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0706.0014
Anna Urbanska
Anna Urbanska (LJK)
Towards an exact adaptive algorithm for the determinant of a rational matrix
null
null
null
null
cs.SC
null
In this paper we propose several strategies for the exact computation of the determinant of a rational matrix. First, we use the Chinese Remaindering Theorem and the rational reconstruction to recover the rational determinant from its modular images. Then we show a preconditioning for the determinant which allows us to skip the rational reconstruction process and reconstruct an integer result. We compare those approaches with matrix preconditioning which allow us to treat integer instead of rational matrices. This allows us to introduce integer determinant algorithms to the rational determinant problem. In particular, we discuss the applicability of the adaptive determinant algorithm of [9] and compare it with the integer Chinese Remaindering scheme. We present an analysis of the complexity of the strategies and evaluate their experimental performance on numerous examples. This experience allows us to develop an adaptive strategy which would choose the best solution at the run time, depending on matrix properties. All strategies have been implemented in LinBox linear algebra library.
[ { "version": "v1", "created": "Thu, 31 May 2007 20:23:08 GMT" } ]
2009-04-16T00:00:00
[ [ "Urbanska", "Anna", "", "LJK" ] ]
0706.0015
E. Leicht
E. A. Leicht, Gavin Clarkson, Kerby Shedden, and M. E. J. Newman
Large-scale structure of time evolving citation networks
10 pages, 6 figures; journal names for 4 references fixed
Eur. Phys. J. B 59, 75-83 (2007)
10.1140/epjb/e2007-00271-7
null
physics.soc-ph cond-mat.stat-mech
null
In this paper we examine a number of methods for probing and understanding the large-scale structure of networks that evolve over time. We focus in particular on citation networks, networks of references between documents such as papers, patents, or court cases. We describe three different methods of analysis, one based on an expectation-maximization algorithm, one based on modularity optimization, and one based on eigenvector centrality. Using the network of citations between opinions of the United States Supreme Court as an example, we demonstrate how each of these methods can reveal significant structural divisions in the network, and how, ultimately, the combination of all three can help us develop a coherent overall picture of the network's shape.
[ { "version": "v1", "created": "Thu, 31 May 2007 20:34:26 GMT" }, { "version": "v2", "created": "Wed, 6 Jun 2007 00:00:47 GMT" } ]
2007-10-18T00:00:00
[ [ "Leicht", "E. A.", "" ], [ "Clarkson", "Gavin", "" ], [ "Shedden", "Kerby", "" ], [ "Newman", "M. E. J.", "" ] ]
0706.0016
Maxim Dzero
M. Dzero and P. Coleman
Superconductivity due to co-operative Kondo effect in Pu 115's
2 pages; Proceedings of SCES'07
Physica B 403, 955-957 (2008)
10.1016/j.physb.2007.10.063
null
cond-mat.str-el cond-mat.supr-con
null
We outline key elements of a theory that accounts for anomalous properties of the PuCoGa$_5$ and PuRhGa$_5$ compounds as a consequence of a two-body interference between two Kondo screening channels. Virtual valence fluctuations of the magnetic Pu configurations create two conduction channels of different symmetry. Using the symplectic large-N approach, we are able to demonstrate our pairing mechanism in an exactly solvable large-N limit. The critical temperature reaches its maximum when the energy levels of excited valence configurations are almost degenerate. The symmetry of the order parameter is determined by the product of the Wannier form factors in the interfering conduction channels.
[ { "version": "v1", "created": "Thu, 31 May 2007 20:41:46 GMT" } ]
2009-11-13T00:00:00
[ [ "Dzero", "M.", "" ], [ "Coleman", "P.", "" ] ]
0706.0017
Davison E. Soper
Zoltan Nagy and Davison E. Soper
Parton showers with quantum interference
83 pages with 10 figures; revised version is close to published version
JHEP 0709:114,2007
10.1088/1126-6708/2007/09/114
CERN-PH-TH/2007-082
hep-ph
null
We specify recursive equations that could be used to generate a lowest order parton shower for hard scattering in hadron-hadron collisions. The formalism is based on the factorization soft and collinear interactions from relatively harder interactions in QCD amplitudes. It incorporates quantum interference between different amplitudes in those cases in which the interference diagrams have leading soft or collinear singularities. It incorporates the color and spin information carried by partons emerging from a hard interaction. One motivation for this work is to have a method that can naturally cooperate with next-to-leading order calculations.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 18:08:38 GMT" }, { "version": "v2", "created": "Tue, 2 Oct 2007 23:48:59 GMT" } ]
2009-04-22T00:00:00
[ [ "Nagy", "Zoltan", "" ], [ "Soper", "Davison E.", "" ] ]
0706.0018
Heiko Bauke
Heiko Bauke and David Sherrington
Local attachment in networks under churn
null
null
null
null
cond-mat.stat-mech
null
In this contribution we introduce local attachment as an universal network-joining protocol for peer-to-peer networks, social networks, or other kinds of networks. Based on this protocol nodes in a finite-size network dynamically create power-law connectivity distributions. Nodes or peers maintain them in a self-organized statistical way by incorporating local information only. We investigate the structural and macroscopic properties of such local attachment networks by extensive numerical simulations, including correlations and scaling relations between exponents. The emergence of the power-law degree distribution is further investigated by considering preferential attachment with a nonlinear attractiveness function as an approximative model for local attachment. This study suggests the local attachment scheme as a procedure to be included in future peer-to-peer protocols to enable the efficient production of stable network topologies in a continuously changing environment.
[ { "version": "v1", "created": "Thu, 31 May 2007 21:28:29 GMT" } ]
2007-06-04T00:00:00
[ [ "Bauke", "Heiko", "" ], [ "Sherrington", "David", "" ] ]
0706.0019
Sergey Koposov E.
S. Koposov (1,2), J. T. A. de Jong (1), V. Belokurov (2), H.-W. Rix (1), D. B. Zucker (2), N. W. Evans (2), G. Gilmore (2), M. J. Irwin (2), E. F. Bell (1) ((1) Max Planck Institute for Astronomy, (2) Institute of Astronomy, University of Cambridge)
The discovery of two extremely low luminosity Milky Way globular clusters
accepted for publication in ApJ, minor revisions
Astrophys.J.669:337-342,2007
10.1086/521422
null
astro-ph
null
We report the discovery of two extremely low luminosity globular clusters in the Milky Way Halo. These objects were detected in the Sloan Digital Sky Survey Data Release 5 and confirmed with deeper imaging at the Calar Alto Observatory. The clusters, Koposov 1 and Koposov 2, are located at $\sim 40-50$ kpc and appear to have old stellar populations and luminosities of only $M_V \sim -1$ mag. Their observed sizes of $\sim 3$ pc are well within the expected tidal limit of $\sim$10 pc at that distance. Together with Palomar 1, AM 4 and Whiting 1, these new clusters are the lowest luminosity globulars orbiting the Milky Way, with Koposov 2 the most extreme. Koposov 1 appears to lie close to distant branch of the Sagittarius stream. The half-mass relaxation times of Koposov 1 and 2 are only $\sim 70$ and $\sim 55$ Myr respectively (2 orders of magnitude shorter than the age of the stellar populations), so it would seem that they have undergone drastic mass segregation. Since they do not appear to be very concentrated, their evaporation timescales may be as low as $\sim 0.1 t_{\rm Hubble}$. These discoveries show that the structural parameter space of globular clusters in the Milky Way halo is not yet fully explored. They also add, through their short remaining survival times, significant direct evidence for a once much larger population of globular clusters.
[ { "version": "v1", "created": "Thu, 31 May 2007 21:01:57 GMT" }, { "version": "v2", "created": "Fri, 14 Sep 2007 16:09:23 GMT" } ]
2010-03-01T00:00:00
[ [ "Koposov", "S.", "" ], [ "de Jong", "J. T. A.", "" ], [ "Belokurov", "V.", "" ], [ "Rix", "H. -W.", "" ], [ "Zucker", "D. B.", "" ], [ "Evans", "N. W.", "" ], [ "Gilmore", "G.", "" ], [ "Irwin", "M. J.", "" ], [ "Bell", "E. F.", "" ] ]
0706.0020
Samuel Lomonaco Jr.
Louis H. Kauffman and Samuel J. Lomonaco, Jr
A 3-Stranded Quantum Algorithm for the Jones Polynomial
19 pages, 10 figures, to appear in Proc. SPIE, 6573-29, (2007)
null
10.1117/12.719399
null
quant-ph
null
Let K be a 3-stranded knot (or link), and let L denote the number of crossings in K. Let $\epsilon_{1}$ and $\epsilon_{2}$ be two positive real numbers such that $\epsilon_{2}$ is less than or equal to 1. In this paper, we create two algorithms for computing the value of the Jones polynomial of K at all points $t=exp(i\phi)$ of the unit circle in the complex plane such that the absolute value of $\phi$ is less than or equal to $\pi/3$. The first algorithm, called the classical 3-stranded braid (3-SB) algorithm, is a classical deterministic algorithm that has time complexity O(L). The second, called the quantum 3-SB algorithm, is a quantum algorithm that computes an estimate of the Jones polynomial of K at $exp(i\phi))$ within a precision of $\epsilon_{1}$ with a probability of success bounded below by $1-\epsilon_{2}%. The execution time complexity of this algorithm is O(nL), where n is the ceiling function of (ln(4/\epsilon_{2}))/(2(\epsilon_{2})^2). The compilation time complexity, i.e., an asymptotic measure of the amount of time to assemble the hardware that executes the algorithm, is O(L).
[ { "version": "v1", "created": "Thu, 31 May 2007 21:06:32 GMT" } ]
2012-08-27T00:00:00
[ [ "Kauffman", "Louis H.", "" ], [ "Lomonaco,", "Samuel J.", "Jr" ] ]
0706.0021
Amilcar Queiroz Mr
A. P. Balachandran, A. R. Queiroz, A. M. Marques and P. Teotonio-Sobrinho
Quantum Fields with Noncommutative Target Spaces
20 pages, 5 figures; Abstract changed. Changes and corrections in the text. References added
Phys.Rev.D77:105032,2008
10.1103/PhysRevD.77.105032
null
hep-th astro-ph gr-qc hep-ph math.QA
null
Quantum field theories (QFT's) on noncommutative spacetimes are currently under intensive study. Usually such theories have world sheet noncommutativity. In the present work, instead, we study QFT's with commutative world sheet and noncommutative target space. Such noncommutativity can be interpreted in terms of twisted statistics and is related to earlier work of Oeckl [1], and others [2,3,4,5,6,7,8]. The twisted spectra of their free Hamiltonians has been found earlier by Carmona et al [9,10]. We review their derivation and then compute the partition function of one such typical theory. It leads to a deformed black body spectrum, which is analysed in detail. The difference between the usual and the deformed black body spectrum appears in the region of high frequencies. Therefore we expect that the deformed black body radiation may potentially be used to compute a GZK cut-off which will depend on the noncommutative parameter $\theta$.
[ { "version": "v1", "created": "Thu, 31 May 2007 21:37:45 GMT" }, { "version": "v2", "created": "Fri, 12 Oct 2007 04:49:53 GMT" }, { "version": "v3", "created": "Wed, 17 Oct 2007 11:39:47 GMT" } ]
2008-11-26T00:00:00
[ [ "Balachandran", "A. P.", "" ], [ "Queiroz", "A. R.", "" ], [ "Marques", "A. M.", "" ], [ "Teotonio-Sobrinho", "P.", "" ] ]
0706.0022
Marko Antonio Rodriguez
Marko A. Rodriguez and Johan Bollen
Modeling Computations in a Semantic Network
project website: http://neno.lanl.gov
null
null
null
cs.AI
null
Semantic network research has seen a resurgence from its early history in the cognitive sciences with the inception of the Semantic Web initiative. The Semantic Web effort has brought forth an array of technologies that support the encoding, storage, and querying of the semantic network data structure at the world stage. Currently, the popular conception of the Semantic Web is that of a data modeling medium where real and conceptual entities are related in semantically meaningful ways. However, new models have emerged that explicitly encode procedural information within the semantic network substrate. With these new technologies, the Semantic Web has evolved from a data modeling medium to a computational medium. This article provides a classification of existing computational modeling efforts and the requirements of supporting technologies that will aid in the further growth of this burgeoning domain.
[ { "version": "v1", "created": "Thu, 31 May 2007 21:56:25 GMT" } ]
2021-08-23T00:00:00
[ [ "Rodriguez", "Marko A.", "" ], [ "Bollen", "Johan", "" ] ]
0706.0023
Cristiano Germani
Cristiano Germani (SISSA and INFN), Nicolas Grandi (La Plata, Inst. Natl. Phys.) and Alex Kehagias (Natl. Tech. U., Athens)
The Cosmological Slingshot Scenario: Myths and Facts
16 pages, 2 figs. Major clarifications and references added, version accepted in Gen. Rel. Grav. (2009)
Gen.Rel.Grav.42:77-101,2010
10.1007/s10714-009-0819-5
SISSA 32/2007/A
hep-th astro-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We generalize the Cosmological Slingshot Scenario for a Slingshot brane moving in a Klebanov-Strassler throat. We show that the horizon and isotropy problems of standard cosmology are avoided, while the flatness problem is acceptably alleviated. Regarding the primordial perturbations, we identify their vacuum state and elucidate the evolution from the quantum to the classical regimes. Also, we calculate their exact power spectrum showing its compatibility with current data. We discuss the bouncing solution from a four dimensional point of view. In this framework the radial and angular motion of the Slingshot brane are described by two scalar fields. We show that the bouncing solution for the scale factor in String frame is mapped into a monotonically increasing (in conformal time) solution in the Einstein frame. We finally discuss about the regularity of the geometry in Einstein frame.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 15:57:41 GMT" }, { "version": "v2", "created": "Mon, 4 Jun 2007 17:37:09 GMT" }, { "version": "v3", "created": "Tue, 27 Nov 2007 17:56:27 GMT" }, { "version": "v4", "created": "Tue, 28 Apr 2009 23:09:29 GMT" } ]
2010-12-01T00:00:00
[ [ "Germani", "Cristiano", "", "SISSA and INFN" ], [ "Grandi", "Nicolas", "", "La Plata, Inst.\n Natl. Phys." ], [ "Kehagias", "Alex", "", "Natl. Tech. U., Athens" ] ]
0706.0024
Rui Carvalho
Rui Carvalho, Giulia Iori
Socioeconomic Networks with Long-Range Interactions
11 pages, 8 figures, minor corrections
null
10.1103/PhysRevE.78.016110
null
physics.soc-ph
null
We study a modified version of a model previously proposed by Jackson and Wolinsky to account for communicating information and allocating goods in socioeconomic networks. In the model, the utility function of each node is given by a weighted sum of contributions from all accessible nodes. The weights, parameterized by the variable $\delta$, decrease with distance. We introduce a growth mechanism where new nodes attach to the existing network preferentially by utility. By increasing $\delta$, the network structure evolves from a power-law to an exponential degree distribution, passing through a regime characterised by shorter average path length, lower degree assortativity and higher central point dominance. In the second part of the paper we compare different network structures in terms of the average utility received by each node. We show that power-law networks provide higher average utility than Poisson random networks. This provides a possible justification for the ubiquitousness of scale-free networks in the real world.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 17:16:56 GMT" }, { "version": "v2", "created": "Tue, 9 Oct 2007 21:46:26 GMT" }, { "version": "v3", "created": "Tue, 11 Mar 2008 13:09:24 GMT" }, { "version": "v4", "created": "Wed, 12 Mar 2008 00:34:37 GMT" }, { "version": "v5", "created": "Thu, 29 May 2008 13:13:44 GMT" } ]
2009-11-13T00:00:00
[ [ "Carvalho", "Rui", "" ], [ "Iori", "Giulia", "" ] ]
0706.0025
Cristiano Germani
Cristiano Germani (SISSA & INFN) and Michele Liguori (DAMTP)
Matching WMAP 3-yrs results with the Cosmological Slingshot Primordial Spectrum
9 pages, 4 figures; v3 clarifications added, version accepted for publication in Gen. Rel. Grav. 2008
Gen.Rel.Grav.41:191-201,2009
10.1007/s10714-008-0666-9
SISSA 37/2007/A; DAMTP-2007-50
astro-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a recently proposed scenario for the generation of primordial cosmological perturbations, the so called Cosmological Slingshot scenario. We firstly obtain a general expression for the Slingshot primordial power spectrum which extends previous results by including a blue pre-bounce residual contribution at large scales. Starting from this expression we numerically compute the CMB temperature and polarization power spectra arising from the Slingshot scenario and show that they excellently match the standard WMAP 3-years best-fit results. In particular, if the residual blue spectrum is far above the largest WMAP observed scale, the Slingshot primordial spectrum fits the data well by only fixing its amplitude and spectral index at the pivot scale k_p=10^{-3}h x Mpc^{-1}. We finally show that all possible distinctive Slingshot signatures in the CMB power spectra are confined to very low multipoles and thus very hard to detect due to large cosmic variance dominated error bars at these scales.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 15:45:26 GMT" }, { "version": "v2", "created": "Mon, 1 Oct 2007 17:12:36 GMT" }, { "version": "v3", "created": "Thu, 3 Jul 2008 19:36:27 GMT" } ]
2009-01-16T00:00:00
[ [ "Germani", "Cristiano", "", "SISSA & INFN" ], [ "Liguori", "Michele", "", "DAMTP" ] ]
0706.0026
Piers Coleman
Eran Lebanon, P. Coleman
Quantum criticality and the break-up of the Kondo pseudo-potential
Invited talk at SCES 2007, Houston, Texas
Physica B, 403, 1194-1198 (2008).
10.1016/j.physb.2007.10.312
null
cond-mat.str-el cond-mat.mes-hall
null
We discuss how Anderson's ideas of nominal and real valence can be incorporated into the current discussion of heavy electron quantum criticality. In the heavy electron phase, the nominal valence of a screened magnetic ion differs from its real valence by one unit. We identify this discrepancy with the formation of a positively charged background we call the Kondo pseudo-potential. At the quantum critical point, the sudden collapse of the heavy electron Fermi surface can be identified with the return of the nominal to the real valence. This leads to the interesting idea that the heavy electron quantum critical point may involve locally critical charge degrees of freedom. We discuss how this might come about within a large N Schwinger boson scheme.
[ { "version": "v1", "created": "Thu, 31 May 2007 21:43:43 GMT" } ]
2009-11-13T00:00:00
[ [ "Lebanon", "Eran", "" ], [ "Coleman", "P.", "" ] ]
0706.0027
Markus J. Pflaum
M.J. Pflaum, H.B. Posthuma, X. Tang, and H.-H. Tseng
Orbifold cup products and ring structures on Hochschild cohomologies
null
Communications in Contemporary Mathematics, Volume 13, Issue 1 (2011), 123--182
null
null
math.KT math-ph math.MP math.SG
null
In this paper we study the Hochschild cohomology ring of convolution algebras associated to orbifolds, as well as their deformation quantizations. In the first case the ring structure is given in terms of a wedge product on twisted polyvectorfields on the inertia orbifold. After deformation quantization, the ring structure defines a product on the cohomology of the inertia orbifold. We study the relation between this product and an $S^1$-equivariant version of the Chen--Ruan product. In particular, we give a de Rham model for this equivariant orbifold cohomology.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:11:25 GMT" } ]
2022-11-11T00:00:00
[ [ "Pflaum", "M. J.", "" ], [ "Posthuma", "H. B.", "" ], [ "Tang", "X.", "" ], [ "Tseng", "H. -H.", "" ] ]
0706.0028
Maor Rosenberg
Maor Rosenberg
Py-Calabi quasi-morphisms and quasi-states on orientable surfaces of higher genus
MSc thesis, Tel Aviv University (Israel), January 2007, 38 pages, 5 figures
null
null
null
math.SG math.FA math.GR
null
We show that Py-Calabi quasi-morphism on the group of Hamiltonian diffeomorphisms of surfaces of higher genus gives rise to a quasi-state.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:18:29 GMT" } ]
2007-06-04T00:00:00
[ [ "Rosenberg", "Maor", "" ] ]
0706.0029
Matthew Pelton
Inhwa Jung, Matthew Pelton, Richard Piner, Dmitriy A. Dikin, Sasha Stankovich, Supinda Watcharotone, Martina Hausner, and Rodney S. Ruoff
Simple approach for high-contrast optical imaging and characterization of graphene-based sheets
New measurements, calculations modified, discussion revised
null
10.1021/nl0714177
null
cond-mat.mes-hall cond-mat.mtrl-sci
null
A simple optical method is presented for identifying and measuring the effective optical properties of nanometer-thick, graphene-based materials, based on the use of substrates consisting of a thin dielectric layer on silicon. High contrast between the graphene-based materials and the substrate is obtained by choosing appropriate optical properties and thickness of the dielectric layer. The effective refractive index and optical absorption coefficient of graphene oxide, thermally reduced graphene oxide, and graphene are obtained by comparing the predicted and measured contrasts.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:25:47 GMT" }, { "version": "v2", "created": "Wed, 5 Sep 2007 16:09:19 GMT" } ]
2015-05-13T00:00:00
[ [ "Jung", "Inhwa", "" ], [ "Pelton", "Matthew", "" ], [ "Piner", "Richard", "" ], [ "Dikin", "Dmitriy A.", "" ], [ "Stankovich", "Sasha", "" ], [ "Watcharotone", "Supinda", "" ], [ "Hausner", "Martina", "" ], [ "Ruoff", "Rodney S.", "" ] ]
0706.0030
Yujie Wang
Y.J. Wang, Kyoung-Su Im, K. Fezzaa
Similarity between the primary and secondary air-assisted liquid jet breakup mechanism
15 pages, 4 figures
null
10.1103/PhysRevLett.100.154502
null
physics.flu-dyn
null
we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide range of air speeds. This finding reveals the intrinsic connections of these two breakup regimes and has deep implications on the unified theoretical approach in treating the breakup mechanism of high speed liquid jet.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:30:38 GMT" } ]
2009-11-13T00:00:00
[ [ "Wang", "Y. J.", "" ], [ "Im", "Kyoung-Su", "" ], [ "Fezzaa", "K.", "" ] ]
0706.0031
Jonathan Roberts
J. P. Roberts
Natural SUSY Dark Matter: A Window on the GUT Scale
6 pages, 3 figures, talk given at Rencontres de Moriond, Electroweak interactions and Unified theories
null
null
null
hep-ph
null
One of the key motivations for supersymmetry is that it provides a natural candidate for dark matter. For a long time the density of this candidate particle fell within cosmological bounds across much of the SUSY parameter space. However with the precision results of WMAP, it has become apparent that the majority of the SUSY parameter space no longer fits the observed relic density. This has given rise to claims that supersymmetry no longer provides a natural explanation of dark matter. We address this claim by quantifying the degree of fine-tuning required for the different dark matter regions. We find that the dark matter regions vary widely in the degree of tuning required. This degree of tuning can then be used to provide valuable insights into the structure of SUSY breaking at the GUT scale.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:41:47 GMT" } ]
2007-06-04T00:00:00
[ [ "Roberts", "J. P.", "" ] ]
0706.0032
Christopher Search
Markku Jaaskelainen, Jaeyoon Jeong, and Christopher P. Search
Bifurcations and bistability in cavity assisted photoassociation of Bose-Einstein condensed molecules
null
null
10.1103/PhysRevA.76.063615
null
cond-mat.other
null
We study the photo-association of Bose-Einstein condensed atoms into molecules using an optical cavity field. The driven cavity field introduces a new dynamical degree of freedom into the photoassociation process, whose role in determining the stationary behavior has not previously been considered. The semiclassical stationary solutions for the atom and molecules as well as the intracavity field are found and their stability and scaling properties are determined in terms of experimentally controllable parameters including driving amplitude of the cavity and the nonlinear interactions between atoms and molecules. For weak cavity driving, we find a bifurcation in the atom and molecule number occurs that signals a transition from a stable steady state to nonlinear Rabi oscillations. For a strongly driven cavity, there exists bistability in the atom and molecule number.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:47:41 GMT" } ]
2009-11-13T00:00:00
[ [ "Jaaskelainen", "Markku", "" ], [ "Jeong", "Jaeyoon", "" ], [ "Search", "Christopher P.", "" ] ]
0706.0033
Steven Allen
S.W. Allen (1), D.A. Rapetti (1), R.W. Schmidt (2), H. Ebeling (3), G. Morris (1), A.C. Fabian (4) ((1) KIPAC, Stanford, (2) Heidelberg, (3) Hawaii, (4) IoA, Cambridge)
Improved constraints on dark energy from Chandra X-ray observations of the largest relaxed galaxy clusters
Published in MNRAS. 20 pages, 11 figures. The data and analysis code (in the form of a patch to CosmoMC) are now available at http://www.stanford.edu/~drapetti/fgas_module/
Mon.Not.Roy.Astron.Soc.383:879-896, 2008
10.1111/j.1365-2966.2007.12610.x
null
astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present constraints on the mean matter density, Omega_m, dark energy density, Omega_de, and the dark energy equation of state parameter, w, using Chandra measurements of the X-ray gas mass fraction (fgas) in 42 hot (kT>5keV), X-ray luminous, dynamically relaxed galaxy clusters spanning the redshift range 0.05<z<1.1. Using only the fgas data for the 6 lowest redshift clusters at z<0.15, for which dark energy has a negligible effect on the measurements, we measure Omega_m=0.28+-0.06 (68% confidence, using standard priors on the Hubble Constant, H_0, and mean baryon density, Omega_bh^2). Analyzing the data for all 42 clusters, employing only weak priors on H_0 and Omega_bh^2, we obtain a similar result on Omega_m and detect the effects of dark energy on the distances to the clusters at ~99.99% confidence, with Omega_de=0.86+-0.21 for a non-flat LCDM model. The detection of dark energy is comparable in significance to recent SNIa studies and represents strong, independent evidence for cosmic acceleration. Systematic scatter remains undetected in the fgas data, despite a weighted mean statistical scatter in the distance measurements of only ~5%. For a flat cosmology with constant w, we measure Omega_m=0.28+-0.06 and w=-1.14+-0.31. Combining the fgas data with independent constraints from CMB and SNIa studies removes the need for priors on Omega_bh^2 and H_0 and leads to tighter constraints: Omega_m=0.253+-0.021 and w=-0.98+-0.07 for the same constant-w model. More general analyses in which we relax the assumption of flatness and/or allow evolution in w remain consistent with the cosmological constant paradigm. Our analysis includes conservative allowances for systematic uncertainties. The small systematic scatter and tight constraints bode well for future dark energy studies using the fgas method. (Abridged)
[ { "version": "v1", "created": "Fri, 1 Jun 2007 00:44:46 GMT" }, { "version": "v2", "created": "Wed, 24 Oct 2007 22:14:55 GMT" }, { "version": "v3", "created": "Thu, 26 Jun 2008 01:50:49 GMT" } ]
2010-04-06T00:00:00
[ [ "Allen", "S. W.", "" ], [ "Rapetti", "D. A.", "" ], [ "Schmidt", "R. W.", "" ], [ "Ebeling", "H.", "" ], [ "Morris", "G.", "" ], [ "Fabian", "A. C.", "" ] ]
0706.0034
Todd Hossbach
George S. King III, Frank T. Avignone III, Christopher E. Cox, Todd W. Hossbach, Wayne Jennings, James H. Reeves
Fabrication and Performance Tests of a Segmented P-Type HPGe Detector
Submitted to Nuclear Instruments and Methods, Section A
Nucl.Instrum.Meth.A595:599-604,2008
10.1016/j.nima.2008.05.034
null
nucl-ex
null
A p-type HPGe detector has been segmented by cutting, with a diamond saw, and etching six circumferential grooves through the Li-diffused dead layer. The degree of segmentation was tested with the 88 keV gamma rays from a well-collimated source of 109Cd. The fraction of events, recognized as occurring in more than one segment, and rejected from the energy interval 2038 +/- 5 keV, was measured as 0.59.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:50:14 GMT" } ]
2008-11-26T00:00:00
[ [ "King", "George S.", "III" ], [ "Avignone", "Frank T.", "III" ], [ "Cox", "Christopher E.", "" ], [ "Hossbach", "Todd W.", "" ], [ "Jennings", "Wayne", "" ], [ "Reeves", "James H.", "" ] ]
0706.0035
Andr\'e Walker-Loud
Jiunn-Wei Chen, Donal O'Connell, Andre Walker-Loud
Universality of Mixed Action Extrapolation Formulae
36 pages, appendix on twisted mass sea fermions added, expanded discussion of NLO operators, version published in JHEP; typographical errors corrected in Eqs. (68) and (69)
JHEP 0904:090,2009
10.1088/1126-6708/2009/04/090
CALT 68-2650, UMD 40762-389
hep-lat hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mixed action theories with chirally symmetric valence fermions exhibit very desirable features both at the level of the lattice calculations as well as in the construction and implementation of the low energy mixed action effective field theory. In this work we show that when such a mixed action effective field theory is projected onto the valence sector, both the Lagrangian and the extrapolation formulae become universal in form through next to leading order, for all variants of discretization methods used for the sea fermions. Our conclusion relies on the chiral nature of the valence quarks. The result implies that for all sea quark methods which are in the same universality class as QCD, the numerical values of the physical coefficients in the various mixed action chiral Lagrangians will be the same up to lattice spacing dependent corrections. This allows us to construct a prescription to determine the mixed action extrapolation formulae for a large class of hadronic correlation functions computed in partially quenched chiral perturbation theory at the one-loop level. For specific examples, we apply this prescription to the nucleon twist--2 matrix elements and the nucleon--nucleon system. In addition, we determine the mixed action extrapolation formula for the neutron EDM as this provides a nice example of a theta-dependent observable; these observables are exceptions to our prescription.
[ { "version": "v1", "created": "Thu, 31 May 2007 22:51:06 GMT" }, { "version": "v2", "created": "Mon, 4 Jun 2007 04:24:15 GMT" }, { "version": "v3", "created": "Tue, 21 Apr 2009 21:59:22 GMT" } ]
2010-05-12T00:00:00
[ [ "Chen", "Jiunn-Wei", "" ], [ "O'Connell", "Donal", "" ], [ "Walker-Loud", "Andre", "" ] ]
0706.0036
Gaston Giribet
Gaston Giribet, Matias Leoni
A twisted FZZ-like dual for the two-dimensional black hole
45 pages; no figures. v2: comments and references added, minor typos corrected
Rept.Math.Phys.61:151-162,2008
10.1016/S0034-4877(08)00010-4
null
hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review and study the duality between string theory formulated on a curved exact background (the two dimensional black hole) and string theory in flat space with a tachyon-like potential. We generalize previous results in this subject by discussing a twisted version of the Fateev-Zamolodchikov-Zamolodchikov conjecture. This duality is shown to hold at the level of N-point correlation functions on the sphere topology, and connects tree-level string amplitudes in the Euclidean version of the 2D black hole (x time) to correlation functions in a non-linear sigma-model in flat space but in presence of a tachyon wall potential and a linear dilaton. The dual CFT corresponds to the perturbed 2D quantum gravity coupled to c<1 matter (x time), where the operator that describes the tachyon-like potential can be seen as a n=2 momentum mode perturbation, while the usual sine-Liouville operator would correspond to the vortex sector n =1. We show how the sine-Liouville interaction term arises through a twisting of the marginal deformation introduced here, and discuss such 'twisting' as a non-trivial realization of the symmetries of the theory. After briefly reviewing the computation of correlation functions in sine-Liouville CFT, we give a precise prescription for computing correlation functions in the twisted model. To show the new version of the correspondence we make use of a formula recently proven by S. Ribault and J. Teschner, which connects the correlation functions in the Wess-Zumino-Witten theory to correlation functions in the Liouville theory. Conversely, the duality discussed here can be thought of as a free field realization of such remarkable formula.
[ { "version": "v1", "created": "Thu, 31 May 2007 23:00:11 GMT" }, { "version": "v2", "created": "Sat, 13 Sep 2008 16:01:41 GMT" } ]
2008-11-26T00:00:00
[ [ "Giribet", "Gaston", "" ], [ "Leoni", "Matias", "" ] ]
0706.0037
Aran Garcia-Bellido
Aran Garcia-Bellido (for the DZero collaboration)
Evidence for single top quark production at D0
6 pages, 4 figures. Presented at 42nd Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, 10-17 Mar 2007
null
null
FERMILAB-CONF-07-144-E
hep-ex
null
The results of the first analysis to show evidence for production of single top quarks are presented. Using 0.9 fb-1 of data collected with the D0 detector at the Fermilab Tevatron, the analysis is performed in the electron+jets and muon+jets decay modes, taking special care in modeling the large backgrounds, applying a new powerful b-quark tagging algorithm and using three multivariate techniques to extract the small signal in the data. The combined measured production cross section is 4.8 +- 1.3 pb. The probability to measure a cross section at this value or higher in the absence of a signal is 0.027%, corresponding to a 3.5 standard deviation significance.
[ { "version": "v1", "created": "Thu, 31 May 2007 23:08:26 GMT" } ]
2007-06-04T00:00:00
[ [ "Garcia-Bellido", "Aran", "", "for the DZero collaboration" ] ]
0706.0038
Ebrahim Samei
Ebrahim Samei
Weak amenability and 2-weak amenability of Beurling algebras
25 pages
null
10.1016/j.jmaa.2008.05.085
null
math.FA
null
Let $L^1_\om(G)$ be a Beurling algebra on a locally compact abelian group $G$. We look for general conditions on the weight which allows the vanishing of continuous derivations of $L^1_\om(G)$. This leads us to introducing vector-valued Beurling algebras and considering the translation of operators on them. This is then used to connect the augmentation ideal to the behavior of derivation space. We apply these results to give examples of various classes of Beurling algebras which are weakly amenable, 2-weakly amenable or fail to be even 2-weakly amenable.
[ { "version": "v1", "created": "Thu, 31 May 2007 23:10:33 GMT" }, { "version": "v2", "created": "Sun, 10 Feb 2008 03:47:13 GMT" } ]
2015-05-13T00:00:00
[ [ "Samei", "Ebrahim", "" ] ]
0706.0039
Kaixuan Ni
J. Angle, E. Aprile, F. Arneodo, L. Baudis, A. Bernstein, A. Bolozdynya, P. Brusov, L.C.C. Coelho, C.E. Dahl, L. DeViveiros, A.D. Ferella, L.M.P. Fernandes, S. Fiorucci, R.J. Gaitskell, K.L. Giboni, R. Gomez, R. Hasty, L. Kastens, J. Kwong, J.A.M. Lopes, N. Madden, A. Manalaysay, A. Manzur, D.N. McKinsey, M.E. Monzani, K. Ni, U. Oberlack, J. Orboeck, G. Plante, R. Santorelli, J.M.F. dos Santos, P. Shagin, T. Shutt, P. Sorensen, S. Schulte, C. Winant, and M. Yamashita (for the XENON Collaboration)
First Results from the XENON10 Dark Matter Experiment at the Gran Sasso National Laboratory
accepted for publication in Phys. Rev. Lett
Phys.Rev.Lett.100:021303,2008
10.1103/PhysRevLett.100.021303
null
astro-ph
null
The XENON10 experiment at the Gran Sasso National Laboratory uses a 15 kg xenon dual phase time projection chamber (XeTPC) to search for dark matter weakly interacting massive particles (WIMPs). The detector measures simultaneously the scintillation and the ionization produced by radiation in pure liquid xenon, to discriminate signal from background down to 4.5 keV nuclear recoil energy. A blind analysis of 58.6 live days of data, acquired between October 6, 2006 and February 14, 2007, and using a fiducial mass of 5.4 kg, excludes previously unexplored parameter space, setting a new 90% C.L. upper limit for the WIMP-nucleon spin-independent cross-section of 8.8 x 10^{-44} cm^2 for a WIMP mass of 100 GeV/c^2, and 4.5 x 10^{-44} cm^2 for a WIMP mass of 30 GeV/c^2. This result further constrains predictions of supersymmetric models.
[ { "version": "v1", "created": "Thu, 31 May 2007 23:20:41 GMT" }, { "version": "v2", "created": "Mon, 3 Dec 2007 18:39:00 GMT" } ]
2019-08-13T00:00:00
[ [ "Angle", "J.", "", "for the XENON Collaboration" ], [ "Aprile", "E.", "", "for the XENON Collaboration" ], [ "Arneodo", "F.", "", "for the XENON Collaboration" ], [ "Baudis", "L.", "", "for the XENON Collaboration" ], [ "Bernstein", "A.", "", "for the XENON Collaboration" ], [ "Bolozdynya", "A.", "", "for the XENON Collaboration" ], [ "Brusov", "P.", "", "for the XENON Collaboration" ], [ "Coelho", "L. C. C.", "", "for the XENON Collaboration" ], [ "Dahl", "C. E.", "", "for the XENON Collaboration" ], [ "DeViveiros", "L.", "", "for the XENON Collaboration" ], [ "Ferella", "A. D.", "", "for the XENON Collaboration" ], [ "Fernandes", "L. M. P.", "", "for the XENON Collaboration" ], [ "Fiorucci", "S.", "", "for the XENON Collaboration" ], [ "Gaitskell", "R. J.", "", "for the XENON Collaboration" ], [ "Giboni", "K. L.", "", "for the XENON Collaboration" ], [ "Gomez", "R.", "", "for the XENON Collaboration" ], [ "Hasty", "R.", "", "for the XENON Collaboration" ], [ "Kastens", "L.", "", "for the XENON Collaboration" ], [ "Kwong", "J.", "", "for the XENON Collaboration" ], [ "Lopes", "J. A. M.", "", "for the XENON Collaboration" ], [ "Madden", "N.", "", "for the XENON Collaboration" ], [ "Manalaysay", "A.", "", "for the XENON Collaboration" ], [ "Manzur", "A.", "", "for the XENON Collaboration" ], [ "McKinsey", "D. N.", "", "for the XENON Collaboration" ], [ "Monzani", "M. E.", "", "for the XENON Collaboration" ], [ "Ni", "K.", "", "for the XENON Collaboration" ], [ "Oberlack", "U.", "", "for the XENON Collaboration" ], [ "Orboeck", "J.", "", "for the XENON Collaboration" ], [ "Plante", "G.", "", "for the XENON Collaboration" ], [ "Santorelli", "R.", "", "for the XENON Collaboration" ], [ "Santos", "J. M. F. dos", "", "for the XENON Collaboration" ], [ "Shagin", "P.", "", "for the XENON Collaboration" ], [ "Shutt", "T.", "", "for the XENON Collaboration" ], [ "Sorensen", "P.", "", "for the XENON Collaboration" ], [ "Schulte", "S.", "", "for the XENON Collaboration" ], [ "Winant", "C.", "", "for the XENON Collaboration" ], [ "Yamashita", "M.", "", "for the XENON Collaboration" ] ]
0706.0040
Jorge Alberto Guccione
Sergio D. Corti, Jorge A. Guccione and Juan J. Guccione
Braided Sweedler cohomology
26 pages
null
null
null
math.RA math.KT
null
We introduced a braided Sweedler cohomology, which is adequate to work with the H-braided cleft extensions studied in [J. A. Guccione and J. J. Guccione, Theory of braided Hopf crossed products, Journal of Algebra, Vol 261 (2003) 54-101]
[ { "version": "v1", "created": "Thu, 31 May 2007 23:40:22 GMT" } ]
2007-06-04T00:00:00
[ [ "Corti", "Sergio D.", "" ], [ "Guccione", "Jorge A.", "" ], [ "Guccione", "Juan J.", "" ] ]
0706.0041
Yevgeniy Kuznetsov
Yevgeniy Kuznetsov
On cosmological constant in Causal Set theory
4 pages
null
null
null
gr-qc
null
Resolution of the cosmological constant problem based on Causal Set theory is discussed. It is argued that one should not observe any spacetime variations in cosmological constant if Causal Set approach is correct.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 01:41:46 GMT" } ]
2007-06-04T00:00:00
[ [ "Kuznetsov", "Yevgeniy", "" ] ]
0706.0042
Changhyun Ahn
Changhyun Ahn
Meta-Stable Brane Configurations by Adding an Orientifold-Plane to Giveon-Kutasov
21 pp, 6 figures; reduced bytes of figures, DBI action analysis added and to appear in JHEP
JHEP 0708:021,2007
10.1088/1126-6708/2007/08/021
null
hep-th
null
In hep-th/0703135, they have found the type IIA intersecting brane configuration where there exist three NS5-branes, D4-branes and anti-D4-branes. By analyzing the gravitational interaction for the D4-branes in the background of the NS5-branes, the phase structures in different regions of the parameter space were studied in the context of classical string theory. In this paper, by adding the orientifold 4-plane and 6-plane to the above brane configuration, we describe the intersecting brane configurations of type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua of these gauge theories.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 00:49:41 GMT" }, { "version": "v2", "created": "Wed, 1 Aug 2007 11:11:17 GMT" } ]
2009-04-17T00:00:00
[ [ "Ahn", "Changhyun", "" ] ]
0706.0043
Shin-Ichi Sasa
Shin-ichi Sasa
A perturbation theory for large deviation functionals in fluctuating hydrodynamics
12pages
null
10.1088/1751-8113/41/4/045006
null
cond-mat.stat-mech
null
We study a large deviation functional of density fluctuation by analyzing stochastic non-linear diffusion equations driven by the difference between the densities fixed at the boundaries. By using a fundamental equality that yields the fluctuation theorem, we first relate the large deviation functional with a minimization problem. We then develop a perturbation method for solving the problem. In particular, by performing an expansion with respect to the average current, we derive the lowest order expression for the deviation from the local equilibrium part. This expression implies that the deviation is written as the space-time integration of the excess entropy production rate during the most probable process of generating the fluctuation that corresponds to the argument of the large deviation functional.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 01:09:38 GMT" } ]
2009-11-13T00:00:00
[ [ "Sasa", "Shin-ichi", "" ] ]
0706.0044
Seung Ki Baek
Seung Ki Baek, Petter Minnhagen and Beom Jun Kim
Phase Transition of XY Model in Heptagonal Lattice
5 pages, 6 figures, to be published in Europhys. Lett
null
10.1209/0295-5075/79/26002
null
cond-mat.stat-mech
null
We numerically investigate the nature of the phase transition of the XY model in the heptagonal lattice with the negative curvature, in comparison to other interaction structures such as a flat two-dimensional (2D) square lattice and a small-world network. Although the heptagonal lattice has a very short characteristic path length like the small-world network structure, it is revealed via calculation of the Binder's cumulant that the former exhibits a zero-temperature phase transition while the latter has the finite-temperature transition of the mean-field nature. Through the computation of the vortex density as well as the correlation function in the low-temperature approximation, we show that the absence of the phase transition originates from the strong spinwave-type fluctuation, which is discussed in relation to the usual 2D XY model.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 01:20:16 GMT" } ]
2009-11-13T00:00:00
[ [ "Baek", "Seung Ki", "" ], [ "Minnhagen", "Petter", "" ], [ "Kim", "Beom Jun", "" ] ]
0706.0045
Yoshifusa Ita
Yoshifusa Ita (1), Toshihiko Tanabe (2), Noriyuki Matsunaga (2), Yoshikazu Nakada (2), Mikako Matsuura (3), Takashi Onaka (4), Hideo Matsuhara (1), Takehiko Wada (1), Naofumi Fujishiro (5), Daisuke Ishihara (4), Hirokazu Kataza (1), Woojung Kim (1), Toshio Matsumoto (1), Hiroshi Murakami (1), Youichi Ohyama (1), Fumihiko Usui (1), Shinki Oyabu (1), Itsuki Sakon (4), Toshinobu Takagi (1), Kazunori Uemizu (1), Munetaka Ueno (6), Hidenori Watarai (7) ((1)Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Kanagawa, Japan (2)Institute of Astronomy, Graduate School of Science, The University of Tokyo, Tokyo, Japan (3)National Astronomical Observatory of Japan, Mitaka, Tokyo, Japan (4) Department of Astronomy, Graduate School of Science, The University of Tokyo, Tokyo, Japan (5) Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo, Japan (6) Department of Earth Science and Astronomy, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan (7)Office of Space Applications, Japan Aerospace Exploration Agency, Ibaraki, Japan)
AKARI observations of circumstellar dust in the globular clusters NGC104 and NGC362
Accepted for publication in PASJ
Publ.Astron.Soc.Jap.59:437-442,2007
10.1093/pasj/59.sp2.S437
null
astro-ph
null
We report preliminary results of AKARI observations of two globular clusters, NGC104 and NGC362. Imaging data covering areas of about 10x10 arcmin^2 centered on the two clusters have been obtained with InfraRed Camera (IRC) at 2.4, 3.2, 4.1, 7.0, 9.0, 11.0, 15.0, 18.0 and 24.0 mu. We used F11/F2 and F24/F7 flux ratios as diagnostics of circumstellar dust emission. Dust emissions are mainly detected from variable stars obviously on the asymptotic giant branch, but some variable stars that reside below the tip of the first-ascending giant branch also show dust emissions. We found eight red sources with F24/F7 ratio greater than unity in NGC362. Six out of the eight have no 2MASS counterparts. However, we found no such source in NGC104.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 01:27:01 GMT" } ]
2015-05-13T00:00:00
[ [ "Ita", "Yoshifusa", "" ], [ "Tanabe", "Toshihiko", "" ], [ "Matsunaga", "Noriyuki", "" ], [ "Nakada", "Yoshikazu", "" ], [ "Matsuura", "Mikako", "" ], [ "Onaka", "Takashi", "" ], [ "Matsuhara", "Hideo", "" ], [ "Wada", "Takehiko", "" ], [ "Fujishiro", "Naofumi", "" ], [ "Ishihara", "Daisuke", "" ], [ "Kataza", "Hirokazu", "" ], [ "Kim", "Woojung", "" ], [ "Matsumoto", "Toshio", "" ], [ "Murakami", "Hiroshi", "" ], [ "Ohyama", "Youichi", "" ], [ "Usui", "Fumihiko", "" ], [ "Oyabu", "Shinki", "" ], [ "Sakon", "Itsuki", "" ], [ "Takagi", "Toshinobu", "" ], [ "Uemizu", "Kazunori", "" ], [ "Ueno", "Munetaka", "" ], [ "Watarai", "Hidenori", "" ] ]
0706.0046
Jingchao Chen
Jing-Chao Chen
Symmetry Partition Sort
null
null
null
null
cs.DS
null
In this paper, we propose a useful replacement for quicksort-style utility functions. The replacement is called Symmetry Partition Sort, which has essentially the same principle as Proportion Extend Sort. The maximal difference between them is that the new algorithm always places already partially sorted inputs (used as a basis for the proportional extension) on both ends when entering the partition routine. This is advantageous to speeding up the partition routine. The library function based on the new algorithm is more attractive than Psort which is a library function introduced in 2004. Its implementation mechanism is simple. The source code is clearer. The speed is faster, with O(n log n) performance guarantee. Both the robustness and adaptivity are better. As a library function, it is competitive.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 01:47:06 GMT" } ]
2007-06-04T00:00:00
[ [ "Chen", "Jing-Chao", "" ] ]
0706.0047
Ping Zhang
Zhigang Wang, Ping Zhang
Conserved spin Hall conductance in two dimensional electron gas in a perpendicular magnetic field
4 pages, 4 figures, to appear in Phys. Rev. B
null
10.1103/PhysRevB.75.233306
null
cond-mat.mes-hall cond-mat.str-el
null
Using the microscopic theory of the conserved spin current [Phys. Rev. Lett. \textbf{96}, 076604 (2006)], we investigate the spin Hall effect in the two dimensional electron gas system with a perpendicular magnetic field. The spin Hall conductance $\sigma_{\mu\nu}^{s}$ as a response to the electric field consists of two parts, i.e., the conventional part $\sigma_{\mu\nu}^{s0}$ and the spin torque dipole correction $\sigma_{\mu\nu}^{s\tau}$. It is shown that the spin-orbit coupling competes with Zeeman splitting by introducing additional degeneracies between different Landau levels at certain values of magnetic field. These degeneracies, if occurring at the Fermi level, turn to give rise to resonances in both $\sigma_{\mu\nu}^{s0}$ and $\sigma_{\mu\nu }^{s\tau}$ in spin Hall conductance. Remarkably, both of these two components have the same sign in the wide range of variation in the magnetic field, which result in an overall enhancement of the total spin Hall current. In particular, the magnitude of $\sigma_{\mu\nu}^{s\tau}$ is much larger than that of $\sigma_{\mu\nu}^{s0}$ around the resonance.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 02:32:02 GMT" } ]
2009-11-13T00:00:00
[ [ "Wang", "Zhigang", "" ], [ "Zhang", "Ping", "" ] ]
0706.0048
Eric Jullo
Eric Jullo, Jean-Paul Kneib, Marceau Limousin, \'Ardis El\'iasd\'ottir, Phil Marshall, Tomas Verdugo
A Bayesian approach to strong lensing modelling of galaxy clusters
Accepted to "Gravitational Lensing" Focus Issue of the New Journal of Physics (invited), 35 pages, 11 figures at reduced resolution
NewJ.Phys.9:447,2007
10.1088/1367-2630/9/12/447
null
astro-ph
null
In this paper, we describe a procedure for modelling strong lensing galaxy clusters with parametric methods, and to rank models quantitatively using the Bayesian evidence. We use a publicly available Markov chain Monte-Carlo (MCMC) sampler ('Bayesys'), allowing us to avoid local minima in the likelihood functions. To illustrate the power of the MCMC technique, we simulate three clusters of galaxies, each composed of a cluster-scale halo and a set of perturbing galaxy-scale subhalos. We ray-trace three light beams through each model to produce a catalogue of multiple images, and then use the MCMC sampler to recover the model parameters in the three different lensing configurations. We find that, for typical Hubble Space Telescope (HST)-quality imaging data, the total mass in the Einstein radius is recovered with ~1-5% error according to the considered lensing configuration. However, we find that the mass of the galaxies is strongly degenerated with the cluster mass when no multiple images appear in the cluster centre. The mass of the galaxies is generally recovered with a 20% error, largely due to the poorly constrained cut-off radius. Finally, we describe how to rank models quantitatively using the Bayesian evidence. We confirm the ability of strong lensing to constrain the mass profile in the central region of galaxy clusters in this way. Ultimately, such a method applied to strong lensing clusters with a very large number of multiple images may provide unique geometrical constraints on cosmology. The implementation of the MCMC sampler used in this paper has been done within the framework of the Lenstool software package, which is publicly available.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 03:39:57 GMT" }, { "version": "v2", "created": "Wed, 26 Dec 2007 12:42:25 GMT" } ]
2008-11-26T00:00:00
[ [ "Jullo", "Eric", "" ], [ "Kneib", "Jean-Paul", "" ], [ "Limousin", "Marceau", "" ], [ "Elíasdóttir", "Árdis", "" ], [ "Marshall", "Phil", "" ], [ "Verdugo", "Tomas", "" ] ]
0706.0049
Gordan Zitkovic
Gordan Zitkovic
A filtered version of the bipolar theorem of Brannath and Schachermayer
null
Journal of Theoretical Probability (2002) vol. 15 no. 1
10.1023/A:1013885121598
null
math.PR math.FA
null
We extend the Bipolar Theorem of Brannath and Schachermayer (1999) to the space of nonnegative cadlag supermartingales on a filtered probability space. We formulate the notion of fork-convexity as an analogue to convexity in this setting. As an intermediate step in the proof of our main result we establish a conditional version of the Bipolar theorem. In an application to mathematical finance we describe the structure of the set of dual processes of the utility maximization problem of Kramkov and Schachermayer (1999) and give a budget-constraint characterization of admissible consumption processes in an incomplete semimartingale market.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 03:25:39 GMT" } ]
2007-06-04T00:00:00
[ [ "Zitkovic", "Gordan", "" ] ]
0706.0050
Tai-Kai Ng
Tai-Kai Ng and Patrick A. Lee
Power-law Conductivity inside the Mott gap: application to $\kappa-(BEDT-TTF)_2Cu_2(CN)_3$
10 pages, 2 figures
null
10.1103/PhysRevLett.99.156402
null
cond-mat.str-el
null
The charge dynamics of spin-liquid states described by U(1) gauge theory coupling to fermionic spinons is discussed in this paper. We find that the gapless spinons give rise to a power law optical conductivity inside the charge gap. The theory is applied to explain the unusual optical conductivity observed recently in the organic compound $\kappa-(BEDT-TTF)_2Cu_2(CN)_3$. We also propose an optical experiment to search for the in-gap excitations in the Kagome spin liquid insulator.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 02:55:34 GMT" } ]
2009-11-13T00:00:00
[ [ "Ng", "Tai-Kai", "" ], [ "Lee", "Patrick A.", "" ] ]
0706.0051
Gordan Zitkovic
Ioannis Karatzas, Gordan Zitkovic
Optimal consumption from investment and random endowment in incomplete semimartingale markets
null
Annals of Probability (2003) vol. 31 no. 4 pp. 1821-1858
null
null
q-fin.PM math.OC math.PR
null
We consider the problem of maximizing expected utility from consumption in a constrained incomplete semimartingale market with a random endowment process, and establish a general existence and uniqueness result using techniques from convex duality. The notion of asymptotic elasticity of Kramkov and Schachermayer is extended to the time-dependent case. By imposing no smoothness requirements on the utility function in the temporal argument, we can treat both pure consumption and combined consumption/terminal wealth problems, in a common framework. To make the duality approach possible, we provide a detailed characterization of the enlarged dual domain which is reminiscent of the enlargement of $L^1$ to its topological bidual $(L^{\infty})^*$, a space of finitely-additive measures. As an application, we treat the case of a constrained It\^ o-process market-model.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 03:07:30 GMT" } ]
2008-12-10T00:00:00
[ [ "Karatzas", "Ioannis", "" ], [ "Zitkovic", "Gordan", "" ] ]
0706.0052
Zhi-Zhong Xing
Zhi-zhong Xing
Massive and Massless Neutrinos on Unbalanced Seesaws
RevTex 8 pages, 1 PS figure. Two crucial references added
Chin.Phys.C32:96-99,2008
10.1088/1674-1137/32/2/004
null
hep-ph
null
The observation of neutrino oscillations requires new physics beyond the standard model (SM). A SM-like gauge theory with p lepton families can be extended by introducing q heavy right-handed Majorana neutrinos but preserving its SU(2)_L x U(1)_Y gauge symmetry. The overall neutrino mass matrix M turns out to be a symmetric (p+q) x (p+q) matrix. Given p>q, the rank of M is in general equal to 2q, corresponding to 2q non-zero mass eigenvalues. The existence of (p-q) massless left-handed Majorana neutrinos is an exact consequence of the model, independent of the usual approximation made in deriving the Type-I seesaw relation between the effective p x p light Majorana neutrino mass matrix M_\nu and the q x q heavy Majorana neutrino mass matrix M_R. In other words, the numbers of massive left- and right-handed neutrinos are fairly matched. A good example to illustrate this seesaw fair play rule is the minimal seesaw model with p=3 and q=2, in which one massless neutrino sits on the unbalanced seesaw.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 14:32:12 GMT" }, { "version": "v2", "created": "Wed, 6 Jun 2007 06:57:22 GMT" } ]
2015-05-13T00:00:00
[ [ "Xing", "Zhi-zhong", "" ] ]
0706.0053
Pietro Colangelo
P. Colangelo, F. De Fazio, R. Ferrandes, S. Nicotri
Puzzles in charm spectroscopy
8 pages, 4 figures. Invited talk given at the YKIS Seminar on New Frontiers in QCD: Exotic Hadrons and Hadronic Matter, Kyoto, Japan, 20 Nov. - 8 Dec. 2006
Prog.Theor.Phys.Suppl.168:202-210,2007
10.1143/PTPS.168.202
BARI-TH/07-566
hep-ph
null
We briefly analyze aspects of open and hidden charm resonances, discussing in particular the mesons $D_{sJ}(2860)$ and X(3872).
[ { "version": "v1", "created": "Fri, 1 Jun 2007 14:10:28 GMT" } ]
2008-11-26T00:00:00
[ [ "Colangelo", "P.", "" ], [ "De Fazio", "F.", "" ], [ "Ferrandes", "R.", "" ], [ "Nicotri", "S.", "" ] ]
0706.0054
Neil M. H. Vaytet
N. M. H. Vaytet, T. J. O'Brien and A. P. Rushton (Jodrell Bank Observatory, School of Physics and Astronomy, The University of Manchester, Macclesfield, Cheshire, UK)
Evidence for ablated flows in the shell of nova DQ Her
7 pages, 6 figures
null
10.1111/j.1365-2966.2007.12057.x
null
astro-ph
null
High-resolution longslit Halpha spectra of the shell of the old nova DQ Her have been obtained with the William Herschel Telescope using the ISIS spectrograph. An equatorial expansion velocity of 370+/-14 km/s is derived from the spectra which, in conjunction with a narrowband Halpha image of the remnant, allows a distance estimate of 525+/-28 pc. An equatorial ring which exhibits enhanced [NII] emission has also been detected and the inclination angle of the shell is found to be 86.8+/-0.2 degrees with respect to the line of sight. The spectra also reveal tails extending from the clumps in the shell, which have a radial velocity increasing along their length. This suggests the presence of a stellar wind, collimated in the polar direction, which ablates fragments of material from the clumps and accelerates them into its stream up to a terminal velocity of order 800-900 km/s.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 14:06:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Vaytet", "N. M. H.", "", "Jodrell Bank\n Observatory, School of Physics and Astronomy, The University of Manchester,\n Macclesfield, Cheshire, UK" ], [ "O'Brien", "T. J.", "", "Jodrell Bank\n Observatory, School of Physics and Astronomy, The University of Manchester,\n Macclesfield, Cheshire, UK" ], [ "Rushton", "A. P.", "", "Jodrell Bank\n Observatory, School of Physics and Astronomy, The University of Manchester,\n Macclesfield, Cheshire, UK" ] ]
0706.0055
Fei Xiang
F. Xiang, E. Churazov, K. Dolag, V. Springel, A. Vikhlinin
On the width of cold fronts in clusters of galaxies due to conduction
Accepted for MNRAS. 9 pages; 6 b&w figures; 2 colour figures
Mon.Not.Roy.Astron.Soc.379:1325-1332,2007
10.1111/j.1365-2966.2007.12032.x
null
astro-ph
null
We consider the impact of thermal conduction in clusters of galaxies on the (unmagnetized) interface between a cold gaseous cloud and a hotter gas flowing over the cloud (the so-called cold front). We argue that near the stagnation point of the flow conduction creates a spatially extended layer of constant thickness $\Delta$, where $\Delta$ is of order $\sim\sqrt{kR/U}$, and $R$ is the curvature radius of the cloud, $U$ is the velocity of the flow at infinity, and $k$ is the conductivity of the gas. For typical parameters of the observed fronts, one finds $\Delta \ll R$. The formation time of such a layer is $\sim R/U$. Once the layer is formed, its thickness only slowly varies with time and the quasi-steady layer may persist for many characteristic time scales. Based on these simple arguments one can use the observed width of the cold fronts in galaxy clusters to constrain the effective thermal conductivity of the intra-cluster medium.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 15:43:17 GMT" } ]
2008-11-26T00:00:00
[ [ "Xiang", "F.", "" ], [ "Churazov", "E.", "" ], [ "Dolag", "K.", "" ], [ "Springel", "V.", "" ], [ "Vikhlinin", "A.", "" ] ]
0706.0056
Tamara Nunner
Tamara S. Nunner, N.A. Sinitsyn, Mario F. Borunda, A.A. Kovalev, Ar. Abanov, Carsten Timm, T. Jungwirth, Jun-ichiro Inoue, A.H. MacDonald, Jairo Sinova
Anomalous Hall effect in a two-dimensional electron gas
11 pages, 5 figures
null
10.1103/PhysRevB.76.235312
null
cond-mat.mtrl-sci
null
The anomalous Hall effect in a magnetic two-dimensional electron gas with Rashba spin-orbit coupling is studied within the Kubo-Streda formalism in the presence of pointlike potential impurities. We find that all contributions to the anomalous Hall conductivity vanish to leading order in disorder strength when both chiral subbands are occupied. In the situation that only the majority subband is occupied, all terms are finite in the weak scattering limit and the total anomalous Hall conductivity is dominated by skew scattering. We compare our results to previous treatments and resolve some of the discrepancies present in the literature.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 14:04:26 GMT" } ]
2009-11-13T00:00:00
[ [ "Nunner", "Tamara S.", "" ], [ "Sinitsyn", "N. A.", "" ], [ "Borunda", "Mario F.", "" ], [ "Kovalev", "A. A.", "" ], [ "Abanov", "Ar.", "" ], [ "Timm", "Carsten", "" ], [ "Jungwirth", "T.", "" ], [ "Inoue", "Jun-ichiro", "" ], [ "MacDonald", "A. H.", "" ], [ "Sinova", "Jairo", "" ] ]
0706.0057
Soon-Tae Hong
Yong Seung Cho, Soon-Tae Hong
Morse theory in path space
6 pages
null
null
null
math-ph math.MP
null
We consider the path space of a curved manifold on which a point particle is introduced in a conservative physical system with constant total energy to formulate its action functional and geodesic equation together with breaks on the path. The second variation of the action functional is exploited to yield the geodesic deviation equation and to discuss the Jacobi fields on the curved manifold. We investigate the topology of the path space using the action functional on it and its physical meaning by defining the gradient of the action functional, the space of bounded flow energy solutions and the moduli space associated with the critical points of the action functional. We also consider the particle motion on the $n$-sphere $S^{n}$ in the conservative physical system to discuss explicitly the moduli space of the path space and the corresponding homology groups.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 03:32:58 GMT" } ]
2007-06-04T00:00:00
[ [ "Cho", "Yong Seung", "" ], [ "Hong", "Soon-Tae", "" ] ]
0706.0058
Amritanshu Prasad
Anne-Marie Aubert, Uri Onn, Amritanshu Prasad, Alexander Stasinski
On Cuspidal Representations of General Linear Groups over Discrete Valuation Rings
20 pages (revised)
Israel Journal of Mathematics, volume 175, page 391-420, 2010
10.1007/s11856-010-0016-y
null
math.RT math.NT
http://creativecommons.org/licenses/by/3.0/
We define a new notion of cuspidality for representations of $\GL_n$ over a finite quotient $\Oh_k$ of the ring of integers $\Oh$ of a non-Archimedean local field $F$ using geometric and infinitesimal induction functors, which involve automorphism groups $G_\lambda$ of torsion $\Oh$\nobreakdash-modules. When $n$ is a prime, we show that this notion of cuspidality is equivalent to strong cuspidality, which arises in the construction of supercuspidal representations of $\GL_n(F)$. We show that strongly cuspidal representations share many features of cuspidal representations of finite general linear groups. In the function field case, we show that the construction of the representations of $\GL_n(\Oh_k)$ for $k\geq 2$ for all $n$ is equivalent to the construction of the representations of all the groups $G_\lambda$. A functional equation for zeta functions for representations of $\GL_n(\Oh_k)$ is established for representations which are not contained in an infinitesimally induced representation. All the cuspidal representations for $\GL_4(\Oh_2)$ are constructed. Not all these representations are strongly cuspidal.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 03:32:59 GMT" }, { "version": "v2", "created": "Tue, 25 Dec 2007 06:56:29 GMT" }, { "version": "v3", "created": "Mon, 14 Jul 2008 04:21:37 GMT" } ]
2010-06-14T00:00:00
[ [ "Aubert", "Anne-Marie", "" ], [ "Onn", "Uri", "" ], [ "Prasad", "Amritanshu", "" ], [ "Stasinski", "Alexander", "" ] ]
0706.0059
Tian De Cao
Tian De Cao
High-Tc superconductivity originated from strong spin-charge correlation: indication from linear temperature dependence of resistivity
4pages,V1 has to be deleted
null
null
null
physics.gen-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Both the highest- and the linear temperature dependence of the resistivity in wide temperature range appear at the optimally doped regions of Cu-based superconductors1,2,3,4,5, and the highest- of Fe-based superconductors6,7 are also associated with the linear temperature dependence of the resistivity in normal states near superconducting states. This means that the high temperature superconductivity and the linear temperature dependence of the resistivity should be dominated by the same mechanism. This letter on theoretic calculation clearly shows that strong spin-charge correlation dominated resistivity behaves the linear temperature dependence, thus high-temperature superconductivity should be induced by strong spin-charge correlation.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 03:39:31 GMT" }, { "version": "v2", "created": "Tue, 5 May 2009 22:28:15 GMT" } ]
2009-05-06T00:00:00
[ [ "De Cao", "Tian", "" ] ]
0706.0060
Qiu-he Peng
Qiu-he Peng and Hao Tong
The physics of strong magnetic fields in neutron stars
With erratum in this version
Mon.Not.Roy.Astron.Soc.378:159,2007
10.1111/j.1365-2966.2007.11772.x
null
astro-ph
null
In this paper we present a new result, namely that the primal magnetic field of the collapsed core during a supernova explosion will, as a result of the conservation of magnetic flux, receive a massive boost to more than 90 times its original value by the Pauli paramagnetization of the highly degenerate relativistic electron gas just after the formation of the neutron star. Thus, the observed super-strong magnetic field of neutron stars may originate from the induced Pauli paramagnetization of the highly degenerate relativistic electron gas in the interior of the neutron star. We therefore have an apparently natural explanation for the surface magnetic field of a neutron star.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 03:50:24 GMT" }, { "version": "v2", "created": "Sat, 21 Jul 2007 07:03:33 GMT" } ]
2008-11-26T00:00:00
[ [ "Peng", "Qiu-he", "" ], [ "Tong", "Hao", "" ] ]
0706.0061
Santanu Maiti K.
Santanu K. Maiti
Quantum transport in mesoscopic ring structures: Effects of impurities, long-range hopping and interactions
26 pages, 35 figures. A brief review article
null
null
null
cond-mat.mes-hall
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present review we make a comprehensive analysis of our understanding on electron transport in mesoscopic single-channel rings and multi-channel cylinders within a tight-binding framework. A spectacular mesoscopic phenomenon where a non-decaying current circulates in a small conducting loop is observed upon the application of an Aharonov-Bohm flux $\phi$. To understand its behavior one has to focus attention on the interplay of quantum phase coherence, electron-electron correlation and disorder. This is a highly challenging problem and here we address it for some simple loop geometries with their detailed energy band structures to get an entire picture at the microscopic level. The behavior of low-field magnetic response of persistent current and its temperature dependence are also discussed.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 04:27:40 GMT" }, { "version": "v2", "created": "Wed, 5 Dec 2007 04:38:02 GMT" }, { "version": "v3", "created": "Tue, 14 Oct 2008 11:42:06 GMT" }, { "version": "v4", "created": "Tue, 21 May 2013 07:41:43 GMT" } ]
2013-05-22T00:00:00
[ [ "Maiti", "Santanu K.", "" ] ]
0706.0062
Ashton Bradley
A. S. Bradley and M. K. Olsen and S. A. Haine and J. J. Hope
Teleportation of massive particles without shared entanglement
4 pages, 3 figures
null
null
null
quant-ph cond-mat.other physics.atom-ph
null
We propose a method for quantum state transfer from one atom laser beam to another via an intermediate optical field, using Raman incoupling and outcoupling techniques. Our proposal utilises existing experimental technologies to teleport macroscopic matter waves over potentially large distances without shared entanglement.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 04:59:15 GMT" } ]
2007-06-13T00:00:00
[ [ "Bradley", "A. S.", "" ], [ "Olsen", "M. K.", "" ], [ "Haine", "S. A.", "" ], [ "Hope", "J. J.", "" ] ]
0706.0063
Motomu Tsuda
Kazunari Shima and Motomu Tsuda
N = 2 Supersymmetric QED equivalence of N = 2 Volkov-Akulov model
11 pages
Mod.Phys.Lett.A22:3027-3036,2007
10.1142/S0217732307026163
null
hep-th
null
We show explicitly in two dimensional spacetime (d = 2) that the N = 2 Volkov-Akulov model is equivalent to the spontaneously broken linear supersymmetry (LSUSY) interacting gauge theory for N = 2 vector and N = 2 scalar supermultiplets. The local gauge interaction of LSUSY is induced by the specific composite structure of the auxiliary fields and the consequent transformations.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 04:36:39 GMT" } ]
2010-11-04T00:00:00
[ [ "Shima", "Kazunari", "" ], [ "Tsuda", "Motomu", "" ] ]
0706.0064
Chee Wei Wong
Yun-Feng Xiao, Jie Gao, Xiaodong Yang, Ranojoy Bose, Guang-Can Guo, Chee Wei Wong
Nanocrystals in silicon photonic crystal standing-wave cavities as spin-photon phase gates for quantum information processing
null
null
10.1063/1.2795798
null
quant-ph
null
By virtue of a silicon high-Q photonic crystal nanocavity, we propose and examine theoretically interactions between a stationary electron spin qubit of a semiconductor nanocrystal and a flying photon qubit. Firstly, we introduce, derive and demonstrate for the first time the explicit conditions towards realization of a spin-photon two-qubit phase gate, and propose these interactions as a generalized quantum interface for quantum information processing. Secondly, we examine novel single-spin-induced reflections as direct evidence of intrinsic bare and dressed modes in our coupled nanocrystal-cavity system. The excellent physical integration of this silicon system provides tremendous potential for large-scale quantum information processing.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 04:46:37 GMT" }, { "version": "v2", "created": "Mon, 13 Aug 2007 22:37:15 GMT" } ]
2009-11-13T00:00:00
[ [ "Xiao", "Yun-Feng", "" ], [ "Gao", "Jie", "" ], [ "Yang", "Xiaodong", "" ], [ "Bose", "Ranojoy", "" ], [ "Guo", "Guang-Can", "" ], [ "Wong", "Chee Wei", "" ] ]
0706.0065
S. L. Narasimhan
S. L. Narasimhan, P. S. R. Krishna, M. Ponmurugan and K. P. N. Murthy
A growth walk model for estimating the canonical partition function of Interacting Self Avoiding Walk
Revised version consisting of 12 pages (RevTeX manuscript, plus three .eps figure files); A few sentences in the second paragraph on Page 4 are rewritten so as to make the definition of the genealogical tree, ${\cal Z}_N$, clearer. Also, the second equality of Eq.(1) on Page 4, and its corresponding statement below have been removed
null
10.1063/1.2806935
null
cond-mat.stat-mech
null
We have explained in detail why the canonical partition function of Interacting Self Avoiding Walk (ISAW), is exactly equivalent to the configurational average of the weights associated with growth walks, such as the Interacting Growth Walk (IGW), if the average is taken over the entire genealogical tree of the walk. In this context, we have shown that it is not always possible to factor the the density of states out of the canonical partition function if the local growth rule is temperature-dependent. We have presented Monte Carlo results for IGWs on a diamond lattice in order to demonstrate that the actual set of IGW configurations available for study is temperature-dependent even though the weighted averages lead to the expected thermodynamic behavior of Interacting Self Avoiding Walk (ISAW).
[ { "version": "v1", "created": "Fri, 1 Jun 2007 04:49:31 GMT" }, { "version": "v2", "created": "Tue, 21 Aug 2007 09:10:48 GMT" } ]
2009-11-13T00:00:00
[ [ "Narasimhan", "S. L.", "" ], [ "Krishna", "P. S. R.", "" ], [ "Ponmurugan", "M.", "" ], [ "Murthy", "K. P. N.", "" ] ]
0706.0066
Tadashi Miyazaki
Tadashi Miyazaki
The $(g,K)$-module structures of principal series representations of $Sp(3,R)$
100 pages
null
null
null
math.RT math.NT
null
We describe explicitly the whole structures of the $(g,K)$-modules of principal series representations of $Sp(3,R)$. We apply this result to determine the holonomic system characterizing those Whittaker functions.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 04:50:23 GMT" } ]
2007-06-04T00:00:00
[ [ "Miyazaki", "Tadashi", "" ] ]
0706.0067
Pankaj Mishra
Pankaj Mishra, Swarn Lata Singh, Jokhan Ram and Yashwant Singh
Pair Correlation Functions and a Free-Energy Functional for the Nematic Phase
27 pages, 11 figures, Accepted in J. Chem. Phys
null
10.1063/1.2752170
null
cond-mat.soft cond-mat.stat-mech
null
In this paper we have presented the calculation of pair correlation functions in a nematic phase for a model of spherical particles with the long-range anisotropic interaction from the mean spherical approximation(MSA) and the Percus-Yevick (PY) integral equation theories. The results found from the MSA theory have been compared with those found analytically by Holovko and Sokolovska (J. Mol. Liq. $\bf 82$, 161(1999)). A free energy functional which involves both the symmetry conserving and symmetry broken parts of the direct pair correlation function has been used to study the properties of the nematic phase. We have also examined the possibility of constructing a free energy functional with the direct pair correlation function which includes only the principal order parameter of the ordered phase and found that the resulting functional gives results that are in good agreement with the original functional. The isotropic-nematic transition has been located using the grand thermodynamic potential. The PY theory has been found to give nematic phase with pair correlation function harmonic coefficients having all the desired features. In a nematic phase the harmonic coefficient of the total pair correlation function $h({\bf x_1},{\bf x_2})$ connected with the correlations of the director transverse fluctuations should develop a long-range tail. This feature has been found in both the MSA and PY theories.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 04:50:39 GMT" } ]
2009-11-13T00:00:00
[ [ "Mishra", "Pankaj", "" ], [ "Singh", "Swarn Lata", "" ], [ "Ram", "Jokhan", "" ], [ "Singh", "Yashwant", "" ] ]
0706.0068
Hidehiro Kaneda
H. Kaneda, T. Suzuki, T. Onaka, Y. Doi, M. Kawada, B.-C. Koo, S. Makiuti, T. Nakagawa, Y. Okada, S. Serjeant, H. Shibai, and M. Shirahata
Far-infrared distributions in nearby spiral galaxies NGC2841 and NGC2976 observed with AKARI/FIS
22 pages, 7 figures, accepted for publication in PASJ AKARI special issue
null
10.1093/pasj/59.sp2.S463
null
astro-ph
null
Far-infrared (IR) images of the nearby Sb galaxy NGC2841 and the Sc galaxy NGC2976 at wavelengths of 65, 90, 140, and 160 um have been obtained with the Far-Infrared Surveyor (FIS) onboard AKARI. Both galaxies reveal similar morphologies of dust rings. They are, however, significantly different in the dust temperature: a cold (21 K) ring for NGC2841 and a warm (30 K) ring for NGC2976, which presumably reflects the difference in the origin of the ring structure for the different Hubble type of the galaxy. In addition to the dust ring structure, a warm dust component is detected from the central region of NGC2841, which may be attributed to the heating by its Low-Ionization Nuclear Emission-line Region nucleus. As for NGC2976, an extended dust component is observed along the minor axis, which shows a distribution somewhat asymmetrical to the galactic disk; this might be associated with the HI bridge in the M81/M82 group that NGC2976 belongs to. By taking advantage of a wealth of the far-IR bands of the FIS, it is demonstrated that the spectral energy distribution of NGC2841 is spatially more variable than that of NGC2976.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 05:02:02 GMT" } ]
2015-05-13T00:00:00
[ [ "Kaneda", "H.", "" ], [ "Suzuki", "T.", "" ], [ "Onaka", "T.", "" ], [ "Doi", "Y.", "" ], [ "Kawada", "M.", "" ], [ "Koo", "B. -C.", "" ], [ "Makiuti", "S.", "" ], [ "Nakagawa", "T.", "" ], [ "Okada", "Y.", "" ], [ "Serjeant", "S.", "" ], [ "Shibai", "H.", "" ], [ "Shirahata", "M.", "" ] ]
0706.0069
Shin-Itiro Goto
Shin-itiro Goto
From a unstable periodic orbit to Lyapunov exponent and macroscopic variable in a Hamiltonian lattice : Periodic orbit dependencies
Accepted to Prog. Theor. Phys., 4 figures
null
10.1143/PTP.118.25
null
nlin.CD
null
We study which and how a periodic orbit in phase space links to both the largest Lyapunov exponent and the expectation values of macroscopic variables in a Hamiltonian system with many degrees of freedom. The model which we use in this paper is the discrete nonlinear Schr\"odinger equation. Using a method based on the modulational estimate of a periodic orbit, we predict the largest Lyapunov exponent and the expectation value of a macroscopic variable. We show that (i) the predicted largest Lyapunov exponent generally depends on the periodic orbit which we employ, and (ii) the predicted expectation value of the macroscopic variable does not depend on the periodic orbit at least in a high energy regime. In addition, the physical meanings of these dependencies are considered.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 05:07:48 GMT" } ]
2009-11-13T00:00:00
[ [ "Goto", "Shin-itiro", "" ] ]
0706.0070
Hidehiro Kaneda
H. Kaneda, W. Kim, T. Onaka, T. Wada, Y. Ita, I. Sakon, and T. Takagi
In-orbit focal adjustment of the AKARI telescope with IRC images
14 pages, 5 figures, accepted for publication in PASJ AKARI special issue
null
10.1093/pasj/59.sp2.S423
null
astro-ph
null
AKARI currently in space carries onboard a cryogenically-cooled lightweight telescope with silicon carbide mirrors. The wavefront error of the AKARI telescope obtained in laboratory measurements at 9 K showed that expected in-orbit imaging performance was diffraction-limited at a wavelength of 6.2 um. The AKARI telescope has a function of focus adjustment by shifting the secondary mirror in parallel to the optical axis. On the 4th day after the jettison of the cryostat aperture lid in the orbit, we observed a star with the InfraRed Camera (IRC) onboard AKARI. Since the initial star images observed in the near-infrared (IR) bands were significantly blurred, we twice moved the secondary mirror for the focal adjustment based on the results of model analyses as well as data analyses of the near-IR images. In consequence, we have successfully adjusted the focus of the telescope. The in-orbit imaging performance thus obtained for the AKARI telescope is diffraction-limited at a wavelength of 7.3 um, slightly degraded from that expected from the laboratory measurement.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 05:15:29 GMT" } ]
2015-05-13T00:00:00
[ [ "Kaneda", "H.", "" ], [ "Kim", "W.", "" ], [ "Onaka", "T.", "" ], [ "Wada", "T.", "" ], [ "Ita", "Y.", "" ], [ "Sakon", "I.", "" ], [ "Takagi", "T.", "" ] ]
0706.0071
Kazunori Takenaga
M. Sakamoto (Kobe) and K. Takenaga (Tohoku)
On Gauge Symmetry Breaking via Euclidean Time Component of Gauge Fields
22 pages, 6 figures, references and typos corrected, version to appear in PRD
Phys.Rev.D76:085016,2007
10.1103/PhysRevD.76.085016
KOBE-TH-07-03, TU-793
hep-th hep-ph
null
We study gauge theories with/without an extra dimension at finite temperature, in which there are two kinds of order parameters of gauge symmetry breaking. The one is the zero mode of the gauge field for the Euclidean time direction and the other is that for the direction of the extra dimension. We evaluate the effective potential for the zero modes in one-loop approximation and investigate the vacuum configuration in detail. Our analyses show that gauge symmetry can be broken only through the zero mode for the direction of the extra dimension and no nontrivial vacuum configuration of the zero mode for the Euclidean time direction is found.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 05:34:03 GMT" }, { "version": "v2", "created": "Sat, 4 Aug 2007 14:39:57 GMT" }, { "version": "v3", "created": "Thu, 11 Oct 2007 04:58:53 GMT" } ]
2008-11-26T00:00:00
[ [ "Sakamoto", "M.", "", "Kobe" ], [ "Takenaga", "K.", "", "Tohoku" ] ]
0706.0072
Shu Chen
Shu Chen, Li Wang, Shi-Jian Gu, and Yupeng Wang
Fidelity and Quantum phase transition for the Heisenberg chain with the next-nearest-neighbor interaction
4 pages, 5 figures, version published in Phys. Rev. E
Phys. Rev. E 76, 061108 (2007)
10.1103/PhysRevE.76.061108
null
cond-mat.other
null
In this paper, we investigate the fidelity for the Heisenberg chain with the next-nearest-neighbor interaction (or the $J_1-J_2$ model) and analyze its connections with quantum phase transition. We compute the fidelity between the ground states and find that the phase transition point of the $J_1-J_2$ model can not be well characterized by the ground state fidelity for finite-size systems. Instead, we introduce and calculate the fidelity between the first excited states. Our results show that the quantum transition can be well characterized by the fidelity of the first excited state even for a small-size system.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 05:56:10 GMT" }, { "version": "v2", "created": "Sat, 8 Dec 2007 07:15:55 GMT" } ]
2007-12-08T00:00:00
[ [ "Chen", "Shu", "" ], [ "Wang", "Li", "" ], [ "Gu", "Shi-Jian", "" ], [ "Wang", "Yupeng", "" ] ]
0706.0073
Yiping Dou
Yiping Dou, Nhu D Le, and James V Zidek
Modeling Hourly Ozone Concentration Fields
25 pages, 10 figures
null
null
null
stat.AP
null
This paper presents a dynamic linear model for modeling hourly ozone concentrations over the eastern United States. That model, which is developed within an Bayesian hierarchical framework, inherits the important feature of such models that its coefficients, treated as states of the process, can change with time. Thus the model includes a time--varying site invariant mean field as well as time varying coefficients for 24 and 12 diurnal cycle components. This cost of this model's great flexibility comes at the cost of computational complexity, forcing us to use an MCMC approach and to restrict application of our model domain to a small number of monitoring sites. We critically assess this model and discover some of its weaknesses in this type of application.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 06:05:44 GMT" } ]
2007-06-04T00:00:00
[ [ "Dou", "Yiping", "" ], [ "Le", "Nhu D", "" ], [ "Zidek", "James V", "" ] ]
0706.0074
Michael A. Dopita
Peter McGregor, Michael Dopita, Ralph Sutherland, Tracy Beck and Thaisa Storchi-Bergmann,
Gemini Observations of Disks and Jets in Young Stellar Objects and in Active Galaxies
Invited paper presented at the 5th Stromlo Symposium. 9 pages, 7 figures. Accepted for publication in Astrophysics & Space Science
Astrophys.SpaceSci.311:223-230,2007
10.1007/s10509-007-9537-1
null
astro-ph
null
We present first results from the Near-infrared Integral Field Spectrograph (NIFS) located at Gemini North. For the active galaxies Cygnus A and Perseus A we observe rotationally-supported accretion disks and adduce the existence of massive central black holes and estimate their masses. In Cygnus A we also see remarkable high-excitation ionization cones dominated by photoionization from the central engine. In the T-Tauri stars HV Tau C and DG Tau we see highly-collimated bipolar outflows in the [Fe II] 1.644 micron line, surrounded by a slower molecular bipolar outflow seen in the H_2 lines, in accordance with the model advocated by Pyo et al. (2002).
[ { "version": "v1", "created": "Fri, 1 Jun 2007 06:38:02 GMT" } ]
2019-08-19T00:00:00
[ [ "McGregor", "Peter", "" ], [ "Dopita", "Michael", "" ], [ "Sutherland", "Ralph", "" ], [ "Beck", "Tracy", "" ], [ "Storchi-Bergmann", "Thaisa", "" ] ]
0706.0075
Vsevolod Adler
V.E. Adler, A.B. Shabat
The model equation of soliton theory
17 p
Theoretical and Mathematical Physics 2007, Volume 153, Issue 1, pp 1373-1387
10.1007/s11232-007-0121-1
null
nlin.SI
null
We consider an hierarchy of integrable 1+2-dimensional equations related to Lie algebra of the vector fields on the line. The solutions in quadratures are constructed depending on $n$ arbitrary functions of one argument. The most interesting result is the simple equation for the generating function of the hierarchy which defines the dynamics for the negative times and also has applications to the second order spectral problems. A rather general theory of integrable 1+1-dimensional equations can be developed by study of polynomial solutions of this equation under condition of regularity of the corresponding potentials.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 06:39:30 GMT" } ]
2014-08-27T00:00:00
[ [ "Adler", "V. E.", "" ], [ "Shabat", "A. B.", "" ] ]
0706.0076
Hiroo Kenzaki
Hiroo Kenzaki, Macoto Kikuchi
Free-Energy Landscape of Kinesin by a Realistic Lattice Model
15 pages, 4 figures
null
null
null
q-bio.BM
null
Structural fluctuations in the thermal equilibrium of the kinesin motor domain are studied using a lattice protein model with Go interactions. By means of the multi-self-overlap ensemble (MSOE) Monte Carlo method and the principal component analysis (PCA), the free-energy landscape is obtained. It is shown that kinesins have two subdomains that exhibit partial folding/unfolding at functionally important regions: one is located around the nucleotide binding site and the other includes the main microtubule binding site. These subdomains are consistent with structural variability that was reported recently based on experimentally-obtained structures. On the other hand, such large structural fluctuations have not been captured by B-factor or normal mode analyses. Thus, they are beyond the elastic regime, and it is essential to take into account chain connectivity for studying the function of kinesins.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 06:45:42 GMT" } ]
2007-06-04T00:00:00
[ [ "Kenzaki", "Hiroo", "" ], [ "Kikuchi", "Macoto", "" ] ]
0706.0077
Bruno. Cessac
B. Cessac
A discrete time neural network model with spiking neurons. Rigorous results on the spontaneous dynamics
56 pages, 1 Figure, to appear in Journal of Mathematical Biology
Journal of Mathematical Biology, Volume 56, Number 3, 311-345 (2008).
null
null
math.DS nlin.CD q-bio.NC
null
We derive rigorous results describing the asymptotic dynamics of a discrete time model of spiking neurons introduced in \cite{BMS}. Using symbolic dynamic techniques we show how the dynamics of membrane potential has a one to one correspondence with sequences of spikes patterns (``raster plots''). Moreover, though the dynamics is generically periodic, it has a weak form of initial conditions sensitivity due to the presence of a sharp threshold in the model definition. As a consequence, the model exhibits a dynamical regime indistinguishable from chaos in numerical experiments.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 06:49:55 GMT" } ]
2008-02-12T00:00:00
[ [ "Cessac", "B.", "" ] ]
0706.0078
Jon-Hsu Ho
J. H. Ho, Y. H. Lai, Y. H. Chiu, and M. F. Lin
Magnetoelectronic states of a monolayer graphite
9 pages and 4 figures
null
null
null
cond-mat.mes-hall
null
The Peierl's tight-binding model, with the band Hamiltonian matrix, is used to calculate the magnetoelectronic structure of a monolayergraphite. There are many flat Landau levels and some oscillatory Landau levels. The low Landau-level energies are characterized by a simple relation, not for others. State degeneracy is, respectively, fourfold degenerate and doubly degenerate at low and high energies. The level spacing declines quickly and then grows gradually in the increase of state energy. The main features of electronic properties are directly reflected in density of states. The predicted results could be verified by the optical spectroscopy.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 06:54:34 GMT" } ]
2007-06-04T00:00:00
[ [ "Ho", "J. H.", "" ], [ "Lai", "Y. H.", "" ], [ "Chiu", "Y. H.", "" ], [ "Lin", "M. F.", "" ] ]
0706.0079
Bludov Yuliy
Yu. V. Bludov, V. A. Brazhnyi, V. V. Konotop
Delocalizing transition in one-dimensional condensates in optical lattices due to inhomogeneous interactions
null
PHYSICAL REVIEW A 76, 023603 (2007)
10.1103/PhysRevA.76.023603
null
cond-mat.other nlin.PS
null
It is shown that inhomogeneous nonlinear interactions in a Bose-Einstein condensate loaded in an optical lattice can result in delocalizing transition in one dimension, what sharply contrasts to the known behavior of discrete and periodic systems with homogeneous nonlinearity. The transition can be originated either by decreasing the amplitude of the linear periodic potential or by the change of the mean value of the periodic nonlinearity. The dynamics of the delocalizing transition is studied.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 14:35:23 GMT" } ]
2007-08-20T00:00:00
[ [ "Bludov", "Yu. V.", "" ], [ "Brazhnyi", "V. A.", "" ], [ "Konotop", "V. V.", "" ] ]
0706.0080
C. Q. Geng
C. Q. Geng, S. H. Ho and J. N. Ng
Neutrino number asymmetry and cosmological birefringence
8 pages, version to be published in JCAP
JCAP0709:010,2007
10.1088/1475-7516/2007/09/010
null
astro-ph hep-ph hep-th
null
We study a new type of effective interactions in terms of the $CPT$-even dimension-six Chern-Simons-like term, which could originate from superstring theory, to generate the cosmological birefringence. We use the neutrino number asymmetry to induce a sizable rotation polarization angle in the data of the cosmic microwave background radiation polarization. The combined effect of the new term and the neutrino asymmetry provides an alternative way to understand the birefringence.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 07:04:52 GMT" }, { "version": "v2", "created": "Tue, 21 Aug 2007 01:30:46 GMT" } ]
2008-11-26T00:00:00
[ [ "Geng", "C. Q.", "" ], [ "Ho", "S. H.", "" ], [ "Ng", "J. N.", "" ] ]
0706.0081
David Branch
David Branch, M. A. Troxel, David J. Jeffery, Kazuhito Hatano, Miriam Musco, Jerod Parrent, E. Baron, Leann Chau Dang, D. Casebeer, Nicholas Hall, and Wesley Ketchum
Comparative Direct Analysis of Type Ia Supernova Spectra. III. Premaximum
Accepted by PASP. 38 pages
null
10.1086/520553
null
astro-ph
null
A comparative study of spectra of 21 Type Ia supernovae (SNe Ia) obtained about one week before maximum light, and 8 spectra obtained 11 or more days before maximum, is presented. To a large extent the premaximum spectra exhibit the defining characteristics of the four groups defined in Paper II (core-normal, broad-line, cool, and shallow-silicon). Comparisons with SYNOW synthetic spectra show that all strong features and most weak ones can be accounted for in a plausible way. The issues of detached high-velocity features, the possible ubiquity of carbon clumps, the maximum detectable ejecta velocities, and the possibility of blueshifted emission-line peaks are discussed.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 13:53:28 GMT" } ]
2009-11-13T00:00:00
[ [ "Branch", "David", "" ], [ "Troxel", "M. A.", "" ], [ "Jeffery", "David J.", "" ], [ "Hatano", "Kazuhito", "" ], [ "Musco", "Miriam", "" ], [ "Parrent", "Jerod", "" ], [ "Baron", "E.", "" ], [ "Dang", "Leann Chau", "" ], [ "Casebeer", "D.", "" ], [ "Hall", "Nicholas", "" ], [ "Ketchum", "Wesley", "" ] ]
0706.0082
Kliment I. Kugel
A.O. Sboychakov, Sergey Savel'ev, A.L. Rakhmanov, K.I. Kugel, and Franco Nori
A mechanism for phase separation in copper oxide superconductors
4 pages, 2 figures, RevTeX, submitted to Phys. Rev. Lett
null
null
null
cond-mat.str-el cond-mat.supr-con
null
A two-band Hubbard model is used to describe the band structure and phase separation (PS) in multiband superconductors, especially in cuprates. We predict a large peak in the density of states at the Fermi level in the case of optimum doping, corresponding to the minimum energy difference between the centers of two hole bands. For strong interband hybridization, a metal-insulator transition occurs near this optimum doping level. We suggest a mechanism of PS related to the redistribution of holes between two Hubbard bands rather than to the usual antiferromagnetic correlations. We show that the critical superconducting temperature $T_c$ can be about its maximum value within a wide range of doping levels due to PS.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 07:34:22 GMT" } ]
2007-06-04T00:00:00
[ [ "Sboychakov", "A. O.", "" ], [ "Savel'ev", "Sergey", "" ], [ "Rakhmanov", "A. L.", "" ], [ "Kugel", "K. I.", "" ], [ "Nori", "Franco", "" ] ]
0706.0083
Erwan Brugall\'e
Erwan Brugall\'e, Grigory Mikhalkin
Enumeration of curves via floor diagrams
5 pages, 3 figures
null
null
null
math.AG math.CO
null
In this note we compute some enumerative invariants of real and complex projective spaces by means of some enriched graphs called floor diagrams.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 07:45:13 GMT" } ]
2007-06-04T00:00:00
[ [ "Brugallé", "Erwan", "" ], [ "Mikhalkin", "Grigory", "" ] ]
0706.0084
Fiedler Thomas
T.Fiedler
The Jones and Alexander polynomials for singular links
10 pages, 11 figures v.2 : References added v.3 : Results improved
null
null
null
math.GT
null
We extend the state models for Jones and Alexander polynomials of classical links to state models of 2-variable polynomials in the case of singular links. Moreover, we extend both of them to polynomials with d+1 variables for long singular knots with exactly d double points. These extensions can detect non-invertibility of long singular knots.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 07:45:40 GMT" }, { "version": "v2", "created": "Wed, 13 Jun 2007 07:25:21 GMT" }, { "version": "v3", "created": "Wed, 3 Oct 2007 12:08:14 GMT" } ]
2007-10-03T00:00:00
[ [ "Fiedler", "T.", "" ] ]
0706.0085
Andrei Novikov-Borodin Dr.
A.V.Novikov-Borodin
Off-site continuums and methods of their mathematical description
Prepared for conf. SNMP-2007, June 24-30, Kiev, Ukraine
null
null
null
physics.gen-ph
null
The hypothesis concerning the off-site continuum existence is investigated from the point of view of the mathematical theory of sets. The principles and methods of the mathematical description of the physical objects from different off-site continuums are introduced and discussed. There are also proposed the mathematical methods of the description of the off-site continuum observable structures and the visual perception of its physical objects from the continuum of the observer.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 07:48:52 GMT" } ]
2007-06-04T00:00:00
[ [ "Novikov-Borodin", "A. V.", "" ] ]
0706.0086
Makoto Natsuume
Makoto Natsuume and Takashi Okamura
Screening length and the direction of plasma winds
20 pages, 4 figures, JHEP3; v2: discussion added and modified
JHEP 0709:039,2007
10.1088/1126-6708/2007/09/039
KEK-TH-1155
hep-th
null
We study the screening length of a heavy quark-antiquark pair in strongly coupled gauge theory plasmas flowing at velocity v following a proposal by Liu, Rajagopal, and Wiedemann. We analyze the screening length as the direction of the plasma winds vary. To leading order in v, this angle-dependence can be studied analytically for many theories by extending our previous formalism. We show that the screening length is locally a minimum (maximum) when the pair is perpendicular (parallel) to the plasma winds, which has been observed for the N=4 plasma. Also, we compare AdS/CFT results with weak coupling ones, and we discuss the subleading dependence on v for the Dp-brane.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 07:53:45 GMT" }, { "version": "v2", "created": "Sun, 19 Aug 2007 04:46:35 GMT" } ]
2009-04-17T00:00:00
[ [ "Natsuume", "Makoto", "" ], [ "Okamura", "Takashi", "" ] ]
0706.0087
Mitko Konstantinov Gaidarov
A.N. Antonov, M.V. Ivanov, M.B. Barbaro, J.A. Caballero, E. Moya de Guerra, M.K. Gaidarov
Superscaling and Neutral Current Quasielastic Neutrino-Nucleus Scattering beyond the Relativistic Fermi Gas Model
10 pages, 6 figures, published in Phys. Rev. C
Phys.Rev.C75:064617,2007
10.1103/PhysRevC.75.064617
null
nucl-th
null
The superscaling analysis is extended to include quasielastic (QE) scattering via the weak neutral current of neutrinos and antineutrinos from nuclei. The scaling function obtained within the coherent density fluctuation model (used previously in calculations of QE inclusive electron and charge-changing (CC) neutrino scattering) is applied to neutral current neutrino and antineutrino scattering with energies of 1 GeV from $^{12}$C with a proton and neutron knockout (u-channel inclusive processes). The results are compared with those obtained using the scaling function from the relativistic Fermi gas model and the scaling function as determined from the superscaling analysis (SuSA) of QE electron scattering.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 07:59:45 GMT" } ]
2008-11-26T00:00:00
[ [ "Antonov", "A. N.", "" ], [ "Ivanov", "M. V.", "" ], [ "Barbaro", "M. B.", "" ], [ "Caballero", "J. A.", "" ], [ "de Guerra", "E. Moya", "" ], [ "Gaidarov", "M. K.", "" ] ]
0706.0088
Nigel Hitchin
Nigel Hitchin
Spherical harmonics and the icosahedron
23 pages, 2 figures. Dedicated to John McKay
null
null
null
math.AG
null
We define a sextic invariant J on the seven-dimensional space of degree three spherical harmonics and show that J is positive if and only if the nodal set of the spherical harmonic contains the vertices of exactly two regular icosahedra. The proof uses the geometry of the Clebsch diagonal cubic surface, Atiyah's classification of vector bundles on an elliptic curve and a Fano threefold introduced by Mukai.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:10:04 GMT" } ]
2007-06-04T00:00:00
[ [ "Hitchin", "Nigel", "" ] ]
0706.0089
Etienne Gallais
\'Etienne Gallais
Sign refinement for combinatorial link Floer homology
17 pages, 10 figures. correction of the Alexander grading and of the formula of lemma 5.2 of the sign refinement
Algebr. Geom. Topol. 8 (2008) 1581-1592
10.2140/agt.2008.8.1581
null
math.GT
null
Link Floer homology is an invariant for links which has recently been described entirely in a combinatorial way. Originally constructed with mod 2 coefficients, it was generalized to integer coefficients thanks to a sign refinement. In this paper, thanks to the spin extension of the permutation group we give an alternative construction of the combinatorial link Floer chain complex associated to a grid diagram with integer coefficients. We prove that the filtered homology of this complex is an invariant for the link and that it gives the previous sign refinement by means of a 2-cohomological class corresponding to the spin extension of the permutation group.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:27:24 GMT" }, { "version": "v2", "created": "Wed, 20 Jun 2007 13:15:07 GMT" }, { "version": "v3", "created": "Thu, 21 Jun 2007 06:49:58 GMT" } ]
2014-10-01T00:00:00
[ [ "Gallais", "Étienne", "" ] ]
0706.0090
Mark Swinbank Dr.
A.M. Swinbank (ICC, Durham), A. Edge (ICC), I. Smail (ICC), J. Stott (ICC), M. Bremer (Bristol), Y. Sato (NAO, Japan), C. van Breukelen (Oxford), M. Jarvis (Oxford), I. Waddington (Sussex), L. Clewley (Oxford), J. Bergeron (IAP), G. Cotter (Sussex), S. Dye (Cardiff), J. Geach (ICC), E. Gonzalez-Solares (IoA), P. Hirst (Gemini), R. Ivison (RoE), S. Rawlings (Oxford), C. Simpson (ARI), G.P. Smith (Birmingham), A. Verma (MPI), T. Yamada (Subaru)
The discovery of a massive supercluster at z=0.9 in the UKIDSS DXS
In press at MNRAS, 11 pages, 5 figures
Mon.Not.Roy.Astron.Soc.379:1343-1351,2007
10.1111/j.1365-2966.2007.12037.x
null
astro-ph
null
We analyse the first publicly released deep field of the UKIDSS Deep eXtragalactic Survey (DXS) to identify candidate galaxy over-densities at z~1 across ~1 sq. degree in the ELAIS-N1 field. Using I-K, J-K and K-3.6um colours we identify and spectroscopically follow-up five candidate structures with Gemini/GMOS and confirm they are all true over-densities with between five and nineteen members each. Surprisingly, all five structures lie in a narrow redshift range at z=0.89+/-0.01, although they are spread across 30Mpc on the sky. We also find a more distant over-density at z=1.09 in one of the spectroscopic survey regions. These five over-dense regions lying in a narrow redshift range indicate the presence of a supercluster in this field and by comparing with mock cluster catalogs from N-body simulations we discuss the likely properties of this structure. Overall, we show that the properties of this supercluster are similar to the well-studied Shapley and Hercules superclusters at lower redshift.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:31:24 GMT" } ]
2008-11-26T00:00:00
[ [ "Swinbank", "A. M.", "", "ICC, Durham" ], [ "Edge", "A.", "", "ICC" ], [ "Smail", "I.", "", "ICC" ], [ "Stott", "J.", "", "ICC" ], [ "Bremer", "M.", "", "Bristol" ], [ "Sato", "Y.", "", "NAO, Japan" ], [ "van Breukelen", "C.", "", "Oxford" ], [ "Jarvis", "M.", "", "Oxford" ], [ "Waddington", "I.", "", "Sussex" ], [ "Clewley", "L.", "", "Oxford" ], [ "Bergeron", "J.", "", "IAP" ], [ "Cotter", "G.", "", "Sussex" ], [ "Dye", "S.", "", "Cardiff" ], [ "Geach", "J.", "", "ICC" ], [ "Gonzalez-Solares", "E.", "", "IoA" ], [ "Hirst", "P.", "", "Gemini" ], [ "Ivison", "R.", "", "RoE" ], [ "Rawlings", "S.", "", "Oxford" ], [ "Simpson", "C.", "", "ARI" ], [ "Smith", "G. P.", "", "Birmingham" ], [ "Verma", "A.", "", "MPI" ], [ "Yamada", "T.", "", "Subaru" ] ]
0706.0091
Ivan Batko
M. Batkova, I. Batko, K. Flachbart, K. Jurek, E.S. Konovalova, J. Kovac, M. Reiffers, V. Sechovsky, N.Shitsevalova, E. Santava, J. Sebek
Anomalous magnetoresistance of EuB$_{5.99}$C$_{0.01}$: Enhancement of magnetoresistance in systems with magnetic polarons
4 pages, 5 figures, Submitted for publication
Physical Review B 78, 224414 (2008)
10.1103/PhysRevB.78.224414
null
cond-mat.mtrl-sci
null
We present results of measurements of electrical, magnetic and thermal properties of EuB$_{5.99}$C$_{0.01}$. The observed anomalously large negative magnetoresistance as above, so below the Curie temperature of ferromagnetic ordering $T_C$ is attributed to fluctuations in carbon concentration. Below $T_C$ the carbon richer regions give rise to helimagnetic domains, which are responsible for an additional scattering term in the resistivity, which can be suppressed by a magnetic field. Above $T_C$ these regions prevent the process of percolation of magnetic polarons (MPs), acting as "spacers" between MPs. We propose that such "spacers", being in fact volumes incompatible with existence of MPs, may be responsible for the decrease of the percolation temperature and for the additional (magneto)resistivity increase in systems with MPs.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:58:54 GMT" } ]
2020-10-08T00:00:00
[ [ "Batkova", "M.", "" ], [ "Batko", "I.", "" ], [ "Flachbart", "K.", "" ], [ "Jurek", "K.", "" ], [ "Konovalova", "E. S.", "" ], [ "Kovac", "J.", "" ], [ "Reiffers", "M.", "" ], [ "Sechovsky", "V.", "" ], [ "Shitsevalova", "N.", "" ], [ "Santava", "E.", "" ], [ "Sebek", "J.", "" ] ]
0706.0092
YaJuan Lei
Y.J. Lei, L.M. Song, J.L. Qu, C.M. Zhang
Rms-flux relation of Cyg X-1 with RXTE: dipping and nondipping cases
15 pages, 12 figures, Accepted for publication in Astrophysics & Space Science
Astrophys.SpaceSci.310:307-315,2007
10.1007/s10509-007-9534-4
null
astro-ph
null
The rms (root mean square) variability is the parameter for understanding the emission temporal properties of X-ray binaries (XRBs) and active galactic nuclei (AGN). The rms-flux relation with Rossi X-ray Timing Explorer (RXTE) data for the dips and nondip of black hole Cyg X-1 has been investigated in this paper. Our results show that there exist the linear rms-flux relations in the frequency range 0.1-10 Hz for the dipping light curve. Moreover, this linear relation still remains during the nondip regime, but with the steeper slope than that of the dipping case in the low energy band. For the high energy band, the slopes of the dipping and nondipping cases are hardly constant within errors. The explanations of the results have been made by means of the ``Propagating Perturbation'' model of Lyubarskii (1997).
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:36:31 GMT" } ]
2008-11-26T00:00:00
[ [ "Lei", "Y. J.", "" ], [ "Song", "L. M.", "" ], [ "Qu", "J. L.", "" ], [ "Zhang", "C. M.", "" ] ]
0706.0093
Simone Recchi
S. Recchi (1,2), Ch. Theis (2), P. Kroupa (3), G. Hensler (2) ((1) INAF - Osservatorio Astronomico di Trieste, Italy, (2) Institute of Astronomy, Vienna University, Austria, (3) Argelander Institute for Astronomy, Bonn, Germany)
The early evolution of tidal dwarf galaxies
4 pages, 4 figures, accepted for publication in A&A Letters
null
10.1051/0004-6361:20077264
null
astro-ph
null
Context: Dwarf galaxies can arise from self-gravitating structures emerging from tidal tails. What fraction of the known dwarf galaxies in the Local Universe can have this origin is still a matter of debate. Aims: In our effort to understand the origin and evolution of tidal dwarf galaxies and their correspondence with local objects, the first step is to understand how these galaxies (which are supposed to have a limited amount of dark matter) react to the feedback of the ongoing star formation. Methods: We make use of 2-D chemodynamical calculations in order to study the early evolution of isolated, dark matter-free dwarf galaxies. We present models in which feedback parameters are varied. We also compare the results with dark matter-dominated dwarf galaxy models. Results: All the considered models show that the star formation proceeds for more than 300 Myr, therefore dwarf galaxies without large dark matter halos are not necessarily quickly destroyed. The chemical evolution of these objects is consistent with the main chemical properties of the dSphs of the Local Group. Models with large dark matter halos show results consistent with models free of dark matter, indicating that the distribution of gas is more important than the depth of the potential well in determining the global behaviour of dSph-sized dwarf galaxies.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:36:38 GMT" } ]
2009-11-13T00:00:00
[ [ "Recchi", "S.", "" ], [ "Theis", "Ch.", "" ], [ "Kroupa", "P.", "" ], [ "Hensler", "G.", "" ] ]
0706.0094
Giorgio Parisi
Giorgio Parisi
Mean field theory of spin glasses: statics and dynamics
40 pages, 6 figures; proceedings of The 2006 Les Houches Summer School
null
null
null
cond-mat.dis-nn cond-mat.stat-mech
null
In these lectures I will review some theoretical results that have been obtained for spin glasses. I will concentrate my attention on the formulation of the mean field approach and on its numerical and experimental verifications. I will present the various hypothesis at the basis of the theory and I will discuss their mathematical and physical status.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:44:50 GMT" } ]
2007-06-04T00:00:00
[ [ "Parisi", "Giorgio", "" ] ]
0706.0095
Markus Kasper
Markus Kasper (ESO), Daniel Apai (Steward Observatory), Markus Janson (MPIA), and Wolfgang Brandner (MPIA)
A novel L-band imaging search for giant planets in the Tucana and Beta Pictoris moving groups
9 pages, 9 figures, accepted for publication in Astronomy & Astrophysics
null
10.1051/0004-6361:20077646
null
astro-ph
null
The paper presents results from a small survey of 22 young, nearby stars that was designed to detect substellar companions and ultimately giant extrasolar planets down to Jupiter masses. The targets are members of the Tucana and Beta Pictoris moving groups apart from the somewhat older star HIP 71395 that has a radial velocity trend suggesting a massive planet in large orbit. The survey was carried out in the L-band using adaptive optics assisted imaging with NAOS-CONICA (NACO) at the VLT. The chosen observation wavelength is well suited to search for close companions around young stars and delivers unprecedented detection limits. The presented technique reaches some of the best sensitivities as of today and is currently the most sensitive method for the contrast limited detection of substellar companions that are cooler than about 1000K. The companion to 51 Eri, GJ 3305, was found to be a very close binary on an eccentric orbit. No substellar companions were found around the target stars, although the method permitted to detect companions down to a few Jupiter masses at orbital distances of typically 5 astronomical units. A planet with a mass >1 M_Jup at distances >5 AU around AU Mic can be excluded at the time of our observations. The absence of detected planets sets constraints on the frequency distribution and maximum orbital distance of giant exoplanets. For example, a radial distribution power law index of 0.2 in combination with a maximum orbital radius exceeding 30 AU can be rejected at a 90% confidence level.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:32:30 GMT" } ]
2009-11-13T00:00:00
[ [ "Kasper", "Markus", "", "ESO" ], [ "Apai", "Daniel", "", "Steward Observatory" ], [ "Janson", "Markus", "", "MPIA" ], [ "Brandner", "Wolfgang", "", "MPIA" ] ]
0706.0096
William Rey Dr.
William Rey
Total singular value decomposition. Robust SVD, regression and location-scale
17 pages
null
null
null
stat.AP math.ST stat.TH
null
Singular Value Decomposition (SVD) is the basic body of many statistical algorithms and few users question whether SVD is properly handling its job. SVD aims at evaluating the decomposition that best approximates a data matrix, given some rank restriction. However often we are interested in the best components of the decomposition rather than in the best approximation . This conflict of objectives leads us to introduce {\em Total SVD}, where the word "Total" is taken as in "Total" least squares. SVD is a least squares method and, therefore, is very sensitive to gross errors in the data matrix. We make SVD robust by imposing a weight to each of the matrix entries. Breakdown properties are excellent. Algorithmic aspects are handled; they rely on high dimension fixed point computations.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:44:54 GMT" }, { "version": "v2", "created": "Thu, 6 Sep 2007 15:29:52 GMT" } ]
2007-09-06T00:00:00
[ [ "Rey", "William", "" ] ]
0706.0097
Fu-Guo Deng
Ping Zhou, Xi-Han Li, Yu-Jie Liang, Fu-Guo Deng, Hong-Yu Zhou
Multiparty quantum secret sharing with pure entangled states and decoy photons
5 pages, no figures
Physica A 381 (2007) 164-169
10.1016/j.physa.2007.04.018
null
quant-ph
null
We present a scheme for multiparty quantum secret sharing of a private key with pure entangled states and decoy photons. The boss, say Alice uses the decoy photons, which are randomly in one of the four nonorthogonal single-photon states, to prevent a potentially dishonest agent from eavesdropping freely. This scheme requires the parties of communication to have neither an ideal single-photon quantum source nor a maximally entangled one, which makes this scheme more convenient than others in a practical application. Moreover, it has the advantage of having high intrinsic efficiency for qubits and exchanging less classical information in principle.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:46:43 GMT" } ]
2009-11-13T00:00:00
[ [ "Zhou", "Ping", "" ], [ "Li", "Xi-Han", "" ], [ "Liang", "Yu-Jie", "" ], [ "Deng", "Fu-Guo", "" ], [ "Zhou", "Hong-Yu", "" ] ]
0706.0098
Fu-Guo Deng
Xi-Han Li, Fu-Guo Deng, Hong-Yu Zhou
Controlled Teleportation of an Arbitrary Multi-Qudit State in a General Form with d-Dimensional Greenberger-Horne-Zeilinger States
3 pages, 1 figure
Chinese Physics Letters 24 (2007) 1151-1153
10.1088/0256-307X/24/5/007
null
quant-ph
null
A general scheme for controlled teleportation of an arbitrary multi-qudit state with d-dimensional Greenberger-Horne-Zeilinger (GHZ) states is proposed. For an arbitrary m-qudit state, the sender Alice performs m generalized Bell-state projective measurements on her 2m qudits and the controllers need only take some single-particle measurements. The receiver Charlie can reconstruct the unknown m-qudit state by performing some single-qudit unitary operations on her particles if she cooperates with all the controllers. As the quantum channel is a sequence of maximally entangled GHZ states, the intrinsic efficiency for qudits in this scheme approaches 100% in principle.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 08:53:18 GMT" } ]
2009-11-13T00:00:00
[ [ "Li", "Xi-Han", "" ], [ "Deng", "Fu-Guo", "" ], [ "Zhou", "Hong-Yu", "" ] ]
0706.0099
Richard B\"ussow Mr
Richard Buessow
An Algorithm for the Continuous Morlet Wavelet Transform
15 pages, 4 figures, revised for MSSP
null
10.1016/j.ymssp.2007.06.001
null
physics.data-an
null
This article consists of a brief discussion of the energy density over time or frequency that is obtained with the wavelet transform. Also an efficient algorithm is suggested to calculate the continuous transform with the Morlet wavelet. The energy values of the Wavelet transform are compared with the power spectrum of the Fourier transform. Useful definitions for power spectra are given. The focus of the work is on simple measures to evaluate the transform with the Morlet wavelet in an efficient way. The use of the transform and the defined values is shown in some examples.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:07:23 GMT" }, { "version": "v2", "created": "Fri, 6 Jul 2007 12:25:29 GMT" } ]
2011-11-10T00:00:00
[ [ "Buessow", "Richard", "" ] ]
0706.0100
Marco Tomassini
L. Luthi, E. Pestelacci, M. Tomassini
Evolutionary Dilemmas in a Social Network
13 pages, 9 figures; to be published in Lecture Notes in Computer Science 2007
null
null
null
physics.soc-ph
null
We simulate the prisoner's dilemma and hawk-dove games on a real social acquaintance network. Using a discrete analogue of replicator dynamics, we show that surprisingly high levels of cooperation can be achieved, contrary to what happens in unstructured mixing populations. Moreover, we empirically show that cooperation in this network is stable with respect to invasion by defectors.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:04:09 GMT" } ]
2007-06-04T00:00:00
[ [ "Luthi", "L.", "" ], [ "Pestelacci", "E.", "" ], [ "Tomassini", "M.", "" ] ]
0706.0101
Luda Markus-Epstein
L.Markus-Epstein
Reading Off Kurosh Decompositions
19 pages with 5 figures
null
null
null
math.GR
null
Geometric methods proposed by Stallings for treating finitely generated subgroups of free groups were successfully used by many authors to solve a wide collection of decision problems for free groups and their subgroups. In the present paper we employ our generalized Stallings' folding method to introduce a procedure, which given a subgroup H of a free product of finite groups reads off its Kurosh decomposition from the subgroup graph of H.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:47:25 GMT" }, { "version": "v2", "created": "Wed, 4 Jul 2007 10:47:37 GMT" } ]
2007-07-04T00:00:00
[ [ "Markus-Epstein", "L.", "" ] ]
0706.0102
Vladimir Peskov
A. Di Mauro, B. Lund-Jensen, P. Martinengo, E. Nappi, R. Oliveira, V. Peskov, L. Periale, P.Picchi, F. Pietropaolo, I.Rodionov, J.C. Santiard
Development of innovative micropattern gaseous detectors with resistive electrodes and first results of their applications
Presented at the 11 Vienna Conference on Instrumentation, February, 2007
Nucl.Instrum.Meth.A581:225-231,2007
10.1016/j.nima.2007.07.083
null
physics.ins-det
null
The paper summarizes our latest progress in the development of newly introduced micro pattern gaseous detectors with resistive electrodes. These resistive electrodes protect the detector and the front-end electronics in case of occasional discharges and thus make the detectors very robust and reliable in operation. As an example, we describe in greater detail a new recently developed GEM-like detector, fully spark-protected with electrodes made of resistive kapton. We discovered that all resistive layers used in these studies (including kapton), that are coated with photosensitive layers, such as CsI, can be used as efficient photo cathodes for detectors operating in a pulse counting mode. We describe the first applications of such detectors combined with CsI or SbCs photo cathodes for the detection of UV photons at room and cryogenic temperatures.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:06:46 GMT" } ]
2008-11-26T00:00:00
[ [ "Di Mauro", "A.", "" ], [ "Lund-Jensen", "B.", "" ], [ "Martinengo", "P.", "" ], [ "Nappi", "E.", "" ], [ "Oliveira", "R.", "" ], [ "Peskov", "V.", "" ], [ "Periale", "L.", "" ], [ "Picchi", "P.", "" ], [ "Pietropaolo", "F.", "" ], [ "Rodionov", "I.", "" ], [ "Santiard", "J. C.", "" ] ]
0706.0103
Giorgi Japaridze
Giorgi Japaridze
Many concepts and two logics of algorithmic reduction
To appear in Studia Logica in the Spring of 2009
Studia Logica 91 (2009), pp. 1-24
10.1007/s11225-009-9164-7
null
cs.LO math.LO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the program of finding axiomatizations for various parts of computability logic, it was proved earlier that the logic of interactive Turing reduction is exactly the implicative fragment of Heyting's intuitionistic calculus. That sort of reduction permits unlimited reusage of the computational resource represented by the antecedent. An at least equally basic and natural sort of algorithmic reduction, however, is the one that does not allow such reusage. The present article shows that turning the logic of the first sort of reduction into the logic of the second sort of reduction takes nothing more than just deleting the contraction rule from its Gentzen-style axiomatization. The first (Turing) sort of interactive reduction is also shown to come in three natural versions. While those three versions are very different from each other, their logical behaviors (in isolation) turn out to be indistinguishable, with that common behavior being precisely captured by implicative intuitionistic logic. Among the other contributions of the present article is an informal introduction of a series of new -- finite and bounded -- versions of recurrence operations and the associated reduction operations. An online source on computability logic can be found at http://www.cis.upenn.edu/~giorgi/cl.html
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:07:20 GMT" }, { "version": "v2", "created": "Sun, 3 Jun 2007 13:59:23 GMT" }, { "version": "v3", "created": "Sun, 13 Jan 2008 16:31:14 GMT" }, { "version": "v4", "created": "Sun, 12 Oct 2008 19:15:22 GMT" } ]
2011-04-15T00:00:00
[ [ "Japaridze", "Giorgi", "" ] ]
0706.0104
Gianni Di Domenico
G. Di Domenico, H. Saudan, G. Bison, P. Knowles, A. Weis
Sensitivity of double resonance alignment magnetometers
null
null
10.1103/PhysRevA.76.023407
null
physics.atom-ph
null
We present an experimental study of the intrinsic magnetometric sensitivity of an optical/rf-frequency double resonance magnetometer in which linearly polarized laser light is used in the optical pumping and detection processes. We show that a semi-empirical model of the magnetometer can be used to describe the magnetic resonance spectra. Then, we present an efficient method to predict the optimum operating point of the magnetometer, i.e., the light power and rf Rabi frequency providing maximum magnetometric sensitivity. Finally, we apply the method to investigate the evolution of the optimum operating point with temperature. The method is very efficient to determine relaxation rates and thus allowed us to determine the three collisional disalignment cross sections for the components of the alignment tensor. Both first and second harmonic signals from the magnetometer are considered and compared.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:07:35 GMT" } ]
2009-11-13T00:00:00
[ [ "Di Domenico", "G.", "" ], [ "Saudan", "H.", "" ], [ "Bison", "G.", "" ], [ "Knowles", "P.", "" ], [ "Weis", "A.", "" ] ]
0706.0105
Janez Bonca
J. Bonca, S. Maekawa, and T. Tohyama
Numerical approach to low-doping regime of the t-J model
6 pages, 6 figures, accepted for publication in PRB
null
10.1103/PhysRevB.76.035121
null
cond-mat.str-el cond-mat.supr-con
null
We develop an efficient numerical method for the description of a single-hole motion in the antiferromagnetic background. The method is free of finite-size effects and allows calculation of physical properties at an arbitrary wavevector. Methodical increase of the functional space leads to results that are valid in the thermodynamic limit. We found good agreement with cumulant expansion, exact- diagonalization approaches on finite lattices as well as self-consistent Born approximations. The method allows a straightforward addition of other inelastic degrees of freedom, such as lattice effects. Our results confirm the existence of a finite quasiparticle weight near the band minimum for a single hole and the existence of string-like peaks in the single-hole spectral function.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:08:42 GMT" } ]
2009-11-13T00:00:00
[ [ "Bonca", "J.", "" ], [ "Maekawa", "S.", "" ], [ "Tohyama", "T.", "" ] ]
0706.0106
Susumu Shinohara
Susumu Shinohara, Takehiro Fukushima, Takahisa Harayama
Light emission patterns from stadium-shaped semiconductor microcavity lasers
5 pages, 4 figures
Phys. Rev. A 77, 033807 (2008)
10.1103/PhysRevA.77.033807
null
physics.optics nlin.CD
null
We study light emission patterns from stadium-shaped semiconductor (GaAs) microcavity lasers theoretically and experimentally. Performing systematic wave calculations for passive cavity modes, we demonstrate that the averaging by low-loss modes, such as those realized in multi-mode lasing, generates an emission pattern in good agreement with the ray model's prediction. In addition, we show that the dependence of experimental far-field emission patterns on the aspect ratio of the stadium cavity is well reproduced by the ray model.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:15:40 GMT" }, { "version": "v2", "created": "Mon, 10 Mar 2008 01:42:16 GMT" } ]
2008-03-10T00:00:00
[ [ "Shinohara", "Susumu", "" ], [ "Fukushima", "Takehiro", "" ], [ "Harayama", "Takahisa", "" ] ]
0706.0107
David Sanchez
David Sanchez, Llorens Serra, Mahn-Soo Choi
Strongly modulated transmission of a spin-split quantum wire with local Rashba interaction
11 pages, 12 figures
Phys. Rev. B 77, 035315 (2008)
10.1103/PhysRevB.77.035315
null
cond-mat.mes-hall
null
We investigate the transport properties of ballistic quantum wires in the presence of Zeeman spin splittings and a spatially inhomogeneous Rashba interaction. The Zeeman interaction is extended along the wire and produces gaps in the energy spectrum which allow electron propagation only for spinors lying along a certain direction. For spins in the opposite direction the waves are evanescent far away from the Rashba region, which plays the role of the scattering center. The most interesting case occurs when the magnetic field is perpendicular to the Rashba field. Then, the spins of the asymptotic wavefunctions are not eigenfunctions of the Rashba Hamiltonian and the resulting coupling between spins in the Rashba region gives rise to sudden changes of the transmission probability when the Fermi energy is swept along the gap. After briefly examining the energy spectrum and eigenfunctions of a wire with extended Rashba coupling, we analyze the transmission through a region of localized Rashba interaction, in which a double interface separates a region of constant Rashba interaction from wire leads free from spin-orbit coupling. For energies slightly above the propagation threshold, we find the ubiquitous occurrence of transmission zeros (antiresonances) which are analyzed by matching methods in the one-dimensional limit. We find that a a minimal tight-binding model yields analytical transmission lineshapes of Fano antiresonance type. More general angular dependences of the external magnetic field is treated within projected Schroedinger equations with Hamiltonian matrix elements mixing wavefunction components. Finally, we consider a realistic quantum wire where the energy subbands are coupled via the Rashba intersubband coupling term and discuss its effect on the transmission zeros.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:21:08 GMT" } ]
2009-11-13T00:00:00
[ [ "Sanchez", "David", "" ], [ "Serra", "Llorens", "" ], [ "Choi", "Mahn-Soo", "" ] ]
0706.0108
Malcolm Fairbairn
M.Fairbairn (CERN), S.N.Gninenko, N.V.Krasnikov, V.A.Matveev (Moscow, INR), T.I.Rashba (Munich, Max Planck Inst. and Troitsk, IZMIRAN), A.Rubbia (Zurich, ETH) and Sergey Troitsky (Moscow, INR)
Searching for energetic cosmic axions in a laboratory experiment: testing the PVLAS anomaly
5 pages, 3 figure
Eur.Phys.J.C52:899-904,2007
10.1140/epjc/s10052-007-0414-4
null
hep-ph
null
Astrophysical sources of energetic gamma rays provide the right conditions for maximal mixing between (pseudo)scalar (axion-like) particles and photons if their coupling is as strong as suggested by the PVLAS claim. This is independent of whether or not the axion interaction is standard at all energies or becomes supressed in the extreme conditions of the stellar interior. The flux of such particles through the Earth could be observed using a metre long, Tesla strength superconducting solenoid thus testing the axion interpretation of the PVLAS anomaly. The rate of events in CAST caused by axions from the Crab pulsar is also estimated for the PVLAS-favoured parameters.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:30:38 GMT" } ]
2008-11-26T00:00:00
[ [ "Fairbairn", "M.", "", "CERN" ], [ "Gninenko", "S. N.", "", "Moscow,\n INR" ], [ "Krasnikov", "N. V.", "", "Moscow,\n INR" ], [ "Matveev", "V. A.", "", "Moscow,\n INR" ], [ "Rashba", "T. I.", "", "Munich, Max Planck Inst. and Troitsk, IZMIRAN" ], [ "Rubbia", "A.", "", "Zurich, ETH" ], [ "Troitsky", "Sergey", "", "Moscow, INR" ] ]
0706.0109
Henri Jaffres
M.Elsen, H. Jaffres, R. Mattana, L. Thevenard, A. Lemaitre and J.-M. George
Spin-Polarized Tunneling as a probe of (Ga,Mn)As electronic properties
6 pages, 4 figures. submitted to Phys. Rev. B
null
null
null
cond-mat.mtrl-sci
null
We present magnetic and tunnel transport properties of (Ga,Mn)As/(In,Ga)As/(Ga,Mn)As structure before and after adequate annealing procedure. The conjugate increase of magnetization and tunnel magnetoresistance obtained after annealing is shown to be associated to the increase of both exchange energy $\Delta$$_{exch}$ and hole concentration by reduction of the Mn interstitial atom in the top magnetic electrode. Through a 6x6 band k.p model, we established general phase diagrams of tunneling magnetoresistance (TMR) and tunneling anisotropic magnetoresistance (TAMR) \textit{vs.} (Ga,Mn)As Fermi energy (E$_F$) and spin-splitting parameter (B$_G$). This allows to give a rough estimation of the exchange energy $\Delta$$_{exch}$=6B$_G$$\simeq$120 meV and hole concentration p$\simeq1.10^{20}$cm$^{-3}$ of (Ga,Mn)As and beyond gives the general trend of TMR and TAMR \textit{vs.} the selected hole band involved in the tunneling transport.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:29:11 GMT" } ]
2007-06-04T00:00:00
[ [ "Elsen", "M.", "" ], [ "Jaffres", "H.", "" ], [ "Mattana", "R.", "" ], [ "Thevenard", "L.", "" ], [ "Lemaitre", "A.", "" ], [ "George", "J. -M.", "" ] ]
0706.0110
Carolijn van Ditzhuijzen
C. S. E. van Ditzhuijzen, A. F. Koenderink, J. V. Hern\'andez, F. Robicheaux, L. D. Noordam, and H. B. van Linden van den Heuvell
Spatially resolved observation of dipole-dipole interaction between Rydberg atoms
4 pages, 4 figures
Phys. Rev. Lett. 100, p. 243201 (2008)
10.1103/PhysRevLett.100.243201
null
quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have observed resonant energy transfer between cold Rydberg atoms in spatially separated cylinders. Resonant dipole-dipole coupling excites the 49s atoms in one cylinder to the 49p state while the 41d atoms in the second cylinder are transferred down to the 42p state. We have measured the production of the 49p state as a function of separation of the cylinders (0 - 80 um) and the interaction time (0 - 25 us). In addition we measured the width of the electric field resonances. A full many-body quantum calculation reproduces the main features of the experiments.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:30:29 GMT" }, { "version": "v2", "created": "Wed, 31 Oct 2007 11:50:00 GMT" }, { "version": "v3", "created": "Mon, 18 Feb 2008 13:17:57 GMT" }, { "version": "v4", "created": "Fri, 20 Jun 2008 19:32:02 GMT" } ]
2008-06-20T00:00:00
[ [ "van Ditzhuijzen", "C. S. E.", "" ], [ "Koenderink", "A. F.", "" ], [ "Hernández", "J. V.", "" ], [ "Robicheaux", "F.", "" ], [ "Noordam", "L. D.", "" ], [ "Heuvell", "H. B. van Linden van den", "" ] ]
0706.0111
Francois Couchot
Francois Couchot (LMNO)
Flat modules over valuation rings
null
Journal of Pure and Applied Algebra 211 (10/2007) 235--247
10.1016/j.jpaa.2007.10.010
null
math.RA
null
Let $R$ be a valuation ring and let $Q$ be its total quotient ring. It is proved that any singly projective (respectively flat) module is finitely projective if and only if $Q$ is maximal (respectively artinian). It is shown that each singly projective module is a content module if and only if any non-unit of $R$ is a zero-divisor and that each singly projective module is locally projective if and only if $R$ is self injective. Moreover, $R$ is maximal if and only if each singly projective module is separable, if and only if any flat content module is locally projective. Necessary and sufficient conditions are given for a valuation ring with non-zero zero-divisors to be strongly coherent or $\pi$-coherent. A complete characterization of semihereditary commutative rings which are $\pi$-coherent is given. When $R$ is a commutative ring with a self FP-injective quotient ring $Q$, it is proved that each flat $R$-module is finitely projective if and only if $Q$ is perfect.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:31:01 GMT" } ]
2007-06-04T00:00:00
[ [ "Couchot", "Francois", "", "LMNO" ] ]
0706.0112
Masashi Takigawa
Takeshi Waki, Koichi Arai, Masashi Takigawa, Yuta Saiga, Yoshiya Uwatoko, Hiroshi Kageyama and Yutaka Ueda
A Novel Ordered Phase in SrCu2(BO3)2 under High Pressure
5 pages, 4 figures, to appear in J. Phys. Soc. Jpn. (July 2007)
null
10.1143/JPSJ.76.073710
null
cond-mat.str-el cond-mat.mtrl-sci
null
We report results of 11B NMR and susceptibility measurements on the quasi 2D frustrated dimer spin system SrCu2(BO3)2 under high pressure. At 2.4 GPa and in a magnetic field of 7 T, NMR lines split with decreasing temperature in two steps. A gradual splitting below T=30 K breaking the four-fold symmetry of magnetic response is followed by a further sudden splitting below 3.6 K. The latter indicates a magnetic phase transition, which is also marked by a kink in the susceptibility at 1.44 GPa. From the magnetic hyperfine shift data, we conclude that the low-T phase has a doubled unit cell containing two types of dimers, one in a nearly singlet state and the other with a finite magnetization down to T=0.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:32:36 GMT" } ]
2009-11-13T00:00:00
[ [ "Waki", "Takeshi", "" ], [ "Arai", "Koichi", "" ], [ "Takigawa", "Masashi", "" ], [ "Saiga", "Yuta", "" ], [ "Uwatoko", "Yoshiya", "" ], [ "Kageyama", "Hiroshi", "" ], [ "Ueda", "Yutaka", "" ] ]
0706.0113
Anirban Banerjee
Anirban Banerjee and J\"urgen Jost
Graph spectra as a systematic tool in computational biology
12 pages, 3 figures, Discrete Applied Mathematics, to appear
Discrete Applied Mathematics, 157(10), 2425-2431,(2009)
null
null
nlin.AO q-bio.QM
null
We present the spectrum of the (normalized) graph Laplacian as a systematic tool for the investigation of networks, and we describe basic properties of eigenvalues and eigenfunctions. Processes of graph formation like motif joining or duplication leave characteristic traces in the spectrum. This can suggest hypotheses about the evolution of a graph representing biological data. To this data, we analyze several biological networks in terms of rough qualitative data of their spectra.
[ { "version": "v1", "created": "Fri, 1 Jun 2007 09:38:52 GMT" } ]
2012-10-19T00:00:00
[ [ "Banerjee", "Anirban", "" ], [ "Jost", "Jürgen", "" ] ]