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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0704.2501 | Frank Lechermann | Frank Lechermann, Silke Biermann, Antoine Georges | Competing itinerant and localized states in strongly correlated BaVS$_3$ | 12 pages, submitted to PRB | Phys. Rev. B 76, 085101 (2007) | 10.1103/PhysRevB.76.085101 | null | cond-mat.str-el cond-mat.mtrl-sci | null | The electronic structure of the quasi-lowdimensional vanadium sulfide \bavs3
is investigated for the different phases above the magnetic ordering
temperature. By means of density functional theory and its combination with
dynamical-mean field theory, we follow the evolution of the relevant low-energy
electronic states on cooling. Hence we go in the metallic regime from the room
temperature hexagonal phase to the orthorhombic phase after the first
structural transition, and close with the monoclinic insulating phase below the
metal-insulator transition. Due to the low symmetry and expected intersite
correlations, the latter phase is treated within cellular dynamical mean-field
theory. It is generally discussed how the intriguing interplay between
band-structure and strong-correlation effects leads to the stabilization of the
various electronic phases with decreasing temperature.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 10:40:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lechermann",
"Frank",
""
],
[
"Biermann",
"Silke",
""
],
[
"Georges",
"Antoine",
""
]
] |
0704.2502 | Shuchi Gupta Ms | Narinder Kaur, K. Dharamvir and V. K. Jindal | Dimerization and Fusion of two C60 Molecules | 18 pages and 8 figures | null | 10.1016/j.chemphys.2007.12.023 | null | cond-mat.mtrl-sci | null | We investigate the dimerization and fusion of C60 molecules to form various
C60 dimers when pushed against each other at several inter-molecular distances.
We study the stability of this dimerized C60 molecule based on its binding
strength provided by intramolecular interactions. Tersoff potential, which is
considered to represent intramolecular interactions well, has been used to
calculate potential energy at these distances of separation and for all
possible orientations of the molecules. We observe that several minimum energy
configurations exist at various distances between the C60 molecules. Our
calculation shows that apart from the dumbbell structures, many interesting
composite phases also result, such as fused, peanut and carbon nanotubes of
geometry (5,5) and (10,0) of certain specific length.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 10:44:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kaur",
"Narinder",
""
],
[
"Dharamvir",
"K.",
""
],
[
"Jindal",
"V. K.",
""
]
] |
0704.2503 | V. Hinich | V. Hinich | Homotopy coherent nerve in Deformation theory | Title fixed. Title changed (the old title was "Another simplicial
nerve") Slightly revised | null | null | null | math.QA math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note we explain that homotopy coherent simplicial nerve has to used
intead of the standard definition in the author's papers on formal deformation
theory. A convenient version of the notion of fibered category is presented
which is useful once one works with simplicial categories.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 10:46:38 GMT"
},
{
"version": "v2",
"created": "Sun, 24 Jun 2007 13:18:21 GMT"
},
{
"version": "v3",
"created": "Fri, 13 Mar 2009 09:16:21 GMT"
},
{
"version": "v4",
"created": "Thu, 2 Jul 2015 06:50:14 GMT"
}
] | 2015-07-03T00:00:00 | [
[
"Hinich",
"V.",
""
]
] |
0704.2504 | Shuchi Gupta Ms | Narinder Kaur, Shuchi Gupta, Keya Dharamvir and V. K. Jindal | Behaviour of a Bucky-ball under Internal and External Pressures | 14 pages and 9 figures | null | null | null | cond-mat.mtrl-sci | null | We study the behaviour of the C60 molecule under very high internal or
external pressure using Tersoff as well as Brenner potentials. As a result, we
estimate the critical internal and external pressures that lead to its
instability. We also calculate stretching force constant and bulk modulus of
this molecule at several pressures under which the molecule remains stable. The
values of these estimated here at zero pressure agree closely with those
obtained in earlier calculations. We also observe that at high pressures, a
finite value of parameter of Tersoff potential gives physically acceptable
results in contrast to its value zero, which is usually taken for the carbon
systems.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 10:53:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kaur",
"Narinder",
""
],
[
"Gupta",
"Shuchi",
""
],
[
"Dharamvir",
"Keya",
""
],
[
"Jindal",
"V. K.",
""
]
] |
0704.2505 | G.Susinder Rajan | G. Susinder Rajan and B. Sundar Rajan | Algebraic Distributed Space-Time Codes with Low ML Decoding Complexity | 5 pages, no figures. To appear in Proceedings of IEEE ISIT 2007,
Nice, France | null | 10.1109/ISIT.2007.4557437 | null | cs.IT cs.DM math.IT | null | "Extended Clifford algebras" are introduced as a means to obtain low ML
decoding complexity space-time block codes. Using left regular matrix
representations of two specific classes of extended Clifford algebras, two
systematic algebraic constructions of full diversity Distributed Space-Time
Codes (DSTCs) are provided for any power of two number of relays. The left
regular matrix representation has been shown to naturally result in space-time
codes meeting the additional constraints required for DSTCs. The DSTCs so
constructed have the salient feature of reduced Maximum Likelihood (ML)
decoding complexity. In particular, the ML decoding of these codes can be
performed by applying the lattice decoder algorithm on a lattice of four times
lesser dimension than what is required in general. Moreover these codes have a
uniform distribution of power among the relays and in time, thus leading to a
low Peak to Average Power Ratio at the relays.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:05:31 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Rajan",
"G. Susinder",
""
],
[
"Rajan",
"B. Sundar",
""
]
] |
0704.2506 | Paul Tod | Paul Tod | Isotropic cosmological singularities in spatially-homogeneous models
with a cosmological constant | 22 pages; | Class.Quant.Grav.24:2415-2432,2007 | 10.1088/0264-9381/24/9/017 | null | gr-qc | null | We prove well-posedness of the initial value problem for the Einstein
equations for spatially-homogeneous cosmologies with data at an isotropic
cosmological singularity, for which the matter content is either a cosmological
constant with collisionless particles of a single mass (possibly zero) or a
cosmological constant with a perfect fluid having the radiation equation of
state. In both cases, with a positive cosmological constant, these solutions,
except possibly for Bianchi-type-IX, will expand forever, and be
geodesically-complete into the future.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:11:20 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Tod",
"Paul",
""
]
] |
0704.2507 | G.Susinder Rajan | G. Susinder Rajan and B. Sundar Rajan | STBCs from Representation of Extended Clifford Algebras | 5 pages, no figures, To appear in Proceedings of IEEE ISIT 2007,
Nice, France | null | 10.1109/ISIT.2007.4557141 | null | cs.IT cs.DM math.IT | null | A set of sufficient conditions to construct $\lambda$-real symbol Maximum
Likelihood (ML) decodable STBCs have recently been provided by Karmakar et al.
STBCs satisfying these sufficient conditions were named as Clifford Unitary
Weight (CUW) codes. In this paper, the maximal rate (as measured in complex
symbols per channel use) of CUW codes for $\lambda=2^a,a\in\mathbb{N}$ is
obtained using tools from representation theory. Two algebraic constructions of
codes achieving this maximal rate are also provided. One of the constructions
is obtained using linear representation of finite groups whereas the other
construction is based on the concept of right module algebra over
non-commutative rings. To the knowledge of the authors, this is the first paper
in which matrices over non-commutative rings is used to construct STBCs. An
algebraic explanation is provided for the 'ABBA' construction first proposed by
Tirkkonen et al and the tensor product construction proposed by Karmakar et al.
Furthermore, it is established that the 4 transmit antenna STBC originally
proposed by Tirkkonen et al based on the ABBA construction is actually a single
complex symbol ML decodable code if the design variables are permuted and
signal sets of appropriate dimensions are chosen.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:16:40 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Rajan",
"G. Susinder",
""
],
[
"Rajan",
"B. Sundar",
""
]
] |
0704.2508 | Paul Tod | Paul Tod | Analyticity of strictly static and strictly stationary, inheriting and
non-inheriting Einstein-Maxwell solutions | 11 pages; to appear in Gen.Rel.Grav | Gen.Rel.Grav.39:1031-1042,2007 | 10.1007/s10714-007-0436-0 | null | gr-qc | null | Following the technique of M\"uller-zum-Hagen, refs [1,2], we show that
strictly static and strictly stationary solutions of the Einstein-Maxwell
equations are analytic in harmonic coordinates. This holds whether or not the
Maxwell field inherits the symmetry.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:23:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Tod",
"Paul",
""
]
] |
0704.2509 | G.Susinder Rajan | G. Susinder Rajan and B. Sundar Rajan | Signal Set Design for Full-Diversity Low-Decoding-Complexity
Differential Scaled-Unitary STBCs | 5 pages, 2 figures. To appear in Proceedings of IEEE ISIT 2007, Nice,
France | null | 10.1109/ISIT.2007.4557453 | null | cs.IT math.IT | null | The problem of designing high rate, full diversity noncoherent space-time
block codes (STBCs) with low encoding and decoding complexity is addressed.
First, the notion of $g$-group encodable and $g$-group decodable linear STBCs
is introduced. Then for a known class of rate-1 linear designs, an explicit
construction of fully-diverse signal sets that lead to four-group encodable and
four-group decodable differential scaled unitary STBCs for any power of two
number of antennas is provided. Previous works on differential STBCs either
sacrifice decoding complexity for higher rate or sacrifice rate for lower
decoding complexity.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:25:23 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Rajan",
"G. Susinder",
""
],
[
"Rajan",
"B. Sundar",
""
]
] |
0704.2510 | Marcus Aguiar de | A. D. Ribeiro and M. A. M. de Aguiar | Controlling Phase Space Caustics in the Semiclassical Coherent State
Propagator | 24 pages, to appear in Ann. of Phys | Annals of Physics 323, 654-672 (2008) | 10.1016/j.aop.2007.04.008 | null | quant-ph | null | The semiclassical formula for the quantum propagator in the coherent state
representation $<\mathbf{z}'' | e^{-i\hat{H}T/\hbar} | \mathbf{z}'>$ is not
free from the problem of caustics. These are singular points along the complex
classical trajectories specified by $\mathbf{z}'$, $\mathbf{z}''$ and $T$ where
the usual quadratic approximation fails, leading to divergences in the
semiclassical formula. In this paper we derive third order approximations for
this propagator that remain finite in the vicinity of caustics. We use Maslov's
method and the dual representation proposed in Phys. Rev. Lett. {\bf 95},
050405 (2005) to derive uniform, regular and transitional semiclassical
approximations for coherent state propagator in systems with two degrees of
freedom.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:28:24 GMT"
}
] | 2008-03-03T00:00:00 | [
[
"Ribeiro",
"A. D.",
""
],
[
"de Aguiar",
"M. A. M.",
""
]
] |
0704.2511 | G.Susinder Rajan | G. Susinder Rajan and B. Sundar Rajan | Noncoherent Low-Decoding-Complexity Space-Time Codes for Wireless Relay
Networks | 5 pages, no figures. To appear in Proceedings of IEEE ISIT 2007,
Nice, France | null | 10.1109/ISIT.2007.4557438 | null | cs.IT math.IT | null | The differential encoding/decoding setup introduced by Kiran et al, Oggier et
al and Jing et al for wireless relay networks that use codebooks consisting of
unitary matrices is extended to allow codebooks consisting of scaled unitary
matrices. For such codebooks to be used in the Jing-Hassibi protocol for
cooperative diversity, the conditions that need to be satisfied by the relay
matrices and the codebook are identified. A class of previously known rate one,
full diversity, four-group encodable and four-group decodable Differential
Space-Time Codes (DSTCs) is proposed for use as Distributed DSTCs (DDSTCs) in
the proposed set up. To the best of our knowledge, this is the first known low
decoding complexity DDSTC scheme for cooperative wireless networks.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:28:49 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Rajan",
"G. Susinder",
""
],
[
"Rajan",
"B. Sundar",
""
]
] |
0704.2512 | David Ploog | Georg Hein, David Ploog | Postnikov-Stability for Complexes | 19 pages | null | null | null | math.AG | null | We present a novel notion of stable objects in the derived category of
coherent sheaves on a smooth projective variety. As one application we
compactify a moduli space of stable bundles using genuine complexes.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:31:23 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hein",
"Georg",
""
],
[
"Ploog",
"David",
""
]
] |
0704.2513 | L\'or\'ant Farkas | L. Farkas | Reaching the Holevo Capacity via von Neumann measurement, and its use | 19 pages | null | null | null | quant-ph | null | In this article we show that the Holevo capacity of a classical quantum
channel, can be reached not only by a POVM but by von Neumann measurement too.
Furthermore we show two use of this fact 1) We can generalize the classical
compound channel to quantum environment and with this new measure technique we
can give an optimal coding/decoding algorithm to it. 2) We give an algorithm,
with it a classical system can be decoded by quantum apparatus in linear time,
which is a surprising result, because best known optimal classical decoding
algorithm need n*log(n) time. This means that if a quantum machine can perform
arbitrarily von Neumann measurement with only two possible outcome, then it can
solve non-polynomial classical problems in linear time.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 11:47:09 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 11:37:01 GMT"
},
{
"version": "v3",
"created": "Tue, 31 Jul 2007 16:01:25 GMT"
},
{
"version": "v4",
"created": "Wed, 1 Aug 2007 07:17:08 GMT"
}
] | 2007-08-01T00:00:00 | [
[
"Farkas",
"L.",
""
]
] |
0704.2514 | Ana Arriaga | A. Arriaga and R. Schiavilla | A relativistic calculation of the deuteron threshold
electrodisintegration at backward angles | 6 figures | Phys.Rev.C76:014007,2007 | 10.1103/PhysRevC.76.014007 | null | nucl-th | null | The threshold electrodisintegration of the deuteron at backward angles is
studied with a relativistic Hamiltonian, including a relativistic
one-pion-exchange potential (OPEP) with off-shell terms as predicted by
pseudovector coupling of pions to nucleons. The bound and scattering states are
obtained in the center-of-mass frame, and then boosted from it to the Breit
frame, where the evaluation of the relevant matrix elements of the
electromagnetic current operator is carried out. The latter includes, in
addition to one-body, also two-body terms due to pion exchange, as obtained,
consistently with the OPEP, in pseudovector pion-nucleon coupling theory. The
full Lorentz structure of these currents is retained. In order to estimate the
magnitude of the relativistic effects we perform, for comparison, the
calculation with a non-relativistic phase-equivalent Hamiltonian and the
standard non-relativistic expressions for the one-body and two-body
pion-exchange currents. Our results for the electrodisintegration cross section
show that, in the calculations using one-body currents, relativistic
corrections become significant ({\it i.e.}, larger than 10%) only at high
momentum transfer $Q$ ($Q^2 \simeq 40$fm$^{-2}$ and beyond). However, the
inclusion of two-body currents makes the relativistic predictions considerably
smaller than the corresponding non-relativistic results in the $Q^2$ region
(18--40) fm$^{-2}$. The calculations based on the relativistic model also
confirm the inadequacy, already established in a non-relativistic context, of
the present electromagnetic current model to reproduce accurately the
experimental data at intermediate values of momentum transfers.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 12:05:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Arriaga",
"A.",
""
],
[
"Schiavilla",
"R.",
""
]
] |
0704.2515 | Lari Tommaso | U. De Sanctis, T. Lari, S. Montesano, C. Troncon | Perspectives for the detection and measurement of Supersymmetry in the
focus point region of mSUGRA models with the ATLAS detector at LHC | null | Eur.Phys.J.C52:743-758,2007 | 10.1140/epjc/s10052-007-0415-3 | ATLAS Scientific Note SN-ATLAS-2007-062 | hep-ex | null | This paper discusses the ATLAS potential to study Supersymmetry for the
"Focus-Point" region of the parameter space of mSUGRA models. The potential to
discovery a deviation from Standard Model expectations with the first few
${fb}^{-1}$ of LHC data was studied using the parametrized simulation of the
ATLAS detector. Several signatures were considered, involving hard jets, large
missing energy, and either $b$-tagged jets, opposite-sign isolated electron or
muon pairs, or top quarks reconstructed exploiting their fully hadronic decays.
With only 1 ${fb}^{-1}$ of data each of these signatures may allow to observe
an excess of events over Standard Model expectation with a statistical
significance exceeding 5 standard deviations. An analytical expression was
derived for the shape of the distribution of the dilepton invariant mass
arising from the three-body leptonic decay of the neutralinos under the
hypothesis of heavy scalars, which is appropriate for the focus-point scenario.
The resulting function was used to fit the distribution of the dilepton
invariant mass obtained with simulated LHC data, and to extract the value of
two kinematic endpoints measuring the $\tilde \chi^0_2 - \tilde \chi^0_1$ and
the $\tilde \chi^0_3 - \tilde \chi^0_1$ mass differences. This information was
used to constrain the MSSM parameter space compatible with the data.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 12:10:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"De Sanctis",
"U.",
""
],
[
"Lari",
"T.",
""
],
[
"Montesano",
"S.",
""
],
[
"Troncon",
"C.",
""
]
] |
0704.2516 | Yuval Ginosar | Nir Ben David and Yuval Ginosar | On groups of central type, non-degenerate and bijective cohomology
classes | 13 pages | null | null | null | math.GR | null | A finite group $G$ is of central type (in the non-classical sense) if it
admits a non-degenerate cohomology class $[c]\in H^2(G,\C^*)$ ($G$ acts
trivially on $\C^*$). Groups of central type play a fundamental role in the
classification of semisimple triangular complex Hopf algebras and can be
determined by their representation theoretical properties.
Suppose that a finite group $Q$ acts on an abelian group $A$ so that there
exists a bijective 1-cocycle $\pi\in Z^1(Q,\ach)$, where
$\ach=\rm{Hom}(A,\C^*)$ is endowed with the diagonal $Q$-action. Under this
assumption, Etingof and Gelaki gave an explicit formula for a non-degenerate
2-cocycle in $Z^2(G,\C^*)$, where $G:=A\rtimes Q$. Hence, the semidirect
product $G$ is of central type.
In this paper we present a more general correspondence between bijective and
non-degenerate cohomology classes. In particular, given a bijective class
$[\pi]\in H^1(Q,\ach)$ as above, we construct non-degenerate classes
$[c_{\pi}]\in H^2(G,\C^*)$ for certain extensions $1\to A\to G\to Q\to 1$ which
are not necessarily split. We thus strictly extend the above family of central
type groups.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 12:27:02 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"David",
"Nir Ben",
""
],
[
"Ginosar",
"Yuval",
""
]
] |
0704.2517 | Florin Spineanu | Radu Balescu | V-Langevin Equations, Continuous Time Random Walks and Fractional
Diffusion | Latex 69 pages including 23 EPS figures | null | 10.1016/j.chaos.2007.01.050 | null | physics.plasm-ph physics.data-an | null | The following question is addressed: under what conditions can a strange
diffusive process, defined by a semi-dynamical V-Langevin equation or its
associated Hybrid kinetic equation (HKE), be described by an equivalent purely
stochastic process, defined by a Continuous Time Random Walk (CTRW) or by a
Fractional Differential Equation (FDE)? More specifically, does there exist a
class of V-Langevin equations with long-range (algebraic) velocity temporal
correlation, that leads to a time-fractional superdiffusive process? The answer
is always affirmative in one dimension. It is always negative in two
dimensions: any algebraically decaying temporal velocity correlation (with a
Gaussian spatial correlation) produces a normal diffusive process. General
conditions relating the diffusive nature of the process to the temporal
exponent of the Lagrangian velocity correlation (in Corrsin approximation) are
derived.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 12:36:42 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Balescu",
"Radu",
""
]
] |
0704.2518 | Jing Qin | Emma Y. Jin, Jing Qin and Christian M. Reidys | Combinatorics Of RNA Structures With Pseudoknots | 24 pages, 7 figures | null | null | null | math.CO math.GM | null | In this paper we derive the generating function of RNA structures with
pseudoknots. We enumerate all $k$-noncrossing RNA pseudoknot structures
categorized by their maximal sets of mutually intersecting arcs. In addition we
enumerate pseudoknot structures over circular RNA. For 3-noncrossing RNA
structures and RNA secondary structures we present a novel 4-term recursion
formula and a 2-term recursion, respectively. Furthermore we enumerate for
arbitrary $k$ all $k$-noncrossing, restricted RNA structures i.e.
$k$-noncrossing RNA structures without 2-arcs i.e. arcs of the form $(i,i+2)$,
for $1\le i\le n-2$.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 12:42:39 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Jin",
"Emma Y.",
""
],
[
"Qin",
"Jing",
""
],
[
"Reidys",
"Christian M.",
""
]
] |
0704.2519 | Igor Pshenichnov | Igor Pshenichnov (Frankfurt U., FIAS and INR, Moscow), Igor Mishustin
(Frankfurt U., FIAS and Kurchatov Inst., Moscow), Walter Greiner (Frankfurt
U., FIAS) | Comparative study of depth-dose distributions for beams of light and
heavy nuclei in tissue-like media | 4 pages, 3 figures | Nucl. Inst. & Meth. Phys. Res. Sec. B 266 (2008) 1094-1098 | 10.1016/j.nimb.2008.02.025 | null | physics.med-ph | null | We study the energy deposition by light and heavy nuclei in tissue-like media
as used for cancer therapy. The depth-dose distributions for protons, $^{3}$He,
$^{12}$C, $^{20}$Ne, and $^{58}$Ni nuclei are calculated within a Monte Carlo
model based on the GEANT4 toolkit. These distributions are compared with each
other and with available experimental data. It is demonstrated that nuclear
fragmentation reactions essentially reduce the peak-to-plateau ratio of the
dose profiles for deeply penetrating energetic ions heavier than $^{3}$He. On
the other hand, all projectiles up to $^{20}$Ne were found equally suitable for
therapeutic use at low penetration depths.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 12:43:21 GMT"
}
] | 2010-11-03T00:00:00 | [
[
"Pshenichnov",
"Igor",
"",
"Frankfurt U., FIAS and INR, Moscow"
],
[
"Mishustin",
"Igor",
"",
"Frankfurt U., FIAS and Kurchatov Inst., Moscow"
],
[
"Greiner",
"Walter",
"",
"Frankfurt\n U., FIAS"
]
] |
0704.2520 | Shin'ichi Nojiri | Shin'ichi Nojiri, Sergei D. Odintsov, and Petr V. Tretyakov | Dark energy from modified F(R)-scalar-Gauss-Bonnet gravity | LaTeX, 8 pages, no figure, refs. added, version to appear in Physics
Letters B | Phys.Lett.B651:224-231,2007 | 10.1016/j.physletb.2007.06.029 | null | hep-th astro-ph gr-qc | null | The modified F(R)-scalar-Gauss-Bonnet gravity is proposed as dark energy
model. The reconstruction program for such theory is developed. It is
explicitly demonstrated that the known classical universe expansion history
(deceleration epoch, transition to acceleration and effective quintessence,
phantom or cosmological constant era) may naturally occur in such unified
theory for some (reconstructed) classes of scalar potentials. Gauss-Bonnet
assisted dark energy is also proposed. The possibility of cosmic acceleration
is studied there.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:20:23 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Apr 2007 02:23:59 GMT"
},
{
"version": "v3",
"created": "Wed, 13 Jun 2007 00:52:08 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nojiri",
"Shin'ichi",
""
],
[
"Odintsov",
"Sergei D.",
""
],
[
"Tretyakov",
"Petr V.",
""
]
] |
0704.2521 | Dirk Frettl\"oh | Dirk Frettl\"oh | Substitution tilings with statistical circular symmetry | 15 pages, 5 figures | null | null | null | math.MG | null | Two new series of substitution tilings are introduced in which the tiles
appear in infinitely many orientations. It is shown that several properties of
the well-known pinwheel tiling do also hold for these new examples, and, in
fact, for all substitution tilings showing tiles in infinitely many
orientations.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:09:22 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Frettlöh",
"Dirk",
""
]
] |
0704.2522 | Gerard Henry Edmond Duchamp | G\'erard Henry Edmond Duchamp (LIPN), Pawel Blasiak, Andrzej Horzela,
Karol A. Penson (LPTMC), Allan I. Solomon | A Three Parameter Hopf Deformation of the Algebra of Feynman-like
Diagrams | null | null | null | null | math-ph math.MP | null | We construct a three-parameter deformation of the Hopf algebra $\LDIAG$. This
is the algebra that appears in an expansion in terms of Feynman-like diagrams
of the {\em product formula} in a simplified version of Quantum Field Theory.
This new algebra is a true Hopf deformation which reduces to $\LDIAG$ for some
parameter values and to the algebra of Matrix Quasi-Symmetric Functions
($\MQS$) for others, and thus relates $\LDIAG$ to other Hopf algebras of
contemporary physics. Moreover, there is an onto linear mapping preserving
products from our algebra to the algebra of Euler-Zagier sums.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 12:55:27 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Sep 2007 15:38:18 GMT"
}
] | 2007-09-04T00:00:00 | [
[
"Duchamp",
"Gérard Henry Edmond",
"",
"LIPN"
],
[
"Blasiak",
"Pawel",
"",
"LPTMC"
],
[
"Horzela",
"Andrzej",
"",
"LPTMC"
],
[
"Penson",
"Karol A.",
"",
"LPTMC"
],
[
"Solomon",
"Allan I.",
""
]
] |
0704.2523 | Gervasi Herranz | G. Herranz, M. Basletic, M. Bibes, C. Carretero, E. Tafra, E. Jacquet,
K. Bouzehouane, C. Deranlot, A. Hamzic, J.-M. Broto, A. Barthelemy, and A.
Fert | High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality
and Perspectives | 4 pages, 4 figures. Accepted for publication in Phys. Rev. Lett | null | 10.1103/PhysRevLett.98.216803 | null | cond-mat.mtrl-sci cond-mat.str-el | null | We have investigated the dimensionality and origin of the magnetotransport
properties of LaAlO3 films epitaxially grown on TiO2-terminated SrTiO3(001)
substrates. High mobility conduction is observed at low deposition oxygen
pressures (PO2 < 10^-5 mbar) and has a three-dimensional character. However, at
higher PO2 the conduction is dramatically suppressed and nonmetallic behavior
appears. Experimental data strongly support an interpretation of these
properties based on the creation of oxygen vacancies in the SrTiO3 substrates
during the growth of the LaAlO3 layer. When grown on SrTiO3 substrates at low
PO2, other oxides generate the same high mobility as LaAlO3 films. This opens
interesting prospects for all-oxide electronics.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:09:33 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Herranz",
"G.",
""
],
[
"Basletic",
"M.",
""
],
[
"Bibes",
"M.",
""
],
[
"Carretero",
"C.",
""
],
[
"Tafra",
"E.",
""
],
[
"Jacquet",
"E.",
""
],
[
"Bouzehouane",
"K.",
""
],
[
"Deranlot",
"C.",
""
],
[
"Hamzic",
"A.",
""
],
[
"Broto",
"J. -M.",
""
],
[
"Barthelemy",
"A.",
""
],
[
"Fert",
"A.",
""
]
] |
0704.2524 | Pierre Py | Pierre Py (UMPA-Ensl) | Quelques plats pour la m\'etrique de Hofer | 9 pages, minor changes | Journal f\"ur die Reine und Angewandte Mathematik 2008, 620 (2008)
185--193 | 10.1515/CRELLE.2008.053 | null | math.DG math.GR math.GT math.SG | null | We show, by an elementary and explicit construction, that the group of
Hamiltonian diffeomorphisms of certain symplectic manifolds, endowed with
Hofer's metric, contains subgroups quasi-isometric to Euclidean spaces of
arbitrary dimension.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:09:33 GMT"
},
{
"version": "v2",
"created": "Wed, 2 May 2007 07:15:47 GMT"
},
{
"version": "v3",
"created": "Wed, 22 Aug 2007 13:04:35 GMT"
}
] | 2008-09-09T00:00:00 | [
[
"Py",
"Pierre",
"",
"UMPA-Ensl"
]
] |
0704.2525 | Andrew Levan | A.J. Levan, P. Jakobsson, C. Hurkett, N.R. Tanvir, J. Gorosabel, P.
Vreeswijk, E. Rol, R. Chapman, N. Gehrels, P.T. O'Brien, J.P. Osborne, R.S.
Priddey, C. Kouveliotou, R. Starling, D. Vanden Berk, K. Wiersema | A case of mistaken identity? GRB 060912A and the nature of the long --
short GRB divide | 9 pages, 5 figures, accepted for publication in MNRAS | Mon.Not.Roy.Astron.Soc.378:1439-1446,2007 | 10.1111/j.1365-2966.2007.11879.x | null | astro-ph | null | We investigate the origin of the GRB 060912A, which has observational
properties that make its classification as either a long or short burst
ambiguous. Short duration GRBs (SGRBs) are thought to have typically lower
energies than long duration bursts, can be found in galaxies with populations
of all ages and are likely to originate from different progenitors to the long
duration bursts. However, it has become clear that duration alone is
insufficient to make a distinction between the two populations in many cases,
leading to a desire to find additional discriminators of burst type. GRB
060912A had a duration of 6 s and occurred only ~10 arcsec from a bright, low
redshift ($z=0.0936$) elliptical galaxy, suggesting that this may have been the
host, which would favour it being a short-burst. However, our deep optical
imaging and spectroscopy of the location of GRB 060912A using the VLT shows
that GRB 060912A more likely originates in a distant star forming galaxy at
z=0.937, and is most likely a long burst. This demonstrates the risk in
identifying bright, nearby galaxies as the hosts of given GRBs without further
supporting evidence. Further, it implies that, in the absence of secure
identifications, "host" type, or more broadly discriminators which rely on
galaxy redshifts, may not be good indicators of the true nature of any given
GRB.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:10:47 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Levan",
"A. J.",
""
],
[
"Jakobsson",
"P.",
""
],
[
"Hurkett",
"C.",
""
],
[
"Tanvir",
"N. R.",
""
],
[
"Gorosabel",
"J.",
""
],
[
"Vreeswijk",
"P.",
""
],
[
"Rol",
"E.",
""
],
[
"Chapman",
"R.",
""
],
[
"Gehrels",
"N.",
""
],
[
"O'Brien",
"P. T.",
""
],
[
"Osborne",
"J. P.",
""
],
[
"Priddey",
"R. S.",
""
],
[
"Kouveliotou",
"C.",
""
],
[
"Starling",
"R.",
""
],
[
"Berk",
"D. Vanden",
""
],
[
"Wiersema",
"K.",
""
]
] |
0704.2526 | Ralf Hofmann | Francesco Giacosa and Ralf Hofmann | Nonperturbative screening of the Landau pole | 11 pages, 3 figures | Phys.Rev.D77:065022,2008 | 10.1103/PhysRevD.77.065022 | KA-TP-09-2007 | hep-th | null | Based on the trace anomaly for the energy-momentum tensor, an effective
theory for the thermodynamics of the deconfining phase, and by assuming the
asymptotic behavior to be determined by one-loop perturbation theory we compute
the nonperturbative beta function for the fundamental coupling $g$ in SU(2) and
SU(3) Yang-Mills theory. With increasing temperature we observe a very rapid
approach to the perturbative running. The Landau pole is nonperturbatively
screened.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:12:58 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Giacosa",
"Francesco",
""
],
[
"Hofmann",
"Ralf",
""
]
] |
0704.2527 | Virgil Pierce | V. U. Pierce and Fei-Ran Tian | Self-Similar Solutions of the Non-Strictly Hyperbolic Whitham Equations
for the KdV Hierarchy | 31 pages, 1 figure | null | null | null | nlin.SI math.AP | null | We study the Whitham equations for all the higher order KdV equations. The
Whitham equations are neither strictly hyperbolic nor genuinely nonlinear. We
are interested in the solution of the Whitham equations when the initial values
are given by a step function.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:13:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Pierce",
"V. U.",
""
],
[
"Tian",
"Fei-Ran",
""
]
] |
0704.2528 | Dirk Frettl\"oh | Dirk Frettl\"oh | Self-dual tilings with respect to star-duality | 15 pages, 6 figures | null | null | null | math.MG | null | The concept of star-duality is described for self-similar cut-and-project
tilings in arbitrary dimensions. This generalises Thurston's concept of a
Galois-dual tiling. The dual tilings of the Penrose tilings as well as the
Ammann-Beenker tilings are calculated. Conditions for a tiling to be self-dual
are obtained.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:18:14 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Frettlöh",
"Dirk",
""
]
] |
0704.2529 | Simon Gr\"oblacher | Simon Groeblacher, Tomasz Paterek, Rainer Kaltenbaek, Caslav Brukner,
Marek Zukowski, Markus Aspelmeyer, Anton Zeilinger | An experimental test of non-local realism | Minor corrections to the manuscript, the final inequality and all its
conclusions do not change; description of corrections (Corrigendum) added as
new Appendix III; Appendix II replaced by a shorter derivation | Nature 446, 871-875 (2007) | 10.1038/nature05677 | null | quant-ph | null | Most working scientists hold fast to the concept of 'realism' - a viewpoint
according to which an external reality exists independent of observation. But
quantum physics has shattered some of our cornerstone beliefs. According to
Bell's theorem, any theory that is based on the joint assumption of realism and
locality (meaning that local events cannot be affected by actions in space-like
separated regions) is at variance with certain quantum predictions. Experiments
with entangled pairs of particles have amply confirmed these quantum
predictions, thus rendering local realistic theories untenable. Maintaining
realism as a fundamental concept would therefore necessitate the introduction
of 'spooky' actions that defy locality. Here we show by both theory and
experiment that a broad and rather reasonable class of such non-local realistic
theories is incompatible with experimentally observable quantum correlations.
In the experiment, we measure previously untested correlations between two
entangled photons, and show that these correlations violate an inequality
proposed by Leggett for non-local realistic theories. Our result suggests that
giving up the concept of locality is not sufficient to be consistent with
quantum experiments, unless certain intuitive features of realism are
abandoned.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:22:57 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Aug 2007 18:45:40 GMT"
}
] | 2007-08-06T00:00:00 | [
[
"Groeblacher",
"Simon",
""
],
[
"Paterek",
"Tomasz",
""
],
[
"Kaltenbaek",
"Rainer",
""
],
[
"Brukner",
"Caslav",
""
],
[
"Zukowski",
"Marek",
""
],
[
"Aspelmeyer",
"Markus",
""
],
[
"Zeilinger",
"Anton",
""
]
] |
0704.2530 | Brad Safnuk | Brad Safnuk | Integration on moduli spaces of stable curves through localization | 11 pages | null | null | null | math.DG math.AG | null | We introduce a new method of calculating intersections on \bar{M}_{g,n},
using localization of equivariant cohomology. As an application, we give a
proof of Mirzakhani's recursion relation for calculating intersections of mixed
psi and kappa_1 classes.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:23:00 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Safnuk",
"Brad",
""
]
] |
0704.2531 | Matteo Ciccotti | M. Ciccotti, M. George, V. Ranieri, L. Wondraczek and C. Marliere | Dynamic condensation of water at crack tips in fused silica glass | Accepted in JNCS. In press | null | 10.1016/j.jnoncrysol.2007.06.090 | null | cond-mat.mtrl-sci | null | Water molecules play a fundamental role in the physics of slow crack
propagation in glasses. It is commonly understood that, during
stress-corrosion, water molecules that move in the crack cavity effectively
reduce the bond strength at the strained crack tip and, thus, support crack
propagation. Yet the details of the environmental condition at the crack tip in
moist air are not well determined. In a previous work, we reported direct
evidence of the presence of a 100 nm long liquid condensate at the crack tip in
fused silica glass during very slow crack propagation (10^-9 to 10^-10 m/s).
These observations are based on in-situ AFM phase imaging techniques applied on
DCDC glass specimens in controlled atmosphere. Here, we discuss the physical
origin of the AFM phase contrast between the liquid condensate and the glass
surface in relation to tip-sample adhesion induced by capillary bridges. We
then report new experimental data on the water condensation length increase
with relative humidity in the atmosphere. The measured condensation lengths
were much larger than what predicted using the Kelvin equation and expected
geometry of the crack tip.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:31:14 GMT"
},
{
"version": "v2",
"created": "Sat, 21 Apr 2007 12:54:17 GMT"
},
{
"version": "v3",
"created": "Mon, 18 Jun 2007 11:00:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ciccotti",
"M.",
""
],
[
"George",
"M.",
""
],
[
"Ranieri",
"V.",
""
],
[
"Wondraczek",
"L.",
""
],
[
"Marliere",
"C.",
""
]
] |
0704.2532 | Aaron Boley | Aaron C. Boley, Richard H. Durisen, Aake Nordlund, Jesse Lord | 3D Radiative Hydrodynamics for Disk Stability Simulations: A Proposed
Testing Standard and New Results | Submitted to ApJ | Astrophys.J.665:1254-1267,2007 | 10.1086/519767 | null | astro-ph | null | Recent three-dimensional radiative hydrodynamics simulations of
protoplanetary disks report disparate disk behaviors, and these differences
involve the importance of convection to disk cooling, the dependence of disk
cooling on metallicity, and the stability of disks against fragmentation and
clump formation. To guarantee trustworthy results, a radiative physics
algorithm must demonstrate the capability to handle both the high and low
optical depth regimes. We develop a test suite that can be used to demonstrate
an algorithm's ability to relax to known analytic flux and temperature
distributions, to follow a contracting slab, and to inhibit or permit
convection appropriately. We then show that the radiative algorithm employed by
Meji\'a (2004) and Boley et al. (2006) and the algorithm employed by Cai et al.
(2006) and Cai et al. (2007, in prep.) pass these tests with reasonable
accuracy. In addition, we discuss a new algorithm that couples flux-limited
diffusion with vertical rays, we apply the test suite, and we discuss the
results of evolving the Boley et al. (2006) disk with this new routine.
Although the outcome is significantly different in detail with the new
algorithm, we obtain the same qualitative answers. Our disk does not cool fast
due to convection, and it is stable to fragmentation. We find an effective
$\alpha\approx 10^{-2}$. In addition, transport is dominated by low-order
modes.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:42:24 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Boley",
"Aaron C.",
""
],
[
"Durisen",
"Richard H.",
""
],
[
"Nordlund",
"Aake",
""
],
[
"Lord",
"Jesse",
""
]
] |
0704.2533 | Frank Schweitzer | Frank Schweitzer | Multi-Agent Approach to the Self-Organization of Networks | 20 papges, to appear in: F. Reed-Tsochas, N. F. Johnson, J.
Efstathiou: Understanding and Managing Complex Agent-Based Dynamical
Networks, Singapore: World Scientific (2007) | null | null | null | nlin.AO physics.bio-ph q-bio.QM | null | Is it possible to link a set of nodes without using preexisting positional
information or any kind of long-range attraction of the nodes? Can the process
of generating positional information, i.e. the detection of ``unknown'' nodes
and the estabishment of chemical gradients, \emph{and} the process of network
formation, i.e. the establishment of links between nodes, occur in parallel, on
a comparable time scale, as a process of co-evolution?
The paper discusses a model where the generation of relevant information for
establishing the links between nodes results from the interaction of many
\emph{agents}, i.e. subunits of the system that are capable of performing some
activities. Their collective interaction is based on (indirect) communication,
which also includes memory effects and the dissemination of information in the
system. The relevant (``pragmatic'') information that leads to the
establishment of the links then emerges from an evolutionary interplay of
selection and reamplification.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:53:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Schweitzer",
"Frank",
""
]
] |
0704.2534 | Guido Gentile | Guido Gentile and Michela Procesi | Periodic solutions for the Schroedinger equation with nonlocal smoothing
nonlinearities in higher dimension | 60 pages 8 figures | Journal of Differential Equations 245 (2008), no. 11, 3095-3544 | null | null | math.AP math.DS | null | We consider the nonlinear Schroedinger equation in higher dimension with
Dirichlet boundary conditions and with a non-local smoothing nonlinearity. We
prove the existence of small amplitude periodic solutions. In the fully
resonant case we find solutions which at leading order are wave packets, in the
sense that they continue linear solutions with an arbitrarily large number of
resonant modes. The main difficulty in the proof consists in solving a "small
divisor problem" which we do by using a renormalisation group approach.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 13:53:35 GMT"
}
] | 2014-03-24T00:00:00 | [
[
"Gentile",
"Guido",
""
],
[
"Procesi",
"Michela",
""
]
] |
0704.2535 | Anna Bonaldi | A. Bonaldi, G. Tormen, K. Dolag, L. Moscardini | Sunyaev-Zel'dovich profiles and scaling relations: modelling effects and
observational biases | 13 pages, 12 figures, accepted by MNRAS | Mon.Not.Roy.Astron.Soc.378:1248-1258,2007 | 10.1111/j.1365-2966.2007.11893.x | null | astro-ph | null | We use high-resolution hydrodynamic re-simulations to investigate the
properties of the thermal Sunyaev-Zel'dovich (SZ) effect from galaxy clusters.
We compare results obtained using different physical models for the
intracluster medium (ICM), and show how they modify the SZ emission in terms of
cluster profiles and scaling relations. We also produce realistic mock
observations to verify whether the results from hydrodynamic simulations can be
confirmed. We find that SZ profiles depend marginally on the modelled physical
processes, while they exhibit a strong dependence on cluster mass. The central
and total SZ emission strongly correlate with the cluster X-ray luminosity and
temperature. The logarithmic slopes of these scaling relations differ from the
self-similar predictions by less than 0.2; the normalization of the relations
is lower for simulations including radiative cooling. The observational test
suggests that SZ cluster profiles are unlikely to be able to probe the ICM
physics. The total SZ decrement appears to be an observable much more robust
than the central intensity, and we suggest using the former to investigate
scaling relations.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:18:10 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Apr 2007 09:05:01 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Bonaldi",
"A.",
""
],
[
"Tormen",
"G.",
""
],
[
"Dolag",
"K.",
""
],
[
"Moscardini",
"L.",
""
]
] |
0704.2536 | Remi Monasson | Remi Monasson (LPTENS) | Introduction to Phase Transitions in Random Optimization Problems | null | Complex Systems, Les Houches Summer School 2006 (2008) 1 | null | null | cond-mat.stat-mech | null | Notes of the lectures delivered in Les Houches during the Summer School on
Complex Systems (July 2006).
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:05:42 GMT"
}
] | 2008-06-20T00:00:00 | [
[
"Monasson",
"Remi",
"",
"LPTENS"
]
] |
0704.2537 | Slava Khruschev | V. V. Khruschov (RRC Ki, Moscow) | Calculation of pseudoscalar and vector mesons' masses in extended model
of quasi-independent quarks | 6 pages | null | null | KI-08/57 | hep-ph | null | Masses of pseudoscalar and vector mesons, which are ground states of light
or/and heavy quarks and antiquarks, have been calculated in the framework of an
extended model of quasi-independent quarks with absolute uncertainties about 30
MeV. It is shown that the assumption on equidistant discrete levels for a mean
field energy does not contradict to existing data and permits to reduce a
number of model parameters. It is obtained, that a difference between
neighbouring mean field energy levels is flavour independent. Values of
spin-spin interaction between quarks and antiquarks with different flavours in
pseudoscalar and vector mesons are presented.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:08:39 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Khruschov",
"V. V.",
"",
"RRC Ki, Moscow"
]
] |
0704.2538 | Pawel Maslanka | K. Bolonek, P. Kosinski | Note on charge interaction in NQED | 4 pages, 1 figure | null | null | null | hep-th | null | The interaction of charges in NQED is discussed. It is shown that the
relativistic correction have the same form as in the commutative case provided
the Weyl ordering rule is used.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:08:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bolonek",
"K.",
""
],
[
"Kosinski",
"P.",
""
]
] |
0704.2539 | Remi Monasson | Simona Cocco (LPS), Remi Monasson (LPTENS) | Reconstructing a Random Potential from its Random Walks | null | Europhysics Letters (EPL) (2008) 81, 20002 | 10.1209/0295-5075/81/20002 | null | cond-mat.stat-mech | null | The problem of how many trajectories of a random walker in a potential are
needed to reconstruct the values of this potential is studied. We show that
this problem can be solved by calculating the probability of survival of an
abstract random walker in a partially absorbing potential. The approach is
illustrated on the discrete Sinai (random force) model with a drift. We
determine the parameter (temperature, duration of each trajectory, ...) values
making reconstruction as fast as possible.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:12:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cocco",
"Simona",
"",
"LPS"
],
[
"Monasson",
"Remi",
"",
"LPTENS"
]
] |
0704.2540 | Hector Bombin | H. Bombin, M.A. Martin-Delgado | Quantum Measurements and Gates by Code Deformation | Revtex4, 6 figures | J. Phys. A: Math. Theor. 42 (2009) 095302 | 10.1088/1751-8113/42/9/095302 | null | quant-ph cond-mat.str-el | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The usual scenario in fault tolerant quantum computation involves certain
amount of qubits encoded in each code block, transversal operations between
them and destructive measurements of ancillary code blocks. We introduce a new
approach in which a single code layer is used for the entire computation, in
particular a surface code. Qubits can be created, manipulated and
non-destructively measured by code deformations that amount to `cut and paste'
operations in the surface. All the interactions between qubits remain purely
local in a two-dimensional setting.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:19:59 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Feb 2009 23:00:38 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Bombin",
"H.",
""
],
[
"Martin-Delgado",
"M. A.",
""
]
] |
0704.2541 | Anatoly Iyudin Dr. | A. Iyudin (SINP, Moscow State University, Moscow, Russia), J. Greiner
(MPE, Garching, Germany), G. Di Cocco (IASF/IANF-Bologna, Italy), S. Larsson
(Stockholm University, Stockholm, Sweden) | Gamma-ray probe of the QSO's obscured evolution | 3 pages, 1 figure, contribution to proceedings of International
Astrophysics Conference "Relativistic Astrophysics and Cosmology-Einsteins
Legacy", held during November 7-11, 2005, Munich, Germany. To be printed in
the Springer-Verlag series "ESO Astrophysics Symposia", Eds. B. Aschenbach,
V. Burwitz, G. Hasinger, and B. Leibundgut | null | 10.1007/978-3-540-74713-0_53 | null | astro-ph | null | The idea that substantial absorption in AGN could be a definite
characteristic of the early phases of QSO evolution was invoked to explain the
submillimeter observations of X-ray absorbed AGN at z~1 to z~3, that have shown
strong emission at 850 mkm. This strong emission is a signature of the copious
star formation. In AGN evolution model, the main obscured growth phase of the
QSO coincides with formation of the host galaxy spheroid, the completion of
which indicates the beginning of the luminous, unobscured phase of the QSO's
evolution. The verification of this model at redshifts up to z~6 appears
possible via application of the gamma-ray resonant absorption method.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:21:14 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Iyudin",
"A.",
"",
"SINP, Moscow State University, Moscow, Russia"
],
[
"Greiner",
"J.",
"",
"MPE, Garching, Germany"
],
[
"Di Cocco",
"G.",
"",
"IASF/IANF-Bologna, Italy"
],
[
"Larsson",
"S.",
"",
"Stockholm University, Stockholm, Sweden"
]
] |
0704.2542 | Joan Llobera | Joan Llobera | Narratives within immersive technologies | 5 pages | null | null | null | cs.HC | null | The main goal of this project is to research technical advances in order to
enhance the possibility to develop narratives within immersive mediated
environments. An important part of the research is concerned with the question
of how a script can be written, annotated and realized for an immersive
context. A first description of the main theoretical framework and the ongoing
work and a first script example is provided. This project is part of the
program for presence research, and it will exploit physiological feedback and
Computational Intelligence within virtual reality.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:27:25 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Llobera",
"Joan",
""
]
] |
0704.2543 | Pierre Brun | P. Brun, G. Bertone, J. Lavalle, P. Salati, R. Taillet | Antiproton and Positron Signal Enhancement in Dark Matter Mini-Spikes
Scenarios | 13 pages, 9 figures, minor changes, version accepted for publication
in PRD | Phys.Rev.D76:083506,2007 | 10.1103/PhysRevD.76.083506 | LAPP-EXP-2007-02, LAPTH-1181/07, CPPM-P-2007-01 | astro-ph | null | The annihilation of dark matter (DM) in the Galaxy could produce specific
imprints on the spectra of antimatter species in Galactic cosmic rays, which
could be detected by upcoming experiments such as PAMELA and AMS02. Recent
studies show that the presence of substructures can enhance the annihilation
signal by a "boost factor" that not only depends on energy, but that is
intrinsically a statistical property of the distribution of DM substructures
inside the Milky Way. We investigate a scenario in which substructures consist
of $\sim 100$ "mini-spikes" around intermediate-mass black holes. Focusing on
primary positrons and antiprotons, we find large boost factors, up to a few
thousand, that exhibit a large variance at high energy in the case of positrons
and at low energy in the case of antiprotons. As a consequence, an estimate of
the DM particle mass based on the observed cut-off in the positron spectrum
could lead to a substantial underestimate of its actual value.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:29:27 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Apr 2007 15:13:52 GMT"
},
{
"version": "v3",
"created": "Fri, 27 Jul 2007 10:00:40 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Brun",
"P.",
""
],
[
"Bertone",
"G.",
""
],
[
"Lavalle",
"J.",
""
],
[
"Salati",
"P.",
""
],
[
"Taillet",
"R.",
""
]
] |
0704.2544 | Vishwambhar Rathi | Vishwambhar Rathi, Ruediger Urbanke | Existence Proofs of Some EXIT Like Functions | To appear in proc. of ISIT 2007 | null | null | null | cs.IT math.IT | null | The Extended BP (EBP) Generalized EXIT (GEXIT) function introduced in
\cite{MMRU05} plays a fundamental role in the asymptotic analysis of sparse
graph codes. For transmission over the binary erasure channel (BEC) the
analytic properties of the EBP GEXIT function are relatively simple and well
understood. The general case is much harder and even the existence of the curve
is not known in general. We introduce some tools from non-linear analysis which
can be useful to prove the existence of EXIT like curves in some cases. The
main tool is the Krasnoselskii-Rabinowitz (KR) bifurcation theorem.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:36:43 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Rathi",
"Vishwambhar",
""
],
[
"Urbanke",
"Ruediger",
""
]
] |
0704.2545 | Henry Joy McCracken | H. J. McCracken, J. A. Peacock, L. Guzzo, P. Capak, C. Porciani, N.
Scoville, H. Aussel, A. Finoguenov, J. B. James, M. G. Kitzbichler, A.
Koekemoer, A. Leauthaud, O. Le F\`evre, R. Massey, Y. Mellier, B. Mobasher,
P. Norberg, J. Rhodes, D. B. Sanders, S. S. Sasaki, Y. Taniguchi, D. J.
Thompson, S. D. M. White, A. El-Zant | The angular correlations of galaxies in the COSMOS field | Six pages, five figures. Accepted for publication in the ApJS COSMOS
special issue, Sept. 2007 | null | 10.1086/518693 | null | astro-ph | null | We present measurements of the two-point galaxy angular correlation function
w(\theta) in the COSMOS field. Independent determinations of w(\theta) as a
function of magnitude limit are presented for both the HST ACS catalog and also
for the ground-based data from Subaru and the CFHT. Despite having
significantly different masks, these three determinations agree well. At bright
magnitudes (IAB<22), our data generally match very well with existing
measurements and with mock catalogs based on semi-analytic galaxy formation
calculations of Kitzbichler and White from the Millennium Simulation. The
exception is that our result is at the upper end of the expected cosmic
variance scatter for \theta > 10 arcmin, which we attribute to a particularly
rich structure known to exist at z~0.8. For fainter samples, however, the level
of clustering is somewhat higher than reported by some previous studies: in all
three catalogues we find w(\theta=1')~0.014 at a median IAB magnitude of 24. At
these very faintest magnitudes, our measurements agree well with the latest
determinations from the Canada-France Legacy Survey. This level of clustering
is approximately double what is predicted by the semi-analytic catalogs (at all
angles). The semi-analytic results allow an estimate of cosmic variance, which
is too small to account for the discrepancy. We therefore conclude that the
mean amplitude of clustering at this level is higher than previously estimated.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:03:49 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"McCracken",
"H. J.",
""
],
[
"Peacock",
"J. A.",
""
],
[
"Guzzo",
"L.",
""
],
[
"Capak",
"P.",
""
],
[
"Porciani",
"C.",
""
],
[
"Scoville",
"N.",
""
],
[
"Aussel",
"H.",
""
],
[
"Finoguenov",
"A.",
""
],
[
"James",
"J. B.",
""
],
[
"Kitzbichler",
"M. G.",
""
],
[
"Koekemoer",
"A.",
""
],
[
"Leauthaud",
"A.",
""
],
[
"Fèvre",
"O. Le",
""
],
[
"Massey",
"R.",
""
],
[
"Mellier",
"Y.",
""
],
[
"Mobasher",
"B.",
""
],
[
"Norberg",
"P.",
""
],
[
"Rhodes",
"J.",
""
],
[
"Sanders",
"D. B.",
""
],
[
"Sasaki",
"S. S.",
""
],
[
"Taniguchi",
"Y.",
""
],
[
"Thompson",
"D. J.",
""
],
[
"White",
"S. D. M.",
""
],
[
"El-Zant",
"A.",
""
]
] |
0704.2546 | Steven Dytman | H. Denizli, J. Mueller, S. Dytman et al. (CLAS Collaboration) | Q^2 Dependence of the S_{11}(1535) Photocoupling and Evidence for a
P-wave resonance in eta electroproduction | 31 pages, 9 figures | Phys.Rev.C76:015204,2007 | 10.1103/PhysRevC.76.015204 | null | nucl-ex | null | New cross sections for the reaction $ep \to e'\eta p$ are reported for total
center of mass energy $W$=1.5--2.3 GeV and invariant squared momentum transfer
$Q^2$=0.13--3.3 GeV$^2$. This large kinematic range allows extraction of new
information about response functions, photocouplings, and $\eta N$ coupling
strengths of baryon resonances. A sharp structure is seen at $W\sim$ 1.7 GeV.
The shape of the differential cross section is indicative of the presence of a
$P$-wave resonance that persists to high $Q^2$. Improved values are derived for
the photon coupling amplitude for the $S_{11}$(1535) resonance. The new data
greatly expands the $Q^2$ range covered and an interpretation of all data with
a consistent parameterization is provided.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:41:42 GMT"
}
] | 2010-04-06T00:00:00 | [
[
"Denizli",
"H.",
"",
"CLAS Collaboration"
],
[
"Mueller",
"J.",
"",
"CLAS Collaboration"
],
[
"al.",
"S. Dytman et",
"",
"CLAS Collaboration"
]
] |
0704.2547 | Remi Monasson | Valentina Baldazzi (LPS), Serena Bradde (LPS), Simona Cocco (LPS),
Enzo Marinari, Remi Monasson (LPTENS) | Inferring DNA sequences from mechanical unzipping data: the
large-bandwidth case | null | Phys. Rev. E 75 (2007) 011904 | 10.1103/PhysRevE.75.011904 | null | q-bio.BM cond-mat.stat-mech | null | The complementary strands of DNA molecules can be separated when stretched
apart by a force; the unzipping signal is correlated to the base content of the
sequence but is affected by thermal and instrumental noise. We consider here
the ideal case where opening events are known to a very good time resolution
(very large bandwidth), and study how the sequence can be reconstructed from
the unzipping data. Our approach relies on the use of statistical Bayesian
inference and of Viterbi decoding algorithm. Performances are studied
numerically on Monte Carlo generated data, and analytically. We show how
multiple unzippings of the same molecule may be exploited to improve the
quality of the prediction, and calculate analytically the number of required
unzippings as a function of the bandwidth, the sequence content, the elasticity
parameters of the unzipped strands.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:45:29 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Baldazzi",
"Valentina",
"",
"LPS"
],
[
"Bradde",
"Serena",
"",
"LPS"
],
[
"Cocco",
"Simona",
"",
"LPS"
],
[
"Marinari",
"Enzo",
"",
"LPTENS"
],
[
"Monasson",
"Remi",
"",
"LPTENS"
]
] |
0704.2548 | Hans Peter Beck | Hans Peter Beck | Triggering at High Luminosity Colliders | Accepted for publication in New Journal of Physics | NewJ.Phys.9:334,2007 | 10.1088/1367-2630/9/9/334 | null | physics.ins-det hep-ex | null | This article discusses the techniques used to select online promising events
at high energy and high luminosity colliders. After a brief introduction,
explaining some general aspects of triggering, the more specific implementation
options for well established machines like the Tevatron and Large Hadron
Collider are presented. An outlook on what difficulties need to be met is given
when designing trigger systems at the Super Large Hadron Collider, or at the
International Linear Collider
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:45:54 GMT"
},
{
"version": "v2",
"created": "Sat, 2 Jun 2007 12:44:19 GMT"
}
] | 2009-04-16T00:00:00 | [
[
"Beck",
"Hans Peter",
""
]
] |
0704.2549 | Neil M. H. Vaytet | N. M. H. Vaytet, T. J. O'Brien, M. F. Bode | Swift observations of the 2006 outburst of the recurrent nova RS
Ophiuchi: II. 1D hydrodynamical models of wind driven shocks | 9 pages, 5 figures | Astrophys.J.665:654-662,2007 | 10.1086/519000 | null | astro-ph | null | Following the early Swift X-ray observations of the latest outburst of the
recurrent nova RS Ophiuchi in February 2006 (Paper I), we present new 1D
hydrodynamical models of the system which take into account all three phases of
the remnant evolution. The models suggest a novel way of modelling the system
by treating the outburst as a sudden increase then decrease in wind mass-loss
rate and velocity. The differences between this wind model and previous
Primakoff-type simulations are described. A more complex structure, even in 1D,
is revealed through the presence of both forward and reverse shocks, with a
separating contact discontinuity. The effects of radiative cooling are
investigated and key outburst parameters such as mass-loss rate, ejecta
velocity and mass are varied. The shock velocities as a function of time are
compared to the ones derived in Paper I. We show how the manner in which the
matter is ejected controls the evolution of the shock and that for a
well-cooled remnant, the shock deceleration rate depends on the amount of
energy that is radiated away.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:49:20 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Vaytet",
"N. M. H.",
""
],
[
"O'Brien",
"T. J.",
""
],
[
"Bode",
"M. F.",
""
]
] |
0704.2550 | Igor Drozdov | I.V. Drozdov and A.A. Stahlhofen | Local Energy Velocity of Classical Fields | 8 Pages | null | null | null | physics.gen-ph | null | It is proposed to apply a recently developed concept of local wave velocities
to the dynamical field characteristics, especially for the canonical field
energy density. It is shown that local energy velocities can be derived from
the lagrangian directly. The local velocities of zero- and first- order for
energy propagation has been obtained for special cases of scalar and vector
fields. Some important special cases of these results are discussed.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:55:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Drozdov",
"I. V.",
""
],
[
"Stahlhofen",
"A. A.",
""
]
] |
0704.2551 | Sophie Lebre | Sophie L\`ebre (SG) | Inferring dynamic genetic networks with low order independencies | null | null | null | null | math.ST q-bio.QM stat.TH | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we propose a novel inference method for dynamic genetic
networks which makes it possible to face with a number of time measurements n
much smaller than the number of genes p. The approach is based on the concept
of low order conditional dependence graph that we extend here in the case of
Dynamic Bayesian Networks. Most of our results are based on the theory of
graphical models associated with the Directed Acyclic Graphs (DAGs). In this
way, we define a minimal DAG G which describes exactly the full order
conditional dependencies given the past of the process. Then, to face with the
large p and small n estimation case, we propose to approximate DAG G by
considering low order conditional independencies. We introduce partial qth
order conditional dependence DAGs G(q) and analyze their probabilistic
properties. In general, DAGs G(q) differ from DAG G but still reflect relevant
dependence facts for sparse networks such as genetic networks. By using this
approximation, we set out a non-bayesian inference method and demonstrate the
effectiveness of this approach on both simulated and real data analysis. The
inference procedure is implemented in the R package 'G1DBN' freely available
from the CRAN archive.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 14:57:27 GMT"
},
{
"version": "v2",
"created": "Tue, 15 May 2007 12:12:09 GMT"
},
{
"version": "v3",
"created": "Thu, 13 Mar 2008 13:14:26 GMT"
},
{
"version": "v4",
"created": "Fri, 18 Apr 2008 13:57:07 GMT"
},
{
"version": "v5",
"created": "Tue, 30 Dec 2008 16:45:39 GMT"
},
{
"version": "v6",
"created": "Fri, 29 May 2009 18:23:31 GMT"
}
] | 2009-05-29T00:00:00 | [
[
"Lèbre",
"Sophie",
"",
"SG"
]
] |
0704.2552 | Nikitas Papasimakis | N. Papasimakis, V. A. Fedotov, F. J. Garcia de Abajo, A. S. Schwanecke
and N. I. Zheludev | Enhanced microwave transmission through quasicrystal hole arrays | 4 pages, 2 figures | Appl. Phys. Lett. 91, 081503 (2007) | 10.1063/1.2773763 | null | physics.optics | null | We report on the observation of enhanced microwave transmission through
quasi-periodic hole arrays in metal films. The fraction of transmitted light
reaches 50% in a self-standing metal film and approaches 90% when the film is
sandwiched between thin dielectric slabs, while the holes occupy only 10% of
the sample area. The maximum transmission is accompanied by zero phase change,
rendering the film almost 'invisible' over a wide frequency range. The
extraordinary transmission phenomenon is interpreted in terms of resonances in
the self-consistent interaction between holes, which are represented by
effective electric and magnetic dipoles.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:23:23 GMT"
}
] | 2010-09-03T00:00:00 | [
[
"Papasimakis",
"N.",
""
],
[
"Fedotov",
"V. A.",
""
],
[
"de Abajo",
"F. J. Garcia",
""
],
[
"Schwanecke",
"A. S.",
""
],
[
"Zheludev",
"N. I.",
""
]
] |
0704.2553 | Carlo Angelantonj | C. Angelantonj and E. Dudas | Metastable String Vacua | 15 pages. v2 refs added and minor improvements | Phys.Lett.B651:239-245,2007 | 10.1016/j.physletb.2007.06.031 | CPHT-RR 017.0417, DFTT 2007/5, LPT-Orsay 07/23 | hep-th | null | We argue that tachyon-free type I string vacua with supersymmetry breaking in
the open sector at the string scale can be interpreted, via S and T-duality
arguments, as metastable vacua of supersymmetric type I superstring. The
dynamics of the process can be partially captured via nucleation of
brane-antibrane pairs out of the non-supersymmetric vacuum and subsequent
tachyon condensation.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 16:00:30 GMT"
},
{
"version": "v2",
"created": "Wed, 23 May 2007 14:41:53 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Angelantonj",
"C.",
""
],
[
"Dudas",
"E.",
""
]
] |
0704.2554 | Yannick Brohard | Brigitte Meyer-Berthaud (AMAP), Anne-Laure Decombeix (AMAP) | A tree without leaves | null | Nature 446, 7138 (2006) 861-862 | 10.1038/446861a | A-07-09 | q-bio.PE | null | The puzzle presented by the famous stumps of Gilboa, New York, finds a
solution in the discovery of two fossil specimens that allow the entire
structure of these early trees to be reconstructed.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 15:11:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Meyer-Berthaud",
"Brigitte",
"",
"AMAP"
],
[
"Decombeix",
"Anne-Laure",
"",
"AMAP"
]
] |
0704.2555 | Benjamin McKay | Benjamin McKay (University College Cork) | Characteristic forms of complex Cartan geometries | 29 pages (on A4 paper). I split off the results about Calabi-Yaus
into a separate paper | Adv. Geom. 11 (2011), no. 1, 139-168 | null | null | math.DG math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate relations on characteristic classes which are obstructions
preventing closed K\"ahler manifolds from carrying holomorphic Cartan
geometries. We apply these relations to give global constraints on the phase
spaces of complex analytic determined and underdetermined systems of
differential equations.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 15:11:58 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Dec 2008 16:31:02 GMT"
}
] | 2019-11-12T00:00:00 | [
[
"McKay",
"Benjamin",
"",
"University College Cork"
]
] |
0704.2556 | Stefan Kebekus | Stefan Kebekus and Sandor Kovacs | Families of varieties of general type over compact bases | null | null | null | null | math.AG | null | Let f: X -> Y be a smooth family of canonically polarized complex varieties
over a smooth base. Generalizing the classical Shafarevich hyperbolicity
conjecture, Viehweg conjectured that Y is necessarily of log general type if
the family has maximal variation. A somewhat stronger and more precise version
of Viehweg's conjecture was shown by the authors in arXiv:math/0511378 in the
case where Y is a quasi-projective surface. Assuming that the minimal model
program holds, this very short paper proves the same result for projective base
manifolds Y of arbitrary dimension.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 15:15:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kebekus",
"Stefan",
""
],
[
"Kovacs",
"Sandor",
""
]
] |
0704.2557 | Vikram Dhillon | V. S. Dhillon, T. R. Marsh, M. J. Stevenson, D. C. Atkinson, P. Kerry,
P. T. Peacocke, A. J. A. Vick, S. M. Beard, D. J. Ives, D. W. Lunney, S. A.
McLay, C. J. Tierney, J. Kelly, S. P. Littlefair, R. Nicholson, R. Pashley,
E. T. Harlaftis, K. O'Brien | ULTRACAM: an ultra-fast, triple-beam CCD camera for high-speed
astrophysics | 17 pages, 7 figures, accepted for publication in MNRAS | Mon.Not.Roy.Astron.Soc.378:825-840,2007 | 10.1111/j.1365-2966.2007.11881.x | null | astro-ph | null | ULTRACAM is a portable, high-speed imaging photometer designed to study faint
astronomical objects at high temporal resolutions. ULTRACAM employs two
dichroic beamsplitters and three frame-transfer CCD cameras to provide
three-colour optical imaging at frame rates of up to 500 Hz. The instrument has
been mounted on both the 4.2-m William Herschel Telescope on La Palma and the
8.2-m Very Large Telescope in Chile, and has been used to study white dwarfs,
brown dwarfs, pulsars, black-hole/neutron-star X-ray binaries, gamma-ray
bursts, cataclysmic variables, eclipsing binary stars, extrasolar planets,
flare stars, ultra-compact binaries, active galactic nuclei, asteroseismology
and occultations by Solar System objects (Titan, Pluto and Kuiper Belt
objects). In this paper we describe the scientific motivation behind ULTRACAM,
present an outline of its design and report on its measured performance.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 15:15:48 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Dhillon",
"V. S.",
""
],
[
"Marsh",
"T. R.",
""
],
[
"Stevenson",
"M. J.",
""
],
[
"Atkinson",
"D. C.",
""
],
[
"Kerry",
"P.",
""
],
[
"Peacocke",
"P. T.",
""
],
[
"Vick",
"A. J. A.",
""
],
[
"Beard",
"S. M.",
""
],
[
"Ives",
"D. J.",
""
],
[
"Lunney",
"D. W.",
""
],
[
"McLay",
"S. A.",
""
],
[
"Tierney",
"C. J.",
""
],
[
"Kelly",
"J.",
""
],
[
"Littlefair",
"S. P.",
""
],
[
"Nicholson",
"R.",
""
],
[
"Pashley",
"R.",
""
],
[
"Harlaftis",
"E. T.",
""
],
[
"O'Brien",
"K.",
""
]
] |
0704.2558 | Dan Hooper | Dan Hooper, Manoj Kaplinghat, Louis E. Strigari and Kathryn M. Zurek | MeV Dark Matter and Small Scale Structure | 4 pages, 3 figures | Phys.Rev.D76:103515,2007 | 10.1103/PhysRevD.76.103515 | FERMILAB-PUB-07-064-A, MADPH-07-1482 | astro-ph hep-ph | null | WIMPs with electroweak scale masses (neutralinos, etc.) remain in kinetic
equilibrium with other particle species until temperatures approximately in the
range of 10 MeV to 1 GeV, leading to the formation of dark matter substructure
with masses as small as $10^{-4} M_{\odot}$ to $10^{-12} M_{\odot}$. However,
if dark matter consists of particles with MeV scale masses, as motivated by the
observation of 511 keV emission from the Galactic Bulge, such particles are
naturally expected to remain in kinetic equilibrium with the cosmic neutrino
background until considerably later times. This would lead to a strong
suppression of small scale structure with masses below about $10^7 M_{\odot}$
to $10^4 M_{\odot}$. This cutoff scale has important implications for present
and future searches for faint Local Group satellite galaxies and for the
missing satellites problem.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:38:17 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hooper",
"Dan",
""
],
[
"Kaplinghat",
"Manoj",
""
],
[
"Strigari",
"Louis E.",
""
],
[
"Zurek",
"Kathryn M.",
""
]
] |
0704.2559 | Hans-Thomas Elze | Hans-Thomas Elze | Is there a relativistic nonlinear generalization of quantum mechanics? | 10 pages; talk at DICE 2006 (Piombino, September 11-15, 2006); to
appear in Journal of Physics: Conference Series (2007) | J.Phys.Conf.Ser.67:012016,2007 | 10.1088/1742-6596/67/1/012016 | null | quant-ph | null | Yes, there is. - A new kind of gauge theory is introduced, where the minimal
coupling and corresponding covariant derivatives are defined in the space of
functions pertaining to the functional Schroedinger picture of a given field
theory. While, for simplicity, we study the example of an U(1) symmetry, this
kind of gauge theory can accommodate other symmetries as well. We consider the
resulting relativistic nonlinear extension of quantum mechanics and show that
it incorporates gravity in the (0+1)-dimensional limit, where it leads to the
Schroedinger-Newton equations. Gravity is encoded here into a universal
nonlinear extension of quantum theory. The probabilistic interpretation, i.e.
Born's rule, holds provided the underlying model has only dimensionless
parameters.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 15:20:34 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Elze",
"Hans-Thomas",
""
]
] |
0704.2560 | Alain-Sol Sznitman | Alain-Sol Sznitman | Vacant Set of Random Interlacements and Percolation | 40 pages, 1 figure | Annals of Mathematics, 171, 2039-2087, 2010 | null | null | math.PR math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a model of random interlacements made of a countable collection
of doubly infinite paths on Z^d, d bigger or equal to 3. A non-negative
parameter u measures how many trajectories enter the picture. This model
describes in the large N limit the microscopic structure in the bulk, which
arises when considering the disconnection time of a discrete cylinder with base
a d-1-dimensional discrete torus of side-length N, or the set of points visited
by simple random walk on the d-dimensional discrete torus of side-length N by
times of order uN^d. We study the percolative properties of the vacant set left
by the interlacement at level u, which is an infinite, connected, translation
invariant random subset of Z^d. We introduce a critical value such that the
vacant set percolates for u below the critical value, and does not percolate
for u above the critical value. Our main results show that the critical value
is finite when d is bigger or equal to 3, and strictly positive when d is
bigger or equal to 7.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 15:45:50 GMT"
},
{
"version": "v2",
"created": "Mon, 21 May 2007 13:05:40 GMT"
},
{
"version": "v3",
"created": "Mon, 14 Dec 2009 18:06:03 GMT"
}
] | 2010-06-08T00:00:00 | [
[
"Sznitman",
"Alain-Sol",
""
]
] |
0704.2561 | Andrey Lazarev | Joseph Chuang and Andrey Lazarev | Dual Feynman transform for modular operads | 27 pages. A few conceptual changes in the last section; in particular
we prove that the two-colored graph complex is a resolution of the
corresponding modular operad. It is now called 'BV-resolution' as suggested
by Sasha Voronov | null | null | null | math.QA hep-th math.AG | null | We introduce and study the notion of a dual Feynman transform of a modular
operad. This generalizes and gives a conceptual explanation of Kontsevich's
dual construction producing graph cohomology classes from a contractible
differential graded Frobenius algebra. The dual Feynman transform of a modular
operad is indeed linear dual to the Feynman transform introduced by Getzler and
Kapranov when evaluated on vacuum graphs. In marked contrast to the Feynman
transform, the dual notion admits an extremely simple presentation via
generators and relations; this leads to an explicit and easy description of its
algebras. We discuss a further generalization of the dual Feynman transform
whose algebras are not necessarily contractible. This naturally gives rise to a
two-colored graph complex analogous to the Boardman-Vogt topological tree
complex.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 16:45:00 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Apr 2007 20:09:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chuang",
"Joseph",
""
],
[
"Lazarev",
"Andrey",
""
]
] |
0704.2562 | Ian Wood | Malcolm Brown, Marco Marletta, Serguei Naboko, Ian Wood | Boundary triplets and M-functions for non-selfadjoint operators, with
applications to elliptic PDEs and block operator matrices | 16 pages, submitted to LMS; v2: including more references and some
minor corrections; changed presentation in section 2, added theorem 4.4,
modified example in section 5; v3: includes new references | null | 10.1112/jlms/jdn006 | null | math.SP math.AP | null | Starting with an adjoint pair of operators, under suitable abstract versions
of standard PDE hypotheses, we consider the Weyl M-function of extensions of
the operators. The extensions are determined by abstract boundary conditions
and we establish results on the relationship between the M-function as an
analytic function of a spectral parameter and the spectrum of the extension. We
also give an example where the M-function does not contain the whole spectral
information of the resolvent, and show that the results can be applied to
elliptic PDEs where the M-function corresponds to the Dirichlet to Neumann map.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 15:33:09 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Sep 2007 11:01:10 GMT"
},
{
"version": "v3",
"created": "Fri, 19 Oct 2007 13:14:30 GMT"
}
] | 2014-02-26T00:00:00 | [
[
"Brown",
"Malcolm",
""
],
[
"Marletta",
"Marco",
""
],
[
"Naboko",
"Serguei",
""
],
[
"Wood",
"Ian",
""
]
] |
0704.2563 | Renaud Parentani | Renaud Parentani | Beyond the semi-classical description of black hole evaporation | 26 pages, 1 figure, revised and updated version | Int.J.Theor.Phys.41:2175-2200,2002 | 10.1023/A:1021133126804 | null | hep-th | null | In the semi-classical treatment, i.e. in a classical black hole geometry,
Hawking quanta emerge from trans-Planckian configurations because of scale
invariance. There is indeed no scale to stop the blue-shifting effect
encountered in the backward propagation towards the event horizon. On the
contrary, when taking into account the gravitational interactions neglected in
the semi-classical treatment, a UV scale stopping the blue-shift could be
dynamically engendered. To show that this is the case, we use a
non-perturbative treatment based on the large-N limit, where $N$ is the number
of matter fields. In this limit, the semi-classical treatment is the leading
contribution. Non-linear gravitational effects appear in the next orders and in
the first of these, the effects are governed by the two-point correlation
function of the energy-momentum tensor evaluated in the vacuum. Taking this
correlator into account, backward propagated modes are dissipated at a distance
from the horizon $\propto G\kappa$ when measured in a freely falling frame.
($G$ is Newton's constant and $\kappa$ the surface gravity.) This result can be
also obtained by considering light propagation in a stochastic ensemble of
metrics whose fluctuations are determined by the above correlator.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:06:08 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Parentani",
"Renaud",
""
]
] |
0704.2564 | Bal\'azs Kozma | Balazs Kozma, Matthew B. Hastings, G. Korniss | Diffusion Processes on Small-World Networks with Distance-Dependent
Random-Links | 36 pages, 27 figures. Minor revisions in response to the referee's
comments. Furthermore, some typos were fixed and new references were added | J. Stat. Mech. (2007) P08014 | 10.1088/1742-5468/2007/08/P08014 | null | cond-mat.stat-mech cond-mat.dis-nn | null | We considered diffusion-driven processes on small-world networks with
distance-dependent random links. The study of diffusion on such networks is
motivated by transport on randomly folded polymer chains, synchronization
problems in task-completion networks, and gradient driven transport on
networks. Changing the parameters of the distance-dependence, we found a rich
phase diagram, with different transient and recurrent phases in the context of
random walks on networks. We performed the calculations in two limiting cases:
in the annealed case, where the rearrangement of the random links is fast, and
in the quenched case, where the link rearrangement is slow compared to the
motion of the random walker or the surface. It has been well-established that
in a large class of interacting systems, adding an arbitrarily small density
of, possibly long-range, quenched random links to a regular lattice interaction
topology, will give rise to mean-field (or annealed) like behavior. In some
cases, however, mean-field scaling breaks down, such as in diffusion or in the
Edwards-Wilkinson process in "low-dimensional" small-world networks. This
break-down can be understood by treating the random links perturbatively, where
the mean-field (or annealed) prediction appears as the lowest-order term of a
naive perturbation expansion. The asymptotic analytic results are also
confirmed numerically by employing exact numerical diagonalization of the
network Laplacian. Further, we construct a finite-size scaling framework for
the relevant observables, capturing the cross-over behaviors in finite
networks. This work provides a detailed account of the
self-consistent-perturbative and renormalization approaches briefly introduced
in two earlier short reports.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 16:11:52 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 17:28:02 GMT"
}
] | 2007-09-05T00:00:00 | [
[
"Kozma",
"Balazs",
""
],
[
"Hastings",
"Matthew B.",
""
],
[
"Korniss",
"G.",
""
]
] |
0704.2565 | Florent Ravelet | F. Ravelet, R. Volk, A. Chiffaudel, F. Daviaud, B. Dubrulle, R.
Monchaux, M. Bourgoin, P. Odier, J.-F. Pinton, M. Berhanu, S. Fauve, N.
Mordant and F. Petrelis | Magnetic induction in a turbulent flow of liquid sodium: mean behaviour
and slow fluctuations | null | null | null | null | physics.flu-dyn | null | We study the flow response to an externally imposed homogeneous magnetic
field in a turbulent swirling flow of liquid sodium -- the VKS2 experiment in
which magnetic Reynolds numbers Rm up to 50 are reached. Induction effects are
larger than in the former VKS1 experiment. At Rm larger than about 25, the
local amplitude of induced field components supersedes that of the applied
field, and exhibits non-Gaussian fluctuations. Slow dynamical instationarities
and low-frequency bimodal dynamics are observed in the induction, presumably
tracing back to large scale fluctuations in the hydrodynamic flow.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 16:34:02 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ravelet",
"F.",
""
],
[
"Volk",
"R.",
""
],
[
"Chiffaudel",
"A.",
""
],
[
"Daviaud",
"F.",
""
],
[
"Dubrulle",
"B.",
""
],
[
"Monchaux",
"R.",
""
],
[
"Bourgoin",
"M.",
""
],
[
"Odier",
"P.",
""
],
[
"Pinton",
"J. -F.",
""
],
[
"Berhanu",
"M.",
""
],
[
"Fauve",
"S.",
""
],
[
"Mordant",
"N.",
""
],
[
"Petrelis",
"F.",
""
]
] |
0704.2566 | Vladimir Sauli | V. Sauli | On the quark propagator singularity | 4pp, 4 fig | null | null | null | hep-ph | null | Using the method of Fukuda and Kugo \cite{FUKKUG} the continuation of
Euclidean solution is performed to the timelike axis of fourmomenta. It is
shown that assumed presence of the real simple pole in quark propagator is not
in agreement with the solution. The simple pole disappears because of the
discontinuity in the resulting quark mass function.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 16:29:11 GMT"
},
{
"version": "v2",
"created": "Mon, 13 Aug 2007 16:26:05 GMT"
},
{
"version": "v3",
"created": "Wed, 31 Oct 2007 19:05:08 GMT"
}
] | 2007-10-31T00:00:00 | [
[
"Sauli",
"V.",
""
]
] |
0704.2567 | Michele Campisi | Michele Campisi | Mechanical Proof of the Second Law of Thermodynamics Based on Volume
Entropy | 17 pages, 1 figure | Studies In History and Philosophy of Modern Physics, Volume 39,
Issue 1, January 2008, Pages 181-194 | 10.1016/j.shpsb.2007.09.002 | null | cond-mat.stat-mech | null | In a previous work (M. Campisi. Stud. Hist. Phil. M. P. 36 (2005) 275-290) we
have addressed the mechanical foundations of equilibrium thermodynamics on the
basis of the Generalized Helmholtz Theorem. It was found that the volume
entropy provides a good mechanical analogue of thermodynamic entropy because it
satisfies the heat theorem and it is an adiabatic invariant. This property
explains the ``equal'' sign in Clausius principle ($S_f \geq S_i$) in a purely
mechanical way and suggests that the volume entropy might explain the ``larger
than'' sign (i.e. the Law of Entropy Increase) if non adiabatic transformations
were considered. Based on the principles of microscopic (quantum or classical)
mechanics here we prove that, provided the initial equilibrium satisfy the
natural condition of decreasing ordering of probabilities, the expectation
value of the volume entropy cannot decrease for arbitrary transformations
performed by some external sources of work on a insulated system. This can be
regarded as a rigorous quantum mechanical proof of the Second Law. We discuss
how this result relates to the Minimal Work Principle and improves over
previous attempts. The natural evolution of entropy is towards larger values
because the natural state of matter is at positive temperature. Actually the
Law of Entropy Decrease holds in artificially prepared negative temperature
systems.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 16:40:33 GMT"
}
] | 2008-03-09T00:00:00 | [
[
"Campisi",
"Michele",
""
]
] |
0704.2568 | Antonio Palazzo | G.L. Fogli, E. Lisi, A. Marrone (Bari U. & INFN, Bari), D. Montanino
(Lecce U. & INFN, Lecce), A. Palazzo (Oxford U. & INFN, Bari) | Probing non-standard decoherence effects with solar and KamLAND
neutrinos | Minor changes. Version accepted for publication in Phys. Rev. D | Phys.Rev.D76:033006,2007 | 10.1103/PhysRevD.76.033006 | null | hep-ph astro-ph gr-qc | null | It has been speculated that quantum gravity might induce a "foamy" space-time
structure at small scales, randomly perturbing the propagation phases of
free-streaming particles (such as kaons, neutrons, or neutrinos). Particle
interferometry might then reveal non-standard decoherence effects, in addition
to standard ones (due to, e.g., finite source size and detector resolution.) In
this work we discuss the phenomenology of such non-standard effects in the
propagation of electron neutrinos in the Sun and in the long-baseline reactor
experiment KamLAND, which jointly provide us with the best available probes of
decoherence at neutrino energies E ~ few MeV. In the solar neutrino case, by
means of a perturbative approach, decoherence is shown to modify the standard
(adiabatic) propagation in matter through a calculable damping factor. By
assuming a power-law dependence of decoherence effects in the energy domain
(E^n with n = 0,+/-1,+/-2), theoretical predictions for two-family neutrino
mixing are compared with the data and discussed. We find that neither solar nor
KamLAND data show evidence in favor of non-standard decoherence effects, whose
characteristic parameter gamma_0 can thus be significantly constrained. In the
"Lorentz-invariant" case n=-1, we obtain the upper limit gamma_0<0.78 x 10^-26
GeV at 95% C.L. In the specific case n=-2, the constraints can also be
interpreted as bounds on possible matter density fluctuations in the Sun, which
we improve by a factor of ~ 2 with respect to previous analyses.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 16:47:31 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Jul 2007 17:22:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Fogli",
"G. L.",
"",
"Bari U. & INFN, Bari"
],
[
"Lisi",
"E.",
"",
"Bari U. & INFN, Bari"
],
[
"Marrone",
"A.",
"",
"Bari U. & INFN, Bari"
],
[
"Montanino",
"D.",
"",
"Lecce U. & INFN, Lecce"
],
[
"Palazzo",
"A.",
"",
"Oxford U. & INFN, Bari"
]
] |
0704.2569 | Ben Davies | Ben Davies, Jorick S. Vink and Ren\'e D. Oudmaijer | Modelling the clumping-induced polarimetric variability of hot star
winds | 12 pages, 11 figures, accepted to A&A | null | 10.1051/0004-6361:20077193 | null | astro-ph | null | Clumping in the winds of massive stars may significantly reduce empirical
mass-loss rates, and which in turn may have a large impact on our understanding
of massive star evolution. Here, we investigate wind-clumping through the
linear polarization induced by light scattering off the clumps. Through the use
of an analytic wind clumping model, we predict the time evolution of the linear
polarimetry over a large parameter space. We concentrate on the Luminous Blue
Variables, which display the greatest amount of polarimetric variability and
for which we recently conducted a spectropolarimetric survey. Our model results
indicate that the observed level of polarimetric variability can be reproduced
for two regimes of parameter space: one of a small number of massive,
optically-thick clumps; and one of a very large number of low-mass clumps.
Although a systematic time-resolved monitoring campaign is required to
distinguish between the two scenarios, we currently favour the latter, given
the short timescale of the observed polarization variability. As the
polarization is predicted to scale linearly with mass-loss rate, we anticipate
that all hot stars with very large mass-loss rates should display polarimetric
variability. This is consistent with recent findings that intrinsic
polarization is more common in stars with strong H$\alpha$ emission.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:26:09 GMT"
}
] | 2016-08-14T00:00:00 | [
[
"Davies",
"Ben",
""
],
[
"Vink",
"Jorick S.",
""
],
[
"Oudmaijer",
"René D.",
""
]
] |
0704.2570 | Christian Wozar | Christian Wozar, Tobias Kaestner, Andreas Wipf, Thomas Heinzl | Inverse Monte-Carlo determination of effective lattice models for SU(3)
Yang-Mills theory at finite temperature | 10 pages, 7 figures | Phys.Rev.D76:085004,2007 | 10.1103/PhysRevD.76.085004 | null | hep-lat hep-th | null | This paper concludes our efforts in describing SU(3)-Yang-Mills theories at
different couplings/temperatures in terms of effective Polyakov-loop models.
The associated effective couplings are determined through an inverse Monte
Carlo procedure based on novel Schwinger-Dyson equations that employ the
symmetries of the Haar measure. Due to the first-order nature of the phase
transition we encounter a fine-tuning problem in reproducing the correct
behavior of the Polyakov-loop from the effective models. The problem remains
under control as long as the number of effective couplings is sufficiently
small.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:28:08 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Wozar",
"Christian",
""
],
[
"Kaestner",
"Tobias",
""
],
[
"Wipf",
"Andreas",
""
],
[
"Heinzl",
"Thomas",
""
]
] |
0704.2571 | Alexander Bolonkin | Alexander Bolonkin | Extraction of Freshwater and Energy from Atmosphere | 14 pages. 7figures, 3 tables | null | null | null | physics.gen-ph physics.ao-ph physics.geo-ph | null | Author offers and researches a new, cheap method for the extraction of
freshwater from the Earth atmosphere. The suggected method is fundamentally
dictinct from all existing methods that extract freshwater from air. All other
industrial methods extract water from a saline water source (in most cases from
seawater). This new method may be used at any point in the Earth except Polar
Zones. It does not require long-distance freshwater transportation. If seawater
is not utilized for increasing its productivity, this inexpensive new method is
very environment-friendly. The author method has two working versions: (1) the
first variant the warm (hot) atmospheric air is lifted by the inflatable tube
in a high altitude and atmospheric steam is condenced into freswater: (2) in
the second version, the warm air is pumped 20-30 meters under the sea-surface.
In the first version, wind and solar heating of air are used for causing air
flow. In version (2) wind and propeller are used for causing air movment.
The first method does not need energy, the second needs a small amount.
Moreover, in variant (1) the freshwater has a high pressure (>30 or more atm.)
and can be used for production of energy such as electricity and in that way
the freshwater cost is lower. For increasing the productivity the seawater is
injected into air and solar air heater may be used. The solar air heater
produces a huge amount of electricity as a very powerful electricity generation
plant. The offered electricity installation in 100 - 200 times cheaper than any
common electric plant of equivalent output.
Key words: Extraction freshwater, method of getting freshwater, receiving
energy from atmosphere, powerful renewal electric plant.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:18:41 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bolonkin",
"Alexander",
""
]
] |
0704.2572 | Yevgen Muntyan | Thomas Delzant, Rostislav Grigorchuk | Homomorphic images of Branch groups, and Serre's property (FA) | 20 pages, 2 figures | null | null | null | math.GR | null | It is shown that a finitely generated branch group has Serre's property (FA)
if and only if it does not surject onto the infinite cyclic group or the
infinite dihedral group. An example of a finitely generated self-similar branch
group surjecting onto the infinite cyclic group is constructed.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:34:30 GMT"
},
{
"version": "v2",
"created": "Wed, 2 May 2007 20:29:24 GMT"
},
{
"version": "v3",
"created": "Fri, 4 May 2007 14:58:05 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Delzant",
"Thomas",
""
],
[
"Grigorchuk",
"Rostislav",
""
]
] |
0704.2573 | Ashley Ross Mr. | Ashley J. Ross, Robert J. Brunner, Adam D. Myers | Higher-Order Angular Galaxy Correlations in the SDSS: Redshift and Color
Dependence of non-Linear Bias | 46 pages, 19 figures, Accepted to ApJ | Astrophys.J.665:67-84,2007 | 10.1086/519020 | null | astro-ph | null | We present estimates of the N-point galaxy, area-averaged, angular
correlation functions $\bar{\omega}_{N}$($\theta$) for $N$ = 2,...,7 for
galaxies from the fifth data release of the Sloan Digital Sky Survey. Our
parent sample is selected from galaxies with $18 \leq r < 21$, and is the
largest ever used to study higher-order correlations. We subdivide this parent
sample into two volume limited samples using photometric redshifts, and these
two samples are further subdivided by magnitude, redshift, and color (producing
early- and late-type galaxy samples) to determine the dependence of
$\bar{\omega}_{N}$($\theta$) on luminosity, redshift, and galaxy-type. We
measure $\bar{\omega}_{N}$($\theta$) using oversampling techniques and use them
to calculate the projected, $s_{N}$. Using models derived from theoretical
power-spectra and perturbation theory, we measure the bias parameters $b_1$ and
$c_2$, finding that the large differences in both bias parameters ($b_1$ and
$c_2$) between early- and late-type galaxies are robust against changes in
redshift, luminosity, and $\sigma_8$, and that both terms are consistently
smaller for late-type galaxies. By directly comparing their higher-order
correlation measurements, we find large differences in the clustering of
late-type galaxies at redshifts lower than 0.3 and those at redshifts higher
than 0.3, both at large scales ($c_2$ is larger by $\sim0.5$ at $z > 0.3$) and
small scales (large amplitudes are measured at small scales only for $z > 0.3$,
suggesting much more merger driven star formation at $z > 0.3$). Finally, our
measurements of $c_2$ suggest both that $\sigma_8 < 0.8$ and $c_2$ is negative.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:51:23 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ross",
"Ashley J.",
""
],
[
"Brunner",
"Robert J.",
""
],
[
"Myers",
"Adam D.",
""
]
] |
0704.2574 | Takao Suzuki | Kenta Fuji and Takao Suzuki | Higher order Painleve system of type D^{(1)}_{2n+2} arising from
integrable hierarchy | 20 pages | null | null | null | math-ph math.MP math.RT | null | A higher order Painleve system of type D^{(1)}_{2n+2} was introduced by Y.
Sasano. It is an extension of the sixth Painleve equation for the affine Weyl
group symmetry. It is also expressed as a Hamiltonian system of order 2n with a
coupled Painleve VI Hamiltonian. In this paper, we discuss a derivation of this
system from a Drinfeld-Sokolov hierarchy.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 17:52:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fuji",
"Kenta",
""
],
[
"Suzuki",
"Takao",
""
]
] |
0704.2575 | Michael Hartmann Mr | Michael J Hartmann and Martin B Plenio | Strong photon non-linearities and photonic Mott insulators | minor changes, to appear in Phys. Rev. Lett | Phys. Rev. Lett. 99, 103601 (2007) | 10.1103/PhysRevLett.99.103601 | null | quant-ph cond-mat.other | null | We show, that photon non-linearities in electromagnetically induced
transparency can be at least one order of magnitude larger than predicted in
all previous approaches. As an application we demonstrate that, in this regime
they give rise to very strong photon - photon interactions which are strong
enough to make an experimental realization of a photonic Mott insulator state
feasible in arrays of coupled ultra high-Q micro-cavities.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:08:51 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Jul 2007 15:21:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hartmann",
"Michael J",
""
],
[
"Plenio",
"Martin B",
""
]
] |
0704.2576 | Georg Biedermann | Georg Biedermann | L-stable functors | 39 pages | null | null | null | math.AT math.CT | null | We generalize and greatly simplify the approach of Lydakis and
Dundas-R\"ondigs-{\O}stv{\ae}r to construct an L-stable model structure for
small functors from a closed symmetric monoidal model category V to a V-model
category M, where L is a small cofibrant object of V. For the special case
V=M=S_* pointed simplicial sets and L=S^1 this is the classical case of linear
functors and has been described as the first stage of the Goodwillie tower of a
homotopy functor. We show, that our various model structures are compatible
with a closed symmetric monoidal product on small functors. We compare them
with other L-stabilizations described by Hovey, Jardine and others. This gives
a particularly easy construction of the classical and the motivic stable
homotopy category with the correct smash product. We establish the monoid axiom
under certain conditions.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:14:44 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Biedermann",
"Georg",
""
]
] |
0704.2577 | Gelys Trancho | Gelys Trancho (1,2), Nate Bastian (3), Bryan W. Miller (4),
Fran\c{c}ois Schweizer (5) | Gemini Spectroscopic Survey of Young Star Clusters in
Merging/Interacting Galaxies. II. NGC 3256 Clusters | 20 pages, 10 figures, 3 tables; Accepted ApJ | Astrophys.J.664:284-295,2007 | 10.1086/518886 | null | astro-ph | null | We present Gemini optical spectroscopy of 23 young star clusters in NGC3256.
We find that the cluster ages range are from few Myr to ~150 Myr. All these
clusters are relatively massive (2--40)x 10^{5} \msun$ and appear to be of
roughly 1.5 \zo metallicity. The majority of the clusters in our sample follow
the same rotation curve as the gas and hence were presumably formed in the
molecular-gas disk. However, a western subsample of five clusters has
velocities that deviate significantly from the gas rotation curve. These
clusters may either belong to the second spiral galaxy of the merger or may
have formed in tidal-tail gas falling back into the system. We discuss our
observations in light of other known cluster populations in merging galaxies,
and suggest that NGC 3256 is similar to Arp 220, and hence may become an
Ultra-luminous Infrared Galaxy as the merger progresses and the star-formation
rate increases.
Some of the clusters which appeared as isolated in our ground-based images
are clearly resolved into multiple sub-components in the HST-ACS images. The
same effect has been observed in the Antennae galaxies, showing that clusters
are often not formed in isolation, but instead tend to form in larger groups or
cluster complexes.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:14:52 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Trancho",
"Gelys",
""
],
[
"Bastian",
"Nate",
""
],
[
"Miller",
"Bryan W.",
""
],
[
"Schweizer",
"François",
""
]
] |
0704.2578 | Xavier Xarles | Oleg Demchenko, Alexander Gurevich, Xavier Xarles | Formal completions of N\'eron models for algebraic tori | 35 pages. New version with new functoriality results. Final version
in the Proceedings of the London Mathematical Society, link:
http://plms.oxfordjournals.org/cgi/content/abstract/pdp039?ijkey=NVyJlz51HbzrzxM&keytype=ref | null | 10.1112/plms/pdp039 | null | math.AG math.NT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the formal group law which represents the completion of the
N\'eron model of an algebraic torus over the rationals that splits in a tamely
ramified abelian extension. As a tools in the proof, we define and give
criterions to compute the Weil restriction of a formal group law and the analog
of the fixed part of a formal group law with respect to the action of a
(finite) group.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:14:53 GMT"
},
{
"version": "v2",
"created": "Wed, 10 Sep 2008 13:32:49 GMT"
},
{
"version": "v3",
"created": "Thu, 19 Nov 2009 18:15:28 GMT"
}
] | 2009-11-19T00:00:00 | [
[
"Demchenko",
"Oleg",
""
],
[
"Gurevich",
"Alexander",
""
],
[
"Xarles",
"Xavier",
""
]
] |
0704.2579 | Mario Rodriguez-Meza | J.L. Cervantes-Cota, M.A. Rodriguez-Meza, R. Gabbasov, and J. Klapp | Newtonian limit of scalar-tensor theories and galactic dynamics:
isolated and interacting galaxies | 10 pages, 8 figures, accepted for publication in Rev. Mex. Fis;
http://rmf.fciencias.unam.mx/pdf/rmf-s/53/4/53_4_0022.pdf | Rev.Mex.Fis.53:S22-S32,2007 | null | null | astro-ph | null | We use the Newtonian limit of a general scalar-tensor theory around a
background field to study astrophysical effects. The gravitational theory
modifies the standard Newtonian potential by adding a Yukawa term to it, which
is quantified by two theoretical parameters: $\lambda$, the lenghtscale of the
gravitational interaction and its strength, $\alpha$. Within this formalism we
firstly present a numerical study on the formation of bars in isolated
galaxies. We have found for positive $\alpha$ that the modified gravity
destabilizes the galactic discs and leads to rapid bar formation in isolated
galaxies. Values of $\lambda$ in the range $\approx 8$ -- 14 kpc produce
strongest bars in isolated models. Then, we extent this work by considering
tidal effects due to interacting galaxies. We send two spirals to collide and
study the bar properties of the remnant. We characterize the bar kinematical
properties in terms of our parameters ($\lambda, \alpha$).
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:18:39 GMT"
}
] | 2011-06-09T00:00:00 | [
[
"Cervantes-Cota",
"J. L.",
""
],
[
"Rodriguez-Meza",
"M. A.",
""
],
[
"Gabbasov",
"R.",
""
],
[
"Klapp",
"J.",
""
]
] |
0704.2580 | Fernando Metz | F. L. Metz and W. K. Theumann | Period-two cycles in a feed-forward layered neural network model with
symmetric sequence processing | 8 pages and 5 figures | Phys. Rev. E 75, 041907 (2007) | 10.1103/PhysRevE.75.041907 | null | cond-mat.dis-nn | null | The effects of dominant sequential interactions are investigated in an
exactly solvable feed-forward layered neural network model of binary units and
patterns near saturation in which the interaction consists of a Hebbian part
and a symmetric sequential term. Phase diagrams of stationary states are
obtained and a new phase of cyclic correlated states of period two is found for
a weak Hebbian term, independently of the number of condensed patterns $c$.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:23:25 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Metz",
"F. L.",
""
],
[
"Theumann",
"W. K.",
""
]
] |
0704.2581 | Bohdan Andraka | C.R. Rotundu, B. Andraka, P. Schlottmann | Exotic Kondo-hole band resistivity and magnetoresistance of
Ce$_{1-x}$La$_{x}$Os$_4$Sb$_{12}$ alloys | null | null | 10.1103/PhysRevB.76.054416 | null | cond-mat.str-el | null | Electrical resistivity measurements of non-magnetic single-crystalline
Ce$_{1-x}$La$_x$Os$_4$Sb$_{12}$ alloys, $x=0.02$ and 0.1, are reported for
temperatures down to 20 mK and magnetic fields up to 18 T. At the lowest
temperatures, the resistivity of Ce$_{0.98}$La$_{0.02}$Os$_4$Sb$_{12}$ has a
Fermi-liquid-like temperature variation $\rho=\rho_0+A T^2$, but with negative
$A$ in small fields. The resistivity has an unusually strong magnetic field
dependence for a paramagnetic metal. The 20 mK resistivity increases by 75%
between H=0 and 4 T and then decreases by 65% between 4 T and 18 T. Similarly,
the $A$ coefficient increases with the field from -77 to 29$
\mu\Omega$cmK$^{-2}$ between H=0 and 7 T and then decreases to 18$
\mu\Omega$cmK$^{-2}$ for 18 T. This nontrivial temperature and field variation
is attributed to the existence of a very narrow Kondo-hole band in the
hybridization gap, which pins the Fermi energy. Due to disorder the Kondo-hole
band has localized states close to the band edges. The resistivity for $x=0.1$
has a qualitatively similar behavior to that of $x=0.02$, but with a larger
Kondo-hole band.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:23:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rotundu",
"C. R.",
""
],
[
"Andraka",
"B.",
""
],
[
"Schlottmann",
"P.",
""
]
] |
0704.2582 | Todor M. Mishonov | T.M. Mishonov, M.V. Stoev | Corbino experimental set-up for Cooper pair mass spectroscopy and
determination of mobility in normal phase | 2 pages, no figures, minor linguistic improvements in second version | null | null | null | cond-mat.supr-con | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We are suggesting an electronic method for Cooper pair mass spectroscopy of
thin superconducting films. The method can be applied, for example, for 100 nm
thin high-T_c films grown on insulator substrate 10 mm X 10 mm. In Corbino
geometry two Ohmic contacts have to be made on the film evaporating Ag or using
silver paste: one circle with radius r_a (1) and a ring electrode with internal
radius r_b (2). In the in-between space (r_a,r_b) a ring electrode from mylar
assures a capacitive connection between the superconducting layer and the
metallized surface (3) of the mylar. In such a way we have an field effect
transistor (FET) type structure with a circular gate. When at low enough
temperatures T << T_c an AC current with frequency omega is applied between the
circle source (1) and the ring-shaped drain (2) an AC Bernoulli voltage with
double frequency 2f appears between the gate (3) and the source (1). The 2f
signal depends on Cooper pair effective mass and its systematic investigation
gives a Cooper pair mass spectroscopy. In the normal phase 2f gives logarithmic
derivative of the density of states (DOS) with respect of Fermi energy.
Applying a gate voltage in the same structure gives the mobility of the normal
phase.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:30:15 GMT"
},
{
"version": "v2",
"created": "Wed, 17 Sep 2008 12:05:44 GMT"
}
] | 2008-09-17T00:00:00 | [
[
"Mishonov",
"T. M.",
""
],
[
"Stoev",
"M. V.",
""
]
] |
0704.2583 | H\"usn\"u Aksakal | Husnu Aksakal | $2\times250$ GeV CLIC $\gamma\gamma$ Collider Based on its Drive Beam
FEL | 20 pages, 4 figures | null | null | null | physics.acc-ph | null | CLIC is a linear $e^+e^-$ ($\gamma\gamma$) collider project which uses a
drive beam to accelerate the main beam. The drive beam provides RF power for
each corresponding unit of the main linac through energy extracting RF
structures. CLIC has a wide range of center-of-mass energy options from 150 GeV
to 3 TeV. The present paper contains optimization of Free Electron Laser (FEL)
using one bunch of CLIC drive beam in order to provide polarized light
amplification using appropriate wiggler and luminosity spectrum of
$\gamma\gamma$ collider for $E_{cm}$=0.5 TeV. Then amplified laser can be
converted to a polarized high-energy $\gamma$ beam at the Conversion point
(CP-prior to electron positron interaction point) in the process of Compton
backscattering. At the CP a powerful laser pulse (FEL) focused to main linac
electrons (positrons). Here this scheme described and it is show that CLIC
drive beam parameters satisfy the requirement of FEL additionally essential
undulator parameters has been defined. Achievable $\gamma\gamma$ luminosity is
above $10^{34}$.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:34:01 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Aksakal",
"Husnu",
""
]
] |
0704.2584 | Theodore Burkhardt | Yingzi Yang, Theodore W. Burkhardt, and Gerhard Gompper | Free energy and extension of a semiflexible polymer in cylindrical
confining geometries | 15 pages without figures, 5 figures | Phys. Rev. E 76, 011804 (2007) | 10.1103/PhysRevE.76.011804 | null | cond-mat.soft | null | We consider a long, semiflexible polymer, with persistence length $P$ and
contour length $L$, fluctuating in a narrow cylindrical channel of diameter
$D$. In the regime $D\ll P\ll L$ the free energy of confinement $\Delta F$ and
the length of the channel $R_\parallel$ occupied by the polymer are given by
Odijk's relations $\Delta F/R_\parallel=A_\circ k_BTP^{-1/3}D^{-2/3}$ and
$R_\parallel=L[1-\alpha_\circ(D/P)^{2/3}]$, where $A_\circ$ and $\alpha_\circ$
are dimensionless amplitudes. Using a simulation algorithm inspired by PERM
(Pruned Enriched Rosenbluth Method), which yields results for very long
polymers, we determine $A_\circ$ and $\alpha_\circ$ and the analogous
amplitudes for a channel with a rectangular cross section. For a semiflexible
polymer confined to the surface of a cylinder, the corresponding amplitudes are
derived with an exact analytic approach. The results are relevant for
interpreting experiments on biopolymers in microchannels or microfluidic
devices.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:38:01 GMT"
}
] | 2011-07-19T00:00:00 | [
[
"Yang",
"Yingzi",
""
],
[
"Burkhardt",
"Theodore W.",
""
],
[
"Gompper",
"Gerhard",
""
]
] |
0704.2585 | Gil de Oliveira-Neto | G. A. Monerat, G. Oliveira-Neto, E. V. Corr\^ea Silva, L. G. Ferreira
Filho, P. Romildo Jr., J. C. Fabris, R. Fracalossi, F. G. Alvarenga, S. V. B.
Gon\c{c}alves | The dynamics of the early universe and the initial conditions for
inflation in a model with radiation and a Chaplygin gas | Revtex file with 12 pages and 6 PS figures | Phys.Rev.D76:024017,2007 | 10.1103/PhysRevD.76.024017 | null | gr-qc | null | The modeling of the early universe is done through the quantization of a
Friedmann-Robertson-Walker model with positive curvature. The material content
consists of two fluids: radiation and Chaplygin gas. The quantization of these
models is made by following the Wheeler and DeWitt's prescriptions. Using the
Schutz formalism, the time notion is recovered and the Wheeler-DeWitt equation
transforms into a time dependent Schr\"{o}dinger equation, which rules the
dynamics of the early universe, under the action of an effective potential
$V_{ef}$. Using a finite differences method and the Crank-Nicholson scheme, in
a code implemented in the program OCTAVE, we solve the corresponding time
dependent Schr\"{o}dinger equation and obtain the time evolution of a initial
wave packet. This wave packet satisfies appropriate boundary conditions. The
calculation of the tunneling probabilities shows that the universe may emerge
from the Planck era to an inflationary phase. It also shows that, the tunneling
probability is a function of the mean energy of the initial wave packet and of
two parameters related to the Chaplygin gas. We also show a comparison between
these results and those obtained by the WKB approximation.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:39:52 GMT"
}
] | 2016-03-28T00:00:00 | [
[
"Monerat",
"G. A.",
""
],
[
"Oliveira-Neto",
"G.",
""
],
[
"Silva",
"E. V. Corrêa",
""
],
[
"Filho",
"L. G. Ferreira",
""
],
[
"Romildo",
"P.",
"Jr."
],
[
"Fabris",
"J. C.",
""
],
[
"Fracalossi",
"R.",
""
],
[
"Alvarenga",
"F. G.",
""
],
[
"Gonçalves",
"S. V. B.",
""
]
] |
0704.2586 | Kerry Soileau | Kerry M. Soileau | Distributions of Roots of Reduced Cubic Equations with Random
Coefficients | Minor typo correction | null | null | null | math.PR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If the coefficients of polynomials are selected by some random process, the
zeros of the resulting polynomials are in some sense random. In this paper the
author rephrases the above in more precise language, and calculates the joint
conditional densities of a random vector whose values determine almost surely
the zeros of a "random" reduced cubic.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:43:42 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 17:41:51 GMT"
},
{
"version": "v3",
"created": "Fri, 23 Nov 2012 14:27:47 GMT"
}
] | 2012-11-26T00:00:00 | [
[
"Soileau",
"Kerry M.",
""
]
] |
0704.2587 | Christopher J. Leininger | Richard P. Kent IV and Christopher J Leininger | Uniform convergence in the mapping class group | v2. Accepted version. Minor revisions incorporating referee's
comments. v1. 21 pages | null | null | null | math.GT math.GR | null | We characterize convex cocompact subgroups of the mapping class group of a
surface in terms of uniform convergence actions on the zero locus of the limit
set. We also construct subgroups that act as uniform convergence groups on
their limit sets, but are not convex cocompact.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 18:57:13 GMT"
},
{
"version": "v2",
"created": "Sun, 26 Aug 2007 15:36:49 GMT"
}
] | 2007-08-26T00:00:00 | [
[
"Kent",
"Richard P.",
"IV"
],
[
"Leininger",
"Christopher J",
""
]
] |
0704.2588 | Wai-Yee Keung | Kingman Cheung, Wai-Yee Keung, and Tzu-Chiang Yuan | Collider signals in unparticle physics | 4 pages including 4 figures | Phys.Rev.Lett.99:051803,2007 | 10.1103/PhysRevLett.99.051803 | null | hep-ph | null | Phenomenology of the notion of an unparticle U, recently perceived by Georgi,
to describe a scale invariant sector with a non-trivial infrared fixed point at
a higher energy scale is explored in details. Behaving like a collection of d_U
(the scale dimension of the unparticle operator O_U) invisible massless
particles, this unparticle can be unveiled by measurements of various energy
distributions for the processes Z to fermion pair + U and e-e+ to gamma U at
e-e+ colliders, as well as mono-jet production at hadron colliders. We also
study the propagator effects of the unparticle through the Drell-Yan tree level
process and the one-loop muon anomaly.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:51:52 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Apr 2007 19:35:51 GMT"
},
{
"version": "v3",
"created": "Thu, 9 Aug 2007 20:02:37 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cheung",
"Kingman",
""
],
[
"Keung",
"Wai-Yee",
""
],
[
"Yuan",
"Tzu-Chiang",
""
]
] |
0704.2589 | Malcolm Coe | M. J.Coe (Southampton), A.J. Bird (Southampton), A.B. Hill
(Southampton), V.A. McBride (Southampton), M. Schurch (Southampton), J.
Galache (CfA), C. A. Wilson (NASA/MSFC), M. Finger (NASA/MSFC), D.A. Buckley
(SAAO) E. Romero-Colmenero (SAAO) | Now you see it, now you don't - the circumstellar disk in the GRO
J1008--57 system | Accepted for publication in MNRAS | Mon.Not.Roy.Astron.Soc.378:1427-1433,2007 | 10.1111/j.1365-2966.2007.11878.x | null | astro-ph | null | Multiwavelength observations are reported here of the Be/X-ray binary pulsar
system GRO J1008-57. Over ten years worth of data are gathered together to show
that the periodic X-ray outbursts are dependant on both the binary motion and
the size of the circumstellar disk. In the first instance an accurate orbital
solution is determined from pulse periods, and in the second case the strength
and shape of the Halpha emission line is shown to be a valuable indicator of
disk size and its behaviour. Furthermore, the shape of the emission line
permits a direct determination of the disk size which is in good agreement with
theoretical estimates. A detailed study of the pulse period variations during
outbursts determined the binary period to be 247.8, in good agreement with the
period determined from the recurrence of the outbursts.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:13:07 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Coe",
"M. J.",
"",
"Southampton"
],
[
"Bird",
"A. J.",
"",
"Southampton"
],
[
"Hill",
"A. B.",
"",
"Southampton"
],
[
"McBride",
"V. A.",
"",
"Southampton"
],
[
"Schurch",
"M.",
"",
"Southampton"
],
[
"Galache",
"J.",
"",
"CfA"
],
[
"Wilson",
"C. A.",
"",
"NASA/MSFC"
],
[
"Finger",
"M.",
"",
"NASA/MSFC"
],
[
"Buckley",
"D. A.",
"",
"SAAO"
],
[
"Romero-Colmenero",
"E.",
"",
"SAAO"
]
] |
0704.2590 | Saverio Russo | S. Russo, J. Tobiska, T.M. Klapwijk and A.F. Morpurgo | Adiabatic quantum pumping at the Josephson frequency | 4 pages, 3 figures | null | 10.1103/PhysRevLett.99.086601 | null | cond-mat.mes-hall cond-mat.supr-con | null | We analyze theoretically adiabatic quantum pumping through a normal conductor
that couples the normal regions of two superconductor/normal
metal/superconductor Josephson junctions. By using the phases of the
superconducting order parameter in the superconducting contacts as pumping
parameters, we demonstrate that a non zero pumped charge can flow through the
device. The device exploits the evolution of the superconducting phases due to
the ac Josephson effect, and can therefore be operated at very high frequency,
resulting in a pumped current as large as a few nanoAmperes. The experimental
relevance of our calculations is discussed.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:16:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Russo",
"S.",
""
],
[
"Tobiska",
"J.",
""
],
[
"Klapwijk",
"T. M.",
""
],
[
"Morpurgo",
"A. F.",
""
]
] |
0704.2591 | Rajamani Narayanan | R. Narayanan, H. Neuberger, F. Reynoso | Phases of three dimensional large N QCD on a continuum torus | 11 pages, 6 figures, 1 table | Phys.Lett.B651:246-252,2007 | 10.1016/j.physletb.2007.06.016 | null | hep-lat hep-th | null | It is established by numerical means that continuum large N QCD defined on a
three dimensional torus can exist in four different phases. They are (i)
confined phase; (ii) deconfined phase; (iii) small box at zero temperature and
(iv) small box at high temperatures.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:18:22 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Narayanan",
"R.",
""
],
[
"Neuberger",
"H.",
""
],
[
"Reynoso",
"F.",
""
]
] |
0704.2592 | Calder Daenzer | Calder Daenzer | A groupoid approach to noncommutative T-duality | Same theorems, typos corrected | null | null | null | math.QA math-ph math.KT math.MP math.OA | null | Topological T-duality is a transformation taking a gerbe on a principal torus
bundle to a gerbe on a principal dual-torus bundle. We give a new geometric
construction of T-dualization, which allows the duality to be extended in
following two directions. First, bundles of groups other than tori, even
bundles of some nonabelian groups, can be dualized. Second, bundles whose duals
are families of noncommutative groups (in the sense of noncommutative geometry)
can be treated, though in this case the base space of the bundles is best
viewed as a topological stack.
Some methods developed for the construction may be of independent interest.
These are a Pontryagin type duality that interchanges commutative principal
bundles with gerbes, a nonabelian Takai type duality for groupoids, and the
computation of certain equivariant Brauer groups.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:35:38 GMT"
},
{
"version": "v2",
"created": "Sat, 6 Oct 2007 22:55:13 GMT"
}
] | 2007-10-07T00:00:00 | [
[
"Daenzer",
"Calder",
""
]
] |
0704.2593 | Monika Sinha | Monika Sinha, Banibrata Mukhopadhyay | CPT and lepton number violation in neutrino sector: Modified mass matrix
and oscillation due to gravity | 16 pages, no figure. A new section included describing effect of
gravity on flavor oscillation; title, abstract, discussion section modified.
Final version to appear in Physical Review D | Phys.Rev.D77:025003,2008 | 10.1103/PhysRevD.77.025003 | null | hep-ph astro-ph gr-qc | null | We study the consequences of CPT and lepton number violation in neutrino
sector. For CPT violation we take gravity with which neutrino and antineutrino
couple differently. Gravity mixes neutrino and antineutrino in an unequal ratio
to give two mass eigenstates. Lepton number violation interaction together with
CPT violation gives rise to neutrino-antineutrino oscillation. Subsequently, we
study the neutrino flavor mixing and oscillation under the influence of
gravity. It is found that gravity changes flavor oscillation significantly
which influences the relative abundance of different flavors in present
universe. We show that the neutrinoless double beta decay rate is modified due
to presence of gravity- the origin of CPT violation, as the mass of the flavor
state is modified.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:32:00 GMT"
},
{
"version": "v2",
"created": "Wed, 21 Nov 2007 15:23:26 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Sinha",
"Monika",
""
],
[
"Mukhopadhyay",
"Banibrata",
""
]
] |
0704.2594 | Harm Derksen | Harm Derksen, Gregor Kemper | Computing invariants of algebraic group actions in arbitrary
characteristic | 43 pages | null | null | null | math.AC math.AG | null | Let G be an affine algebraic group acting on an affine variety
X. We present an algorithm for computing generators of the invariant ring
K[X]^G in the case where G is reductive. Furthermore, we address the case where
G is connected and unipotent, so the invariant ring need not be finitely
generated. For this case, we develop an algorithm which computes K[X]^G in
terms of a so-called colon-operation. From this, generators of K[X]^G can be
obtained in finite time if it is finitely generated. Under the additional
hypothesis that K[X] is factorial, we present an algorithm that finds a
quasi-affine variety whose coordinate ring is K[X]^G. Along the way, we develop
some techniques for dealing with non-finitely generated algebras. In
particular, we introduce the finite generation locus ideal.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:34:36 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Derksen",
"Harm",
""
],
[
"Kemper",
"Gregor",
""
]
] |
0704.2595 | Oliver Hahn | Oliver Hahn (1), C. Marcella Carollo (1), Cristiano Porciani (1) and
Avishai Dekel (2) ((1) ETH Zurich, (2) HU Jerusalem) | The Evolution of Dark Matter Halo Properties in Clusters, Filaments,
Sheets and Voids | 12 pages, 12 figures. Version accepted for publication in MNRAS.
Version with high-resolution figures available at
http://www.exp-astro.phys.ethz.ch/hahn/pub/HCPD07.pdf | null | 10.1111/j.1365-2966.2007.12249.x | null | astro-ph | null | We use a series of N-body simulations of the LCDM cosmology to investigate
the redshift evolution since z=1 of the properties and alignment with the
large-scale structure of haloes in clusters, filaments, sheets and voids. We
find that: (i) Once a rescaling of the halo mass with M*, the mass scale
collapsing at redshift z, is performed, there is no further significant
redshift dependence in the halo properties; (ii) The environment influences
halo shape and formation time at all investigated redshifts for haloes with
masses M<M*; and (iii) There is a significant alignment of both spin and shape
of haloes with filaments and sheets. In detail, at all redshifts up to z=1: a)
Haloes with M<M* tend to be more oblate when located in clusters than in the
other environments; this trend is reversed at higher masses: above about M*,
halos in clusters are typically more prolate than similar massive haloes in
sheets, filaments and voids. b) Haloes with M>M* in filaments spin more rapidly
than similar mass haloes in clusters; haloes in voids have the lowest median
spin parameters; c) Haloes with M<M* tend to be younger in voids and older in
clusters; d) In sheets, halo spin vectors tend to lie within the sheet plane
independent of mass; in filaments, instead, haloes with M<M* tend to spin
parallel to the filament and haloes with M>M* perpendicular to it. For masses
M>M*, the major axis of haloes in filaments and sheets is strongly aligned with
the filament or the sheet. Such halo-LSS alignments may be of importance in
weak lensing analyses of cosmic shear. A question that is opened by our study
is why, in the 0 < z < 1 redshift regime that we have investigated, the mass
scale M* sets roughly the threshold below which the LSS-environment either
begins to affect, or reverses, the properties of dark matter haloes.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:36:53 GMT"
},
{
"version": "v2",
"created": "Tue, 21 Aug 2007 14:48:13 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hahn",
"Oliver",
"",
"ETH Zurich"
],
[
"Carollo",
"C. Marcella",
"",
"ETH Zurich"
],
[
"Porciani",
"Cristiano",
"",
"ETH Zurich"
],
[
"Dekel",
"Avishai",
"",
"HU Jerusalem"
]
] |
0704.2596 | Markus Grassl | Markus Grassl | Computing Extensions of Linear Codes | accepted for publication at ISIT 07 | Proceedings 2007 IEEE International Symposium on Information
Theory (ISIT 2007), Nice, France, June 2007, pp. 476-480 | 10.1109/ISIT.2007.4557095 | null | cs.IT cs.DM math.IT | null | This paper deals with the problem of increasing the minimum distance of a
linear code by adding one or more columns to the generator matrix. Several
methods to compute extensions of linear codes are presented. Many codes
improving the previously known lower bounds on the minimum distance have been
found.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:28:33 GMT"
}
] | 2011-03-31T00:00:00 | [
[
"Grassl",
"Markus",
""
]
] |
0704.2597 | Marek Ku\'s | Jan Samsonowicz, Marek Kus, Maciej Lewenstein | Separability, entanglement and full families of commuting normal
matrices | 14 pages, some typos corrected, a reference added, in print in Phys.
Rev. A | null | 10.1103/PhysRevA.76.022314 | null | quant-ph | null | We reduce the question whether a given quantum mixed state is separable or
entangled to the problem of existence of a certain full family of commuting
normal matrices whose matrix elements are partially determined by components of
the pure states constituting a decomposition of the considered mixture. The
method reproduces many known entanglement and/or separability criteria, and
provides yet another geometrical characterization of mixed separable states.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:49:58 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 22:38:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Samsonowicz",
"Jan",
""
],
[
"Kus",
"Marek",
""
],
[
"Lewenstein",
"Maciej",
""
]
] |
0704.2598 | Susan Cox | S. Cox, J.C. Loudon, A.J. Williams, J.P. Attfield, J. Singleton, P.A.
Midgley, N.D. Mathur | Very weak electron-phonon coupling and strong strain coupling in
manganites | 6 pages, 7 figures | null | 10.1103/PhysRevB.78.035129 | null | cond-mat.str-el | null | The coupling of the manganite stripe phase to the lattice and to strain has
been investigated via transmission electron microscopy studies of
polycrystalline and thin film manganites. In polycrystalline \PCMOfiftwo a
lockin to $q/a^*=0.5$ in a sample with $x>0.5$ has been observed for the first
time. Such a lockin has been predicted as a key part of the Landau CDW theory
of the stripe phase. Thus it is possible to constrain the size of the
electron-phonon coupling in the CDW Landau theory to between 0.04% and 0.05% of
the electron-electron coupling term. In the thin film samples, films of the
same thickness grown on two different substrates exhibited different
wavevectors. The different strains present in the films on the two substrates
can be related to the wavevector observed via Landau theory. It is demonstrated
that the the elastic term which favours an incommensurate modulation has a
similar size to the coupling between the strain and the wavevector, meaning
that the coupling of strain to the superlattice is unexpectedly strong.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 19:50:00 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 05:31:38 GMT"
},
{
"version": "v3",
"created": "Fri, 19 Oct 2007 06:29:39 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cox",
"S.",
""
],
[
"Loudon",
"J. C.",
""
],
[
"Williams",
"A. J.",
""
],
[
"Attfield",
"J. P.",
""
],
[
"Singleton",
"J.",
""
],
[
"Midgley",
"P. A.",
""
],
[
"Mathur",
"N. D.",
""
]
] |
0704.2599 | Jungil Lee | Geoffrey T. Bodwin (Argonne), Eric Braaten, Daekyoung Kang (Ohio State
U.), Jungil Lee (Korea U.) | Inclusive Charm Production in chi_b Decays | 39 pages, 3 figures, Minor corrections, Version published in Phys.
Rev. D | Phys.Rev.D76:054001,2007 | 10.1103/PhysRevD.76.054001 | ANL-HEP-PR-07-20 | hep-ph | null | We calculate the inclusive decay rate of the spin-triplet bottomonium states
chi_{bJ} into charm hadrons, including the leading-order color-singlet and
color-octet bb-bar annihilation mechanisms. We also calculate the momentum
distribution of the charm quark from the decay of chi_{bJ}. The infrared
divergences from the color-singlet process bb-bar -> cc-bar g are factored into
the probability density at the origin for a bb-bar pair in a color-octet state.
That probability density can be determined phenomenologically from the fraction
of decays of chi_{bJ} that include charm hadrons. It can then be used to
predict the partial widths into light hadrons for all four states in the P-wave
bottomonium multiplet.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 21:04:48 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Sep 2007 01:46:59 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bodwin",
"Geoffrey T.",
"",
"Argonne"
],
[
"Braaten",
"Eric",
"",
"Ohio State\n U."
],
[
"Kang",
"Daekyoung",
"",
"Ohio State\n U."
],
[
"Lee",
"Jungil",
"",
"Korea U."
]
] |
0704.2600 | Juan Gonzalez-Meneses | Juan Gonzalez-Meneses, Volker Gebhardt | On the cycling operation in braid groups | 20 pages | null | null | null | math.GT math.GR | null | The cycling operation is a special kind of conjugation that can be applied to
elements in Artin's braid groups, in order to reduce their length. It is a key
ingredient of the usual solutions to the conjugacy problem in braid groups. In
their seminal paper on braid-cryptography, Ko, Lee et al. proposed the {\it
cycling problem} as a hard problem in braid groups that could be interesting
for cryptography. In this paper we give a polynomial solution to that problem,
mainly by showing that cycling is surjective, and using a result by Maffre
which shows that pre-images under cycling can be computed fast. This result
also holds in every Artin-Tits group of spherical type.
On the other hand, the conjugacy search problem in braid groups is usually
solved by computing some finite sets called (left) ultra summit sets
(left-USS), using left normal forms of braids. But one can equally use right
normal forms and compute right-USS's. Hard instances of the conjugacy search
problem correspond to elements having big (left and right) USS's. One may think
that even if some element has a big left-USS, it could possibly have a small
right-USS. We show that this is not the case in the important particular case
of rigid braids. More precisely, we show that the left-USS and the right-USS of
a given rigid braid determine isomorphic graphs, with the arrows reversed, the
isomorphism being defined using iterated cycling. We conjecture that the same
is true for every element, not necessarily rigid, in braid groups and
Artin-Tits groups of spherical type.
| [
{
"version": "v1",
"created": "Thu, 19 Apr 2007 20:24:58 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gonzalez-Meneses",
"Juan",
""
],
[
"Gebhardt",
"Volker",
""
]
] |
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