from the countries belonging to the
European Union. These clusters are here revisited from the point of view of
graph theory and social network analysis. This is a quantitative and structural
analysis. In fact, the Internet is a computer network that connects people and
organizations. Thus we may consider it to be a social network. The set of Web
academic sites represents an empirical social network, and is viewed as a
virtual community. The network structural properties are here analysed applying
together cluster analysis, graph theory and social network analysis.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:47:32 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Polanco",
"Xavier",
"",
"INIST"
]
] |
0707.1453 | Anna Stasto | M. Ciafaloni, D. Colferai, G.P. Salam, A.M. Stasto | A matrix formulation for small-x singlet evolution | 36 pages, 5 figures | JHEP 0708:046,2007 | 10.1088/1126-6708/2007/08/046 | CERN-PH-TH/2007-104, DFF 436/07/07 | hep-ph | null | We propose a matrix evolution equation in (x,kt)-space for flavour singlet,
unintegrated quark and gluon densities, which generalizes DGLAP and BFKL
equations in the relevant limits. The matrix evolution kernel is constructed so
as to satisfy renormalization group constraints in both the ordered and
antiordered regions of exchanged momenta kt, and incorporates the known NLO
anomalous dimensions in the MSbar scheme as well as the NLx BFKL kernel. We
provide a hard Pomeron exponent and effective eigenvalue functions that include
the n_f-dependence, and give also the matrix of resummed DGLAP splitting
functions. The results connect smoothly with those of the single-channel
approach. The novel P_{qa} splitting functions show resummation effects delayed
down to x=0.0001, while both P_{ga} entries show a shallow dip around x=0.001,
similarly to the gluon-gluon single-channel results. We remark that the matrix
formulation poses further constraints on the consistency of a BFKL framework
with the MSbar scheme, which are satisfied at NLO, but marginally violated by
small n_f/N_c^2-suppressed terms at NNLO.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:56:26 GMT"
}
] | 2010-03-25T00:00:00 | [
[
"Ciafaloni",
"M.",
""
],
[
"Colferai",
"D.",
""
],
[
"Salam",
"G. P.",
""
],
[
"Stasto",
"A. M.",
""
]
] |
0707.1454 | Guifre Vidal | G. Evenbly, G. Vidal | Algorithms for entanglement renormalization | 23 pages, 28 figures | Phys. Rev. B 79, 144108 (2009) | 10.1103/PhysRevB.79.144108 | null | cond-mat.str-el cond-mat.other quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe an iterative method to optimize the multi-scale entanglement
renormalization ansatz (MERA) for the low-energy subspace of local Hamiltonians
on a D-dimensional lattice. For translation invariant systems the cost of this
optimization is logarithmic in the linear system size. Specialized algorithms
for the treatment of infinite systems are also described. Benchmark simulation
results are presented for a variety of 1D systems, namely Ising, Potts, XX and
Heisenberg models. The potential to compute expected values of local
observables, energy gaps and correlators is investigated.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:50:06 GMT"
},
{
"version": "v2",
"created": "Wed, 16 Apr 2008 01:32:35 GMT"
},
{
"version": "v3",
"created": "Wed, 8 Oct 2008 09:45:39 GMT"
},
{
"version": "v4",
"created": "Mon, 13 Apr 2009 09:32:59 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Evenbly",
"G.",
""
],
[
"Vidal",
"G.",
""
]
] |
0707.1455 | Xavier Portell | X. Portell (for the CDF and D0 Collaborations) | Supersymmetry Searches at the Tevatron | 6 pages, 5 figures, Proceedings Symposium Hadron Collider Physics
2006 (HCP 2006), Durham, NC, May 22-26, 2006 | null | null | FERMILAB-CONF-06-326-E | hep-ex | null | CDF and DO detectors have already collected 1.3 fb^{-1} of data delivered by
the Tevatron collider at 1.96 TeV center-of-mass energy. We present here the
various analyses that are currently testing the possibility of a supersymmetric
extension of the Standard Model. No evidence for such processes have been found
in luminosities that range from 300 to 800 pb^{-1} and different limits on the
different supersymmetric models are set. Constraints coming from indirect
searches are also presented.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:51:05 GMT"
}
] | 2019-08-14T00:00:00 | [
[
"Portell",
"X.",
"",
"for the CDF and D0 Collaborations"
]
] |
0707.1456 | Shane Davis | Shane W. Davis, Jong-Hak Woo, Omer M. Blaes | The UV Continuum of Quasars: Models and SDSS Spectral Slopes | To be published in ApJ, 18 pages, 10 figures | null | 10.1086/521393 | null | astro-ph | null | We measure long (2200-4000 ang) and short (1450-2200 ang) wavelength spectral
slopes \alpha (F_\nu proportional to \nu^\alpha) for quasar spectra from the
Sloan Digital Sky Survey. The long and short wavelength slopes are computed
from 3646 and 2706 quasars with redshifts in the z=0.76-1.26 and z=1.67-2.07
ranges, respectively. We calculate mean slopes after binning the data by
monochromatic luminosity at 2200 ang and virial mass estimates based on
measurements of the MgII line width and 3000 ang continuum luminosity. We find
little evidence for mass dependent variations in the mean slopes, but a
significant luminosity dependent trend in the near UV spectral slopes is
observed with larger (bluer) slopes at higher luminosities. The far UV slopes
show no clear variation with luminosity and are generally lower (redder) than
the near UV slopes at comparable luminosities, suggesting a slightly concave
quasar continuum shape. We compare these results with Monte Carlo distributions
of slopes computed from models of thin accretion disks, accounting for
uncertainties in the mass estimates. The model slopes produce mass dependent
trends which are larger than observed, though this conclusion is sensitive to
the assumed uncertainties in the mass estimates. The model slopes are also
generally bluer than observed, and we argue that reddening by dust intrinsic to
the source or host galaxy may account for much of the discrepancy.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:53:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Davis",
"Shane W.",
""
],
[
"Woo",
"Jong-Hak",
""
],
[
"Blaes",
"Omer M.",
""
]
] |
0707.1457 | Fernando C. Lombardo | Paula I. Villar and Fernando C. Lombardo | Visibility Fringe Reduction Due to Noise-Induced Effects: Microscopic
Approach to Interference Experiments | 14 pages, 5 figures. Version to appear in Mod. Phys. B | Int.J.Mod.Phys.B21:4659-4676,2007 | 10.1142/S021797920703806X | null | quant-ph cond-mat.other hep-ph | null | Decoherence is the main process behind the quantum to classical transition.
It is a purely quantum mechanical effect by which the system looses its ability
to exhibit coherent behavior. The recent experimental observation of
diffraction and interference patterns for large molecules raises some
interesting questions. In this context, we identify possible agents of
decoherence to take into account when modeling these experiments and study
theirs visible (or not) effects on the interference pattern. Thereby, we
present an analysis of matter wave interferometry in the presence of a dynamic
quantum environment and study how much the visibility fringe is reduced and in
which timescale the decoherence effects destroy the interference of massive
objects. Finally, we apply our results to the experimental data reported on
fullerenes and cold neutrons.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:13:58 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Villar",
"Paula I.",
""
],
[
"Lombardo",
"Fernando C.",
""
]
] |
0707.1458 | Stefaan Vaes | Stefaan Vaes | Explicit computations of all finite index bimodules for a family of II_1
factors | Minor modifications, final version | Annales Scientifiques de l'Ecole Normale Superieure, 41 (2008),
743-788. | null | null | math.OA | null | We study II_1 factors M and N associated with good generalized Bernoulli
actions of groups having an infinite almost normal subgroup with the relative
property (T). We prove the following rigidity result: every finite index
M-N-bimodule (in particular, every isomorphism between M and N) is described by
a commensurability of the groups involved and a commensurability of their
actions. The fusion algebra of finite index M-M-bimodules is identified with an
extended Hecke fusion algebra, providing the first explicit computations of the
fusion algebra of a II_1 factor. We obtain in particular explicit examples of
II_1 factors with trivial fusion algebra, i.e. only having trivial finite index
subfactors.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 13:55:52 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Aug 2007 15:52:50 GMT"
},
{
"version": "v3",
"created": "Mon, 11 Feb 2008 11:06:45 GMT"
}
] | 2009-01-20T00:00:00 | [
[
"Vaes",
"Stefaan",
""
]
] |
0707.1459 | Jianqiang Zhao | Jianqiang Zhao | Standard Relations of Multiple Polylogarithm Values at Roots of Unity | By numerical computation we propose more non-standard relations | Documenta Mathematica 15 (2010), pp. 1-34 | null | null | math.NT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Let $N$ be a positive integer. In this paper we shall study the special
values of multiple polylogarithms at $N$th roots of unity, called multiple
polylogarithm values (MPVs) of level $N$. These objects are generalizations of
multiple zeta values and alternating Euler sums, which was studied by Euler,
and more recently, many mathematicians and theoretical physicists.. Our primary
goal in this paper is to investigate the relations among the MPVs of the same
weight and level by using the regularized double shuffle relations, regularized
distribution relations, lifted versions of such relations from lower weights,
and seeded relations which are produced by relations of weight one MPVs. We
call relations from the above four families \emph{standard}. Let $d(w,N)$ be
the $\Q$-dimension of $\Q$-span of all MPVs of weight $w$ and level $N$. Then
we obtain upper bound for $d(w,N)$ by the standard relations which in general
are no worse or no better than the one given by Deligne and Goncharov depending
on whether $N$ is a prime-power or not, respectively, except for 2- and
3-powers, in which case standard relations seem to be often incomplete whereas
Deligne shows that their bound should be sharp by a variant of Grothedieck's
period conjecture. This suggests that in general there should be other linear
relations among MPVs besides the standard relations, some of which are written
down in this paper explicitly with good numerical verification. We also provide
a few conjectures which are supported by our computational evidence.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:45:38 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 09:37:23 GMT"
},
{
"version": "v3",
"created": "Mon, 23 Jul 2007 10:15:17 GMT"
},
{
"version": "v4",
"created": "Wed, 12 Sep 2007 13:56:37 GMT"
},
{
"version": "v5",
"created": "Fri, 28 Sep 2007 23:30:56 GMT"
},
{
"version": "v6",
"created": "Wed, 19 Dec 2007 00:21:34 GMT"
},
{
"version": "v7",
"created": "Mon, 6 Oct 2008 19:34:03 GMT"
}
] | 2010-08-16T00:00:00 | [
[
"Zhao",
"Jianqiang",
""
]
] |
0707.1460 | Allan Sacha Brun | Mark S. Miesch (HA0/NCAR), Allan Sacha Brun (CEA-Saclay/SAp-AIM), Marc
L. Derosa (LMSAL) and Juri Toomre (Univ. of Colorado/JILA) | Structure and Evolution of Giant Cells in Global Models of Solar
Convection | 22 pages, 16 figures (color figures are low res), uses emulateapj.cls
Latex class file, Results shown during a Press release at the AAS meeting in
June 2007. Submitted to ApJ | null | 10.1086/523838 | null | astro-ph | null | The global scales of solar convection are studied through three-dimensional
simulations of compressible convection carried out in spherical shells of
rotating fluid which extend from the base of the convection zone to within 15
Mm of the photosphere. Such modelling at the highest spatial resolution to date
allows study of distinctly turbulent convection, revealing that coherent
downflow structures associated with giant cells continue to play a significant
role in maintaining the strong differential rotation that is achieved. These
giant cells at lower latitudes exhibit prograde propagation relative to the
mean zonal flow, or differential rotation, that they establish, and retrograde
propagation of more isotropic structures with vortical character at mid and
high latitudes. The interstices of the downflow networks often possess strong
and compact cyclonic flows. The evolving giant-cell downflow systems can be
partly masked by the intense smaller scales of convection driven closer to the
surface, yet they are likely to be detectable with the helioseismic probing
that is now becoming available. Indeed, the meandering streams and varying
cellular subsurface flows revealed by helioseismology must be sampling
contributions from the giant cells, yet it is difficult to separate out these
signals from those attributed to the faster horizontal flows of
supergranulation. To aid in such detection, we use our simulations to describe
how the properties of giant cells may be expected to vary with depth, how their
patterns evolve in time, and analyze the statistical features of correlations
within these complex flow fields.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:34:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Miesch",
"Mark S.",
"",
"HA0/NCAR"
],
[
"Brun",
"Allan Sacha",
"",
"CEA-Saclay/SAp-AIM"
],
[
"Derosa",
"Marc L.",
"",
"LMSAL"
],
[
"Toomre",
"Juri",
"",
"Univ. of Colorado/JILA"
]
] |
0707.1461 | Thierry Klein | Fabrice Gamboa (IMT), Thierry Klein (IMT), Cl\'ementine Prieur (IMT) | Conditional large and moderate deviations for sums of discrete random
variables. Combinatoric applications | 18 PAGES | null | null | null | math.PR | null | We prove large and moderate deviation principles for the distribution of an
empirical mean conditioned by the value of the sum of discrete i.i.d. random
variables. Some applications for combinatoric problems are discussed.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:06:29 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Gamboa",
"Fabrice",
"",
"IMT"
],
[
"Klein",
"Thierry",
"",
"IMT"
],
[
"Prieur",
"Clémentine",
"",
"IMT"
]
] |
0707.1462 | Volker Betz | Volker Betz, Olaf Wittich | Non-Uniqueness of Gibbs measures relative to Brownian motion | This paper has been withdrawn by the author due to a fatal error in
Theorem 3.5 (the main theorem, unfortunately) | null | null | null | math.PR math-ph math.MP | null | We consider Gibbs measures relative to Brownian motion of Feynman-Kac type,
with single site potential V. We show that for a large class of V, including
the Coulomb potential, there exist infinitely many infinite volume Gibbs
measures.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:07:28 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Jul 2010 15:55:04 GMT"
}
] | 2010-07-16T00:00:00 | [
[
"Betz",
"Volker",
""
],
[
"Wittich",
"Olaf",
""
]
] |
0707.1463 | Hendrik Adorf | Hendrik Adorf and Michael Flohr | Continuously Crossing u=z in the H3+ Boundary CFT | version to appear in JHEP - 12 pages now; sign error with impact on
some parts of the interpretation fixed; material added to become more
self-contained; role of bulk-boundary OPE in section 4 more carefully
discussed; 3 references added | JHEP 0711:024,2007 | 10.1088/1126-6708/2007/11/024 | ITP-UH-14/07 | hep-th | null | For AdS boundary conditions, we give a solution of the H3+ two point function
involving degenerate field with SL(2)-label b^{-2}/2, which is defined on the
full (u,z) unit square. It consists of two patches, one for z<u and one for
u<z. Along the u=z "singularity", the solutions from both patches are shown to
have finite limits and are merged continuously as suggested by the work of
Hosomichi and Ribault. From this two point function, we can derive
b^{-2}/2-shift equations for AdS_2 D-branes. We show that discrete as well as
continuous AdS_2 branes are consistent with our novel shift equations without
any new restrictions.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:50:07 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Nov 2007 11:08:39 GMT"
}
] | 2009-04-30T00:00:00 | [
[
"Adorf",
"Hendrik",
""
],
[
"Flohr",
"Michael",
""
]
] |
0707.1464 | David Kastor | Mohamed M. Anber and David Kastor | The Attractor Mechanism in Gauss-Bonnet Gravity | 15 pages, 3 figures; v2 - references added; v3 - minor revisions,
references added | JHEP 0710:084,2007 | 10.1088/1126-6708/2007/10/084 | null | hep-th | null | We study extremal black hole solutions of D=5 Gauss-Bonnet gravity coupled to
a system of gauge and scalar fields. As in Einstein gravity, we find that the
values of the scalar fields on the horizon must extremize a certain effective
potential that depends on the black hole charges. If the matrix of second
derivatives of the effective potential at this extremum has positive
eigenvalues, we give evidence, based on a near horizon perturbative expansion,
that the attractor mechanism continues to hold in this general class of
theories. We numerically construct solutions to a particular simple single
scalar field model that display the attractor mechanism over a wide range of
asymptotic values for the scalar field. We also numerically construct
non-extremal solutions and show that the attractor mechanism fails to hold away
from extremality.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:23:33 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 17:10:42 GMT"
},
{
"version": "v3",
"created": "Thu, 4 Oct 2007 18:24:23 GMT"
}
] | 2009-04-30T00:00:00 | [
[
"Anber",
"Mohamed M.",
""
],
[
"Kastor",
"David",
""
]
] |
0707.1465 | Peter van der Straten | K.M.R. van der Stam, R. Meppelink, J.M. Vogels, J.W. Thomsen, and P.
van der Straten | Resonant superradiant backward-scattering as a source for many-particle
entanglement | 5 pages, 6 figures | null | null | null | cond-mat.other | null | We investigate the atom pair production by superradiant backward-scattering
from a Bose-Einstein condensate. By driving the superradiant process with two
frequencies we can extend both the range of pulse duration and intensity by two
orders of magnitude and obtain full control over the number of scattered atoms
in forward and backward direction. We show that the atoms scattered in forward
direction are strongly correlated with the atoms scattered in backward
direction, which makes resonant superradiant backward-scattering a promising
candidate for many-particle entanglement.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:36:49 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"van der Stam",
"K. M. R.",
""
],
[
"Meppelink",
"R.",
""
],
[
"Vogels",
"J. M.",
""
],
[
"Thomsen",
"J. W.",
""
],
[
"van der Straten",
"P.",
""
]
] |
0707.1466 | Herbert Lange | H. Lange and P. E. Newstead | Coherent systems of genus 0, III: Computation of flips for k=1 | Two improved formulae, an additional comment and a new reference | null | null | null | math.AG | null | In this paper we continue the investigation of coherent systems of type
$(n,d,k)$ on the projective line which are stable with respect to some value of
a parameter $\alpha$. We consider the case $k=1$ and study the variation of the
moduli spaces with $\alpha$. We determine inductively the first and last moduli
spaces and the flip loci, and give an explicit description for ranks 2 and 3.
We also determine the Hodge polynomials explicitly for ranks 2 and 3 and in
certain cases for arbitrary rank.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 14:31:42 GMT"
},
{
"version": "v2",
"created": "Mon, 8 Oct 2007 06:50:41 GMT"
}
] | 2007-10-08T00:00:00 | [
[
"Lange",
"H.",
""
],
[
"Newstead",
"P. E.",
""
]
] |
0707.1467 | Matteo Calandra | Matteo Calandra and Francesco Mauri | Electron-phonon coupling and electron self-energy in electron-doped
graphene: calculation of angular resolved photoemission spectra | 9 pages, 7 figures, see also Matteo Calandra and Francesco Mauri,
arXiv:0707.1492 | null | 10.1103/PhysRevB.76.205411 | null | cond-mat.supr-con cond-mat.mes-hall cond-mat.mtrl-sci | null | We obtain analytical expressions for the electron self-energy and the
electron-phonon coupling in electron-doped graphene using electron-phonon
matrix elements extracted from density functional theory simulations. From the
electron self-energies we calculate angle resolved photoemission spectra. We
demonstrate that the measured kink at $\approx -0.2$ eV from the Fermi level is
actually composed of two features, one at $\approx -0.195$ eV due to the
twofold degenerate E$_{2g}$ mode, and a second one at $\approx -0.16$ eV due to
the A$_{1}^{'}$ mode. The electron-phonon coupling extracted from the kink
observed in ARPES experiments is roughly a factor of 5.5 larger than the
calculated one. This disagreement can only be partially reconciled by the
inclusion of resolution effects. Indeed we show that a finite resolution
increases the apparent electron-phonon coupling by underestimating the
renormalization of the electron velocity at energies larger than the kinks
positions. The discrepancy between theory and experiments is thus reduced to a
factor of $\approx$ 2.2. From the linewidth of the calculated ARPES spectra we
obtain the electron relaxation time. A comparison with available experimental
data in graphene shows that the electron relaxation time detected in ARPES is
almost two orders of magnitudes smaller than what measured by other
experimental techniques.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:44:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Calandra",
"Matteo",
""
],
[
"Mauri",
"Francesco",
""
]
] |
0707.1468 | R. C. Penner | R. C. Penner and Greg McShane | Stable curves and screens on fatgraphs | 23 pages, 4 figures | null | null | null | math.GT math.AG | null | The mapping class group invariant ideal cell decomposition of the
Teichmueller space of a punctured surface times an open simplex has been used
in a number of computations. This paper answers a question about the
asymptotics of this decomposition, namely, in a given cell of the
decomposition, which curves can be short? Screens are a new combinatorial
structure which provide an answer to this question. The heart of the
calculation here involves Ptolemy transformations and the triangle inequalities
on lambda lengths.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:01:09 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 20:07:22 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Penner",
"R. C.",
""
],
[
"McShane",
"Greg",
""
]
] |
0707.1469 | Jeffrey Brock | Jeffrey Brock and Howard Masur | Coarse and synthetic Weil-Petersson geometry: quasi-flats, geodesics,
and relative hyperbolicity | References added apropos of equivalence of the notion of
asymptotically tree-graded and strong relative-hyperbolicity in the sense of
Drutu-Sapir. We thank Jason Behrstock for bringing this to our attention.
Proof of thickness in higher dimension streamlined, some comments, questions
and references added | Geom. Topol. 12 (2008) 2453-2495 | 10.2140/gt.2008.12.2453 | null | math.GT | null | We analyze the coarse geometry of the Weil-Petersson metric on Teichm\"uller
space, focusing on applications to its synthetic geometry (in particular the
behavior of geodesics). We settle the question of the strong relative
hyperbolicity of the Weil-Petersson metric via consideration of its coarse
quasi-isometric model, the "pants graph." We show that in dimension~3 the pants
graph is strongly relatively hyperbolic with respect to naturally defined
product regions and show any quasi-flat lies a bounded distance from a single
product. For all higher dimensions there is no non-trivial collection of
subsets with respect to which it strongly relatively hyperbolic; this extends a
theorem of [BDM] in dimension 6 and higher into the intermediate range (it is
hyperbolic if and only if the dimension is 1 or 2 [BF]). Stability and relative
stability of quasi-geodesics in dimensions up through 3 provide for a strong
understanding of the behavior of geodesics and a complete description of the
CAT(0)-boundary of the Weil-Petersson metric via curve-hierarchies and their
associated "boundary laminations."
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:01:59 GMT"
},
{
"version": "v2",
"created": "Thu, 12 Jul 2007 13:44:27 GMT"
},
{
"version": "v3",
"created": "Tue, 25 Sep 2007 17:25:06 GMT"
}
] | 2014-11-11T00:00:00 | [
[
"Brock",
"Jeffrey",
""
],
[
"Masur",
"Howard",
""
]
] |
0707.1470 | Yingbin Liang | Yingbin Liang, H. Vincent Poor and Shlomo Shamai (Shitz) | Secrecy Capacity Region of Fading Broadcast Channels | Proc. of IEEE International Symposium on Information Theory (ISIT),
June 2007 | null | 10.1109/ISIT.2007.4557401 | null | cs.IT math.IT | null | The fading broadcast channel with confidential messages (BCC) is
investigated, where a source node has common information for two receivers
(receivers 1 and 2), and has confidential information intended only for
receiver 1. The confidential information needs to be kept as secret as possible
from receiver 2. The channel state information (CSI) is assumed to be known at
both the transmitter and the receivers. The secrecy capacity region is first
established for the parallel Gaussian BCC, and the optimal source power
allocations that achieve the boundary of the secrecy capacity region are
derived. In particular, the secrecy capacity region is established for the
Gaussian case of the Csiszar-Korner BCC model. The secrecy capacity results are
then applied to give the ergodic secrecy capacity region for the fading BCC.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:16:13 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Liang",
"Yingbin",
"",
"Shitz"
],
[
"Poor",
"H. Vincent",
"",
"Shitz"
],
[
"Shamai",
"Shlomo",
"",
"Shitz"
]
] |
0707.1471 | Vladyslav Yaskin | V.Yaskin | On strict inclusions in hierarchies of convex bodies | 10 pages | null | null | null | math.MG math.FA | null | Let $\mathcal I_k$ be the class of convex $k$-intersection bodies in
$\mathbb{R}^n$ (in the sense of Koldobsky) and $\mathcal I_k^m$ be the class of
convex origin-symmetric bodies all of whose $m$-dimensional central sections
are $k$-intersection bodies. We show that 1) $\mathcal I_k^m\not\subset
\mathcal I_k^{m+1}$, $k+3\le m<n$, and 2) $\mathcal I_l \not\subset \mathcal
I_k$, $1\le k<l < n-3$.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:24:18 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Yaskin",
"V.",
""
]
] |
0707.1472 | Yi Li Dr. | Yi Li, Tianxing Ma, and Ruibao Tao | Extra Current and Integer Quantum Hall Conductance in the Spin-Orbit
Coupling System | 6 pages | EPL, 83 (2008) 27002 | 10.1209/0295-5075/83/27002 | null | cond-mat.mes-hall | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the extra term of particle current in a 2D k-cubic Rashba spin-orbit
coupling system and the integer quantization of the Hall conductance in this
system. We provide a correct formula of charge current in this system and the
careful consideration of extra currents provides a stronger theoretical basis
for the theory of the quantum Hall effect which has not been considered before.
The non-trivial extra contribution to the particle current density and local
conductivity, which originates from the cubic dependence on the momentum
operator in the Hamiltonian, will have no effect on the integer quantization of
the Hall conductance. The extension of Noether's theorem for the 2D k-cubic
Rashba system is also addressed. The two methods reach to exactly the same
results.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:30:48 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jun 2008 12:24:02 GMT"
}
] | 2008-06-23T00:00:00 | [
[
"Li",
"Yi",
""
],
[
"Ma",
"Tianxing",
""
],
[
"Tao",
"Ruibao",
""
]
] |
0707.1473 | Peng Gao | Peng Gao | On l^p norms of weighted mean matrices | 18 pages | null | null | null | math.FA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study $l^{p}$ operator norms of weighted mean matrices using the
approaches of Kaluza-Szeg\"o and Redheffer. As an application, we prove a
conjecture of Bennett.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:32:10 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Aug 2007 22:16:59 GMT"
},
{
"version": "v3",
"created": "Tue, 4 Sep 2007 18:35:04 GMT"
},
{
"version": "v4",
"created": "Thu, 29 Nov 2007 13:40:37 GMT"
},
{
"version": "v5",
"created": "Tue, 24 Jun 2008 15:09:19 GMT"
},
{
"version": "v6",
"created": "Sun, 31 Aug 2008 07:12:46 GMT"
}
] | 2008-08-31T00:00:00 | [
[
"Gao",
"Peng",
""
]
] |
0707.1474 | Andrew McCafferty | A.J. McCafferty | Integrable operators and squares of Hankel Matrices | 9 pages | null | null | null | math.FA | null | In this note, we find sufficient conditions for an operator with kernel of
the form $A(x)B(y)-A(x)B(y)/(x-y)$ (which we call a Tracy-Widom type operator)
to be the square of a Hankel operator. We consider two contexts: infinite
matrices on $\ell^2$, and integral operators on the Hardy space
$H^2(\mathbb{T})$. The results can be applied to the discrete Bessel kernel,
which is significant in random matrix theory.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:41:22 GMT"
},
{
"version": "v2",
"created": "Wed, 11 Jul 2007 09:42:34 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"McCafferty",
"A. J.",
""
]
] |
0707.1475 | Alfonso Garc\'ia-Parrado G\'omez-Lobo Dr. | Alfonso Garc\'ia-Parrado G\'omez-Lobo | Dynamical laws of superenergy in General Relativity | 27 pages, no figures. Typos corrected, section 9 suppressed and more
acknowledgments added. To appear in Classical and Quantum Gravity | Class.Quant.Grav.25:015006,2008 | 10.1088/0264-9381/25/1/015006 | null | gr-qc | null | The Bel and Bel-Robinson tensors were introduced nearly fifty years ago in an
attempt to generalize to gravitation the energy-momentum tensor of
electromagnetism. This generalization was successful from the mathematical
point of view because these tensors share mathematical properties which are
remarkably similar to those of the energy-momentum tensor of electromagnetism.
However, the physical role of these tensors in General Relativity has remained
obscure and no interpretation has achieved wide acceptance. In principle, they
cannot represent {\em energy} and the term {\em superenergy} has been coined
for the hypothetical physical magnitude lying behind them. In this work we try
to shed light on the true physical meaning of {\em superenergy} by following
the same procedure which enables us to give an interpretation of the
electromagnetic energy. This procedure consists in performing an orthogonal
splitting of the Bel and Bel-Robinson tensors and analysing the different parts
resulting from the splitting. In the electromagnetic case such splitting gives
rise to the electromagnetic {\em energy density}, the Poynting vector and the
electromagnetic stress tensor, each of them having a precise physical
interpretation which is deduced from the {\em dynamical laws} of
electromagnetism (Poynting theorem). The full orthogonal splitting of the Bel
and Bel-Robinson tensors is more complex but, as expected, similarities with
electromagnetism are present. Also the covariant divergence of the Bel tensor
is analogous to the covariant divergence of the electromagnetic energy-momentum
tensor and the orthogonal splitting of the former is found. The ensuing {\em
equations} are to the superenergy what the Poynting theorem is to
electromagnetism. See paper for full abstract.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:42:29 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Nov 2007 13:56:58 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gómez-Lobo",
"Alfonso García-Parrado",
""
]
] |
0707.1476 | Vladyslav Yaskin | V.Yaskin | Modified Shephard's problem on projections of convex bodies | 15 pages | null | null | null | math.MG | null | We disprove a conjecture of A. Koldobsky asking whether it is enough to
compare $(n-2)$-derivatives of the projection functions of two symmetric convex
bodies in the Shephard problem in order to get a positive answer in all
dimensions.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:45:07 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Yaskin",
"V.",
""
]
] |
0707.1477 | Nathalie Pothier | S\'ebastien Lantenois (ISTO, ICGICMMM), Jean-Michel B\'eny (ISTO),
Fabrice Muller (ISTO), R\'emi Champallier (ISTO) | Integration of iron in natural and synthetic Al-pyrophyllites: an
infrared spectroscopic study | null | Clay Minerals 42 (2007) 129-143 | 10.1180/claymin.2007.042.1.09 | null | physics.geo-ph | null | Numerous studies focus on the relationships between chemical composition and
OHband positions in the infrared (IR) spectra of micaceous minerals. These
studies are based on the coexistence, in dioctahedral micas or smectites, of
several cationic pairs around the hydroxyl group which each produce a
characteristic band in the IR spectrum. The aim of this work is to obtain the
wavenumber values of the IR OH vibration bands of the (Al-Fe3+)-OH and
(Fe3+-Fe3+)-OH local cationic environments of 'pyrophyllite type' in order to
prove, disprove or modify a model of dioctahedral phyllosilicate OH-stretching
band decomposition. Natural samples are characterized by powder X-ray
diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopies
and electron microprobe; the hydrothermal synthesis products are also analysed
by powder XRD and FTIR after inductively coupled plasma measurements to obtain
the chemical compositions of nascent gel phases. Natural samples contain some
impurities which were eliminated after acid treatment; nevertheless, a small Fe
content is found in the pyrophyllite structure. The amount of Fe which is
incorporated within the pyrophyllite structure is much more important for the
synthetic samples than for the natural ones. The IR OH bands were clearly
observed in both natural and synthetic pyrophyllites and assigned to hydroxides
bonded to (Al-Al), (Al-Fe) and (Fe-Fe) cationic pairs. During this study, three
samples were analysed by DTG to check the cis- or trans-vacant character of the
layers and to determine the influence of this structural character on the
OH-stretching band position in IR spectroscopy.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:45:30 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Lantenois",
"Sébastien",
"",
"ISTO, ICGICMMM"
],
[
"Bény",
"Jean-Michel",
"",
"ISTO"
],
[
"Muller",
"Fabrice",
"",
"ISTO"
],
[
"Champallier",
"Rémi",
"",
"ISTO"
]
] |
0707.1478 | Elena Bannikova Yu. | Elena Yu. Bannikova and Victor M. Kontorovich | A Dipole Vortex Model of Obscuring Tori in Active Galaxy Nuclei | 17 pages, 11 figures, version of this paper is published in Astronomy
Reports | Astron.Rep.51:264-273,2007 | 10.1134/S1063772907040026 | null | astro-ph | null | The torus concept as an essential structural component of active galactic
nuclei (AGN) is generally accepted. Here, the situation is discussed when the
torus "twisting" by the radiation or wind transforms it into a dipole toroidal
vortex which in turn can be a source of matter replenishing the accretion disk.
Thus emerging instability which can be responsible for quasar radiation flares
accompanied by matter outbursts is also discussed. The "Matreshka" scheme for
an obscuring vortex torus structure capable of explaining the AGN variability
and evolution is proposed. The model parameters estimated numerically for the
luminosity close to the Eddington limit agree well with the observations.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 15:59:54 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bannikova",
"Elena Yu.",
""
],
[
"Kontorovich",
"Victor M.",
""
]
] |
0707.1479 | Laurent Chemin | Laurent Chemin, Claude Carignan, Philippe Amram | Dark matter in low mass surface density galaxies | 2 pages, 1 figure, proceedings of the conference "Pathways Through an
Eclectic Universe", Johan Knapen, Terry Mahoney, and Alexandre Vazdekis eds | null | null | null | astro-ph | null | Low mass surface density spiral and irregular galaxies like low surface
brightness (LSB) and dwarf galaxies are unique laboratories to study the
dynamical properties of Dark Matter halos because their mass is generally
dominated by dark matter at all galactocentric radii. We present results from
the largest sample ever assembled of high resolution Halpha velocity fields of
LSB and dwarf galaxies in order to study their mass distributions.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:01:27 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Chemin",
"Laurent",
""
],
[
"Carignan",
"Claude",
""
],
[
"Amram",
"Philippe",
""
]
] |
0707.1480 | Rene Chalon | Ren\'e Chalon (ICTT), Bertrand T. David (ICTT) | IRVO: an Interaction Model for designing Collaborative Mixed Reality
systems | 10 pages | Human Computer International 2005, U.S. CD (11/08/2005) 1-10 | null | null | cs.HC | null | This paper presents an interaction model adapted to mixed reality
environments known as IRVO (Interacting with Real and Virtual Objects). IRVO
aims at modeling the interaction between one or more users and the Mixed
Reality system by representing explicitly the objects and tools involved and
their relationship. IRVO covers the design phase of the life cycle and models
the intended use of the system. In a first part, we present a brief review of
related HCI models. The second part is devoted to the IRVO model, its notation
and some examples. In the third part, we present how IRVO is used for designing
applications and in particular we show how this model can be integrated in a
Model-Based Approach (CoCSys) which is currently designed at our lab.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:01:30 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Chalon",
"René",
"",
"ICTT"
],
[
"David",
"Bertrand T.",
"",
"ICTT"
]
] |
0707.1481 | Dipangkar Dutta | B. Clasie, et al | Measurement of Nuclear Transparency for the A(e,e' pi^+) Reaction | 5 pages, 3 figs Changes to figure 2 and 3 (error band updated and
theory curves updated) | Phys.Rev.Lett.99:242502,2007 | 10.1103/PhysRevLett.99.242502 | null | nucl-ex hep-ph nucl-th | null | We have measured the nuclear transparency of the A(e,e' pi^+) process in
^{2}H,^{12}C, ^{27}Al, ^{63}Cu and ^{197}Au targets. These measurements were
performed at the Jefferson Laboratory over a four momentum transfer squared
range Q^2 = 1.1 - 4.7 (GeV/c)^2. The nuclear transparency was extracted as the
super-ratio of $(\sigma_A/\sigma_H)$ from data to a model of
pion-electroproduction from nuclei without pi-N final state interactions. The
Q^2 and atomic number dependence of the nuclear transparency both show
deviations from traditional nuclear physics expectations, and are consistent
with calculations that include the quantum chromodynamical phenomenon of color
transparency.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:16:20 GMT"
},
{
"version": "v2",
"created": "Mon, 17 Dec 2007 17:21:55 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Clasie",
"B.",
""
]
] |
0707.1482 | Joachim Wambsganss | Joachim Wambsganss, Jeremiah P. Ostriker and Paul Bode | The effect of baryon cooling on the statistics of giant arcs and
multiple quasars | 20 pages, 7 figures, submitted to ApJ | null | 10.1086/527529 | null | astro-ph | null | The statistics of giant arcs and large separation lensed quasars provide
powerful constraints for the parameters of the underlying cosmological model.
So far, most investigations have been carried out using pure dark matter
simulations. Here we present a recipe for including the effects of baryon
cooling (i.e. large galaxy formation) in dark matter N-body simulations that is
consistent with observations of massive galaxies. Then we quantitatively
compare lensing with and without applying this baryon correction to the pure
dark matter case. Including the baryon correction significantly increases the
frequency of giant arcs and lensed quasars, particularly on scales of 10 arcsec
and smaller: the overall frequency of multiple images increases by about 25%
for source redshifts between z_s = 1.5 and 7.5 and splittings larger than about
3 arcsec. The baryon rearrangement also slightly increases the fraction of
quadruple images over doubles.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:03:19 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Wambsganss",
"Joachim",
""
],
[
"Ostriker",
"Jeremiah P.",
""
],
[
"Bode",
"Paul",
""
]
] |
0707.1483 | Aldo Lorenzo Cotrone | A.L. Cotrone | On the YM and QCD spectra from five dimensional strings | 21 pages; V2: added corrections and references to match the published
version | Int.J.Mod.Phys.A24:4117-4132,2009 | 10.1142/S0217751X09045467 | ECM-PF-07/21 | hep-th hep-lat hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a non-critical five dimensional string setup which could provide
a dual description of QCD in the limit of large number of colors and flavors.
The model corresponds to N_c color D3-branes and N_f D4/anti D4-brane pairs
supporting flavor degrees of freedom. The matching of the string model spectrum
with the dual field theory one is considered. We discuss the consequences of
the possible matching of the gravity modes with the light glueballs and the
interpretation of the brane spectrum in Yang-Mills and QCD.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:07:15 GMT"
},
{
"version": "v2",
"created": "Wed, 2 Sep 2009 10:43:32 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Cotrone",
"A. L.",
""
]
] |
0707.1484 | Oleg Verkhodanov | Pavel D. Naselsky (1,2), Oleg V. Verkhodanov (3), Mikkel T.B. Nielsen
(1) ((1) Niels Bohr Institute, Copenhagen; (2) South Federal University,
Rostov-na-Donu, Russia; (3) Special astrophysical observatory, Nizhnij
Arkhyz, Russia) | Instability of reconstruction of the low CMB multipoles | 11 pages, 5 figures | Astrophys.Bull.63:216-227,2008 | 10.1134/S1990341308030024 | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the problem of the bias of the Internal Linear Combination (ILC)
CMB map and show that it is closely related to the coefficient of
cross-correlation K(l) of the true CMB and the foreground for each multipole l.
We present analysis of the cross-correlation for the WMAP ILC quadrupole and
octupole from the first (ILC(I)) and the third (ILC(III)) year data releases
and show that these correlations are about -0.52-0.6. Analysing 10^4 Monte
Carlo simulations of the random Gaussian CMB signals, we show that the
distribution function for the corresponding coefficient of the
cross-correlation has a polynomial shape P(K,l)\propto(1-K^2)^(l-1). We show
that the most probable value of the cross-correlation coefficient of the ILC
and foreground quadrupole has two extrema at K ~= +/-0.58$. Thus, the ILC(III)
quadrupole represents the most probable value of the coefficient K. We analyze
the problem of debiasing of the ILC CMB and pointed out that reconstruction of
the bias seems to be very problematic due to statistical uncertainties. In
addition, instability of the debiasing illuminates itself for the quadrupole
and octupole components through the flip-effect, when the even (l+m) modes can
be reconstructed with significant error. This error manifests itself as
opposite, in respect to the true sign of even low multipole modes, and leads to
significant changes of the coefficient of cross-correlation with the
foreground. We show that the CMB realizations, whose the sign of quadrupole
(2,0) component is negative (and the same, as for all the foregrounds), the
corresponding probability to get the positive sign after implementation of the
ILC method is about 40%.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:38:52 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Sep 2008 16:51:31 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Naselsky",
"Pavel D.",
""
],
[
"Verkhodanov",
"Oleg V.",
""
],
[
"Nielsen",
"Mikkel T. B.",
""
]
] |
0707.1485 | Graham Everest | Graham Everest and Kirsten Eisentraeger | Descent on Elliptic Curves and Hilbert's Tenth Problem | Second author added. Paper now accepted by Proc AMS | null | null | null | math.NT math.LO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Descent via an isogeny on an elliptic curve is used to construct two subrings
of the field of rational numbers, which are complementary in a strong sense,
and for which Hilbert's Tenth Problem is undecidable. This method further
develops that of Poonen, who used elliptic divisibility sequences to obtain
undecidability results for some large subrings of the rational numbers.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:10:37 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 14:06:32 GMT"
},
{
"version": "v3",
"created": "Fri, 14 Sep 2007 16:04:48 GMT"
},
{
"version": "v4",
"created": "Mon, 31 Mar 2008 15:10:08 GMT"
},
{
"version": "v5",
"created": "Wed, 1 Oct 2008 10:57:35 GMT"
}
] | 2008-10-01T00:00:00 | [
[
"Everest",
"Graham",
""
],
[
"Eisentraeger",
"Kirsten",
""
]
] |
0707.1486 | Michael J. Gruber | Michael J. Gruber and Ivan Veseli\'c | The modulus of continuity of Wegner estimates for random Schr\"odinger
operators on metric graphs | 8 pages | Random Oper. Stoch. Equ. 16.1 (2008), 1-10 | 10.1515/ROSE.2008.001 | Isaac Newton Institute preprint NI07056-AGA | math.SP math-ph math.MP | null | We consider an alloy type potential on an infinite metric graph. We assume a
covering condition on the single site potentials. For random Schr\"odingers
operator associated with the alloy type potential restricted to finite volume
subgraphs we prove a Wegner estimate which reproduces the modulus of continuity
of the single site distribution measure. The Wegner constant is independent of
the energy.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:41:24 GMT"
}
] | 2011-01-25T00:00:00 | [
[
"Gruber",
"Michael J.",
""
],
[
"Veselić",
"Ivan",
""
]
] |
0707.1487 | Oleg Zaslavskii | O. B. Zaslavskii | Traversable wormholes: minimum violation of null energy condition
revisited | 12 pages. To appear in PRD | Phys.Rev.D76:044017,2007 | 10.1103/PhysRevD.76.044017 | null | gr-qc astro-ph hep-th | null | It was argued in literature that traversable wormholes can exist with
arbitrarily small violation of null energy conditions. We show that if the
amount of exotic material near the wormhole throat tends to zero, either this
leads to a horn instead of a wormhole or the throat approaches the horizon in
such a way that infnitely large stresses develop on the throat.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:14:32 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Zaslavskii",
"O. B.",
""
]
] |
0707.1488 | Neil Spooner | S. Burgos, J. Forbes, C. Ghag, M. Gold, V.A. Kudryavtsev, T.B. Lawson,
D. Loomba, P. Majewski, D. Muna, A.StJ. Murphy, G.G. Nicklin, S.M. Paling, A.
Petkov, S.J.S. Plank, M. Robinson, N. Sanghi, N.J.T. Smith, D.P.
Snowden-Ifft, N.J.C. Spooner, T.J. Sumner, J. Turk, E. Tziaferi | First Results from the DRIFT-IIa Dark Matter Detector | 43 pages, 14 figures, submitted to Astroparticle Physics | Astropart.Phys.28:409-421,2007 | 10.1016/j.astropartphys.2007.08.007 | null | hep-ex | null | Data from the DRIFT-IIa directional dark matter experiment are presented,
collected during a near continuous 6 month running period. A detailed
calibration analysis comparing data from gamma-ray, x-ray and neutron sources
to a GEANT4 Monte Carlo simulations reveals an efficiency for detection of
neutron induced recoils of 94+/-2(stat.)+/-5(sys.)%. Software-based cuts,
designed to remove non-nuclear recoil events, are shown to reject 60Co
gamma-rays with a rejection factor of better than 8x10-6 for all energies above
threshold. An unexpected event population has been discovered and is shown here
to be due to the alpha-decay of 222Rn daughter nuclei that have attached to the
central cathode. A limit on the flux of neutrons in the Boulby Underground
Laboratory is derived from analysis of unshielded and shielded data.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:14:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Burgos",
"S.",
""
],
[
"Forbes",
"J.",
""
],
[
"Ghag",
"C.",
""
],
[
"Gold",
"M.",
""
],
[
"Kudryavtsev",
"V. A.",
""
],
[
"Lawson",
"T. B.",
""
],
[
"Loomba",
"D.",
""
],
[
"Majewski",
"P.",
""
],
[
"Muna",
"D.",
""
],
[
"Murphy",
"A. StJ.",
""
],
[
"Nicklin",
"G. G.",
""
],
[
"Paling",
"S. M.",
""
],
[
"Petkov",
"A.",
""
],
[
"Plank",
"S. J. S.",
""
],
[
"Robinson",
"M.",
""
],
[
"Sanghi",
"N.",
""
],
[
"Smith",
"N. J. T.",
""
],
[
"Snowden-Ifft",
"D. P.",
""
],
[
"Spooner",
"N. J. C.",
""
],
[
"Sumner",
"T. J.",
""
],
[
"Turk",
"J.",
""
],
[
"Tziaferi",
"E.",
""
]
] |
0707.1489 | Colin Wilkin | C. Wilkin, M. Buescher, D. Chiladze, S. Dymov, C. Hanhart, M.
Hartmann, V. Hejny, A. Kacharava, I. Keshelashvili, A. Khoukaz, Y. Maeda, T.
Mersmann, M. Mielke, S. Mikirtychiants, M. Papenbrock, F. Rathmann, T.
Rausmann, R. Schleichert, H. Stroeher, A. Taeschner, Yu. Valdau, and A.
Wronska | Is there an eta-3He quasi--bound state ? | 10 pages with two eps figures | Phys.Lett.B654:92-96,2007 | 10.1016/j.physletb.2007.08.041 | null | nucl-ex nucl-th | null | The observed variation of the total cross section for the dp -> 3He eta
reaction near threshold means that the magnitude of the s--wave amplitude falls
very rapidly with the eta centre--of--mass momentum. It is shown here that
recent measurements of the momentum dependence of the angular distribution
imply a strong variation also in the phase of this amplitude. Such a behaviour
is that expected from a quasi--bound or virtual eta-3He state. The
interpretation can be investigated further through measurements of the deuteron
or proton analysing powers and/or spin--correlations.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:18:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Wilkin",
"C.",
""
],
[
"Buescher",
"M.",
""
],
[
"Chiladze",
"D.",
""
],
[
"Dymov",
"S.",
""
],
[
"Hanhart",
"C.",
""
],
[
"Hartmann",
"M.",
""
],
[
"Hejny",
"V.",
""
],
[
"Kacharava",
"A.",
""
],
[
"Keshelashvili",
"I.",
""
],
[
"Khoukaz",
"A.",
""
],
[
"Maeda",
"Y.",
""
],
[
"Mersmann",
"T.",
""
],
[
"Mielke",
"M.",
""
],
[
"Mikirtychiants",
"S.",
""
],
[
"Papenbrock",
"M.",
""
],
[
"Rathmann",
"F.",
""
],
[
"Rausmann",
"T.",
""
],
[
"Schleichert",
"R.",
""
],
[
"Stroeher",
"H.",
""
],
[
"Taeschner",
"A.",
""
],
[
"Valdau",
"Yu.",
""
],
[
"Wronska",
"A.",
""
]
] |
0707.1490 | Gianluca Argentini | Gianluca Argentini | Fast computing of velocity field for flows in industrial burners and
pumps | 14 pages, 5 figures; paper accepted for Special Issue "Application of
distributed and grid computing", Future Generation Computer Systems journal,
2007 | null | null | null | math.NA cs.MS | null | In this work we present a technique of fast numerical computation for
solutions of Navier-Stokes equations in the case of flows of industrial
interest. At first the partial differential equations are translated into a set
of nonlinear ordinary differential equations using the geometrical shape of the
domain where the flow is developing, then these ODEs are numerically resolved
using a set of computations distributed among the available processors. We
present some results from simulations on a parallel hardware architecture using
native multithreads software and simulating a shared-memory or a
distributed-memory environment.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:23:43 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Argentini",
"Gianluca",
""
]
] |
0707.1491 | Carlos Merino | G. H. Arakelyan, C. Merino, and Yu. M. Shabelski | Secondary Baryon Asymmetry in pi(+-)p Collisions | Contribution to the Proceedings of QCD@Work 2007, International
Workshop on Quantum Chromodynamics, Theory and Experiment, Martina
Franca-Valle d'Itria, Italy, June 16-20, 2007 (6 pages and 4 figures) | AIPConf.Proc.964:65-70,2007 | 10.1063/1.2823882 | null | hep-ph | null | The process of secondary baryon production in pi(+-)p collisions at high
energies in the central and forward fragmentation regions is considered in the
framework of the Quark-Gluon String Model. The contribution of the
string-junction mechanism to the baryon production is analysed. The results of
numerical calculations are in reasonable agreement with the experimental data
on the Lambda/bar(Lambda) and p/bar(p)$ asymmetries.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:37:57 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Arakelyan",
"G. H.",
""
],
[
"Merino",
"C.",
""
],
[
"Shabelski",
"Yu. M.",
""
]
] |
0707.1492 | Matteo Calandra | Matteo Calandra and Francesco Mauri | Electronic structure of heavily-doped graphene: the role of foreign atom
states | 4 pages, 2 figures, see also M. Calandra and F. Mauri,arXiv:0707.1467 | null | 10.1103/PhysRevB.76.161406 | null | cond-mat.mtrl-sci cond-mat.mes-hall cond-mat.supr-con | null | Using density functional theory calculations we investigate the electronic
structure of graphene doped by deposition of foreign atoms. We demonstrate
that, as the charge transfer to the graphene layer increases, the band
structure of the pristine graphene sheet is substantially affected. This is
particularly relevant when Ca atoms are deposed on graphene at CaC$_{6}$
stoichiometry. Similarly to what happens in superconducting graphite
intercalated compounds, a Ca bands occurs at the Fermi level. Its hybridization
with the C states generates a strong non-linearity in one of the $\pi^{*}$
bands below the Fermi level, at energies comparable to the graphene E$_{2g}$
phonon frequency. This strong non-linearity, and not manybody effects as
previously proposed, explains the large and anisotropic values of the apparent
electron-phonon coupling measured in angular resolved photoemission.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:39:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Calandra",
"Matteo",
""
],
[
"Mauri",
"Francesco",
""
]
] |
0707.1493 | Sebastian Lipari L. | S. Lipari, M. Bergmann, S. F. Sanchez, R. Terlevich, E. Mediavilla, B.
Punsly, B. Garcia-Lorenzo, W. Zheng, Y. Taniguchi, R. Sistero | The Role of Exploding QSOs in Explosive Models of Evolution, Formation
and End of Galaxies | Cordoba-Argentina Workshop, May 2007 (5 pages) | null | null | null | astro-ph | null | In this work we analise the role and evidence of exploding BAL + IR + Fe II
QSOs, and their relation with new -and previous- explosive models for
evolution, formation and end of galaxies.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:41:55 GMT"
},
{
"version": "v2",
"created": "Thu, 12 Jul 2007 12:36:27 GMT"
},
{
"version": "v3",
"created": "Sun, 22 Jul 2007 12:30:16 GMT"
}
] | 2007-07-22T00:00:00 | [
[
"Lipari",
"S.",
""
],
[
"Bergmann",
"M.",
""
],
[
"Sanchez",
"S. F.",
""
],
[
"Terlevich",
"R.",
""
],
[
"Mediavilla",
"E.",
""
],
[
"Punsly",
"B.",
""
],
[
"Garcia-Lorenzo",
"B.",
""
],
[
"Zheng",
"W.",
""
],
[
"Taniguchi",
"Y.",
""
],
[
"Sistero",
"R.",
""
]
] |
0707.1494 | Lazhar Dhaouadi | Lazhar Dhaouadi | Heisenberg Uncertainty Principle for the q-Bessel Fourier transform | null | null | null | null | math.CA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we uses an I.I. Hirschman-W. Beckner entropy argument to give
an uncertainty inequality for the $q$-Bessel Fourier transform: $$
\mathcal{F}_{q,v}f(x)=c_{q,v}\int_{0}^{\infty}f(t)j_{v}(xt,q^{2})t^{2v
+1}d_{q}t, $$ where $j_v(x,q)$ is the normalized Hahn-Exton $q$-Bessel
function.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:44:47 GMT"
},
{
"version": "v2",
"created": "Tue, 1 Jul 2008 12:19:15 GMT"
}
] | 2008-07-01T00:00:00 | [
[
"Dhaouadi",
"Lazhar",
""
]
] |
0707.1495 | Antonio Palazzo | A. Palazzo (Oxford U. and INFN, Bari), D. Cumberbatch, A. Slosar and
J. Silk (Oxford U.) | Sterile neutrinos as subdominant warm dark matter | Minor changes; added references; version accepted for publication in
Phys. Rev. D | Phys.Rev.D76:103511,2007 | 10.1103/PhysRevD.76.103511 | null | astro-ph hep-ph | null | In light of recent findings which seem to disfavor a scenario with (warm)
dark matter entirely constituted of sterile neutrinos produced via the
Dodelson-Widrow (DW) mechanism, we investigate the constraints attainable for
this mechanism by relaxing the usual hypothesis that the relic neutrino
abundance must necessarily account for all of the dark matter. We first study
how to reinterpret the limits attainable from X-ray non-detection and
Lyman-alpha forest measurements in the case that sterile neutrinos constitute
only a fraction fs of the total amount of dark matter. Then, assuming that
sterile neutrinos are generated in the early universe solely through the DW
mechanism, we show how the X-ray and Lyman-alpha results jointly constrain the
mass-mixing parameters governing their production. Furthermore, we show how the
same data allow us to set a robust upper limit fs < 0.7 at the 2 sigma level,
rejecting the case of dominant dark matter (fs = 1) at the ~ 3 sigma level.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:54:27 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Sep 2007 22:59:22 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Palazzo",
"A.",
"",
"Oxford U. and INFN, Bari"
],
[
"Cumberbatch",
"D.",
"",
"Oxford U."
],
[
"Slosar",
"A.",
"",
"Oxford U."
],
[
"Silk",
"J.",
"",
"Oxford U."
]
] |
0707.1496 | Ernie Croot | Ernie Croot | Subsets of F_p^n without three term arithmetic progressions have several
large Fourier coefficients | This is a preliminary draft. Later drafts will have more references
and cleaner proofs | null | null | null | math.CO math.NT | null | Suppose that f : F_p^n -> [0,1] has expected value t in [p^(-n/9),1] (so, the
density t can be quite low!). Furthermore, suppose that support(f) has no
three-term arithmetic progressions. Then, we develop non-trivial lower bounds
for f_j, which is the jth largest Fourier coefficient of f.
This result is similar in spirit to that appearing in an earlier paper [1] by
the author; however, in that paper the focus was on the ``small'' Fourier
coefficients, whereas here the focus is on the ``large'' Fourier coefficients.
Furthermore, the proof in the present paper requires much more sophisticated
arguments than those of that other paper.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:02:47 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Croot",
"Ernie",
""
]
] |
0707.1497 | Christopher Ogden | E. K. Irish, C. D. Ogden, M. S. Kim | Polaritonic characteristics of insulator and superfluid phases in a
coupled-cavity array | 7 pages, 9 figures, 1 table, REVTeX 4; published version | Phys. Rev. A 77, 033801 (2008) | 10.1103/PhysRevA.77.033801 | null | quant-ph | null | Recent studies of quantum phase transitions in coupled atom-cavity arrays
have focused on the similarities between such systems and the Bose-Hubbard
model. However, the bipartite nature of the atom-cavity systems that make up
the array introduces some differences. In order to examine the unique features
of the coupled-cavity system, the behavior of a simple two-site model is
studied over a wide range of parameters. Four regions are identified, in which
the ground state of the system may be classified as either a polaritonic
insulator, a photonic superfluid, an atomic insulator, or a polaritonic
superfluid.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 16:56:35 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 10:19:40 GMT"
},
{
"version": "v3",
"created": "Sat, 8 Sep 2007 18:45:14 GMT"
},
{
"version": "v4",
"created": "Wed, 5 Mar 2008 14:49:18 GMT"
}
] | 2013-05-29T00:00:00 | [
[
"Irish",
"E. K.",
""
],
[
"Ogden",
"C. D.",
""
],
[
"Kim",
"M. S.",
""
]
] |
0707.1498 | Felipe de Freitas Munarin | F. F. Munarin, K. Nelissen, W. P. Ferreira, G. A. Farias, and F. M.
Peeters | Hysteresis and re-entrant melting of a self-organized system of
classical particles confined in a parabolic trap | 8 pages, 6 figures | null | 10.1103/PhysRevE.77.031608 | null | cond-mat.soft | null | A self-organized system composed of classical particles confined in a
two-dimensional parabolic trap and interacting through a potential with a
short-range attractive part and long-range repulsive part is studied as
function of temperature. The influence of the competition between the
short-range attractive part of the inter-particle potential and its long-range
repulsive part on the melting temperature is studied. Different behaviors of
the melting temperature are found depending on the screening length ($\kappa$)
and the strength ($B$) of the attractive part of the inter-particle potential.
A re-entrant behavior and a thermal induced phase transition is observed in a
small region of ($\kappa,B$)-space. A structural hysteresis effect is observed
as a function of temperature and physically understood as due to the presence
of a potential barrier between different configurations of the system.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 19:20:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Munarin",
"F. F.",
""
],
[
"Nelissen",
"K.",
""
],
[
"Ferreira",
"W. P.",
""
],
[
"Farias",
"G. A.",
""
],
[
"Peeters",
"F. M.",
""
]
] |
0707.1499 | Fabio Trani | F. Trani | Polarization anisotropy in the optical properties of silicon ellipsoids | 5 pages, 4 figures, International Conference on NANO-Structures
Self-Assembling | Surface Science 601, 2702 (2007) | 10.1016/j.susc.2006.12.020 | null | cond-mat.mtrl-sci | null | A new real space quantum mechanical approach with local field effects
included is applied to the calculation of the optical properties of silicon
nanocrystals. Silicon ellipsoids are studied and the role of surface
polarization is discussed in details. In particular, surface polarization is
shown to be responsible for a strong optical anisotropy in silicon ellipsoids,
much more pronounced with respect to the case in which only quantum confinement
effects are considered. The static dielectric constant and the absorption
spectra are calculated, showing that the perpendicular and parallel components
have a very different dependence on the ellipsoid aspect ratio. Then, a
comparison with the classical dielectric model is performed, showing that the
model only works for large and regular structures, but it fails for thin
elongated ellipsoids.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:20:33 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Trani",
"F.",
""
]
] |
0707.1500 | Sebastian White Phd | Sebastian N. White | On the Correlation of Subevents in the ATLAS and CMS/Totem Experiments | This paper was produced using Mathematica 6.0. It is 20 pages long
and has lots of graphics an animations | null | null | null | hep-ex hep-ph | null | We analyze the problem of correlating pp interaction data from the central
detectors with a subevent measured in an independent system of leading proton
detectors using FP420 as an example.
FP420 is an R&D project conducted by a collaboration formed by members of
ATLAS and CMS to investigate the possibility of detecting new physics in the
central exclusive channel, PP -> P + X + P,where the central system X may be a
single particle, for example a Standard Model Higgs boson. With standard LHC
optics, the protons emerge from the beam at a distance of 420m from the
Interaction Point, for M_X ~ 120 GeV. The mass of the central system can be
measured from the outgoing protons alone, with a resolution of order 2 GeV
irrespective of the decay products of the central system. In addition, to a
very good approximation, only central systems with 0^++ quantum numbers can be
produced, meaning that observation of a SM or MSSM Higgs Boson in this channel
would lead to a direct determination of the quantum numbers.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:28:55 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 18:42:13 GMT"
},
{
"version": "v3",
"created": "Thu, 2 Aug 2007 09:25:10 GMT"
}
] | 2007-08-02T00:00:00 | [
[
"White",
"Sebastian N.",
""
]
] |
0707.1501 | Alexander Ushakov | Alexei G. Myasnikov, Alexander Ushakov | Random subgroups and analysis of the length-based and quotient attacks | null | null | null | null | math.GR cs.CR | null | In this paper we discuss generic properties of "random subgroups" of a given
group G. It turns out that in many groups G (even in most exotic of them) the
random subgroups have a simple algebraic structure and they "sit" inside G in a
very particular way. This gives a strong mathematical foundation for
cryptanalysis of several group-based cryptosystems and indicates on how to
chose "strong keys". To illustrate our technique we analyze the
Anshel-Anshel-Goldfeld (AAG) cryptosystem and give a mathematical explanation
of recent success of some heuristic length-based attacks on it. Furthermore, we
design and analyze a new type of attacks, which we term the quotient attacks.
Mathematical methods we develop here also indicate how one can try to choose
"parameters" in AAG to foil the attacks.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:38:26 GMT"
}
] | 2007-07-12T00:00:00 | [
[
"Myasnikov",
"Alexei G.",
""
],
[
"Ushakov",
"Alexander",
""
]
] |
0707.1502 | Christopher H Cashen | Christopher H Cashen | Quasi-isometries Between Tubular Groups | 44 pages, 11 figures. PDFLaTeX. Improved exposition and added some
auxiliary material to make the paper more self contained, per referee's
comments | Groups Geom. Dyn. 4 (2010), no. 3, 473-516 | 10.4171/GGD/92 | null | math.GR math.GT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give a method of constructing maps between tubular groups inductively
according to a set of strategies. This map will be a quasi-isometry exactly
when the set of strategies is consistent. Conversely, if there exists a
quasi-isometry between tubular groups, then there is a consistent set of
strategies for them.
There is an algorithm that will in finite time either produce a consistent
set of strategies or decide that such a set does not exist. Consequently, this
algorithm decides whether or not the groups are quasi-isometric.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:13:51 GMT"
},
{
"version": "v2",
"created": "Mon, 31 Dec 2007 22:06:19 GMT"
},
{
"version": "v3",
"created": "Wed, 19 Nov 2008 00:03:26 GMT"
}
] | 2010-07-20T00:00:00 | [
[
"Cashen",
"Christopher H",
""
]
] |
0707.1503 | Ricardo V\^encio | Ricardo V\^encio and Ilya Shmulevich | ProbCD: enrichment analysis accounting for categorization uncertainty | 16 pages, 3 figures, submitted to a journal in the Bioinformatics
field | BMC Bioinformatics 2007, 8:383 | 10.1186/1471-2105-8-383 | null | q-bio.QM q-bio.GN | null | As in many other areas of science, systems biology makes extensive use of
statistical association and significance estimates in contingency tables, a
type of categorical data analysis known in this field as enrichment (also
over-representation or enhancement) analysis. In spite of efforts to create
probabilistic annotations, especially in the Gene Ontology context, or to deal
with uncertainty in high throughput-based datasets, current enrichment methods
largely ignore this probabilistic information since they are mainly based on
variants of the Fisher Exact Test. We developed an open-source R package to
deal with probabilistic categorical data analysis, ProbCD, that does not
require a static contingency table. The contingency table for the enrichment
problem is built using the expectation of a Bernoulli Scheme stochastic process
given the categorization probabilities. An on-line interface was created to
allow usage by non-programmers and is available at:
http://xerad.systemsbiology.net/ProbCD/ . We present an analysis framework and
software tools to address the issue of uncertainty in categorical data
analysis. In particular, concerning the enrichment analysis, ProbCD can
accommodate: (i) the stochastic nature of the high-throughput experimental
techniques and (ii) probabilistic gene annotation.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:42:34 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Vêncio",
"Ricardo",
""
],
[
"Shmulevich",
"Ilya",
""
]
] |
0707.1504 | Thomas Schaefer | Thomas Schaefer (North Carolina State University) | Perfect Fluidity in Atomic Physics | Talk given at 23rd Winter Workshop on Nuclear Dynamics, Big Sky,
Montana, 11-18 Feb 2007, Acta Physica Hungarica, in press | null | null | null | nucl-th | null | Experimental results obtained at the Relativistic Heavy Ion Collider (RHIC)
have been interpreted in terms of a strongly interacting quark gluon plasma.
The strongly interacting plasma is characterized by ``perfect fluidity'', i.e.
a ratio of shear viscosity to entropy density that saturates a proposed lower
bound. In this contribution we explore the possibility that a similar
phenomenon takes place in a strongly coupled non-relativistic Fermi liquid in
which the scattering length between the Fermions is infinitely large.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:46:17 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Schaefer",
"Thomas",
"",
"North Carolina State University"
]
] |
0707.1505 | Joseph H. Silverman | Joseph H. Silverman | Variation of Periods Modulo p in Arithmetic Dynamics | 15 pages | New York Journal of Math. 14 (2008), 601--616 (electronic) | null | null | math.NT math.DS | null | Let F : V --> V be a self-morphism of a quasiprojective variety defined over
a number field K and let P be a point in V(K) with infinite orbit under
iteration of F. For each prime ideal p of good reduction, let m_p(F,P) be the
size of the F-orbit of the reduction of P modulo p. Fix any e > 0. We show that
for almost all primes p, in the sense of analytic density, the orbit size
m_p(F,P) is larger than (log(N(p)))^(1-e), where N(p) is the norm of the ideal
p.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:53:25 GMT"
}
] | 2011-05-30T00:00:00 | [
[
"Silverman",
"Joseph H.",
""
]
] |
0707.1506 | Daniel de Florian | Daniel de Florian, Rodolfo Sassot, Marco Stratmann | Global Analysis of Fragmentation Functions for Protons and Charged
Hadrons | 14 pages, 14 figures | Phys.Rev.D76:074033,2007 | 10.1103/PhysRevD.76.074033 | null | hep-ph | null | We present new sets of fragmentation functions for protons and inclusive
charged hadrons obtained in combined NLO QCD analyses of single-inclusive
hadron production in electron-positron annihilation, proton-proton collisions,
and deep-inelastic lepton-proton scattering. These analyses complement previous
results for pion and kaon fragmentation functions with charge and flavor
discrimination. The Lagrange multiplier technique is used to assess the
uncertainties in the extraction of the new sets of fragmentation functions.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 17:56:51 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"de Florian",
"Daniel",
""
],
[
"Sassot",
"Rodolfo",
""
],
[
"Stratmann",
"Marco",
""
]
] |
0707.1507 | Carlo Ewerz | Carlo Ewerz, Otto Nachtmann | Diffractive Neutral Pion Production, Chiral Symmetry and the Odderon | 6 pages, based on invited talks given by C.E. at XVth International
Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2007),
Munich, April 2007, and by O.N. at 12th International Conference on Elastic
and Diffractive Scattering (EDS07), DESY Hamburg, May 2007 | null | null | ECT*-07-14, HD-THEP-07-15 | hep-ph | null | We discuss the diffractive photo- and electroproduction of a single neutral
pion at high energies where it can occur due to odderon exchange. We show that
this process is dynamically suppressed as a consequence of chiral symmetry. Our
result reconciles earlier theoretical expectations with the non-observation of
this reaction at HERA.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:05:43 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Ewerz",
"Carlo",
""
],
[
"Nachtmann",
"Otto",
""
]
] |
0707.1508 | Mark Heinz | Mark Heinz (for the STAR Collaboration) | How important are next-to-leading order models in predicting strange
particle spectra in p+p collisions at STAR ? | 5 pages, HotQuarks 2006 conference proceedings | Eur.Phys.J.C49:129-133,2007 | 10.1140/epjc/s10052-006-0098-1 | null | hep-ex | null | STAR has measured a variety of strange particle species in p + p collisions
at $\sqrt{s}$ = 200 GeV. These high statistics data are ideal for comparing to
existing leading- and next-to-leading order perturbative QCD (pQCD) models.
Next-to-leading (NLO) models have been successful in describing inclusive
hadron production using parameterized fragmentation functions (FF) for quarks
and gluons. However, in order to describe identied strange particle spectra at
NLO, knowledge of flavor separated FF is essential. Such FF have recently been
parameterized using data by the OPAL experiment and allow for the first time to
perform NLO calculation for strange baryons. In fact, comparing the STAR Lambda
data with these calculations allow to put a constraint on the gluon
fragmentation function. We show that the Leading-order (LO) event generator
PYTHIA has to be tuned significantly to reproduce the STAR identified strange
particle data. In particular, it fails to describe the observed enhancement of
baryon-to-meson ratio at intermediate pT (2-6 GeV/c). In heavy-ion (HI)
collisions this observable has been extensively compared with models and shows
a strong dependency on collision centrality or parton density. In the HI
context the observed enhancement has been explained by recent approaches in
terms of parton coalescense and recombination models.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:07:33 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Heinz",
"Mark",
"",
"for the STAR Collaboration"
]
] |
0707.1509 | Sergei Burdin | Sergey Burdin (for the CDF Collaboration and the D0 Collaboration) | Bs Properties at the Tevatron | Presented at the Hadron Collider Physics Symposium 2006 (Duke
University, Durham), added references | null | null | FERMILAB-CONF-06-545-E | hep-ex | null | Results on Bs properties obtained by the CDF and D0 collaborations using the
data samples collected at the Tevatron Collider in the period 2002-2006 were
presented at the Hadron Collider Physics Symposium 2006 (Duke University,
Durham). The measurements of Bs mass and width differences are discussed in
details.
Prospects on measurements of CP violation in Bs system are given.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:47:13 GMT"
},
{
"version": "v2",
"created": "Fri, 10 Aug 2007 08:11:55 GMT"
}
] | 2019-08-14T00:00:00 | [
[
"Burdin",
"Sergey",
"",
"for the CDF Collaboration and the D0 Collaboration"
]
] |
0707.1510 | Mark Heinz | Mark Heinz (for the STAR Collaboration) | STAR identifed particle measurements at high transverse momentum in p+p
$\sqrt{s}$ = 200 GeV | 4 pages, Proceedings for DIS 2007, Munich, Germany | null | null | null | hep-ex | null | We present the STAR measurement of transverse momentum spectra at
mid-rapidity for identified particles in p+p collisions at $\sqrt{s}$ = 200
GeV. These high statistics data are ideal for comparing to existing leading-
and next-to-leading order (NLO) perturbative QCD calculations. Next-to-leading
models have been successful in describing inclusive hadron production using
parameterized fragmentation functions (FF) for quarks and gluons. However, in
order to describe baryon spectra at NLO, knowledge of flavor separated FF is
essential. Such FF have recently been parameterized using data by the OPAL
experiment and allow for the first time to obtain good agreement between NLO
and identified baryons from p+p collisions.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:18:14 GMT"
}
] | 2007-07-11T00:00:00 | [
[
"Heinz",
"Mark",
"",
"for the STAR Collaboration"
]
] |
0707.1511 | Eli A. Meirom | E. A. Meirom, N. H. Lindner, Y. Berlatzky, E. Poem, N. Akopian, J. E.
Avron and D. Gershoni | Distilling entanglement from cascades with partial "Which Path"
ambiguity | null | Phys. Rev. A 77, 062310 (2008) | 10.1103/PhysRevA.77.062310 | null | quant-ph cond-mat.str-el | null | We develop a framework to calculate the density matrix of a pair of photons
emitted in a decay cascade with partial "which path" ambiguity. We describe an
appropriate entanglement distillation scheme which works also for certain
random cascades. The qualitative features of the distilled entanglement are
presented in a two dimensional "phase diagram". The theory is applied to the
quantum tomography of the decay cascade of a biexciton in a semiconductor
quantum dot. Agreement with experiment is obtained.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 19:28:52 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Mar 2008 09:16:44 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Meirom",
"E. A.",
""
],
[
"Lindner",
"N. H.",
""
],
[
"Berlatzky",
"Y.",
""
],
[
"Poem",
"E.",
""
],
[
"Akopian",
"N.",
""
],
[
"Avron",
"J. E.",
""
],
[
"Gershoni",
"D.",
""
]
] |
0707.1512 | Selman Akbulut | Selman Akbulut, Baris Efe, and Sema Salur | Mirror Duality in a Joyce Manifold | 9 pages, 4 figures, revised version, to appear in Advances in
Mathematics | null | null | null | math.GT hep-th math.DG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Previously the two of the authors defined a notion of dual Calabi-Yau
manifolds in a G_2 manifold, and described a process to obtain them. Here we
apply this process to a compact G_2 manifold, constructed by Joyce, and as a
result we obtain a pair of Borcea-Voisin Calabi-Yau manifolds, which are known
to be mirror duals of each other.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 19:38:27 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Jul 2007 12:53:11 GMT"
},
{
"version": "v3",
"created": "Wed, 19 Aug 2009 13:28:35 GMT"
}
] | 2009-08-19T00:00:00 | [
[
"Akbulut",
"Selman",
""
],
[
"Efe",
"Baris",
""
],
[
"Salur",
"Sema",
""
]
] |
0707.1513 | Vratko Pol\'ak | Vladim\'ir Balek and Vratko Pol\'ak | Group velocity of gravitational waves in an expanding universe | 19 pages, 2 figures; structure reorganized, discussion of
electromagnetic waves altered | Gen.Rel.Grav.41:505-524,2009 | 10.1007/s10714-008-0681-x | null | gr-qc | null | The group velocity of gravitational waves in a flat Friedman-Robertson-Walker
universe is investigated. For plane waves with wavelength well inside the
horizon, and a universe filled with an ideal fluid with the pressure to density
ratio less than 1/3, the group velocity is greater than the velocity of light.
As a result, a planar pulse of gravitational waves propagating through the
universe during the matter/dark energy dominated era arrives to the observer
with the peak shifted towards the forefront. For gravitational waves emitted by
inspiralling supermassive black holes at the edge of the observable universe,
the typical shift that remains after the effects of nonplanarity are suppressed
is of order of ten picoseconds.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:43:39 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Sep 2007 19:43:27 GMT"
},
{
"version": "v3",
"created": "Fri, 9 May 2008 13:07:22 GMT"
}
] | 2011-02-01T00:00:00 | [
[
"Balek",
"Vladimír",
""
],
[
"Polák",
"Vratko",
""
]
] |
0707.1514 | Magdalena Constantin | Clare C. Yu, Magdalena Constantin and John M. Martinis | Effect of Two Level System Saturation on Charge Noise in Josephson
Junction Qubits | 4 pages | null | null | null | cond-mat.mes-hall | null | We show that charge noise $S_Q$ in Josephson qubits can be produced by
fluctuating two level systems (TLS) with electric dipole moments in the
substrate using a flat density of states. At high frequencies the frequency and
temperature dependence of the charge noise depends on the ratio $J/J_c$ of the
electromagnetic flux $J$ to the critical flux $J_c$. It is not widely
appreciated that TLS in small qubits can easily be strongly saturated with
$J/J_c\gg 1$. Our results are consistent with experimental conclusions that
$S_Q\sim 1/f$ at low frequencies and $S_Q\sim f$ at high frequencies.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 19:11:21 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Yu",
"Clare C.",
""
],
[
"Constantin",
"Magdalena",
""
],
[
"Martinis",
"John M.",
""
]
] |
0707.1515 | Gun Srijuntongsiri | Gun Srijuntongsiri, Stephen A. Vavasis | Properties of polynomial bases used in a line-surface intersection
algorithm | null | null | null | null | cs.NA cs.CG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In [5], Srijuntongsiri and Vavasis propose the "Kantorovich-Test Subdivision
algorithm", or KTS, which is an algorithm for finding all zeros of a polynomial
system in a bounded region of the plane. This algorithm can be used to find the
intersections between a line and a surface. The main features of KTS are that
it can operate on polynomials represented in any basis that satisfies certain
conditions and that its efficiency has an upper bound that depends only on the
conditioning of the problem and the choice of the basis representing the
polynomial system.
This article explores in detail the dependence of the efficiency of the KTS
algorithm on the choice of basis. Three bases are considered: the power, the
Bernstein, and the Chebyshev bases. These three bases satisfy the basis
properties required by KTS. Theoretically, Chebyshev case has the smallest
upper bound on its running time. The computational results, however, do not
show that Chebyshev case performs better than the other two.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:56:05 GMT"
},
{
"version": "v2",
"created": "Wed, 11 Jul 2007 00:37:41 GMT"
},
{
"version": "v3",
"created": "Mon, 22 Oct 2007 03:20:49 GMT"
},
{
"version": "v4",
"created": "Mon, 8 Sep 2008 09:18:56 GMT"
},
{
"version": "v5",
"created": "Fri, 27 Feb 2009 10:43:30 GMT"
}
] | 2009-02-27T00:00:00 | [
[
"Srijuntongsiri",
"Gun",
""
],
[
"Vavasis",
"Stephen A.",
""
]
] |
0707.1516 | Thomas Papenbrock | G. Hagen, D. J. Dean, M. Hjorth-Jensen, T. Papenbrock, A. Schwenk | Benchmark calculations for 3H, 4He, 16O and 40Ca with ab-initio
coupled-cluster theory | 8 pages, 13 figures | Phys.Rev.C76:044305,2007 | 10.1103/PhysRevC.76.044305 | null | nucl-th | null | We present ab-initio calculations for 3H, 4He, 16O, and 40Ca based on
two-nucleon low-momentum interactions Vlowk within coupled-cluster theory. For
3H and 4He, our results are within 70 keV and 10 keV of the corresponding
Faddeev and Faddeev-Yakubovsky energies. We study in detail the convergence
with respect to the size of the model space and the single-particle basis. For
the heavier nuclei, we report practically converged binding energies and
compare with other approaches.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 18:56:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hagen",
"G.",
""
],
[
"Dean",
"D. J.",
""
],
[
"Hjorth-Jensen",
"M.",
""
],
[
"Papenbrock",
"T.",
""
],
[
"Schwenk",
"A.",
""
]
] |
0707.1517 | Rachel Gilmour | R. Gilmour, M. E. Gray, O. Almaini, P. Best, C. Wolf, K. Meisenheimer,
C.Papovich, and E. Bell | Environmental dependence of AGN activity in the supercluster A901/2 | 20 pages, 15 figures. MNRAS accepted. Version with full resolution
figures, including Figure 14, is available at
http://www.sc.eso.org/~rgilmour/ | null | 10.1111/j.1365-2966.2007.12127.x | null | astro-ph | null | We present XMM data for the supercluster A901/2, at z ~ 0.17, which is
combined with deep imaging and 17-band photometric redshifts (from the COMBO-17
survey), 2dF spectra and Spitzer 24um data, to identify AGN in the
supercluster. The 90ksec XMM image contains 139 point sources, of which 11 are
identified as supercluster AGN with L_X(0.5-7.5keV) > 1.7x10^41 erg/cm2/s. The
host galaxies have M_R < -20 and only 2 of 8 sources with spectra could have
been identified as AGN by the detected optical emission lines. Using a large
sample of 795 supercluster galaxies we define control samples of massive
galaxies with no detected AGN. The local environments of the AGN and control
samples differ at >98 per cent significance. The AGN host galaxies lie
predominantly in areas of moderate projected galaxy density and with more local
blue galaxies than the control sample, with the exception of one very bright
Type I AGN very near the centre of a cluster. These environments are similar
to, but not limited to, cluster outskirts and blue groups. Despite the large
number of potential host galaxies, no AGN are found in regions with the highest
galaxy density (excluding some cluster cores where emission from the ICM
obscures moderate luminosity AGN). AGN are also absent from the areas with
lowest galaxy density. We conclude that the prevalence of cluster AGN is linked
to their environment.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 22:24:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gilmour",
"R.",
""
],
[
"Gray",
"M. E.",
""
],
[
"Almaini",
"O.",
""
],
[
"Best",
"P.",
""
],
[
"Wolf",
"C.",
""
],
[
"Meisenheimer",
"K.",
""
],
[
"Papovich",
"C.",
""
],
[
"Bell",
"E.",
""
]
] |
0707.1518 | Ernest Ma | Ernest Ma (UC Riverside) | Gluino Axion, Neutrino Seesaw, Dynamical Gaugino Mass, and A = 0
Supersymmetry | 7 pages, 2 figures | Mod.Phys.Lett.A22:2721-2725,2007 | 10.1142/S0217732307025820 | UCRHEP-T433 (July 2007) | hep-ph | null | In the axionic solution of the strong CP problem, fermions which transform
under quantum chromodynamics (QCD) are required. In supersymmetry, by equating
U(1)_{PQ} with U(1)_R, the natural candidates are the gluinos, as pointed out
some years ago. A new specific implementation of this idea is proposed, linking
the gluino axion scale to that of the canonical seesaw mechanism for neutrinos.
Gaugino masses are generated dynamically and the A term is predicted to be very
small.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 20:07:40 GMT"
},
{
"version": "v2",
"created": "Thu, 12 Jul 2007 18:07:55 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] |
0707.1519 | Sergiu Vacaru I. | Sergiu I. Vacaru | Deformation Quantization of Almost Kahler Models and Lagrange-Finsler
Spaces | the latex 2e variant of the manuscript accepted for JMP, 11pt, 23
pages | J.Math.Phys.48:123509,2007 | 10.1063/1.2821249 | null | gr-qc hep-th math-ph math.MP math.SG | null | Finsler and Lagrange spaces can be equivalently represented as almost Kahler
manifolds enabled with a metric compatible canonical distinguished connection
structure generalizing the Levi Civita connection. The goal of this paper is to
perform a natural Fedosov-type deformation quantization of such geometries. All
constructions are canonically derived for regular Lagrangians and/or
fundamental Finsler functions on tangent bundles.
| [
{
"version": "v1",
"created": "Wed, 11 Jul 2007 17:44:26 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Nov 2007 15:05:51 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Vacaru",
"Sergiu I.",
""
]
] |
0707.1520 | Gautam Rupak | Gautam Rupak and Thomas Schaefer | Shear viscosity of a superfluid Fermi gas in the unitarity limit | 9 pages, 7 figures, LaTeX2e | Phys.Rev.A76:053607,2007 | 10.1103/PhysRevA.76.053607 | null | cond-mat.other hep-ph nucl-th | null | We compute the shear viscosity of a superfluid atomic Fermi gas in the
unitarity limit. The unitarity limit is characterized by a divergent scattering
length between the atoms, and it has been argued that this will result in a
very small viscosity. We show that in the low temperature T limit the shear
viscosity scales as xi^5/T^5, where the universal parameter 'xi' relates the
chemical potential and the Fermi energy, mu=xi E_F. Combined with the high
temperature expansions of the viscosity our results suggest that the viscosity
has a minimum near the critical temperature T_c. A naive extrapolation
indicates that the minimum value of the ratio of viscosity over entropy density
is within a factor of ~ 5 of the proposed lower bound hbar/(4\pi k_B).
| [
{
"version": "v1",
"created": "Wed, 11 Jul 2007 19:02:33 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Rupak",
"Gautam",
""
],
[
"Schaefer",
"Thomas",
""
]
] |
0707.1521 | Gilad Gour | Gilad Gour | Reexamination of entanglement of superpositions | 5 pages, Published version | Phys. Rev. A 76, 052320 (2007) | 10.1103/PhysRevA.76.052320 | null | quant-ph | null | We find tight lower and upper bounds on the entanglement of a superposition
of two bipartite states in terms of the entanglement of the two states
constituting the superposition. Our upper bound is dramatically tighter than
the one presented in Phys. Rev. Lett 97, 100502 (2006) and our lower bound can
be used to provide lower bounds on different measures of entanglement such as
the entanglement of formation and the entanglement of subspaces. We also find
that in the case in which the two states are one-sided orthogonal, the
entanglement of the superposition state can be expressed explicitly in terms of
the entanglement of the two states in the superposition.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 20:19:35 GMT"
},
{
"version": "v2",
"created": "Wed, 21 Nov 2007 22:13:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gour",
"Gilad",
""
]
] |
0707.1522 | Georges Bouzerar | Georges Bouzerar, Richard Bouzerar and Olivier Cepas | Superexchange induced canted ferromagnetism in dilute magnets | 6 figures, submitted to Phys. Rev | null | 10.1103/PhysRevB.76.144419 | null | cond-mat.dis-nn cond-mat.str-el | null | We argue, in contrast to recent studies, that the antiferromagnetic
superexchange coupling between nearest neighbour spins does not fully destroy
the ferromagnetism in dilute magnets with long-ranged ferromagnetic couplings.
Above a critical coupling, we find a \textit{canted} ferromagnetic phase with
unsaturated moment. We have calculated the transition temperature using a
simplified local Random Phase Approximation procedure which accounts for the
canting. For the dilute magnetic semiconductors, such as GaMnAs, using
\textit{ab-initio} couplings allows us to predict the existence of a canted
phase and provide an explanation to the apparent contradictions observed in
experimental measurements. Finally, we have compared with previous studies that
used RKKY couplings and reported non-ferromagnetic state when the superexchange
is too strong. Even in this case the ferromagnetism should remain essentially
stable in the form of a canted phase.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 20:38:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bouzerar",
"Georges",
""
],
[
"Bouzerar",
"Richard",
""
],
[
"Cepas",
"Olivier",
""
]
] |
0707.1523 | Genevieve J. Graves | Genevieve J. Graves, Sandra M. Faber, Ricardo P. Schiavon, Renbin Yan | Ages and Abundances of Red Sequence Galaxies as a Function of LINER
Emission Line Strength | 25 pages, 17 figures, Accepted for publication in ApJ as of 16 July
2007; acceptance status updated, paper unchanged | null | 10.1086/522325 | null | astro-ph | null | Although the spectrum of a prototypical early-type galaxy is assumed to lack
emission lines, a substantial fraction (likely as high as 30%) of nearby red
sequence galaxy spectra contain emission lines with line ratios characteristic
of low ionization nuclear emission-line regions (LINERs). We use spectra of
~6000 galaxies from the Sloan Digital Sky Survey (SDSS) in a narrow redshift
slice (0.06 < z < 0.08) to compare the stellar populations of red sequence
galaxies with and without LINER-like emission. The spectra are binned by
internal velocity dispersion and by emission properties to produce high S/N
stacked spectra. The recent stellar population models of R. Schiavon (2007)
make it possible to measure ages, [Fe/H], and individual elemental abundance
ratios [Mg/Fe], [C/Fe], [N/Fe], and [Ca/Fe] for each of the stacked spectra. We
find that red sequence galaxies with strong LINER-like emission are
systematically 2-3.5 Gyr (10-40%) younger than their emission-free counterparts
at the same velocity dispersion. This suggests a connection between the
mechanism powering the emission (whether AGN, post-AGB stars, shocks, or
cooling flows) and more recent star formation in the galaxy. We find that mean
stellar age and [Fe/H] increase with velocity dispersion for all galaxies.
Elemental abundance [Mg/Fe] increases modestly with velocity dispersion in
agreement with previous results, and [C/Fe] and [N/Fe] increase more strongly
with velocity dispersion than does [Mg/Fe]. [Ca/Fe] appears to be roughly solar
for all galaxies. At fixed velocity dispersion, galaxies with fainter r-band
luminosities have lower [Fe/H] and older ages but similar abundance ratios
compared to brighter galaxies.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 20:12:36 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Jul 2007 13:17:11 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Graves",
"Genevieve J.",
""
],
[
"Faber",
"Sandra M.",
""
],
[
"Schiavon",
"Ricardo P.",
""
],
[
"Yan",
"Renbin",
""
]
] |
0707.1524 | Sergiu Vacaru I. | Sergiu I. Vacaru | Finsler-Lagrange Geometries and Standard Theories in Physics: New
Methods in Einstein and String Gravity | latex 2e, 11pt, 86 pages, v3 with a up-dated references; a short
variant of this review was accepted for IJGMMP (2008), see also arXiv:
0801.4958 [gr-qc] | null | null | null | gr-qc hep-th math-ph math.MP math.SG | null | In this article, we review the current status of Finsler-Lagrange geometry
and generalizations. The goal is to aid non-experts on Finsler spaces, but
physicists and geometers skilled in general relativity and particle theories,
to understand the crucial importance of such geometric methods for applications
in modern physics. We also would like to orient mathematicians working in
generalized Finsler and Kahler geometry and geometric mechanics how they could
perform their results in order to be accepted by the community ''orthodox''
physicists. Although the bulk of former models of Finsler-Lagrange spaces where
elaborated on tangent bundles, the surprising result advocated in our works is
that such locally anisotropic structures can be modelled equivalently on
Riemann-Cartan spaces, even as exact solutions in Einstein and/or string
gravity, if nonholonomic distributions and moving frames of references are
introduced into consideration. We also propose a canonical scheme when
geometrical objects on a (pseudo) Riemannian space are nonholonomically
deformed into generalized Lagrange, or Finsler, configurations on the same
manifold or on a corresponding tangent bundle. Such canonical transforms are
defined by the coefficients of a prime metric (it can be a solution of the
Einstein equations) and generate target spaces as generalized Lagrange
structures, their models of almost Hermitian/ Kahler, or nonholonomic Riemann
spaces with constant curvature, for some Finsler like connections. There are
formulated the criteria when such constructions can be redefined equivalently
in terms of the Levi Civita connection.
| [
{
"version": "v1",
"created": "Wed, 11 Jul 2007 17:49:19 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Jul 2007 23:55:14 GMT"
},
{
"version": "v3",
"created": "Thu, 31 Jan 2008 19:40:59 GMT"
}
] | 2008-01-31T00:00:00 | [
[
"Vacaru",
"Sergiu I.",
""
]
] |
0707.1525 | Marco Fontana | Marco Fontana and K. Alan Loper | The patch topology and the ultrafilter topology on the prime spectrum of
a commutative ring | A Remark was added at the end of the paper. To appear in Comm.
Algebra | null | null | null | math.AC math.AG | null | Let R be a commutative ring and let Spec(R) denote the collection of prime
ideals of R. We define a topology on Spec(R) by using ultrafilters and
demonstrate that this topology is identical to the well known patch or
constructible topology. The proof is accomplished by use of a von Neumann
regular ring canonically associated with $R$.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 20:41:59 GMT"
},
{
"version": "v2",
"created": "Sun, 14 Oct 2007 11:21:12 GMT"
}
] | 2007-10-14T00:00:00 | [
[
"Fontana",
"Marco",
""
],
[
"Loper",
"K. Alan",
""
]
] |
0707.1526 | Sergiu Vacaru I. | Sergiu I. Vacaru | Generalized Lagrange Transforms: Finsler Geometry Methods and
Deformation Quantization of Gravity | latex 2e, 11pt, 17 pages, to be published: An. St. Univ. Al. I. Cuza,
Iasi, s I a, Matematica, vol LIII (suplement), 2007 | , An. St. Univ. Al. I. Cuza din Iasi (S.N.), Matematica, vol LIII,
2007, Supliment, 327-342 | null | null | gr-qc hep-th math-ph math.MP math.SG | null | We propose a natural Fedosov type quantization of generalized Lagrange models
and gravity theories with metrics lifted on tangent bundle, or extended to
higher dimension, following some stated geometric/ physical conditions (for
instance, nonholonomic and/or conformal transforms to some physically important
metrics or mapping into a gauge model). Such generalized Lagrange transforms
define canonical nonlinear connection, metric and linear connection structures
and model almost Kahler geometries with induced canonical symplectic structure
and compatible affine connection. The constructions are possible due to a
synthesis of the nonlinear connection formalism developed in Finsler and
Lagrange geometries and deformation quantization methods.
| [
{
"version": "v1",
"created": "Wed, 11 Jul 2007 17:55:49 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Oct 2007 18:41:28 GMT"
}
] | 2008-01-08T00:00:00 | [
[
"Vacaru",
"Sergiu I.",
""
]
] |
0707.1527 | Anya Tafliovich | Anya Tafliovich, Eric C.R. Hehner | Programming Telepathy: Implementing Quantum Non-Locality Games | null | null | null | null | quant-ph cs.PL | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Quantum pseudo-telepathy is an intriguing phenomenon which results from the
application of quantum information theory to communication complexity. To
demonstrate this phenomenon researchers in the field of quantum communication
complexity devised a number of quantum non-locality games. The setting of these
games is as follows: the players are separated so that no communication between
them is possible and are given a certain computational task. When the players
have access to a quantum resource called entanglement, they can accomplish the
task: something that is impossible in a classical setting. To an observer who
is unfamiliar with the laws of quantum mechanics it seems that the players
employ some sort of telepathy; that is, they somehow exchange information
without sharing a communication channel. This paper provides a formal framework
for specifying, implementing, and analysing quantum non-locality games.
| [
{
"version": "v1",
"created": "Wed, 11 Jul 2007 19:50:25 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Jul 2009 15:25:07 GMT"
}
] | 2009-07-29T00:00:00 | [
[
"Tafliovich",
"Anya",
""
],
[
"Hehner",
"Eric C. R.",
""
]
] |
0707.1528 | Ryan Epstein | R. J. Epstein, S. Seidelin, D. Leibfried, J. H. Wesenberg, J. J.
Bollinger, J. M. Amini, R. B. Blakestad, J. Britton, J. P. Home, W. M. Itano,
J. D. Jost, E. Knill, C. Langer, R. Ozeri, N. Shiga, and D. J. Wineland | Simplified motional heating rate measurements of trapped ions | null | Phys. Rev. A 76, 033411 (2007) | 10.1103/PhysRevA.76.033411 | null | quant-ph physics.atom-ph | null | We have measured motional heating rates of trapped atomic ions, a factor that
can influence multi-ion quantum logic gate fidelities. Two simplified
techniques were developed for this purpose: one relies on Raman sideband
detection implemented with a single laser source, while the second is even
simpler and is based on time-resolved fluorescence detection during Doppler
recooling. We applied these methods to determine heating rates in a
microfrabricated surface-electrode trap made of gold on fused quartz, which
traps ions 40 microns above its surface. Heating rates obtained from the two
techniques were found to be in reasonable agreement. In addition, the trap
gives rise to a heating rate of 300 plus or minus 30 per second for a motional
frequency of 5.25 MHz, substantially below the trend observed in other traps.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 21:20:09 GMT"
}
] | 2009-02-14T00:00:00 | [
[
"Epstein",
"R. J.",
""
],
[
"Seidelin",
"S.",
""
],
[
"Leibfried",
"D.",
""
],
[
"Wesenberg",
"J. H.",
""
],
[
"Bollinger",
"J. J.",
""
],
[
"Amini",
"J. M.",
""
],
[
"Blakestad",
"R. B.",
""
],
[
"Britton",
"J.",
""
],
[
"Home",
"J. P.",
""
],
[
"Itano",
"W. M.",
""
],
[
"Jost",
"J. D.",
""
],
[
"Knill",
"E.",
""
],
[
"Langer",
"C.",
""
],
[
"Ozeri",
"R.",
""
],
[
"Shiga",
"N.",
""
],
[
"Wineland",
"D. J.",
""
]
] |
0707.1529 | Alex Koshelev | L.N. Bulaevskii and A.E. Koshelev | Radiation Due to Josephson Oscillations in Layered Superconductors | 4 pages, 1 figure, to be published in Phys. Rev. Lett | Phys. Rev. Lett. 99, 057002 (2007) | 10.1103/PhysRevLett.99.057002 | null | cond-mat.supr-con cond-mat.mtrl-sci | null | We derive the power of direct radiation into free space induced by Josephson
oscillations in intrinsic Josephson junctions of highly anisotropic layered
superconductors. We consider the super-radiation regime for a crystal cut in
the form of a thin slice parallel to the c-axis. We find that the radiation
correction to the current-voltage characteristic in this regime depends only on
crystal shape. We show that at large enough number of junctions oscillations
are synchronized providing high radiation power and efficiency in the THz
frequency range. We discuss crystal parameters and bias current optimal for
radiation power and crystal cooling.
| [
{
"version": "v1",
"created": "Tue, 10 Jul 2007 21:36:19 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Bulaevskii",
"L. N.",
""
],
[
"Koshelev",
"A. E.",
""
]
] |
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