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0704.1901
Saikat Guha
Saikat Guha, Jeffrey H. Shapiro
Classical Information Capacity of the Bosonic Broadcast Channel
5 pages, 4 figures, to appear in Proceedings of ISIT 2007
null
null
null
quant-ph
null
We show that when coherent-state encoding is employed in conjunction with coherent detection, the Bosonic broadcast channel is equivalent to a classical degraded Gaussian broadcast channel whose capacity region is dual to that of the classical Gaussian multiple-access channel. We further show that if a minimum output-entropy conjecture holds true, then the ultimate classical information capacity of the Bosonic broadcast channel can be achieved by a coherent-state encoding. We provide some evidence in support of the conjecture.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 13:17:32 GMT" }, { "version": "v2", "created": "Tue, 17 Apr 2007 23:17:04 GMT" } ]
2007-05-23T00:00:00
[ [ "Guha", "Saikat", "" ], [ "Shapiro", "Jeffrey H.", "" ] ]
0704.1902
Haim Beidenkopf
H. Beidenkopf, T. Verdene, Y. Myasoedov, H. Shtrikman, E. Zeldov, B. Rosenstein, D. Li, T. Tamegai
Interplay of Anisotropy and Disorder in the Doping-Dependent Melting and Glass Transitions of Vortices in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$
4 pages, 4 figures
null
10.1103/PhysRevLett.98.167004
null
cond-mat.supr-con cond-mat.stat-mech
null
We study the oxygen doping dependence of the equilibrium first-order melting and second-order glass transitions of vortices in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. Doping affects both anisotropy and disorder. Anisotropy scaling is shown to collapse the melting lines only where thermal fluctuations are dominant. Yet, in the region where disorder breaks that scaling, the glass lines are still collapsed. A quantitative fit to melting and replica symmetry breaking lines of a 2D Ginzburg-Landau model further reveals that disorder amplitude weakens with doping, but to a lesser degree than thermal fluctuations, enhancing the relative role of disorder.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 13:23:27 GMT" } ]
2015-05-13T00:00:00
[ [ "Beidenkopf", "H.", "" ], [ "Verdene", "T.", "" ], [ "Myasoedov", "Y.", "" ], [ "Shtrikman", "H.", "" ], [ "Zeldov", "E.", "" ], [ "Rosenstein", "B.", "" ], [ "Li", "D.", "" ], [ "Tamegai", "T.", "" ] ]
0704.1903
Shigeo Maruyama
Kei Hasegawa, Suguru Noda, Hisashi Sugime, Kazunori Kakehi, Shigeo Maruyama, Yukio Yamaguchi
Growth window and possible mechanism of millimeter-thick single-walled carbon nanotube forests
6 pages, 6 figures. Submitted to J. Nanosci. Nanotech
null
null
null
cond-mat.mtrl-sci
null
Our group recently reproduced the water-assisted growth method, so-called "super growth", of millimeter-thick single-walled carbon nanotube (SWNT) forests by using C2H4/ H2/ H2O/ Ar reactant gas and Fe/ Al2O3 catalyst. In this current work, a parametric study was carried out on both reaction and catalyst conditions. Results revealed that a thin Fe catalyst layer (about 0.5 nm) yielded rapid growth of SWNTs only when supported on Al2O3, and that Al2O3 support enhanced the activity of Fe, Co, and Ni catalysts. The growth window for the rapid SWNT growth was narrow, however. Optimum amount of added H2O increased the SWNT growth rate but further addition of H2O degraded both the SWNT growth rate and quality. Addition of H2 was also essential for rapid SWNT growth, but again, further addition decreased both the SWNT growth rate and quality. Because Al2O3 catalyzes hydrocarbon reforming, Al2O3 support possibly enhances the SWNT growth rate by supplying the carbon source to the catalyst nanoparticles. The origin of the narrow window for rapid SWNT growth will also be discussed.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 14:27:59 GMT" } ]
2007-05-23T00:00:00
[ [ "Hasegawa", "Kei", "" ], [ "Noda", "Suguru", "" ], [ "Sugime", "Hisashi", "" ], [ "Kakehi", "Kazunori", "" ], [ "Maruyama", "Shigeo", "" ], [ "Yamaguchi", "Yukio", "" ] ]
0704.1904
Alexander Bershadskii
A. Bershadskii
Nonlocal interactions versus viscosity in turbulence
null
Phys.Fluids.20:085103,2008
10.1063/1.2969473
null
nlin.CD astro-ph cond-mat.stat-mech
null
It is shown that nonlocal interactions determine energy spectrum in isotropic turbulence at small Reynolds numbers. It is also shown that for moderate Reynolds numbers the bottleneck effect is determined by the same nonlocal interactions. Role of the large and small scales covariance at the nonlocal interactions and in energy balance has been investigated. A possible hydrodynamic mechanism of the nonlocal solution instability at large scales has been briefly discussed. A quantitative relationship between effective strain of the nonlocal interactions and viscosity has been found. All results are supported by comparison with the data of experiments and numerical simulations.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 15:27:50 GMT" }, { "version": "v2", "created": "Sun, 22 Apr 2007 18:23:08 GMT" }, { "version": "v3", "created": "Sun, 6 May 2007 14:51:20 GMT" }, { "version": "v4", "created": "Sun, 20 May 2007 16:20:49 GMT" } ]
2008-11-07T00:00:00
[ [ "Bershadskii", "A.", "" ] ]
0704.1905
Tomislav Prokopec
Ante Bilandzic (Nikhef) and Tomislav Prokopec (Utrecht University)
Quantum radiative corrections to slow-roll inflation
31 pages, 2 eps figures, references added and an improved introduction
Phys.Rev.D76:103507,2007
10.1103/PhysRevD.76.103507
NIKHEF-2007-09, SPIN-07-11, ITP-UU-07-18
astro-ph
null
We consider the nonminimally coupled lambda phi^4 scalar field theory in de Sitter space and construct the renormalization group improved renormalized effective theory at the one-loop level. Based on the corresponding quantum Friedmann equation and the scalar field equation of motion, we calculate the quantum radiative corrections to the scalar spectral index n_s, gravitational wave spectral index n_g and the ratio r of tensor to scalar perturbations. When compared with the standard (tree-level) values, we find that the quantum contributions are suppressed by lambda N^2 where N denotes the number of e-foldings. Hence there is an N^2 enhancement with respect to the naive expectation, which is due to the infrared enhancement of scalar vacuum fluctuations characterising de Sitter space. Since observations constrain lambda to be very small lambda ~ 10^(-12) and N ~ 50-60, the quantum corrections in this inflationary model are unobservably small.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 16:12:16 GMT" }, { "version": "v2", "created": "Thu, 17 May 2007 17:44:13 GMT" } ]
2008-11-26T00:00:00
[ [ "Bilandzic", "Ante", "", "Nikhef" ], [ "Prokopec", "Tomislav", "", "Utrecht University" ] ]
0704.1906
Liviu Hozoi
L. Hozoi, U. Birkenheuer, P. Fulde, A. Mitrushchenkov, and H. Stoll
Ab initio wavefunction based methods for excited states in solids: correlation corrections to the band structure of ionic oxides
null
Phys. Rev. B 76, 085109 (2007)
10.1103/PhysRevB.76.085109
null
cond-mat.mtrl-sci cond-mat.other
null
Ab initio wavefunction based methods are applied to the study of electron correlation effects on the band structure of oxide systems. We choose MgO as a prototype closed-shell ionic oxide. Our analysis is based on a local Hamiltonian approach and performed on finite fragments cut from the infinite solid. Localized Wannier functions and embedding potentials are obtained from prior periodic Hartree-Fock (HF) calculations. We investigate the role of various electron correlation effects in reducing the HF band gap and modifying the band widths. On-site and nearest-neighbor charge relaxation as well as long-range polarization effects are calculated. Whereas correlation effects are essential for computing accurate band gaps, we found that they produce smaller changes on the HF band widths, at least for this material. Surprisingly, a broadening effect is obtained for the O 2p valence bands. The ab initio data are in good agreement with the energy gap and band width derived from thermoreflectance and x-ray photoemission experiments. The results show that the wavefunction based approach applied here allows for well controlled approximations and a transparent identification of the microscopic processes which determine the electronic band structure.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 16:32:37 GMT" } ]
2007-08-13T00:00:00
[ [ "Hozoi", "L.", "" ], [ "Birkenheuer", "U.", "" ], [ "Fulde", "P.", "" ], [ "Mitrushchenkov", "A.", "" ], [ "Stoll", "H.", "" ] ]
0704.1907
Peter Robert Wood
J. A. McSaveney, P. R. Wood, M. Scholz, J. C. Lattanzio and K. H. Hinkle
Abundances in intermediate-mass AGB stars undergoing third dredge-up and hot-bottom burning
Accepted for publication in MNRAS
null
10.1111/j.1365-2966.2007.11845.x
null
astro-ph
null
High dispersion near-infrared spectra have been taken of seven highly-evolved, variable, intermediate-mass (4-6 Msun) AGB stars in the LMC and SMC in order to look for C, N and O variations that are expected to arise from third dredge-up and hot-bottom burning. The pulsation of the objects has been modelled, yielding stellar masses, and spectral synthesis calculations have been performed in order to derive abundances from the observed spectra. For two stars, abundances of C, N, O, Na, Al, Ti, Sc and Fe were derived and compared with the abundances predicted by detailed AGB models. Both stars show very large N enhancements and C deficiencies. These results provide the first observational confirmation of the long-predicted production of primary nitrogen by the combination of third dredge-up and hot-bottom burning in intermediate-mass AGB stars. It was not possible to derive abundances for the remaining five stars: three were too cool to model, while another two had strong shocks in their atmospheres which caused strong emission to fill the line cores and made abundance determination impossible. The latter occurrence allows us to predict the pulsation phase interval during which observations should be made if successful abundance analysis is to be possible.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 17:18:01 GMT" } ]
2009-11-13T00:00:00
[ [ "McSaveney", "J. A.", "" ], [ "Wood", "P. R.", "" ], [ "Scholz", "M.", "" ], [ "Lattanzio", "J. C.", "" ], [ "Hinkle", "K. H.", "" ] ]
0704.1908
Radek Erban
Radek Erban, Jonathan Chapman and Philip Maini
A practical guide to stochastic simulations of reaction-diffusion processes
35 pages
null
null
null
q-bio.SC physics.ed-ph q-bio.QM
null
A practical introduction to stochastic modelling of reaction-diffusion processes is presented. No prior knowledge of stochastic simulations is assumed. The methods are explained using illustrative examples. The article starts with the classical Gillespie algorithm for the stochastic modelling of chemical reactions. Then stochastic algorithms for modelling molecular diffusion are given. Finally, basic stochastic reaction-diffusion methods are presented. The connections between stochastic simulations and deterministic models are explained and basic mathematical tools (e.g. chemical master equation) are presented. The article concludes with an overview of more advanced methods and problems.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 17:50:38 GMT" }, { "version": "v2", "created": "Mon, 19 Nov 2007 03:47:24 GMT" } ]
2007-11-19T00:00:00
[ [ "Erban", "Radek", "" ], [ "Chapman", "Jonathan", "" ], [ "Maini", "Philip", "" ] ]
0704.1909
Sergey Mikhailov
S. A. Mikhailov
Non-linear electromagnetic response of graphene
5 pages, 3 figures
Europhys. Lett. 79, 27002 (2007)
10.1209/0295-5075/79/27002
null
cond-mat.mes-hall
null
It is shown that the massless energy spectrum of electrons and holes in graphene leads to the strongly non-linear electromagnetic response of this system. We predict that the graphene layer, irradiated by electromagnetic waves, emits radiation at higher frequency harmonics and can work as a frequency multiplier. The operating frequency of the graphene frequency multiplier can lie in a broad range from microwaves to the infrared.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 17:56:19 GMT" } ]
2007-07-24T00:00:00
[ [ "Mikhailov", "S. A.", "" ] ]
0704.1910
Eric Pfahl
Eric Pfahl (KITP), Phil Arras (UVa), Bill Paxton (KITP)
Ellipsoidal Oscillations Induced by Substellar Companions: A Prospect for the Kepler Mission
13 pages (emulateapj), 9 figures, 3 tables, submitted to ApJ
Astrophys.J.679:783-796,2008
10.1086/586878
null
astro-ph
null
Hundreds of substellar companions to solar-type stars will be discovered with the Kepler satellite. Kepler's extreme photometric precision gives access to low-amplitude stellar variability contributed by a variety of physical processes. We discuss in detail the periodic flux modulations arising from the tidal force on the star due to a substellar companion. An analytic expression for the variability is derived in the equilibrium-tide approximation. We demonstrate analytically and through numerical solutions of the linear, nonadiabatic stellar oscillation equations that the equilibrium-tide formula works extremely well for stars of mass <1.4 Msun with thick surface convection zones. More massive stars with largely radiative envelopes do not conform to the equilibrium-tide approximation and can exhibit flux variations $\ga$10 times larger than naive estimates. Over the full range of stellar masses considered, we treat the oscillatory response of the convection zone by adapting a prescription that A. J. Brickhill developed for pulsating white dwarfs. Compared to other sources of periodic variability, the ellipsoidal lightcurve has a distinct dependence on time and system parameters. We suggest that ellipsoidal oscillations induced by giant planets may be detectable from as many as ~100 of the 10^5 Kepler target stars. (Abridged)
[ { "version": "v1", "created": "Sun, 15 Apr 2007 18:00:07 GMT" } ]
2011-02-07T00:00:00
[ [ "Pfahl", "Eric", "", "KITP" ], [ "Arras", "Phil", "", "UVa" ], [ "Paxton", "Bill", "", "KITP" ] ]
0704.1911
Igor Kulic
Herve Mohrbach and Igor M. Kulic
Motor driven microtubule shape fluctuations - force from within the lattice
null
null
10.1103/PhysRevLett.99.218102
null
cond-mat.soft
null
We develop a general theory of microtubule (MT) deformations by molecular motors generating internal force doublets within the MT lattice. We describe two basic internal excitations, the S and V shape, and compare them with experimental observations from literature. We explain the special role of tubulin vacancies and the dramatic deformation amplifying effect observed for katanin acting at positions of defects. Experimentally observed shapes are used to determine the ratio of MT shear and stretch moduli ($\approx 6\times10^{-5}$) and to estimate the forces induced in the MT lattice by katanin (10's of pN). For many motors acting on a single MT we derive expressions for the end-to-end distance reduction and provide criteria for dominance of this new effect over thermal fluctuations. We conclude that molecular motors if acting cooperatively can ''animate'' MTs from within the lattice and induce slack even without cross-bridging to other structures, a scenario very much reminiscent of the motor driven axoneme.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:04:09 GMT" } ]
2009-11-13T00:00:00
[ [ "Mohrbach", "Herve", "" ], [ "Kulic", "Igor M.", "" ] ]
0704.1912
Adrian Melott
L.C. Natarajan, A.L. Melott, B.M. Rothschild, and L.D. Martin (University of Kansas)
Bone Cancer Rates in Dinosaurs Compared with Modern Vertebrates
As published in Transactions of the Kansas Academy of Science
TKAS 110, 155-158 (2007)
null
null
q-bio.PE astro-ph physics.geo-ph
null
Data on the prevalence of bone cancer in dinosaurs is available from past radiological examination of preserved bones. We statistically test this data for consistency with rates extrapolated from information on bone cancer in modern vertebrates, and find that there is no evidence of a different rate. Thus, this test provides no support for a possible role of ionizing radiation in the K-T extinction event.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:08:16 GMT" }, { "version": "v2", "created": "Mon, 10 Sep 2007 16:28:09 GMT" }, { "version": "v3", "created": "Tue, 11 Sep 2007 14:19:34 GMT" }, { "version": "v4", "created": "Tue, 16 Oct 2007 18:17:26 GMT" } ]
2007-10-16T00:00:00
[ [ "Natarajan", "L. C.", "", "University of Kansas" ], [ "Melott", "A. L.", "", "University of Kansas" ], [ "Rothschild", "B. M.", "", "University of Kansas" ], [ "Martin", "L. D.", "", "University of Kansas" ] ]
0704.1913
Pran Nath
Tarek Ibrahim
Effective Lagrangian for the $\chi^{+}_j \chi^{-}_kH^{0}_l$ interaction in the minimal supersymmetric standard model and neutral Higgs decays
36 pages, 14 figues, revised version was published in Phys. Rev. D
Phys.Rev.D76:075012,2007
10.1103/PhysRevD.76.075012
null
hep-ph
null
We extend previous analyses of the supersymmetric loop correction to the neutral Higgs couplings to include the coupling $\chi^{+}_j \chi^{-}_kH^{0}_l$. The analysis completes the previous analyses where similar corrections were computed for the $\bar{\tau} \tau H^{0}_l$, $\bar{b} b H^{0}_l$, $\bar{c} c H^{0}_l$ and for $\bar{t} t H^{0}_l$ couplings within the minimal supersymmetric standard model. The effective one loop Lagrangian is then applied to the computation of the neutral Higgs decays. The sizes of the supersymmetric loop corrections of the neutral Higgs decay widths into $\chi^{+}_i \chi^{-}_j$ ($i=1,2$; $j=1,2$) are investigated and the supersymmetric loop correction is found to be in the range of $7\sim15%$ in significant regions of the parameter space. By including the loop corrections of the other decay channels $\bar{b} b$, $\bar{t} t$, $\bar{\tau} \tau$, $\bar{c} c$, and $\chi^0_i \chi^0_j$ ($i=1-4$; $j=1-4$), the corrections to branching ratios for $H^{0}_l\to \chi^{+}_i \chi^{-}_j$ can reach as high as 40%. The effects of CP phases on the branching ratio are also investigated.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:11:53 GMT" }, { "version": "v2", "created": "Thu, 5 Jul 2007 20:02:35 GMT" }, { "version": "v3", "created": "Wed, 31 Oct 2007 22:22:58 GMT" } ]
2008-11-26T00:00:00
[ [ "Ibrahim", "Tarek", "" ] ]
0704.1914
Abdelouahab Arouche
Abdelouahab Arouche (LATN)
Finite Representations of the braid group commutator subgroup
null
null
null
null
math.DS
null
We study the representations of the commutator subgroup K_{n} of the braid group B_{n} into a finite group . This is done through a symbolic dynamical system. Some experimental results enable us to compute the number of subgroups of K_{n} of a given (finite) index, and, as a by-product, to recover the well known fact that every representation of K_{n} into S_{r}, with n > r, must be trivial.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:17:21 GMT" } ]
2007-05-23T00:00:00
[ [ "Arouche", "Abdelouahab", "", "LATN" ] ]
0704.1915
Marco Delbo
Marco Delbo (INAF-Osservatorio Astronomico Di Torino, Oca), Aldo Dell'oro (INAF-Osservatorio Astronomico Di Torino), Alan W. Harris (DLR Institute of Planetary Research), Stefano Mottola (DLR Institute of Planetary Research), Michael Mueller (DLR Institute of Planetary Research)
Thermal inertia of near-Earth asteroids and implications for the magnitude of the Yarkovsky effect
Icarus (30/03/2007) in press
null
10.1016/j.icarus.2007.03.007
null
astro-ph
null
Thermal inertia determines the temperature distribution over the surface of an asteroid and therefore governs the magnitude the Yarkovsky effect. The latter causes gradual drifting of the orbits of km-sized asteroids and plays an important role in the delivery of near-Earth asteroids (NEAs) from the main belt and in the dynamical spreading of asteroid families. At present, very little is known about the thermal inertia of asteroids in the km size range. Here we show that the average thermal inertia of a sample of NEAs in the km-size range is 200 $\pm$ 40 J m&#8722;2 s&#8722;0.5 K&#8722;1. Furthermore, we identify a trend of increasing thermal inertia with decreasing asteroid diameter, D. This indicates that the dependence of the drift rate of the orbital semimajor axis on the size of asteroids due to the Yarkovsky effect is a more complex function than the generally adopted D^(&#8722;1) dependence, and that the size distribution of objects injected by Yarkovsky-driven orbital mobility into the NEA source regions is less skewed to smaller sizes than generally assumed. We discuss how this fact may help to explain the small difference in the slope of the size distribution of km-sized NEAs and main-belt asteroids.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:20:24 GMT" } ]
2007-05-23T00:00:00
[ [ "Delbo", "Marco", "", "INAF-Osservatorio Astronomico Di Torino, Oca" ], [ "Dell'oro", "Aldo", "", "INAF-Osservatorio Astronomico Di Torino" ], [ "Harris", "Alan W.", "", "DLR\n Institute of Planetary Research" ], [ "Mottola", "Stefano", "", "DLR Institute of Planetary\n Research" ], [ "Mueller", "Michael", "", "DLR Institute of Planetary Research" ] ]
0704.1916
Hans J. Haubold
R.K. Saxena, A.M. Mathai, H.J. Haubold
Solutions of certain fractional kinetic equations and a fractional diffusion equation
10 pages, LaTeX,corrected typos
Journal of Mathematical Physics 51(2010)103506
10.1063/1.3496829
null
math.CA
null
In view of the usefulness and importance of the kinetic equation in certain physical problems, the authors derive the explicit solution of a fractional kinetic equation of general character, that unifies and extends earlier results. Further, an alternative shorter method based on a result developed by the authors is given to derive the solution of a fractional diffusion equation.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:20:52 GMT" }, { "version": "v2", "created": "Tue, 7 Aug 2007 16:15:22 GMT" } ]
2015-05-13T00:00:00
[ [ "Saxena", "R. K.", "" ], [ "Mathai", "A. M.", "" ], [ "Haubold", "H. J.", "" ] ]
0704.1917
Dan Bohr
Dan Bohr and Peter Schmitteckert
Strong enhancement of transport by interaction on contact links
Published version -- references corrected
Phys. Rev. B 75, 241103(R) (2007)
10.1103/PhysRevB.75.241103
null
cond-mat.str-el
null
Strong repulsive interactions within a one dimensional Fermi system in a two-probe configuration normally lead to a reduced off-resonance conductance. We show that if the repulsive interaction extends to the contact regions, a strong increase of the conductance may occur, even for systems where one would expect to find a reduced conductance. An essential ingredient in our calculations is a momentum-space representation of the leads, which allows a high energy resolution. Further, we demonstrate that these results are independent of the high-energy cutoff and that the relevant scale is set by the Fermi velocity.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:21:27 GMT" }, { "version": "v2", "created": "Thu, 14 Jun 2007 09:10:24 GMT" }, { "version": "v3", "created": "Mon, 18 Jun 2007 07:00:11 GMT" } ]
2007-06-18T00:00:00
[ [ "Bohr", "Dan", "" ], [ "Schmitteckert", "Peter", "" ] ]
0704.1918
Christoffer Wittmann
C. Wittmann, D. Elser, U. L. Andersen, R. Filip, P. Marek, G. Leuchs
Quantum Filtering of Optical Coherent States
6 pages, 5 figures
null
10.1103/PhysRevA.78.032315
null
quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose and experimentally demonstrate non-destructive and noiseless removal (filtering) of vacuum states from an arbitrary set of coherent states of continuous variable systems. Errors i.e. vacuum states in the quantum information are diagnosed through a weak measurement, and on that basis, probabilistically filtered out. We consider three different filters based on on/off detection phase stabilized and phase randomized homodyne detection. We find that on/off etection, optimal in the ideal theoretical setting, is superior to the homodyne strategy in a practical setting.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 15:55:42 GMT" }, { "version": "v2", "created": "Mon, 13 Aug 2007 16:41:28 GMT" }, { "version": "v3", "created": "Mon, 29 Sep 2008 13:53:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Wittmann", "C.", "" ], [ "Elser", "D.", "" ], [ "Andersen", "U. L.", "" ], [ "Filip", "R.", "" ], [ "Marek", "P.", "" ], [ "Leuchs", "G.", "" ] ]
0704.1919
Francois Fressin
Francois Fressin (LG), Tristan Guillot (OCA), Vincent Morello (OCA), Fr\'ed\'eric Pont
Interpreting and predicting the yield of transit surveys: Giant planets in the OGLE fields
article in press in A&A, 21 pages, 18 figures
Astron.Astrophys.475:729-746,2007
10.1051/0004-6361:20077138
null
astro-ph
null
Transiting extrasolar planets are now discovered jointly by photometric surveys and by radial velocimetry. We want to determine whether the different data sets are compatible between themselves and with models of the evolution of extrasolar planets. We simulate directly a population of stars corresponding to the OGLE transit survey and assign them planetary companions based on radial velocimetry discoveries. We use a model of the evolution and structure of giant planets assuming a variable fraction of heavy elements. The output list of detectable planets of the simulations is compared to the real detections. We confirm that the radial velocimetry and photometric survey data sets are compatible within the statistical errors, assuming that planets with periods between 1 and 2 days are approximately 5 times less frequent than planets with periods between 2 and 5 days. We show that evolution models fitting present observational constraints predict a lack of small giant planets with large masses. We also identify distinct populations of planets: those with short periods (P < 10d) are only found in orbit around metal-rich stars with [Fe/H] > -0.07. We further confirm the relative absence of low-mass giant planets at small orbital distances.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 19:25:16 GMT" } ]
2011-08-04T00:00:00
[ [ "Fressin", "Francois", "", "LG" ], [ "Guillot", "Tristan", "", "OCA" ], [ "Morello", "Vincent", "", "OCA" ], [ "Pont", "Frédéric", "" ] ]
0704.1920
Manuel Ortega-Rodr\'iguez
Manuel Ortega-Rodriguez, Robert V. Wagoner
Global Disk Oscillation Modes in Cataclysmic Variables and Other Newtonian Accretors
1 figure
Astrophys.J.668:1158-1164,2007
10.1086/521419
null
astro-ph
null
Diskoseismology, the theoretical study of small adiabatic hydrodynamical global perturbations of geometrically thin, optically thick accretion disks around black holes (and other compact objects), is a potentially powerful probe of the gravitational field. For instance, the frequencies of the normal mode oscillations can be used to determine the elusive angular momentum parameter of the black hole. The general formalism developed by diskoseismologists for relativistic systems can be readily applied to the Newtonian case of cataclysmic variables (CVs). Some of these systems (e.g., the dwarf nova SS Cygni) show rapid oscillations in the UV with periods of tens of seconds and high coherence. In this paper, we assess the possibility that these dwarf nova oscillations (DNOs) are diskoseismic modes. Besides its importance in investigating the physical origin of DNOs, the present work could help us to answer the following question. To what extent are the similarities in the oscillation phenomenology of CVs and X-ray binaries (XRBs) indicative of a common physical mechanism?
[ { "version": "v1", "created": "Sun, 15 Apr 2007 20:33:38 GMT" } ]
2009-11-16T00:00:00
[ [ "Ortega-Rodriguez", "Manuel", "" ], [ "Wagoner", "Robert V.", "" ] ]
0704.1921
Isabelle Herbauts
I.M.Herbauts and D.J.Dunstan
Quantum molecular dynamics study of the pressure dependence of the ammonia inversion transition
pdf format, 10 pages, 4 figures
Physical Review A (Vol.76, No.6, December 2007)
10.1103/PhysRevA.76.062506
null
quant-ph cond-mat.other
null
The mechanism of the shift, broadening and quenching of the ammonia inversion frequency with gas pressure has been a problem of lively interest for over seventy years. A simple quantum model of the ammonia molecule perturbed by collisions with ideal gas molecules displays the essential features of the experimental data for NH3 and for ND3. The model does not display the behaviour expected from theories of quantum localisation such as quantum state diffusion and decoherence. On the other hand, models of perturbed classical oscillators do display similar behaviour to our model. The quenching of the ammonia inversion transition cannot therefore be interpreted as spatial localisation of the wavefunction.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 20:36:58 GMT" } ]
2008-01-08T00:00:00
[ [ "Herbauts", "I. M.", "" ], [ "Dunstan", "D. J.", "" ] ]
0704.1922
Mahan Mj
Mahan Mj
Relative Rigidity, Quasiconvexity and C-Complexes
23pgs, v3: Relative rigidity proved for relatively hyperbolic groups and higher rank symmetric spaces, v4: final version incorporating referee's comments. To appear in "Algebraic and Geometric Topology"
Algebraic & Geometric Topology 8 (2008) 1691-1716
10.2140/agt.2008.8.1691
null
math.GT math.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce and study the notion of relative rigidity for pairs $(X,\JJ)$ where 1) $X$ is a hyperbolic metric space and $\JJ$ a collection of quasiconvex sets 2) $X$ is a relatively hyperbolic group and $\JJ$ the collection of parabolics 3) $X$ is a higher rank symmetric space and $\JJ$ an equivariant collection of maximal flats Relative rigidity can roughly be described as upgrading a uniformly proper map between two such $\JJ$'s to a quasi-isometry between the corresponding $X$'s. A related notion is that of a $C$-complex which is the adaptation of a Tits complex to this context. We prove the relative rigidity of the collection of pairs $(X, \JJ)$ as above. This generalises a result of Schwarz for symmetric patterns of geodesics in hyperbolic space. We show that a uniformly proper map induces an isomorphism of the corresponding $C$-complexes. We also give a couple of characterizations of quasiconvexity. of subgroups of hyperbolic groups on the way.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 19:49:19 GMT" }, { "version": "v2", "created": "Tue, 19 Jun 2007 09:16:20 GMT" }, { "version": "v3", "created": "Thu, 6 Sep 2007 18:52:58 GMT" }, { "version": "v4", "created": "Mon, 4 Aug 2008 00:54:42 GMT" } ]
2011-03-24T00:00:00
[ [ "Mj", "Mahan", "" ] ]
0704.1923
Oleksiy Roslyak V
Oleksiy Roslyak and Joseph L. Birman
Theory of enhanced second-harmonic generation by the quadrupole-dipole hybrid exciton
8 pages, 3 figures
null
10.1088/0953-8984/20/23/235238
null
cond-mat.mtrl-sci
null
We report calculated substantial enhancement of the second harmonic generation (SHG) in cuprous oxide crystals resonantly hybridized with an appropriate organic material (DCM2:CA:PS 'solid-state solvent'). The quadrupole origin of the inorganic part of the quadrupole-dipole hybrid provides inversion symmetry breaking and the organic part contributes to the oscillator strength of the hybrid. We show that the enhancement of the SHG, compared to bulk cuprous oxide crystal, is proportional to the ratio of the DCM2 dipole moment and the effective dipole moment of the quadrupole transitions in the cuprous oxide. It is also inversely proportional to the line-width of the hybrid and bulk excitons. The enhancement may be regulated by adjusting the organic blend (mutual concentration of the DCM2 and CA part of the solvent) and pumping conditions(varying the angle of incidence in case of optical pumping or populating the minimum of the lower branch of the hybrid in case of electrical pumping).
[ { "version": "v1", "created": "Sun, 15 Apr 2007 21:23:40 GMT" }, { "version": "v2", "created": "Sat, 5 May 2007 15:00:10 GMT" }, { "version": "v3", "created": "Mon, 24 Mar 2008 18:12:55 GMT" } ]
2009-11-13T00:00:00
[ [ "Roslyak", "Oleksiy", "" ], [ "Birman", "Joseph L.", "" ] ]
0704.1924
Marcel Arndt
Marcel Arndt, Mitchell Luskin
Error Estimation and Atomistic-Continuum Adaptivity for the Quasicontinuum Approximation of a Frenkel-Kontorova Model
23 pages, 5 figures
null
null
null
math.NA math-ph math.MP
null
We propose and analyze a goal-oriented a posteriori error estimator for the atomistic-continuum modeling error in the quasicontinuum method. Based on this error estimator, we develop an algorithm which adaptively determines the atomistic and continuum regions to compute a quantity of interest to within a given tolerance. We apply the algorithm to the computation of the structure of a crystallographic defect described by a Frenkel-Kontorova model and present the results of numerical experiments. The numerical results show that our method gives an efficient estimate of the error and a nearly optimal atomistic-continuum modeling strategy.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 21:26:18 GMT" } ]
2007-05-23T00:00:00
[ [ "Arndt", "Marcel", "" ], [ "Luskin", "Mitchell", "" ] ]
0704.1925
Yuanning Yu
Yuanning Yu, Athina P. Petropulu and H. Vincent Poor
Blind Identification of Distributed Antenna Systems with Multiple Carrier Frequency Offsets
To appear in the Proceedings of the 8th IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Helsinki, Finland, June 17-20, 2007
null
null
null
cs.IT math.IT
null
In spatially distributed multiuser antenna systems, the received signal contains multiple carrier-frequency offsets (CFOs) arising from mismatch between the oscillators of transmitters and receivers. This results in a time-varying rotation of the data constellation, which needs to be compensated at the receiver before symbol recovery. In this paper, a new approach for blind CFO estimation and symbol recovery is proposed. The received base-band signal is over-sampled, and its polyphase components are used to formulate a virtual Multiple-Input Multiple-Output (MIMO) problem. By applying blind MIMO system estimation techniques, the system response can be estimated and decoupled versions of the user symbols can be recovered, each one of which contains a distinct CFO. By applying a decision feedback Phase Lock Loop (PLL), the CFO can be mitigated and the transmitted symbols can be recovered. The estimated MIMO system response provides information about the CFOs that can be used to initialize the PLL, speed up its convergence, and avoid ambiguities usually linked with PLL.
[ { "version": "v1", "created": "Sun, 15 Apr 2007 23:58:08 GMT" } ]
2007-07-13T00:00:00
[ [ "Yu", "Yuanning", "" ], [ "Petropulu", "Athina P.", "" ], [ "Poor", "H. Vincent", "" ] ]
0704.1926
Nicholas S. Witte
Peter J. Forrester and Nicholas S. Witte
The Distribution of the first Eigenvalue Spacing at the Hard Edge of the Laguerre Unitary Ensemble
65 pages, 1 eps figure, typos and references corrected
null
null
null
math.CA math-ph math.MP
null
The distribution function for the first eigenvalue spacing in the Laguerre unitary ensemble of finite rank random matrices is found in terms of a Painlev\'e V system, and the solution of its associated linear isomonodromic system. In particular it is characterised by the polynomial solutions to the isomonodromic equations which are also orthogonal with respect to a deformation of the Laguerre weight. In the scaling to the hard edge regime we find an analogous situation where a certain Painlev\'e \IIId system and its associated linear isomonodromic system characterise the scaled distribution. We undertake extensive analytical studies of this system and use this knowledge to accurately compute the distribution and its moments for various values of the parameter $ a $. In particular choosing $ a=\pm 1/2 $ allows the first eigenvalue spacing distribution for random real orthogonal matrices to be computed.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 00:23:19 GMT" }, { "version": "v2", "created": "Thu, 12 Jul 2007 00:46:27 GMT" } ]
2007-07-12T00:00:00
[ [ "Forrester", "Peter J.", "" ], [ "Witte", "Nicholas S.", "" ] ]
0704.1927
Hyerim Noh
J. Hwang and H. Noh
Second-order perturbations of cosmological fluids: Relativistic effects of pressure, multi-component, curvature, and rotation
41 pages, no figure
Phys.Rev.D76:103527,2007
10.1103/PhysRevD.76.103527
null
astro-ph
null
We present general relativistic correction terms appearing in Newton's gravity to the second-order perturbations of cosmological fluids. In our previous work we have shown that to the second-order perturbations, the density and velocity perturbation equations of general relativistic zero-pressure, irrotational, single-component fluid in a flat background coincide exactly with the ones known in Newton's theory. Here, we present the general relativistic second-order correction terms arising due to (i) pressure, (ii) multi-component, (iii) background curvature, and (iv) rotation. In case of multi-component zero-pressure, irrotational fluids under the flat background, we effectively do not have relativistic correction terms, thus the relativistic result again coincides with the Newtonian ones. In the other three cases we generally have pure general relativistic correction terms. In case of pressure, the relativistic corrections appear even in the level of background and linear perturbation equations. In the presence of background curvature, or rotation, pure relativistic correction terms directly appear in the Newtonian equations of motion of density and velocity perturbations to the second order. In the small-scale limit (far inside the horizon), relativistic equations including the rotation coincide with the ones in Newton's gravity.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 01:10:13 GMT" } ]
2008-12-18T00:00:00
[ [ "Hwang", "J.", "" ], [ "Noh", "H.", "" ] ]
0704.1928
Jonathan Pietarila Graham
J. Pietarila Graham (1 and 2), Darryl Holm (3 and 4), Pablo Mininni (1 and 5), and Annick Pouquet (1) ((1) National Center for Atmospheric Research, Boulder, USA, (2) Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (3) Department of Mathematics, Imperial College London, UK, (4) Computer and Computational Science Division, Los Alamos National Laboratory, Los Alamos, USA (5) Departamento de Fisica, Universidad de Buenos Aires, Buenos Aires, Argentina)
Highly turbulent solutions of LANS-alpha and their LES potential
37 pages, 17 figures
null
10.1103/PhysRevE.76.056310
null
physics.flu-dyn nlin.CD
null
We compute solutions of the Lagrangian-Averaged Navier-Stokes alpha-model (LANS) for significantly higher Reynolds numbers (up to Re 8300) than have previously been accomplished. This allows sufficient separation of scales to observe a Navier-Stokes (NS) inertial range followed by a 2nd LANS inertial range. The analysis of the third-order structure function scaling supports the predicted l^3 scaling; it corresponds to a k^(-1) scaling of the energy spectrum. The energy spectrum itself shows a different scaling which goes as k^1. This latter spectrum is consistent with the absence of stretching in the sub-filter scales due to the Taylor frozen-in hypothesis employed as a closure in the derivation of LANS. These two scalings are conjectured to coexist in different spatial portions of the flow. The l^3 (E(k) k^(-1)) scaling is subdominant to k^1 in the energy spectrum, but the l^3 scaling is responsible for the direct energy cascade, as no cascade can result from motions with no internal degrees of freedom. We verify the prediction for the size of the LANS attractor resulting from this scaling. From this, we give a methodology either for arriving at grid-independent solutions for LANS, or for obtaining a formulation of a LES optimal in the context of the alpha models. The fully converged grid-independent LANS may not be the best approximation to a direct numerical simulation of the NS equations since the minimum error is a balance between truncation errors and the approximation error due to using LANS instead of the primitive equations. Furthermore, the small-scale behavior of LANS contributes to a reduction of flux at constant energy, leading to a shallower energy spectrum for large alpha. These small-scale features, do not preclude LANS to reproduce correctly the intermittency properties of high Re flow.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 01:58:12 GMT" }, { "version": "v2", "created": "Mon, 3 Sep 2007 09:30:53 GMT" }, { "version": "v3", "created": "Mon, 22 Oct 2007 08:13:05 GMT" } ]
2007-11-15T00:00:00
[ [ "Graham", "J. Pietarila", "", "1 and 2" ], [ "Holm", "Darryl", "", "3 and 4" ], [ "Mininni", "Pablo", "", "1\n and 5" ], [ "Pouquet", "Annick", "" ] ]
0704.1929
Stephan Rosenkranz
Qing'An Li, K.E. Gray, H. Zheng, H. Claus, S. Rosenkranz, S. Nyborg Ancona, R. Osborn, J.F. Mitchell, Y. Chen, and J.W. Lynn
Reentrant Orbital Order and the True Ground State of LaSr2Mn2O7
4 pages, RevTex4
Phys. Rev. Lett. 98, 167201 (2007)
10.1103/PhysRevLett.98.167201
null
cond-mat.str-el
null
Contrary to conventional wisdom, our purified La2-2xSr1+2xMn2O7 crystals exhibit CE-type orbital and charge order as the low-temperature ground state for a hole doping level h = 0.5. For small deviations from h = 0.5, the high temperature CE phase is replaced at low temperatures by an A-type antiferromagnet without coexistence. Larger deviations result in a lack of CE order at any temperature. Thus, small inhomogeneities in cation or oxygen composition could explain why others commonly see this reentrance with coexistence.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 03:25:56 GMT" } ]
2007-05-23T00:00:00
[ [ "Li", "Qing'An", "" ], [ "Gray", "K. E.", "" ], [ "Zheng", "H.", "" ], [ "Claus", "H.", "" ], [ "Rosenkranz", "S.", "" ], [ "Ancona", "S. Nyborg", "" ], [ "Osborn", "R.", "" ], [ "Mitchell", "J. F.", "" ], [ "Chen", "Y.", "" ], [ "Lynn", "J. W.", "" ] ]
0704.1930
Muhammad Sharif
M. Sharif and Sehar Aziz
Addendum: A Classification of Plane Symmetric Kinematic Self-similar Solutions
7 pages Latex
J.Korean Phys.Soc.50:947-949,2007
10.3938/jkps.50.947
null
gr-qc
null
In our recent paper, we classified plane symmetric kinematic self-similar perfect fluid and dust solutions of the second, zeroth and infinite kinds. However, we have missed some solutions during the process. In this short communication, we add up those missing solutions. We have found a total of seven solutions, out of which five turn out to be independent and cannot be found in the earlier paper
[ { "version": "v1", "created": "Mon, 16 Apr 2007 02:27:47 GMT" } ]
2011-08-04T00:00:00
[ [ "Sharif", "M.", "" ], [ "Aziz", "Sehar", "" ] ]
0704.1931
Sebastien Louis Mr
Sebastien G.R. Louis, Kae Nemoto, W.J. Munro and T.P. Spiller
Weak non-linearities and cluster states
5 pages, to appear in Phys. Rev. A
Phys. Rev. A 75, 042323 (2007)
10.1103/PhysRevA.75.042323
null
quant-ph
null
We propose a scalable approach to building cluster states of matter qubits using coherent states of light. Recent work on the subject relies on the use of single photonic qubits in the measurement process. These schemes have a low initial success probability and low detector efficiencies cause a serious blowup in resources. In contrast, our approach uses continuous variables and highly efficient measurements. We present a two-qubit scheme, with a simple homodyne measurement system yielding an entangling operation with success probability 1/2. Then we extend this to a three-qubit interaction, increasing this probability to 3/4. We discuss the important issues of the overhead cost and the time scaling, showing how these can be vastly improved with access to this new probability range.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 02:32:18 GMT" } ]
2009-11-13T00:00:00
[ [ "Louis", "Sebastien G. R.", "" ], [ "Nemoto", "Kae", "" ], [ "Munro", "W. J.", "" ], [ "Spiller", "T. P.", "" ] ]
0704.1932
Pengjie Zhang
Pengjie Zhang (SHAO), Michele Liguori (Cambridge), Rachel Bean (Cornell), Scott Dodelson (Fermilab/Chicago)
A discriminating probe of gravity at cosmological scales
v2: minor revisions in the main text, fig, table and references. Slightly longer than the PRL version in press. V3: update the figure (minor change due to a coding bug. No other changes
Phys.Rev.Lett.99:141302,2007
10.1103/PhysRevLett.99.141302
null
astro-ph
null
The standard cosmological model is based on general relativity and includes dark matter and dark energy. An important prediction of this model is a fixed relationship between the gravitational potentials responsible for gravitational lensing and the matter overdensity. Alternative theories of gravity often make different predictions for this relationship. We propose a set of measurements which can test the lensing/matter relationship, thereby distinguishing between dark energy/matter models and models in which gravity differs from general relativity. Planned optical, infrared and radio galaxy and lensing surveys will be able to measure $E_G$, an observational quantity whose expectation value is equal to the ratio of the Laplacian of the Newtonian potentials to the peculiar velocity divergence, to percent accuracy. We show that this will easily separate alternatives such as $\Lambda$CDM, DGP, TeVeS and $f(R)$ gravity.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 03:01:24 GMT" }, { "version": "v2", "created": "Mon, 10 Sep 2007 12:18:03 GMT" }, { "version": "v3", "created": "Wed, 28 Nov 2007 10:40:43 GMT" } ]
2008-11-26T00:00:00
[ [ "Zhang", "Pengjie", "", "SHAO" ], [ "Liguori", "Michele", "", "Cambridge" ], [ "Bean", "Rachel", "", "Cornell" ], [ "Dodelson", "Scott", "", "Fermilab/Chicago" ] ]
0704.1933
Jonathan Tsai
Jonathan Tsai
The Loewner driving function of trajectory arcs of quadratic differentials
22 pages, 4 figures Changes in v2: Changed some definitions and exchanged ordering of theorems for clarity purposes. Typos corrected. Changes in v3: Mistakes corrected. Added new Lemma 2.2. Overall clarity improved
J. Math. Anal. Appl. 360:561-576 (2009)
null
null
math.CV
null
We obtain a first order differential equation for the driving function of the chordal Loewner differential equation in the case where the domain is slit by a curve which is a trajectory arc of certain quadratic differentials. In particular this includes the case when the curve is a path on the square, triangle or hexagonal lattice in the upper halfplane or, indeed, in any domain with boundary on the lattice. We also demonstrate how we use this to calculate the driving function numerically. Equivalent results for other variants of the Loewner differential equation are also obtained: Multiple slits in the chordal Loewner differential equation and the radial Loewner differential equation. The method also works for other versions of the Loewner differential equation. The proof of our formula uses a generalization of Schwarz-Christoffel mapping to domains bounded by trajectory arcs of rotations of a given quadratic differential that is of interest in its own right.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 19:31:12 GMT" }, { "version": "v2", "created": "Tue, 22 May 2007 19:42:26 GMT" }, { "version": "v3", "created": "Tue, 19 Feb 2008 09:14:10 GMT" } ]
2011-12-12T00:00:00
[ [ "Tsai", "Jonathan", "" ] ]
0704.1934
Alexey A. Kryukov
Alexey A. Kryukov
On the measurement problem for a two-level quantum system
for related papers, see http://www.uwc.edu/dept/math/faculty/kryukov/
Found. Phys. 37, 3 (2007)
10.1007/s10701-006-9093-5
null
quant-ph math-ph math.MP
null
A geometric approach to quantum mechanics with unitary evolution and non-unitary collapse processes is developed. In this approach the Schrodinger evolution of a quantum system is a geodesic motion on the space of states of the system furnished with an appropriate Riemannian metric. The measuring device is modeled by a perturbation of the metric. The process of measurement is identified with a geodesic motion of state of the system in the perturbed metric. Under the assumption of random fluctuations of the perturbed metric, the Born rule for probabilities of collapse is derived. The approach is applied to a two-level quantum system to obtain a simple geometric interpretation of quantum commutators, the uncertainty principle and Planck's constant. In light of this, a lucid analysis of the double-slit experiment with collapse and an experiment on a pair of entangled particles is presented.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 04:29:32 GMT" } ]
2015-05-13T00:00:00
[ [ "Kryukov", "Alexey A.", "" ] ]
0704.1935
Cristine Nunes Ferreira crisnfer
C. N. Ferreira, J. A. Helayel-Neto, W. G. Ney
Global-String and Vortex Superfluids in a Supersymmetric Scenario
9 pages. This version presented the relation between Lorentz symmetry violation by the background and the appearance of terms that explicitly break SUSY
Phys.Rev.D77:105028,2008
10.1103/PhysRevD.77.105028
null
hep-th
null
The main goal of this work is to investigate the possibility of finding the supersymmetric version of the U(1)-global string model which behaves as a vortex-superfluid. To describe the superfluid phase, we introduce a Lorentz-symmetry breaking background that, in an approach based on supersymmetry, leads to a discussion on the relation between the violation of Lorentz symmetry and explicit soft supersymmetry breakings. We also study the relation between the string configuration and the vortex-superfluid phase. In the framework we settle down in terms of superspace and superfields, we actually establish a duality between the vortex degrees of freedom and the component fields of the Kalb-Ramond superfield. We make also considerations about the fermionic excitations that may appear in connection with the vortex formation.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 03:49:55 GMT" }, { "version": "v2", "created": "Sun, 27 May 2007 07:12:17 GMT" }, { "version": "v3", "created": "Mon, 14 Jan 2008 01:45:30 GMT" } ]
2009-11-16T00:00:00
[ [ "Ferreira", "C. N.", "" ], [ "Helayel-Neto", "J. A.", "" ], [ "Ney", "W. G.", "" ] ]
0704.1936
S. M. Abrarov Dr.
S. M. Abrarov, R. M. Abrarov
Identities for number series and their reciprocals: Dirac delta function approach
9 pages, minor corrections
null
null
null
math.GM
null
Dirac delta function (delta-distribution) approach can be used as efficient method to derive identities for number series and their reciprocals. Applying this method, a simple proof for identity relating prime counting function (pi-function) and logarithmic integral (Li-function) can be obtained.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 17:47:19 GMT" }, { "version": "v2", "created": "Wed, 18 Apr 2007 19:56:50 GMT" }, { "version": "v3", "created": "Fri, 20 Apr 2007 19:43:11 GMT" } ]
2007-05-23T00:00:00
[ [ "Abrarov", "S. M.", "" ], [ "Abrarov", "R. M.", "" ] ]
0704.1937
Tomomi Ishikawa
CP-PACS/JLQCD Collaborations: T. Ishikawa, S. Aoki, M. Fukugita, S. Hashimoto, K-I. Ishikawa, N. Ishizuka, Y. Iwasaki, K. Kanaya, T. Kaneko, Y. Kuramashi, M. Okawa, Y. Taniguchi, N. Tsutsui, A. Ukawa, N. Yamada and T. Yoshi\'e
Light quark masses from unquenched lattice QCD
4 pages, 3 figures, revtex4; v2: contents partly modified, published version
Phys.Rev.D78:011502,2008
10.1103/PhysRevD.78.011502
UTCCS-P-31, UTHEP-542, KEK-CP-193, HUPD-0702, RBRC-666
hep-lat hep-ex hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the light meson spectrum and the light quark masses by lattice QCD simulation, treating all light quarks dynamically and employing the Iwasaki gluon action and the nonperturbatively O(a)-improved Wilson quark action. The calculations are made at the squared lattice spacings at an equal distance a^2~0.005, 0.01 and 0.015 fm^2, and the continuum limit is taken assuming an O(a^2) discretization error. The light meson spectrum is consistent with experiment. The up, down and strange quark masses in the \bar{MS} scheme at 2 GeV are \bar{m}=(m_{u}+m_{d})/2=3.55^{+0.65}_{-0.28} MeV and m_s=90.1^{+17.2}_{-6.1} MeV where the error includes statistical and all systematic errors added in quadrature. These values contain the previous estimates obtained with the dynamical u and d quarks within the error.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 04:47:14 GMT" }, { "version": "v2", "created": "Mon, 21 Jul 2008 18:44:08 GMT" } ]
2012-08-27T00:00:00
[ [ "JLQCD Collaboration", "", "" ], [ "Ishikawa", "T.", "" ], [ "Aoki", "S.", "" ], [ "Fukugita", "M.", "" ], [ "Hashimoto", "S.", "" ], [ "Ishikawa", "K-I.", "" ], [ "Ishizuka", "N.", "" ], [ "Iwasaki", "Y.", "" ], [ "Kanaya", "K.", "" ], [ "Kaneko", "T.", "" ], [ "Kuramashi", "Y.", "" ], [ "Okawa", "M.", "" ], [ "Taniguchi", "Y.", "" ], [ "Tsutsui", "N.", "" ], [ "Ukawa", "A.", "" ], [ "Yamada", "N.", "" ], [ "Yoshié", "T.", "" ] ]
0704.1938
Michishige Tezuka
Yasuhiko Kamiyama and Michishige Tezuka
The Chow ring of the moduli space and its related homogeneous space of bundles on P^2 with charge 1
null
null
null
null
math.AT
null
For an algebraically closed field K with ch K \not = 2, we determine the Chow ring of the moduli space of holomorphic bundles on a projective plane with the structure group SO(n,K) and half the first Pontryagin index being equal to 1, each of which is trivial on a fixed line and has a fixed holomorphic trivialization there.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 04:44:18 GMT" } ]
2007-05-23T00:00:00
[ [ "Kamiyama", "Yasuhiko", "" ], [ "Tezuka", "Michishige", "" ] ]
0704.1939
Hyunchul Nha
Hyunchul Nha
Entanglement condition via su(2) and su(1,1) algebra using Schr{\"o}dinger-Robertson uncertainty relation
published version, 3.5 pages, 1 figure
Phys. Rev. A 76, 014305 (2007)
10.1103/PhysRevA.76.014305
null
quant-ph
null
The Schr{\"o}dinger-Robertson inequality generally provides a stronger bound on the product of uncertainties for two noncommuting observables than the Heisenberg uncertainty relation, and as such, it can yield a stricter separability condition in conjunction with partial transposition. In this paper, using the Schr{\"o}dinger-Robertson uncertainty relation, the separability condition previously derived from the su(2) and the su(1,1) algebra is made stricter and refined to a form invariant with respect to local phase shifts. Furthermore, a linear optical scheme is proposed to test this invariant separability condition.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 05:40:09 GMT" }, { "version": "v2", "created": "Mon, 10 Sep 2007 09:09:33 GMT" } ]
2009-11-13T00:00:00
[ [ "Nha", "Hyunchul", "" ] ]
0704.1940
Yum-Tong Siu
Yum-Tong Siu
Additional Explanatory Notes on the Analytic Proof of the Finite Generation of the Canonical Ring
null
null
null
null
math.AG math.CV
null
This set of notes provides some additional explanatory material on the analytic proof of the finite generation of the canonical ring for a compact complex algebraic manifold of general type.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 17:12:20 GMT" } ]
2007-05-23T00:00:00
[ [ "Siu", "Yum-Tong", "" ] ]
0704.1941
Alexander Stoimenow
A. Stoimenow
Tait's conjectures and odd crossing number amphicheiral knots
5 pages, 1 figure; this is an elementarily written research announcement; some/full account is/will be given in (a revision of) math/0606255
Bull. Amer. Math. Soc. 45 (2008), 285--291.
null
null
math.GT math.HO
null
We give a brief historical overview of the Tait conjectures, made 120 years ago in the course of his pioneering work in tabulating the simplest knots, and solved a century later using the Jones polynomial. We announce the solution, again based on a substantial study of the Jones polynomial, of one (possibly his last remaining?) problem of Tait, with the construction of amphicheiral knots of almost all odd crossing numbers. An application to the non-triviality problem for the Jones polynomial is also outlined.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 05:31:09 GMT" } ]
2008-08-30T00:00:00
[ [ "Stoimenow", "A.", "" ] ]
0704.1942
Masanori Sato
Masanori Sato
A revisit of the papers on the theory of relativity: Reconsideration of the hypothesis of ether-dragging
16 pages, 8 figures
null
null
null
physics.gen-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper revisits previous papers related to the theory of relativity. Afterwards, a reconsideration of the hypothesis of ether-dragging is discussed. The ether is compatible with the theory of relativity and historical experiments; this paper explains the Michelson-Morley experiment using the ether-dragging hypothesis without the orthodox interpretation that the speed c is a fixed constant in terms of any system of inertial coordinates.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 05:36:10 GMT" }, { "version": "v2", "created": "Tue, 29 May 2007 02:14:37 GMT" }, { "version": "v3", "created": "Fri, 21 Nov 2008 08:59:03 GMT" }, { "version": "v4", "created": "Thu, 27 Nov 2008 02:46:10 GMT" }, { "version": "v5", "created": "Thu, 26 Mar 2009 06:12:20 GMT" }, { "version": "v6", "created": "Fri, 23 Oct 2009 07:28:45 GMT" }, { "version": "v7", "created": "Fri, 13 Nov 2009 06:58:40 GMT" } ]
2009-11-13T00:00:00
[ [ "Sato", "Masanori", "" ] ]
0704.1943
Gunter M. Ziegler
Pavle V. M. Blagojevi\'c, G\"unter M. Ziegler
The ideal-valued index for a dihedral group action, and mass partition by two hyperplanes
new version revised according to referee's comments, 44 pages, many diagrams; a shorter version of this will appear in Topology and its Applications (ATA 2010 proceedings)
null
null
null
math.AT math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the complete Fadell-Husseini index of the 8 element dihedral group D_8 acting on S^d \times S^d, both for F_2 and for integer coefficients. This establishes the complete goup cohomology lower bounds for the two hyperplane case of Gr"unbaum's 1960 mass partition problem: For which d and j can any j arbitrary measures be cut into four equal parts each by two suitably-chosen hyperplanes in R^d? In both cases, we find that the ideal bounds are not stronger than previously established bounds based on one of the maximal abelian subgroups of D_8.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 05:51:33 GMT" }, { "version": "v2", "created": "Mon, 21 Jul 2008 17:55:19 GMT" }, { "version": "v3", "created": "Tue, 7 Dec 2010 08:42:38 GMT" }, { "version": "v4", "created": "Thu, 9 Dec 2010 15:20:57 GMT" } ]
2015-03-13T00:00:00
[ [ "Blagojević", "Pavle V. M.", "" ], [ "Ziegler", "Günter M.", "" ] ]
0704.1944
Yoshihiro Iwata
Y. Iwata, Y. Inoue, M. Minowa
A new method of alpha ray measurement using a Quadrupole Mass Spectrometer
8 pages, 6 figures
Nucl.Instrum.Meth.A577:619-622,2007
10.1016/j.nima.2007.04.123
RESCEU-57/08
nucl-ex
null
We propose a new method of alpha($\alpha$)-ray measurement that detects helium atoms with a Quadrupole Mass Spectrometer(QMS). A demonstration is undertaken with a plastic-covered $^{241}$Am $\alpha$-emitting source to detect $\alpha$-rays stopped in the capsule. We successfully detect helium atoms that diffuse out of the capsule by accumulating them for one to 20 hours in a closed chamber. The detected amount is found to be proportional to the accumulation time. Our method is applicable to probe $\alpha$-emitting radioactivity in bulk material.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 05:45:28 GMT" } ]
2008-11-26T00:00:00
[ [ "Iwata", "Y.", "" ], [ "Inoue", "Y.", "" ], [ "Minowa", "M.", "" ] ]
0704.1945
Yudai Suwa Dr.
Yudai Suwa, Tomoya Takiwaki, Kei Kotake, Katsuhiko Sato
Magnetorotational Collapse of Population III Stars
24 pages, 17 figures. Accepted for publication in PASJ. A paper with high-resolution figures available at "http://www-utap.phys.s.u-tokyo.ac.jp/~suwa/paper/mrcp3.pdf"
Publ.Astron.Soc.Jap.59:771-785,2007
10.1093/pasj/59.4.771
UTAP-553, RESCEU-4/07
astro-ph
null
We perform a series of two-dimensional magnetorotational core-collapse simulations of Pop III stars. Changing the initial distributions of rotation and magnetic fields prior to collapse in a parametric manner, we compute 19 models. By so doing, we systematically investigate how rotation and magnetic fields affect the collapse dynamics and explore how the properties of the black-hole formations and neutrino emissions could be affected. As for the microphysics, we employ a realistic equation of state and approximate the neutrino transfer by a multiflavour leakage scheme. With these computations, we find that the jet-like explosions are obtained by the magnetodriven shock waves if the initial magnetic field is as large as $10^{12}$ G. We point out that the black-hole masses at the formation decrease with the initial field strength, on the other hand, increase with the initial rotation rates. As for the neutrino properties, we point out that the degree of the differential rotation plays an important role to determine which species of the neutrino luminosity is more dominant than the others. Furthermore, we find that the stronger magnetic fields make the peak neutrino luminosities smaller, because the magnetic pressure acts to halt the collapse in the central regions, leading to the suppression of the releasable gravitational binding energies.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 07:16:29 GMT" } ]
2015-05-13T00:00:00
[ [ "Suwa", "Yudai", "" ], [ "Takiwaki", "Tomoya", "" ], [ "Kotake", "Kei", "" ], [ "Sato", "Katsuhiko", "" ] ]
0704.1946
Paul Indelicato
J.P. Marques (CFA), F. Parente (CFA, DFFCT), Paul Indelicato (LKB - Jussieu)
Hyperfine Quenching of the $4s4p ^{3}P_{0}$ Level in Zn-like Ions
null
European Physical Journal D 41, 3 (31/01/2007) 457
10.1140/epjd/e2007-00018-8
null
physics.atom-ph
null
In this paper, we used the multiconfiguration Dirac-Fock method to compute with high precision the influence of the hyperfine interaction on the $[Ar]3d^{10} 4s4p ^3P_0$ level lifetime in Zn-like ions for stable and some quasi-stable isotopes of nonzero nuclear spin between Z=30 and Z=92. The influence of this interaction on the $[Ar]3d^{10} 4s4p ^3P_1 - [Ar]3d^{10} 4s4p ^3P_0$ separation energy is also calculated for the same ions.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 07:03:35 GMT" } ]
2007-05-23T00:00:00
[ [ "Marques", "J. P.", "", "CFA" ], [ "Parente", "F.", "", "CFA, DFFCT" ], [ "Indelicato", "Paul", "", "LKB -\n Jussieu" ] ]
0704.1947
Todor Popov
O. Ogievetsky, T. Popov
R-matrices in Rime
50 pages, typos corrected
null
null
null
math.QA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We replace the ice Ansatz on matrix solutions of the Yang-Baxter equation by a weaker condition which we call "rime". Rime solutions include the standard Drinfeld-Jimbo R-matrix. Solutions of the Yang--Baxter equation within the rime Ansatz which are maximally different from the standard one we call "strict rime". A strict rime non-unitary solution is parameterized by a projective vector. We show that this solution transforms to the Cremmer-Gervais R-matrix by a change of basis with a matrix containing symmetric functions in the components of the parameterizing vector. A strict unitary solution (the rime Ansatz is well adapted for taking a unitary limit) is shown to be equivalent to a quantization of a classical "boundary" r-matrix of Gerstenhaber and Giaquinto. We analyze the structure of the elementary rime blocks and find, as a by-product, that all non-standard R-matrices of GL(1|1)-type can be uniformly described in a rime form. We discuss then connections of the classical rime solutions with the Bezout operators. The Bezout operators satisfy the (non-)homogeneous associative classical Yang--Baxter equation which is related to the Rota-Baxter operators. We classify the rime Poisson brackets: they form a 3-dimensional pencil. A normal form of each individual member of the pencil depends on the discriminant of a certain quadratic polynomial. We also classify orderable quadratic rime associative algebras. For the standard Drinfeld-Jimbo solution, there is a choice of the multiparameters, for which it can be non-trivially rimed. However, not every Belavin-Drinfeld triple admits a choice of the multiparameters for which it can be rimed. We give a minimal example.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 07:30:57 GMT" }, { "version": "v2", "created": "Mon, 5 May 2008 17:11:20 GMT" }, { "version": "v3", "created": "Wed, 6 May 2009 16:16:40 GMT" } ]
2009-05-06T00:00:00
[ [ "Ogievetsky", "O.", "" ], [ "Popov", "T.", "" ] ]
0704.1948
S\'ebastien Gautier
Sebastien Gautier
Quadratic centers defining elliptic surfaces
24 pages, 16 Figures, 8 Tables
null
null
null
math.DS
null
Let $X$ be a quadratic vector field with a center whose generic orbits are algebraic curves of genus one. To each $X$ we associate an elliptic surface (a smooth complex compact surface which is a genus one fibration). We give the list of all such vector fields and determine the corresponding elliptic surfaces.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 07:35:36 GMT" }, { "version": "v2", "created": "Tue, 29 Jan 2008 13:41:32 GMT" } ]
2008-01-29T00:00:00
[ [ "Gautier", "Sebastien", "" ] ]
0704.1949
Tomotoshi Nishino
Kouji Ueda, Roman Krcmar, Andrej Gendiar, and Tomotoshi Nishino
Corner Transfer Matrix Renormalization Group Method Applied to the Ising Model on the Hyperbolic Plane
4 pages, 5 figures
J. Phys. Soc. Jpn. 76 (2007) 084004
10.1143/JPSJ.76.084004
null
cond-mat.stat-mech
null
Critical behavior of the Ising model is investigated at the center of large scale finite size systems, where the lattice is represented as the tiling of pentagons. The system is on the hyperbolic plane, and the recursive structure of the lattice makes it possible to apply the corner transfer matrix renormalization group method. From the calculated nearest neighbor spin correlation function and the spontaneous magnetization, it is concluded that the phase transition of this model is mean-field like. One parameter deformation of the corner Hamiltonian on the hyperbolic plane is discussed.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 07:57:28 GMT" } ]
2010-05-20T00:00:00
[ [ "Ueda", "Kouji", "" ], [ "Krcmar", "Roman", "" ], [ "Gendiar", "Andrej", "" ], [ "Nishino", "Tomotoshi", "" ] ]
0704.1950
Melanie Lebental
M. Lebental, N. Djellali, C. Arnaud, J.-S. Lauret, J. Zyss, R. Dubertrand, C. Schmit, and E. Bogomolny
Inferring periodic orbits from spectra of simple shaped micro-lasers
13 pages, 19 figures, accepted for publication in Physical Review A
Physical Review A 76 023830 (2007)
10.1103/PhysRevA.76.023830
null
physics.optics nlin.CD
null
Dielectric micro-cavities are widely used as laser resonators and characterizations of their spectra are of interest for various applications. We experimentally investigate micro-lasers of simple shapes (Fabry-Perot, square, pentagon, and disk). Their lasing spectra consist mainly of almost equidistant peaks and the distance between peaks reveals the length of a quantized periodic orbit. To measure this length with a good precision, it is necessary to take into account different sources of refractive index dispersion. Our experimental and numerical results agree with the superscar model describing the formation of long-lived states in polygonal cavities. The limitations of the two-dimensional approximation are briefly discussed in connection with micro-disks.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 08:23:41 GMT" }, { "version": "v2", "created": "Fri, 15 Jun 2007 09:51:33 GMT" } ]
2009-11-13T00:00:00
[ [ "Lebental", "M.", "" ], [ "Djellali", "N.", "" ], [ "Arnaud", "C.", "" ], [ "Lauret", "J. -S.", "" ], [ "Zyss", "J.", "" ], [ "Dubertrand", "R.", "" ], [ "Schmit", "C.", "" ], [ "Bogomolny", "E.", "" ] ]
0704.1951
Enric Nart
Gabriel Cardona and Enric Nart
Zeta function and cryptographic exponent of supersingular curves of genus 2
null
null
null
null
math.NT
null
We compute in a direct (not algorithmic) way the zeta function of all supersingular curves of genus 2 over a finite field k, with many geometric automorphisms. We display these computations in an appendix where we select a family of representatives of all these curves up to geometric isomorphism and we exhibit equations and the zeta function of all their twists. As an application we obtain a direct computation of the cryptographic exponent of the Jacobians of these curves.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 08:49:17 GMT" } ]
2007-05-23T00:00:00
[ [ "Cardona", "Gabriel", "" ], [ "Nart", "Enric", "" ] ]
0704.1952
Ingve Simonsen
Ingve Simonsen, Lubos Buzna, Karsten Peters, Stefan Bornholdt, and Dirk Helbing
Dynamic Effects Increasing Network Vulnerability to Cascading Failures
4 pages Latex, 4 figures
Phys. Rev. Lett. 100, 218701 (2008)
10.1103/PhysRevLett.100.218701
null
physics.soc-ph physics.class-ph
null
We study cascading failures in networks using a dynamical flow model based on simple conservation and distribution laws to investigate the impact of transient dynamics caused by the rebalancing of loads after an initial network failure (triggering event). It is found that considering the flow dynamics may imply reduced network robustness compared to previous static overload failure models. This is due to the transient oscillations or overshooting in the loads, when the flow dynamics adjusts to the new (remaining) network structure. We obtain {\em upper} and {\em lower} limits to network robustness, and it is shown that {\it two} time scales $\tau$ and $\tau_0$, defined by the network dynamics, are important to consider prior to accurately addressing network robustness or vulnerability. The robustness of networks showing cascading failures is generally determined by a complex interplay between the network topology and flow dynamics, where the ratio $\chi=\tau/\tau_0$ determines the relative role of the two of them.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:01:59 GMT" }, { "version": "v2", "created": "Thu, 3 Apr 2008 12:19:41 GMT" } ]
2010-05-04T00:00:00
[ [ "Simonsen", "Ingve", "" ], [ "Buzna", "Lubos", "" ], [ "Peters", "Karsten", "" ], [ "Bornholdt", "Stefan", "" ], [ "Helbing", "Dirk", "" ] ]
0704.1953
Vyacheslav Yukalov
E.R.F. Ramos, L. Sanz, V.I. Yukalov, and V.S. Bagnato
Ramsey fringes formation during excitation of topological modes in a Bose-Einstein condensate
Latex file, 12 pages, 5 figures
Phys. Lett. A 365 (2007) 126-130
10.1016/j.nuclphysa.2007.03.025
null
cond-mat.stat-mech cond-mat.mes-hall
null
The Ramsey fringes formation during the excitation of topological coherent modes of a Bose-Einstein condensate by an external modulating field is considered. The Ramsey fringes appear when a series of pulses of the excitation field is applied. In both Rabi and Ramsey interrogations, there is a shift of the population maximum transfer due to the strong non-linearity present in the system. It is found that the Ramsey pattern itself retains information about the accumulated relative phase between both ground and excited coherent modes.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:04:32 GMT" } ]
2009-11-13T00:00:00
[ [ "Ramos", "E. R. F.", "" ], [ "Sanz", "L.", "" ], [ "Yukalov", "V. I.", "" ], [ "Bagnato", "V. S.", "" ] ]
0704.1954
Matthias R\"oger
Luca Mugnai, Matthias R\"oger
The Allen-Cahn Action functional in higher dimensions
33 pages, 4 figures; minor changes and additions
null
null
null
math.AP
null
The Allen-Cahn action functional is related to the probability of rare events in the stochastically perturbed Allen-Cahn equation. Formal calculations suggest a reduced action functional in the sharp interface limit. We prove in two and three space dimensions the corresponding lower bound. One difficulty is that diffuse interfaces may collapse in the limit. We therefore consider the limit of diffuse surface area measures and introduce a generalized velocity and generalized reduced action functional in a class of evolving measures. As a corollary we obtain the Gamma convergence of the action functional in a class of regularly evolving hypersurfaces.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:08:07 GMT" }, { "version": "v2", "created": "Thu, 26 Jul 2007 09:33:42 GMT" } ]
2007-07-26T00:00:00
[ [ "Mugnai", "Luca", "" ], [ "Röger", "Matthias", "" ] ]
0704.1955
Florent Baudier
Florent Baudier
Metrical characterization of super-reflexivity and linear type of Banach spaces
to appear in Archiv der Mathematik
Arch. Math. (Basel) 89 (2007), no. 5, 419-429
10.1007/s00013-007-2108-4
null
math.FA math.MG
null
We prove that a Banach space X is not super-reflexive if and only if the hyperbolic infinite tree embeds metrically into X. We improve one implication of J.Bourgain's result who gave a metrical characterization of super-reflexivity in Banach spaces in terms of uniforms embeddings of the finite trees. A characterization of the linear type for Banach spaces is given using the embedding of the infinite tree equipped with a suitable metric.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:11:02 GMT" } ]
2017-09-27T00:00:00
[ [ "Baudier", "Florent", "" ] ]
0704.1956
Oldrich Kepka
O. Kepka and C. Royon ((1) DAPNIA/Service de physique des particules, CEA/Saclay, Gif-sur-Yvette cedex, France, (2) IPNP, Faculty of Mathematics and Physics, Charles University, Prague, (3) Center for Particle Physics, Institute of Physics, Academy of Science, Prague)
Search for exclusive events using the dijet mass fraction at the Tevatron
21 pages, 21 figures, submitted to Physical Review D
Phys.Rev.D76:034012,2007
10.1103/PhysRevD.76.034012
null
hep-ph
null
In this paper, we discuss the observation of exclusive events using the dijet mass fraction as measured by the CDF collaboration at the Tevatron. We compare the data to pomeron exchange inspired models as well as Soft color interaction ones. We also provide the prediction on dijet mass fraction at the LHC using both exclusive and inclusive diffractive events.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:19:37 GMT" } ]
2008-11-26T00:00:00
[ [ "Kepka", "O.", "" ], [ "Royon", "C.", "" ] ]
0704.1957
Nilanjana Datta
Garry Bowen and Nilanjana Datta
Entanglement Cost for Sequences of Arbitrary Quantum States
Published version
Journal of Physics A: Math. Theor. vol.44, (2011) 045302
null
null
quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The entanglement cost of arbitrary sequences of bipartite states is shown to be expressible as the minimization of a conditional spectral entropy rate over sequences of separable extensions of the states in the sequence. The expression is shown to reduce to the regularized entanglement of formation when the n-th state in the sequence consists of n copies of a single bipartite state.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 19:54:26 GMT" }, { "version": "v2", "created": "Fri, 19 Jun 2009 15:32:41 GMT" }, { "version": "v3", "created": "Thu, 6 Jan 2011 14:57:07 GMT" } ]
2011-01-07T00:00:00
[ [ "Bowen", "Garry", "" ], [ "Datta", "Nilanjana", "" ] ]
0704.1958
Fausto Vagnetti
D.Trevese, D.Paris, G. M. Stirpe, F.Vagnetti, V. Zitelli
Line and continuum variability of two intermediate-redshift, high-luminosity quasars
6 pages, 5 figures, A&A in press
null
10.1051/0004-6361:20077237
null
astro-ph
null
It has been shown that the luminosity of AGNs and the size of their broad line region obey a simple relation of the type R=a L^g, from faint Seyfert nuclei to bright quasars, allowing single-epoch determination of the central black hole mass M=b L^g D^2 from their luminosity L and width of H_beta emission line. Adopting this mass determination for cosmological studies requires the extrapolation to high z and L of a relation whose calibration relies so far on reverberation mapping measurements performed for L<10^46 erg/s and z<0.4. We initiated a campaign for the monitoring of a few luminous, intermediate z quasars whose apparent magnitude V<15.7 allows observations with a 1.8m telescope, aimed at proving that emission lines vary and respond to continuum variations even for luminosities >10^47 erg/s, and determining eventually their M_BH from reverberation mapping. We have repeatedly performed simultaneous observations of quasars and reference stars to determine relative variability of continuum and emission lines. We describe the observations and methods of analysis. For the quasars PG1634+706 and PG1247+268 we obtain light-curves respectively for CIII], MgII and for CIV, CIII] emission lines with the relevant continua. During 3.2 years of observation, in the former case no continuum variability has been detected and the evidence for line variability is marginal, while in the latter case both continuum and line variability are detected with high significance and the line variations appear correlated with continuum variations. The detection of the emission line variability in a quasar with L~10^47 erg/s encourages the prosecution of the campaign which should provide a black hole mass estimate in other 5-6 years, constraining the M_BH-L relation in a poorly explored range of luminosity.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:25:25 GMT" } ]
2009-11-13T00:00:00
[ [ "Trevese", "D.", "" ], [ "Paris", "D.", "" ], [ "Stirpe", "G. M.", "" ], [ "Vagnetti", "F.", "" ], [ "Zitelli", "V.", "" ] ]
0704.1959
Boris Fainberg
B.D. Fainberg and V.A. Gorbunov
Adiabatic passage in a three-state system with non-Markovian relaxation: The role of excited-state absorption and two-exciton processes
38 pages, 7 figures; submitted to JPC
J. Phys. Chem. A, v.111, pp9560-9569 (2007)
10.1021/jp0728611
null
physics.chem-ph physics.optics
null
The influence of excited-state absorption (ESA) and two-exciton processes on a coherent population transfer with intense ultrashort chirped pulses in molecular systems in solution has been studied. An unified treatment of adiabatic rapid passage (ARP) in such systems has been developed using a three-state electronic system with relaxation treated as a diffusion on electronic potential energy surfaces. We have shown that ESA has a profound effect on coherent population transfer in large molecules that necessitates a more accurate interpretation of experimental data. A simple and physically clear model for ARP in molecules with three electronic states in solution has been developed by extending the Landau-Zener calculations putting in a third level to random crossing of levels. A method for quantum control of two-exciton states in molecular complexes has been proposed.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:29:14 GMT" } ]
2016-09-28T00:00:00
[ [ "Fainberg", "B. D.", "" ], [ "Gorbunov", "V. A.", "" ] ]
0704.1960
Karl-Henning Rehren
Nikolay M. Nikolov, Karl-Henning Rehren, Ivan Todorov
Harmonic bilocal fields generated by globally conformal invariant scalar fields
29 pages. v2: corrected an argument, v4: final version as to be published in CMP
Commun.Math.Phys.279:225-250,2008
10.1007/s00220-007-0394-0
ICTP Trieste IC/2007021, ESI Vienna ESI 1907 (2007)
hep-th math-ph math.MP
null
The twist two contribution in the operator product expansion of phi_1(x_1) phi_2(x_2) for a pair of globally conformal invariant, scalar fields of equal scaling dimension d in four space-time dimensions is a field V_1(x_1,x_2) which is harmonic in both variables. It is demonstrated that the Huygens bilocality of V_1 can be equivalently characterized by a "single-pole property" concerning the pole structure of the (rational) correlation functions involving the product phi_1(x_1) phi_2(x_2). This property is established for the dimension d=2 of phi_1, phi_2. As an application we prove that any system of GCI scalar fields of conformal dimension 2 (in four space-time dimensions) can be presented as a (possibly infinite) superposition of products of free massless fields.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:36:03 GMT" }, { "version": "v2", "created": "Mon, 14 May 2007 10:13:07 GMT" }, { "version": "v3", "created": "Tue, 5 Jun 2007 10:32:54 GMT" }, { "version": "v4", "created": "Wed, 16 Jan 2008 13:34:30 GMT" } ]
2008-11-26T00:00:00
[ [ "Nikolov", "Nikolay M.", "" ], [ "Rehren", "Karl-Henning", "" ], [ "Todorov", "Ivan", "" ] ]
0704.1961
Yi Liao
Yi Liao (Nankai U.)
Impact of spin-zero particle-photon interactions on light polarization in external magnetic fields
To appear in PLB, 10 pp, 0 figs; thanks to the anonymous referee for useful comments/suggestions. Main changes: (1)English hopefully improved. (2)The word `interference' deleted. (3)Results unchanged but discussions extended. (4)Quote Ref [26] where spin-zero particles with mixed parity appear. (5)Acknowledgements added
Phys.Lett.B650:257-261,2007
10.1016/j.physletb.2007.05.020
null
hep-ph hep-ex
null
If the recent PVLAS results on polarization changes of a linearly polarized laser beam passing through a magnetic field are interpreted by an axion-like particle, it is almost certain that it is not a standard QCD axion. Considering this, we study the general effective interactions of photons with spin-zero particles without restricting the latter to be a pseudo-scalar or a scalar, i.e., a parity eigenstate. At the lowest order in effective field theory, there are two dimension-5 interactions, each of which has previously been treated separately for a pseudo-scalar or a scalar particle. By following the evolution in an external magnetic field of the system of spin-zero particles and photons, we compute the changes in light polarization and the transition probability for two experimental set-ups: one-way propagation and round-trip propagation. While the first may be relevant for astrophysical sources of spin-zero particles, the second applies to laboratory optical experiments like PVLAS. In the one-way propagation, interesting phenomena can occur for special configurations of polarization where, for instance, transition occurs but light polarization does not change. For the round-trip propagation, however, the standard results of polarization changes for a pseudoscalar or a scalar are only modified by a factor that depends on the relative strength of the two interactions.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:38:32 GMT" }, { "version": "v2", "created": "Thu, 17 May 2007 03:15:12 GMT" } ]
2008-11-26T00:00:00
[ [ "Liao", "Yi", "", "Nankai U." ] ]
0704.1962
Robert Alicki
Robert Alicki and Nicholas Van Ryn
A simple test of quantumness for a single system
3 pages, no figures, corrected typos, text essentially amended
J. Phys. A: Math. Theor. 41 (2008) 062001
10.1088/1751-8113/41/6/062001
null
quant-ph
null
We propose a simple test of quantumness which can decide whether for the given set of accessible experimental data the classical model is insufficient. Take two observables $ A,B$ such that for any state $\psi$ their mean values satisfy $0\leq <\psi|A|\psi>\leq <\psi|B|\psi>\leq 1$. If there exists a state $\phi$ such that the second moments fulfill the inequality $<\phi|A^2|\phi> ><\phi|B^2|\phi>$ then the system cannot be described by the classical probabilistic scheme. An example of an optimal triple $(A,B,\phi)$ in the case of a qubit is given.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:39:33 GMT" }, { "version": "v2", "created": "Tue, 8 May 2007 17:33:10 GMT" }, { "version": "v3", "created": "Mon, 2 Jul 2007 11:10:55 GMT" } ]
2012-10-26T00:00:00
[ [ "Alicki", "Robert", "" ], [ "Van Ryn", "Nicholas", "" ] ]
0704.1963
David Barrado y Navascues
D. Barrado y Navascues, J. R. Stauffer, M. Morales-Calderon, A. Bayo, G. Fazzio, T. Megeath, L. Allen, L. W. Hartmann, N. Calvet
SPITZER: Accretion in Low Mass Stars and Brown Dwarfs in the Lambda Orionis Cluster
ApJ, in press
Astrophys.J.664:481-500,2007
10.1086/518816
null
astro-ph
null
We present multi-wavelength optical and infrared photometry of 170 previously known low mass stars and brown dwarfs of the 5 Myr Collinder 69 cluster (Lambda Orionis). The new photometry supports cluster membership for most of them, with less than 15% of the previous candidates identified as probable non-members. The near infrared photometry allows us to identify stars with IR excesses, and we find that the Class II population is very large, around 25% for stars (in the spectral range M0 - M6.5) and 40% for brown dwarfs, down to 0.04 Msun, despite the fact that the H(alpha) equivalent width is low for a significant fraction of them. In addition, there are a number of substellar objects, classified as Class III, that have optically thin disks. The Class II members are distributed in an inhomogeneous way, lying preferentially in a filament running toward the south-east. The IR excesses for the Collinder 69 members range from pure Class II (flat or nearly flat spectra longward of 1 micron), to transition disks with no near-IR excess but excesses beginning within the IRAC wavelength range, to two stars with excess only detected at 24 micron. Collinder 69 thus appears to be at an age where it provides a natural laboratory for the study of primordial disks and their dissipation.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:41:29 GMT" } ]
2009-06-23T00:00:00
[ [ "Navascues", "D. Barrado y", "" ], [ "Stauffer", "J. R.", "" ], [ "Morales-Calderon", "M.", "" ], [ "Bayo", "A.", "" ], [ "Fazzio", "G.", "" ], [ "Megeath", "T.", "" ], [ "Allen", "L.", "" ], [ "Hartmann", "L. W.", "" ], [ "Calvet", "N.", "" ] ]
0704.1964
Yi Pan
Yi Pan, Alessandra Buonanno, John G. Baker, Joan Centrella, Bernard J. Kelly, Sean T. McWilliams, Frans Pretorius and James R. van Meter
A data-analysis driven comparison of analytic and numerical coalescing binary waveforms: nonspinning case
19 pages, 17 figures, added references, corrected typos, changed figure 16
Phys.Rev.D77:024014,2008
10.1103/PhysRevD.77.024014
null
gr-qc
null
We compare waveforms obtained by numerically evolving nonspinning binary black holes to post-Newtonian (PN) template families currently used in the search for gravitational waves by ground-based detectors. We find that the time-domain 3.5PN template family, which includes the inspiral phase, has fitting factors (FFs) >= 0.96 for binary systems with total mass M = 10 ~ 20 Msun. The time-domain 3.5PN effective-one-body template family, which includes the inspiral, merger and ring-down phases, gives satisfactory signal-matching performance with FFs >= 0.96 for binary systems with total mass M = 10 ~ 120 Msun. If we introduce a cutoff frequency properly adjusted to the final black-hole ring-down frequency, we find that the frequency-domain stationary-phase-approximated template family at 3.5PN order has FFs >= 0.96 for binary systems with total mass M = 10 ~ 20 Msun. However, to obtain high matching performances for larger binary masses, we need to either extend this family to unphysical regions of the parameter space or introduce a 4PN order coefficient in the frequency-domain GW phase. Finally, we find that the phenomenological Buonanno-Chen-Vallisneri family has FFs >= 0.97 with total mass M=10 ~ 120Msun. The main analyses use the noise spectral-density of LIGO, but several tests are extended to VIRGO and advanced LIGO noise-spectral densities.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:16:41 GMT" }, { "version": "v2", "created": "Sat, 25 Aug 2007 20:39:11 GMT" } ]
2008-11-26T00:00:00
[ [ "Pan", "Yi", "" ], [ "Buonanno", "Alessandra", "" ], [ "Baker", "John G.", "" ], [ "Centrella", "Joan", "" ], [ "Kelly", "Bernard J.", "" ], [ "McWilliams", "Sean T.", "" ], [ "Pretorius", "Frans", "" ], [ "van Meter", "James R.", "" ] ]
0704.1965
Phoenix S. Y. Poon
Phoenix S. Y. Poon and C. K. Law
Quantum entanglement of decohered two-mode squeezed states in absorbing and amplifying environment
9 pages, 7 figures
Phys. Rev. A 76, 012333 (2007)
10.1103/PhysRevA.76.012333
null
quant-ph
null
We investigate the properties of quantum entanglement of two-mode squeezed states interacting with linear baths with general gain and loss parameters. By explicitly solving for \rho from the master equation, we determine analytical expressions of eigenvalues and eigenvectors of \rho^{T_A} (the partial transposition of density matrix \rho). In Fock space, \rho^{T_A} is shown to maintain a block diagonal structure as the system evolves. In addition, we discover that the decoherence induced by the baths would break the degeneracy of \rho^{T_A}, and leads to a novel set of eigenvectors for the construction of entanglement witness operators. Such eigenvectors are shown to be time-independent, which is a signature of robust entanglement of two-mode squeezed states in the presence of noise.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:44:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Poon", "Phoenix S. Y.", "" ], [ "Law", "C. K.", "" ] ]
0704.1966
Gautam Bharali
Gautam Bharali
Some new observations on interpolation in the spectral unit ball
Added a definition (Def.1.1); 2 of the 4 results herein are minor refinements of those in the author's preprint math.CV/0608177; to appear in Integral Eqns. Operator Theory
Integral Equations Operator Theory 59 (2007) no. 3, 329-343
10.1007/s00020-007-1534-9
null
math.CV math.OA
null
We present several results associated to a holomorphic-interpolation problem for the spectral unit ball \Omega_n, n\geq 2. We begin by showing that a known necessary condition for the existence of a $\mathcal{O}(D;\Omega_n)$-interpolant (D here being the unit disc in the complex plane), given that the matricial data are non-derogatory, is not sufficient. We provide next a new necessary condition for the solvability of the two-point interpolation problem -- one which is not restricted only to non-derogatory data, and which incorporates the Jordan structure of the prescribed data. We then use some of the ideas used in deducing the latter result to prove a Schwarz-type lemma for holomorphic self-maps of \Omega_n, n\geq 2.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:49:01 GMT" }, { "version": "v2", "created": "Mon, 17 Sep 2007 16:36:57 GMT" } ]
2008-02-14T00:00:00
[ [ "Bharali", "Gautam", "" ] ]
0704.1967
Francesco Becattini
F. Becattini, L. Ferroni (University of Florence and INFN Florence)
The microcanonical ensemble of the ideal relativistic quantum gas
31 pages; published version with minor corrections
Eur.Phys.J.C51:899-912,2007
10.1140/epjc/s10052-007-0340-5
null
nucl-th cond-mat.stat-mech quant-ph
null
We derive the microcanonical partition function of the ideal relativistic quantum gas of spinless bosons in a quantum field framework as an expansion over fixed multiplicities. Our calculation generalizes well known expressions in literature in that it does not introduce any large volume approximation and it is valid at any volume. We discuss the issues concerned with the definition of the microcanonical ensemble for a free quantum field at volumes comparable with the Compton wavelength and provide a consistent prescription of calculating the microcanonical partition function, which is finite at finite volume and yielding the correct thermodynamic limit. Besides an immaterial overall factor, the obtained expression turns out to be the same as in the non-relativistic multi-particle approach. This work is introductory to derive the most general expression of the microcanonical partition function fixing the maximal set of observables of the Poincare' group.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:54:22 GMT" }, { "version": "v2", "created": "Tue, 9 Oct 2007 10:58:49 GMT" } ]
2008-11-26T00:00:00
[ [ "Becattini", "F.", "", "University of Florence and INFN Florence" ], [ "Ferroni", "L.", "", "University of Florence and INFN Florence" ] ]
0704.1968
L\'aszl\'o \'A Gergely
L\'aszl\'o \'A. Gergely, Peter L. Biermann
The spin-flip phenomenon in supermassive black hole binary mergers
v3: 36 pages, 1 figure; discussion on the validity of the model and estimates for the angular value of the spin-flip added to Section 5; v4: minor changes, 2 new references, published version
Astrophys.J.697:1621-1633,2009
10.1088/0004-637X/697/2/1621
null
astro-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Massive merging black holes will be the primary sources of powerful gravitational waves at low frequency, and will permit to test general relativity with candidate galaxies close to a binary black hole merger. In this paper we identify the typical mass ratio of the two black holes but then show that the distance when gravitational radiation becomes the dominant dissipative effect (over dynamical friction) does not depend on the mass ratio. However the dynamical evolution in the gravitational wave emission regime does. For the typical range of mass ratios the final stage of the merger is preceded by a rapid precession and a subsequent spin-flip of the main black hole. This already occurs in the inspiral phase, therefore can be described analytically by post-Newtonian techniques. We then identify the radio galaxies with a super-disk as those in which the rapidly precessing jet produces effectively a powerful wind, entraining the environmental gas to produce the appearance of a thick disk. These specific galaxies are thus candidates for a merger of two black holes to happen in the astronomically near future.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:06:41 GMT" }, { "version": "v2", "created": "Mon, 23 Jun 2008 15:32:05 GMT" }, { "version": "v3", "created": "Tue, 21 Apr 2009 12:36:11 GMT" }, { "version": "v4", "created": "Fri, 15 May 2009 22:13:05 GMT" } ]
2009-06-23T00:00:00
[ [ "Gergely", "László Á.", "" ], [ "Biermann", "Peter L.", "" ] ]
0704.1969
Janvier Nzeutchap
Janvier Nzeutchap
On the Young-Fibonacci insertion algorithm
19 pages, to appear in the Proceedings of FPSAC'07
null
null
null
math.CO
null
This work is concerned with some properties of the Young-Fibonacci insertion algorithm and its relation with Fomin's growth diagrams. It also investigates a relation between the combinatorics of Young-Fibonacci tableaux and the study of Okada's algebra associated to the Young-Fibonacci lattice. The original algorithm was introduced by Roby and we redefine it in such a way that both the insertion and recording tableaux of any permutation are \emph{conveniently} interpreted as chains in the Young-Fibonacci lattice. A property of Killpatrick's evacuation is given a simpler proof, but this evacuation is no longer needed in making Roby's and Fomin's constructions coincide. We provide the set of Young-Fibonacci tableaux of size $n$ with a structure of graded poset, induced by the weak order on permutations of the symmetric group, and realized by transitive closure of elementary transformations on tableaux. We show that this poset gives a combinatorial interpretation of the coefficients in the transition matrix from the analogue of complete symmetric functions to analogue of the Schur functions in Okada's algebra. We end with a quite similar observation for four posets on Young-tableaux studied by Taskin.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 09:57:53 GMT" } ]
2007-05-23T00:00:00
[ [ "Nzeutchap", "Janvier", "" ] ]
0704.1970
Koichi Izawa
K. Izawa, K. Behnia, Y. Matsuda, H. Shishido, R.Settai, Y. Onuki and J. Flouquet
Thermoelectric response near a quantum critical point: the case of CeCoIn5
4 pages, 4 figures,final published version
Phys. Rev. Lett. 99, 147005 (2007)
10.1103/PhysRevLett.99.147005
null
cond-mat.str-el cond-mat.supr-con
null
We present a study of thermoelectric coefficients in CeCoIn_5 down to 0.1 K and up to 16 T in order to probe the thermoelectric signatures of quantum criticality. In the vicinity of the field-induced quantum critical point, the Nernst coefficient nu exhibits a dramatic enhancement without saturation down to lowest measured temperature. The dimensionless ratio of Seebeck coefficient to electronic specific heat shows a minimum at a temperature close to threshold of the quasiparticle formation. Close to T_c(H), in the vortex-liquid state, the Nernst coefficient behaves anomalously in puzzling contrast with other superconductors and standard vortex dynamics.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:00:58 GMT" }, { "version": "v2", "created": "Tue, 9 Oct 2007 10:34:40 GMT" } ]
2009-11-13T00:00:00
[ [ "Izawa", "K.", "" ], [ "Behnia", "K.", "" ], [ "Matsuda", "Y.", "" ], [ "Shishido", "H.", "" ], [ "Settai", "R.", "" ], [ "Onuki", "Y.", "" ], [ "Flouquet", "J.", "" ] ]
0704.1971
Natalia Berloff
Natalia G. Berloff and Anthony J. Youd
Dissipative dynamics of superfluid vortices at non-zero temperatures
4 pages, 3 figures
null
10.1103/PhysRevLett.99.145301
null
cond-mat.soft
null
We consider the evolution and dissipation of vortex rings in a condensate at non-zero temperature, in the context of the classical field approximation, based on the defocusing nonlinear Schr\"odinger equation. The temperature in such a system is fully determined by the total number density and the number density of the condensate. A vortex ring is introduced into a condensate in a state of thermal equilibrium, and interacts with non-condensed particles. These interactions lead to a gradual decrease in the vortex line density, until the vortex ring completely disappears. We show that the square of the vortex line length changes linearly with time, and obtain the corresponding universal decay law. We relate this to mutual friction coefficients in the fundamental equation of vortex motion in superfluids.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:05:11 GMT" }, { "version": "v2", "created": "Thu, 21 Jun 2007 17:15:23 GMT" } ]
2009-11-13T00:00:00
[ [ "Berloff", "Natalia G.", "" ], [ "Youd", "Anthony J.", "" ] ]
0704.1972
Arno Kuijlaars
A.R. Its, A.B.J. Kuijlaars, and J. Ostensson
Critical edge behavior in unitary random matrix ensembles and the thirty fourth Painleve transcendent
51 pages, 6 figures
International Mathematics Research Notices 2008, article ID rnn017
null
null
math.CA math-ph math.MP
null
We describe a new universality class for unitary invariant random matrix ensembles. It arises in the double scaling limit of ensembles of random $n \times n$ Hermitian matrices $Z_{n,N}^{-1} |\det M|^{2\alpha} e^{-N \Tr V(M)} dM$ with $\alpha > -1/2$, where the factor $|\det M|^{2\alpha}$ induces critical eigenvalue behavior near the origin. Under the assumption that the limiting mean eigenvalue density associated with $V$ is regular, and that the origin is a right endpoint of its support, we compute the limiting eigenvalue correlation kernel in the double scaling limit as $n, N \to \infty$ such that $n^{2/3}(n/N-1) = O(1)$. We use the Deift-Zhou steepest descent method for the Riemann-Hilbert problem for polynomials on the line orthogonal with respect to the weight $|x|^{2\alpha} e^{-NV(x)}$. Our main attention is on the construction of a local parametrix near the origin by means of the $\psi$-functions associated with a distinguished solution of the Painleve XXXIV equation. This solution is related to a particular solution of the Painleve II equation, which however is different from the usual Hastings-McLeod solution.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:22:20 GMT" } ]
2010-07-30T00:00:00
[ [ "Its", "A. R.", "" ], [ "Kuijlaars", "A. B. J.", "" ], [ "Ostensson", "J.", "" ] ]
0704.1973
Jernej Mravlje
Jernej Mravlje, Anton Ramsak, Rok Zitko
Vibrational effects on low-temperature properties of molecular conductors
2 pages, 3 figures, to be presented on "The International Conference on Strongly Correlated Electron Systems" SCES'07, May 13-18, Houston, USA
Physica B 403, 1484 (2008)
10.1016/j.physb.2007.10.170
null
cond-mat.mes-hall cond-mat.str-el
null
We calculate characteristic correlation functions for the Anderson model with additional phonon-assisted coupling to the odd conduction channel. This model describes, for example, the behavior of a molecule embedded between two electrodes in linear transport experiments where the position of the molecule with respect to the leads affects the tunneling amplitudes. We use variational projection-operator method and numerical renormalization group (NRG) method. The spin is Kondo screened either by even or odd conduction channel depending on the gate voltage and electron-phonon coupling. However, in all regimes the gate-voltage dependence of the zero temperature conductance is found to be qualitatively the same as in the model with no coupling to the vibrational mode.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:45:05 GMT" } ]
2008-03-05T00:00:00
[ [ "Mravlje", "Jernej", "" ], [ "Ramsak", "Anton", "" ], [ "Zitko", "Rok", "" ] ]
0704.1974
Helene Perrin
Olivier Morizot (LPL), Julien De Lapeyre De Bellair (LPL), Fabrice Wiotte (LPL), Olivier Lopez (LPL), Paul-Eric Pottie (LPL), H\'el\`ene Perrin (LPL)
Agile low phase noise radio-frequency sine wave generator applied to experiments on ultracold atoms
10 pages, 6 figures
null
null
null
physics.atom-ph
null
We report on the frequency performance of a low cost (~500$) radio-frequency sine wave generator, using direct digital synthesis (DDS) and a field-programmable gate array (FPGA). The output frequency of the device may be changed dynamically to any arbitrary value ranging from DC to 10 MHz without any phase slip. Sampling effects are substantially reduced by a high sample rate, up to 1 MHz, and by a large memory length, more than 2.10^5 samples. By using a low noise external oscillator to clock the DDS, we demonstrate a phase noise as low as that of the master clock, that is at the level of -113 dB.rad^2/Hz at 1 Hz from the carrier for an output frequency of 3.75 MHz. The device is successfully used to confine an ultracold atomic cloud of rubidium 87 in a RF-based trap, and there is no extra heating from the RF source.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:36:55 GMT" } ]
2007-05-23T00:00:00
[ [ "Morizot", "Olivier", "", "LPL" ], [ "De Bellair", "Julien De Lapeyre", "", "LPL" ], [ "Wiotte", "Fabrice", "", "LPL" ], [ "Lopez", "Olivier", "", "LPL" ], [ "Pottie", "Paul-Eric", "", "LPL" ], [ "Perrin", "Hélène", "", "LPL" ] ]
0704.1975
Eugene Gutkin
Eugene Gutkin, Michal Rams
Growth rates for geometric complexities and counting functions in polygonal billiards
25 pages, 2 figures
Ergodic Theory & Dynamical Systems 29 (2009), 1163 -- 1183
10.1017/S0143385708080620
null
math.DS math.DG
null
We introduce a new method for estimating the growth of various quantities arising in dynamical systems. We apply our method to polygonal billiards on surfaces of constant curvature. For instance, we obtain power bounds of degree two plus epsilon in length for the number of billiard orbits between almost all pairs of points in a planar polygon.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:24:36 GMT" } ]
2010-12-14T00:00:00
[ [ "Gutkin", "Eugene", "" ], [ "Rams", "Michal", "" ] ]
0704.1976
Dorje C. Brody
Dorje C. Brody, Lane P. Hughston, Andrea Macrina
Information-Based Asset Pricing
32 pages. No figure
International Journal of Theoretical and Applied Finance 11, 107-142 (2008)
null
null
q-fin.PR math.PR math.ST stat.TH
null
A new framework for asset price dynamics is introduced in which the concept of noisy information about future cash flows is used to derive the price processes. In this framework an asset is defined by its cash-flow structure. Each cash flow is modelled by a random variable that can be expressed as a function of a collection of independent random variables called market factors. With each such "X-factor" we associate a market information process, the values of which are accessible to market agents. Each information process is a sum of two terms; one contains true information about the value of the market factor; the other represents "noise". The noise term is modelled by an independent Brownian bridge. The market filtration is assumed to be that generated by the aggregate of the independent information processes. The price of an asset is given by the expectation of the discounted cash flows in the risk-neutral measure, conditional on the information provided by the market filtration. When the cash flows are the dividend payments associated with equities, an explicit model is obtained for the share-price, and the prices of options on dividend-paying assets are derived. Remarkably, the resulting formula for the price of a European call option is of the Black-Scholes-Merton type. The information-based framework also generates a natural explanation for the origin of stochastic volatility.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:50:48 GMT" } ]
2013-01-31T00:00:00
[ [ "Brody", "Dorje C.", "" ], [ "Hughston", "Lane P.", "" ], [ "Macrina", "Andrea", "" ] ]
0704.1977
Xuanming Ye
Xuanming Ye
The Jumping Phenomenon of Hodge Numbers
null
null
null
null
math.AG math.DG
null
Let $X$ be a compact complex manifold, consider a small deformation $\phi: \mathcal{X} \to B$ of $X$, the dimension of the Dolbeault cohomology groups $H^q(X_t,\Omega_{X_t}^p)$ may vary under this defromation. This paper will study such phenomenons by studying the obstructions to deform a class in $H^q(X,\Omega_X^p)$ with the parameter $t$ and get the formula for the obstructions.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 15:27:45 GMT" } ]
2007-05-23T00:00:00
[ [ "Ye", "Xuanming", "" ] ]
0704.1978
Yoichi Ikeda
Y. Ikeda and T. Sato
Strange dibaryon resonance in the anti-KNN--piYN system
22 pages, 10 figures; added extended KNN-piYN calculation, Appendix
Phys.Rev.C76:035203,2007
10.1103/PhysRevC.76.035203
null
nucl-th
null
Three-body resonances in the \bar{K}NN system have been studied within a framework of the \bar{K}NN-\pi YN coupled hannel Faddeev equation. By solving the three-body equation the energy dependence of the resonant \bar{K}N amplitude is fully taken into account. The S-matrix pole has been investigated from the eigenvalue of the kernel with the analytic continuation of the scattering amplitude on the unphysical Riemann sheet. The \barKN interaction is constructed from the leading order term of the chiral Lagrangian using relativistic kinematics. The \Lambda(1405) resonance is dynamically generated in this model, where the \bar{K}N interaction parameters are fitted to the data of scattering length. As a result we find a three-body resonance of the strange dibaryon system with binding energy, B~79 MeV, and width, \Gamma~74 MeV. The energy of the three-body resonance is found to be sensitive to the model of the I=0 \barKN interaction.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 10:58:24 GMT" }, { "version": "v2", "created": "Fri, 7 Sep 2007 10:58:22 GMT" } ]
2008-11-26T00:00:00
[ [ "Ikeda", "Y.", "" ], [ "Sato", "T.", "" ] ]
0704.1979
Jernej Mravlje
Jernej Mravlje, Anton Ramsak, Tomaz Rejec
SU(2) and SU(4) Kondo effect in double quantum dots
5 pages, 2 figures, presented on "XI Training Course in the Physics of Strongly Correlated Systems", Vietri sul Mare, Salerno, Italy
AIP Conference Proceedings 918, 312 (2006)
10.1063/1.2752001
null
cond-mat.mes-hall cond-mat.str-el
null
We investigate serial double quantum dot systems with on-site and inter-site interaction by means of Sch\"onhammer-Gunnarsson projection-operator method. The ground state is established by the competition between extended Kondo phases and localized singlet phases in spi$ degrees of freedom. We present and discuss different phases, as discerned by characteristic correlation functions. We discuss also how different phases would be seen in linear transport measurements.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:00:24 GMT" } ]
2007-12-20T00:00:00
[ [ "Mravlje", "Jernej", "" ], [ "Ramsak", "Anton", "" ], [ "Rejec", "Tomaz", "" ] ]
0704.1980
Cristina Tablino Possio
C. Tablino Possio
V-cycle optimal convergence for DCT-III matrices
19 pages
null
null
null
math.NA
null
The paper analyzes a two-grid and a multigrid method for matrices belonging to the DCT-III algebra and generated by a polynomial symbol. The aim is to prove that the convergence rate of the considered multigrid method (V-cycle) is constant independent of the size of the given matrix. Numerical examples from differential and integral equations are considered to illustrate the claimed convergence properties.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:07:30 GMT" } ]
2007-05-23T00:00:00
[ [ "Possio", "C. Tablino", "" ] ]
0704.1981
David W. Hertzog
MuLan Collaboration: D.B. Chitwood, T.I. Banks, M.J. Barnes, S. Battu, R.M. Carey, S. Cheekatmalla, S.M. Clayton, J. Crnkovic, K.M. Crowe, P.T. Debevec, S. Dhamija, W. Earle, A. Gafarov, K. Giovanetti, T.P. Gorringe, F.E. Gray, M. Hance, D.W. Hertzog, M.F. Hare, P. Kammel, B. Kiburg, J. Kunkle, B. Lauss, I. Logashenko, K.R. Lynch, R. McNabb, J.P. Miller, F. Mulhauser, C.J.G. Onderwater, C.S. Ozben, Q. Peng, C.C. Polly, S. Rath, B.L. Roberts, V. Tishchenko, G.D. Wait, J. Wasserman, D.M. Webber, P. Winter, P.A. Zolnierczuk
Improved Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant
As published version (PRL, July 2007)
Phys.Rev.Lett.99:032001,2007
10.1103/PhysRevLett.99.032001
null
hep-ex nucl-ex
null
The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, tau_mu = 2.197013(24) us, is in excellent agreement with the previous world average. The new world average tau_mu = 2.197019(21) us determines the Fermi constant G_F = 1.166371(6) x 10^-5 GeV^-2 (5 ppm). Additionally, the precision measurement of the positive muon lifetime is needed to determine the nucleon pseudoscalar coupling g_P.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 17:07:24 GMT" }, { "version": "v2", "created": "Fri, 8 Feb 2008 16:02:11 GMT" } ]
2008-11-26T00:00:00
[ [ "MuLan Collaboration", "", "" ], [ "Chitwood", "D. B.", "" ], [ "Banks", "T. I.", "" ], [ "Barnes", "M. J.", "" ], [ "Battu", "S.", "" ], [ "Carey", "R. M.", "" ], [ "Cheekatmalla", "S.", "" ], [ "Clayton", "S. M.", "" ], [ "Crnkovic", "J.", "" ], [ "Crowe", "K. M.", "" ], [ "Debevec", "P. T.", "" ], [ "Dhamija", "S.", "" ], [ "Earle", "W.", "" ], [ "Gafarov", "A.", "" ], [ "Giovanetti", "K.", "" ], [ "Gorringe", "T. P.", "" ], [ "Gray", "F. E.", "" ], [ "Hance", "M.", "" ], [ "Hertzog", "D. W.", "" ], [ "Hare", "M. F.", "" ], [ "Kammel", "P.", "" ], [ "Kiburg", "B.", "" ], [ "Kunkle", "J.", "" ], [ "Lauss", "B.", "" ], [ "Logashenko", "I.", "" ], [ "Lynch", "K. R.", "" ], [ "McNabb", "R.", "" ], [ "Miller", "J. P.", "" ], [ "Mulhauser", "F.", "" ], [ "Onderwater", "C. J. G.", "" ], [ "Ozben", "C. S.", "" ], [ "Peng", "Q.", "" ], [ "Polly", "C. C.", "" ], [ "Rath", "S.", "" ], [ "Roberts", "B. L.", "" ], [ "Tishchenko", "V.", "" ], [ "Wait", "G. D.", "" ], [ "Wasserman", "J.", "" ], [ "Webber", "D. M.", "" ], [ "Winter", "P.", "" ], [ "Zolnierczuk", "P. A.", "" ] ]
0704.1982
Neil Seshadri
Neil Seshadri
Some notes on analytic torsion of the Rumin complex on contact manifolds
This paper has been withdrawn by the author, due a crucial error on page 8. A corrected and extended version of this paper appears at arXiv:0802.0123
null
null
null
math.DG
null
We propose a definition for analytic torsion of the Rumin complex on contact manifolds. This is given by the derivative at zero of a well-chosen combination of zeta functions of a fourth-order modified Rumin Laplacian. The regular value at zero (before differentiation) of this well-chosen combination of zeta functions is shown to be a contact invariant. The variation of our analytic torsion is given as the integral of local terms, together with a global term coming from the null-space of the Laplacian.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:19:55 GMT" }, { "version": "v2", "created": "Mon, 4 Feb 2008 01:38:27 GMT" } ]
2008-02-04T00:00:00
[ [ "Seshadri", "Neil", "" ] ]
0704.1983
Yi-Fang Chang
Yi-Fang Chang
Universal 2+1-Dimensional Plane Equations in General Relativity and Evolutions of Disk Nebula
7 pages
null
null
null
physics.gen-ph
null
The general relativity is the base for any exact evolutionary theory of large scale structures. We calculate the universal 2+1-dimensional plane equations of gravitational field in general relativity. Based on the equations, the evolutions of disk nebula are discussed. A system of nebula can form binary stars or single star for different conditions. While any simplified linear theory forms only a single star system. It is proved that the nonlinear interactions are very general, so the binary stars are also common.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:21:57 GMT" } ]
2007-05-23T00:00:00
[ [ "Chang", "Yi-Fang", "" ] ]
0704.1984
Herbert Muther
P. G\"ogelein and H. M\"uther, (Universit\"at T\"ubingen, Germany)
Nuclear matter in the crust of neutron stars
23 pages, 8 figures
Phys.Rev.C76:024312,2007
10.1103/PhysRevC.76.024312
null
nucl-th
null
The properties of inhomogeneous nuclear matter are investigated considering the self-consistent Skyrme Hartree-Fock approach with inclusion of pairing correlations. For a comparison we also consider a relativistic mean field approach. The inhomogeneous infinite matter is described in terms of cubic Wigner-Seitz cells, which leads to a smooth transition to the limit of homogeneous nuclear matter. The possible existence of various structures in the so-called pasta phase is investigated within this self-consistent approach and a comparison is made to results obtained within the Thomas-Fermi approximation. Results for the proton abundances and the pairing properties are discussed for densities for which clustering phenomena are obtained.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:25:47 GMT" } ]
2008-11-26T00:00:00
[ [ "Gögelein", "P.", "" ], [ "Müther", "H.", "" ] ]
0704.1985
Jeremy Miller
J. S. Miller
Electromagnetic Higgs production
23 pages, 5 figures
null
null
null
hep-ph
null
The cross section for central diffractive Higgs production is calculated, for the LHC range of energies. The graphs for the possible mechanisms for Higgs production, through pomeron fusion and photon fusions are calculated for all possibilities allowed by the standard model. The cross section for central diffractive Higgs production through pomeron fusion, must be multiplied by a factor for the survival probability, to isolate the Higgs signal and reduce the background. Due to the small value of the survival probability $\Lb 4 \times 10^{-3}\Rb $, the cross sections for central diffractive Higgs production, in the two cases for pomeron fusion and photon fusion, are competitive.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:34:18 GMT" }, { "version": "v2", "created": "Tue, 13 Nov 2007 10:10:06 GMT" } ]
2007-11-13T00:00:00
[ [ "Miller", "J. S.", "" ] ]
0704.1986
Nabil Youssef L
Nabil L. Youssef
Characterization of Closed Vector Fields in Finsler Geometry
10 pages, LaTeX file, Presented in "The International Conference on Finsler Extensions of Relativity Theory" held at Cairo, Egypt, November 4-10, 2006
Hadronic J., 30,2 (2007), 193-207.
null
null
math.DG
null
The $\pi$-exterior derivative ${\o}d$, which is the Finslerian generalization of the (usual) exterior derivative $d$ of Riemannian geometry, is defined. The notion of a ${\o}d$-closed vector field is introduced and investigated. Various characterizations of ${\o}d$-closed vector fields are established. Some results concerning ${\o}d$-closed vector fields in relation to certain special Finsler spaces are obtained.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:45:44 GMT" } ]
2007-09-07T00:00:00
[ [ "Youssef", "Nabil L.", "" ] ]
0704.1987
Anilesh Mohari
Anilesh Mohari
Pure inductive limit state and Kolmogorov's property
null
null
null
null
math.OA math.PR
null
Let $(\clb,\lambda_t,\psi)$ be a $C^*$-dynamical system where $(\lambda_t: t \in \IT_+)$ be a semigroup of injective endomorphism and $\psi$ be an $(\lambda_t)$ invariant state on the $C^*$ subalgebra $\clb$ and $\IT_+$ is either non-negative integers or real numbers. The central aim of this exposition is to find a useful criteria for the inductive limit state $\clb \raro^{\lambda_t} \clb$ canonically associated with $\psi$ to be pure. We achieve this by exploring the minimal weak forward and backward Markov processes associated with the Markov semigroup on the corner von-Neumann algebra of the support projection of the state $\psi$ to prove that Kolmogorov's property [Mo2] of the Markov semigroup is a sufficient condition for the inductive state to be pure. As an application of this criteria we find a sufficient condition for a translation invariant factor state on a one dimensional quantum spin chain to be pure. This criteria in a sense complements criteria obtained in [BJKW,Mo2] as we could go beyond lattice symmetric states.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:46:36 GMT" } ]
2007-05-23T00:00:00
[ [ "Mohari", "Anilesh", "" ] ]
0704.1988
Emmanuel Clouet
Emmanuel Clouet (SRMP), Maylise Nastar (SRMP)
Classical nucleation theory in ordering alloys precipitating with L12 structure
null
Physical Review B 75, 13 (12/04/2007) 132102
10.1103/PhysRevB.75.132102
null
cond-mat.mtrl-sci
null
By means of low-temperature expansions (LTEs), the nucleation free energy and the precipitate interface free energy are expressed as functions of the solubility limit for alloys which lead to the precipitation of a stoichiometric L12 compound such as Al-Sc or Al-Zr alloys. Classical nucleation theory is then used to obtain a simple expression of the nucleation rate whose validity is demonstrated by a comparison with atomic simulations. LTEs also explain why simple mean-field approximation like the Bragg-Williams approximation fails to predict correct nucleation rates in such an ordering alloy.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:51:44 GMT" } ]
2007-05-23T00:00:00
[ [ "Clouet", "Emmanuel", "", "SRMP" ], [ "Nastar", "Maylise", "", "SRMP" ] ]
0704.1989
Anilesh Mohari
Anilesh Mohari
Jones index of a quantum dynamical semigroup
null
null
null
null
math.OA math.PR
null
In this paper we consider a semigroup of completely positive maps $\tau=(\tau_t,t \ge 0)$ with a faithful normal invariant state $\phi$ on a type-$II_1$ factor $\cla_0$ and propose an index theory. We :achieve this via a more general Kolmogorov's type of construction for stationary Markov processes which naturally associate a nested isomorphic von-Neumann algebras. In particular this construction generalizes well known Jones construction associated with a sub-factor of type-II$_1$ factor.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 11:58:56 GMT" } ]
2007-05-23T00:00:00
[ [ "Mohari", "Anilesh", "" ] ]
0704.1990
Eugenio R. Bezerra de Mello
J. Spinelly and E. R. Bezerra de Mello
Vacuum Polarization by a Magnetic Flux Tube at Finite Temperature in the Cosmic String Spacetime
16 pages, 1 figure
Int.J.Mod.Phys.D18:53-70,2009
10.1142/S0218271809014273
null
hep-th gr-qc
null
In this paper we analyse the effect produced by the temperature in the vacuum polarization associated with charged massless scalar field in the presence of magnetic flux tube in the cosmic string spacetime. Three different configurations of magnetic fields are taken into account: $(i)$ a homogeneous field inside the tube, $(ii)$ a field proportional to $1/r$ and $(iii)$ a cylindrical shell with $\delta$-function. In these three cases, the axis of the infinitely long tube of radius $R$ coincides with the cosmic string. Because the complexity of this analysis in the region inside the tube, we consider the thermal effect in the region outside. In order to develop this analysis, we construct the thermal Green function associated with this system for the three above mentioned situations considering points in the region outside the tube. We explicitly calculate in the high-temperature limit, the thermal average of the field square and the energy-momentum tensor.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:02:57 GMT" }, { "version": "v2", "created": "Thu, 3 Apr 2008 17:37:47 GMT" } ]
2009-03-24T00:00:00
[ [ "Spinelly", "J.", "" ], [ "de Mello", "E. R. Bezerra", "" ] ]
0704.1991
Ingo Schienbein
E. A. Paschos, I. Schienbein, J.-Y. Yu
Single pion electro-- and neutrinoproduction on heavy targets
21 pages, 8 figures
null
null
DO-TH-07-05,LPSC-07-29,SMU-HEP-07-07
hep-ph
null
We present a calculation of single pion electroproduction cross sections on heavy targets in the kinematic region of the Delta(1232) resonance. Final state interactions of the pions are taken into account using the pion multiple scattering model of Adler, Nussinov and Paschos (ANP model). For electroproduction and neutral current reactions we obtain results for carbon, oxygen, argon and iron targets and find a significant reduction of the W-spectra for pi^0 as compared to the free nucleon case. On the other hand, the charged pion spectra are only little affected by final state interactions. Measurements of such cross sections with the CLAS detector at JLAB could help to improve our understanding of pion rescattering effects and serve as important/valuable input for calculations of single pion neutrinoproduction on heavy targets relevant for current and future long baseline neutrino experiments. Two ratios, in Eq. (3.8) and (3.10), will test important properties of the model.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:35:04 GMT" } ]
2007-05-23T00:00:00
[ [ "Paschos", "E. A.", "" ], [ "Schienbein", "I.", "" ], [ "Yu", "J. -Y.", "" ] ]
0704.1992
Massimiliano Procura
Wolfram Weise
Yukawa's Pion, Low-Energy QCD and Nuclear Chiral Dynamics
21 pages, 13 figures. Proc. Yukawa-Tomonaga Symposium, Kyoto, Dec.06; to be publ. in Progr. Theor. Phys. Suppl. (Kyoto)
Prog.Theor.Phys.Suppl.170:161-184,2007
10.1143/PTPS.170.161
null
nucl-th
null
A survey is given of the evolution from Yukawa's early work, via the understanding of the pion as a Nambu-Goldstone boson of spontaneously broken chiral symmetry in QCD, to modern developments in the theory of the nucleus based on the chiral effective field theory representing QCD in its low-energy limit.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:11:48 GMT" } ]
2008-11-26T00:00:00
[ [ "Weise", "Wolfram", "" ] ]
0704.1993
Tomasz Polak T.P.
T. P. Polak, T. K. Kopec
Competition between local and nonlocal dissipation effects in two-dimensional quantum Josephson junction arrays
accepted to Physica C Ref. No.: PHYSC-D-06-00244R1
null
10.1016/j.physc.2007.01.032
null
cond-mat.supr-con
null
We discuss the local and nonlocal dissipation effects on the existence of the global phase coherence transitions in two dimensional Josephson-coupled junctions. The quantum phase transitions are also examined for various lattice geometries: square, triangular and honeycomb. The T=0 superconductor-insulator phase transition is analyzed as a function of several control parameters which include self-capacitance and junction capacitance and both local and nonlocal dissipation effects. We found the critical value of the nonlocal dissipation parameter \alpha_{1} depends on a geometry of the lattice. The critical value of the normal state conductance seems to be difficult to obtain experimentally if we take into consideration different damping mechanisms which are presented in real physical systems.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:16:50 GMT" } ]
2015-05-13T00:00:00
[ [ "Polak", "T. P.", "" ], [ "Kopec", "T. K.", "" ] ]
0704.1994
Jeroen Vandenbrink
Gianluca Giovannetti, Petr A. Khomyakov, Geert Brocks, Paul J. Kelly and Jeroen van den Brink
Substrate-induced bandgap in graphene on hexagonal boron nitride
5 pages, 4 figures, Phys. Rev. B, in press
Phys. Rev B. 76, 073103 (2007)
10.1103/PhysRevB.76.073103
null
cond-mat.mtrl-sci cond-mat.mes-hall
null
We determine the electronic structure of a graphene sheet on top of a lattice-matched hexagonal boron nitride (h-BN) substrate using ab initio density functional calculations. The most stable configuration has one carbon atom on top of a boron atom, the other centered above a BN ring. The resulting inequivalence of the two carbon sites leads to the opening of a gap of 53 meV at the Dirac points of graphene and to finite masses for the Dirac fermions. Alternative orientations of the graphene sheet on the BN substrate generate similar band gaps and masses. The band gap induced by the BN surface can greatly improve room temperature pinch-off characteristics of graphene-based field effect transistors.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:18:13 GMT" }, { "version": "v2", "created": "Mon, 30 Jul 2007 14:51:02 GMT" } ]
2015-05-13T00:00:00
[ [ "Giovannetti", "Gianluca", "" ], [ "Khomyakov", "Petr A.", "" ], [ "Brocks", "Geert", "" ], [ "Kelly", "Paul J.", "" ], [ "Brink", "Jeroen van den", "" ] ]
0704.1995
Qiang Gu
Qiang Gu, Haibo Qiu
Coherent dynamics of domain formation in the Bose Ferromagnet
4 pages, 3 figures
Phys. Rev. Lett. 98, 200401 (2007)
10.1103/PhysRevLett.98.200401
null
cond-mat.other cond-mat.stat-mech
null
We present a theory to describe domain formation observed very recently in a quenched Rb-87 gas, a typical ferromagnetic spinor Bose system. An overlap factor is introduced to characterize the symmetry breaking of M_F=\pm 1 components for the F=1 ferromagnetic condensate. We demonstrate that the domain formation is a co-effect of the quantum coherence and the thermal relaxation. A thermally enhanced quantum-oscillation is observed during the dynamical process of the domain formation. And the spatial separation of domains leads to significant decay of the M_F=0 component fraction in an initial M_F=0 condensate.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:19:13 GMT" }, { "version": "v2", "created": "Sat, 19 May 2007 08:40:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Gu", "Qiang", "" ], [ "Qiu", "Haibo", "" ] ]
0704.1996
Troost Jan
Costas Kounnas, Nicolaos Toumbas and Jan Troost
A Wave-function for Stringy Universes
30 pages, 3 figures, v3: references added
JHEP 0708:018,2007
10.1088/1126-6708/2007/08/018
LPTENS-07/16
hep-th
null
We define a wave-function for string theory cosmological backgrounds. We give a prescription for computing its norm following an earlier analysis within general relativity. Under Euclidean continuation, the cosmologies we discuss in this paper are described in terms of compact parafermionic worldsheet systems. To define the wave-function we provide a T-fold description of the parafermionic conformal field theory, and of the corresponding string cosmology. In specific examples, we compute the norm of the wave-function and comment on its behavior as a function of moduli.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:19:21 GMT" }, { "version": "v2", "created": "Mon, 14 May 2007 15:59:12 GMT" }, { "version": "v3", "created": "Fri, 27 Jul 2007 08:58:30 GMT" } ]
2009-11-13T00:00:00
[ [ "Kounnas", "Costas", "" ], [ "Toumbas", "Nicolaos", "" ], [ "Troost", "Jan", "" ] ]
0704.1997
Yi-Fang Chang
Yi-Fang Chang
Query on Negative Temperature, Internal Interactions and Decrease of Entropy
9 pages
null
null
null
physics.gen-ph
null
After negative temperature is restated, we find that it will derive necessarily decrease of entropy. Negative temperature is based on the Kelvin scale and the condition dU>0 and dS<0. Conversely, there is also negative temperature for dU<0 and dS>0. But, negative temperature is contradiction with usual meaning of temperature and with some basic concepts of physics and mathematics. It is a question in nonequilibrium thermodynamics. We proposed a possibility of decrease of entropy due to fluctuation magnified and internal interactions in some isolated systems. From this we discuss some possible examples and theories.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:20:09 GMT" } ]
2007-05-23T00:00:00
[ [ "Chang", "Yi-Fang", "" ] ]
0704.1998
Alexander Kaganovich B.
E. I. Guendelman and A. B. Kaganovich
Absence of the Fifth Force Problem in a Model with Spontaneously Broken Dilatation Symmetry
23 pages, some explanations expanded, misprints corrected, reference added
AnnalsPhys.323:866-882,2008
10.1016/j.aop.2007.09.003
null
gr-qc astro-ph hep-th
null
A scale invariant model containing dilaton $\phi$ and dust (as a model of matter) is studied where the shift symmetry $\phi\to\phi +const.$ is spontaneously broken at the classical level due to intrinsic features of the model. The dilaton to matter coupling "constant" $f$ appears to be dependent of the matter density. In normal conditions, i.e. when the matter energy density is many orders of magnitude larger than the dilaton contribution to the dark energy density, $f$ becomes less than the ratio of the "mass of the vacuum" in the volume occupied by the matter to the Planck mass. The model yields this kind of "Archimedes law" without any especial (intended for this) choice of the underlying action and without fine tuning of the parameters. The model not only explains why all attempts to discover a scalar force correction to Newtonian gravity were unsuccessful so far but also predicts that in the near future there is no chance to detect such corrections in the astronomical measurements as well as in the specially designed fifth force experiments on intermediate, short (like millimeter) and even ultrashort (a few nanometer) ranges. This prediction is alternative to predictions of other known models.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:23:48 GMT" }, { "version": "v2", "created": "Thu, 19 Apr 2007 11:39:56 GMT" }, { "version": "v3", "created": "Mon, 30 Apr 2007 10:29:23 GMT" } ]
2008-11-26T00:00:00
[ [ "Guendelman", "E. I.", "" ], [ "Kaganovich", "A. B.", "" ] ]
0704.1999
Roya Mohayaee
Roya Mohayaee, Sergei Shandarin, Joseph Silk
Dark matter caustics and the enhancement of self-annihilation flux
To appear in JCAP, 4 pages, 3 figures
JCAP 0705:015,2007
10.1088/1475-7516/2007/05/015
null
astro-ph
null
Cold dark matter haloes are populated by caustics, which are yet to be resolved in N-body simulations or observed in the Universe. Secondary infall model provides a paradigm for the study of caustics in "typical" haloes assuming that they have had no major mergers and have grown only by smooth accretion. This is a particular characteristic of the smallest dark matter haloes of about 10^{-5} Mo, which although "atypical" contain no substructures and could have survived until now with no major mergers. Thus using this model as the first guidline, we evaluate the neutralino self-annihilation flux for these haloes. Our results show that caustics could leave a distinct sawteeth signature on the differential and cumulative fluxes coming from the outer regions of these haloes. The total annihilation signal from the regions away from the centre can be boosted by about forty percents.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:24:03 GMT" } ]
2009-11-13T00:00:00
[ [ "Mohayaee", "Roya", "" ], [ "Shandarin", "Sergei", "" ], [ "Silk", "Joseph", "" ] ]
0704.2000
John D. Hobbs
D0 Collaboration, V. Abazov, et al
Search for a Higgs boson produced in association with a Z boson in ppbar collisions
8 pages, 2 figures. Submitted to Phys. Lett. B
Phys.Lett.B655:209-216,2007
10.1016/j.physletb.2007.08.070
FERMILAB-PUB-07-076-E
hep-ex
null
We describe a search for the standard model Higgs boson with a mass of 105 GeV/c^2 to 145 GeV/c^2 in data corresponding to an integrated luminosity of approximately 450 pb^{-1} collected with the D0 detector at the Fermilab Tevatron ppbar collider at a center-of-mass energy of 1.96 TeV. The Higgs boson is required to be produced in association with a Z boson, and the Z boson is required to decay to either electrons or muons with the Higgs boson decaying to a bbbar pair. The data are well described by the expected background, leading to 95% confidence level cross section upper limits sigma(\ppbar\to ZH)x B(H\to\bbbar) in the range of 3.1 pb to 4.4 pb.
[ { "version": "v1", "created": "Mon, 16 Apr 2007 12:25:19 GMT" } ]
2008-11-26T00:00:00
[ [ "D0 Collaboration", "", "" ], [ "Abazov", "V.", "" ] ]