July 2006 arXiv papers
Showing 1–100 of 4,443 papers
Proposed experiment to test the non-locality hypothesis in transient light-interference phenomena
quant-phMasanori Sato
The transient phenomena of the Mach-Zender interferometer are discussed. To test the non-locality hypothesis, a single mode laser with a large coherence length is used. The behavior of a photon and its wave packets in the paths of the interferometer are discussed. Coherent photons have wave packets that overlap, thus their interference pattern is influenced
Measurement of CP-Violating Asymmetries in $B^0\to(ρπ)^0$ Using a Time-Dependent Dalitz Plot Analysis
hep-exThe BABAR Collaboration, B. Aubert
We report a measurement of CP-violating asymmetries in $B^0\to(ρπ)^0\toπ^+π^-π^0$ decays using a time-dependent Dalitz plot analysis. The results are obtained from a data sample of 347 million $Υ(4S) \to B\bar{B}$ decays, collected by the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure 26 coefficients of the bilinear form factor
Christopher J. Hillar, Troels Windfeldt
Let $K$ be a field, and let $R = K[X]$ be the polynomial ring in an infinite collection $X$ of indeterminates over $K$. Let ${\mathfrak S}_{X}$ be the symmetric group of $X$. The group ${\mathfrak S}_{X}$ acts naturally on $R$, and this in turn gives $R$ the structure of a left module over the (left) group ring $R[{\mathfrak S}_{X}]$. A recent theorem of Asc
Dan A. Lee, Robert Lipshitz
Heegaard Floer homology, first introduced by P. Ozsvath and Z. Szabo, associates to a 3-manifold Y a family of relatively graded Abelian groups HF(Y,t), indexed by Spin^c structures t on Y. In the case that Y is a rational homology sphere, Ozsvath and Szabo lift the relative Z-grading to an absolute Q-grading. This induces a relative Q-grading on \bigoplus_{
Kevin Graham, Anatoly Konechny, Joerg Teschner
We discuss how to describe time-dependent phenomena in string theory like the decay of unstable D-branes with the help of the world-sheet formulation. It is shown in a nontrivial well-controlled example that the coupling of the tachyons to propagating on-shell modes which escape to infinity can lead to time-dependent relaxation into a stationary final state.
Aaron V. B. Arellano, Francisco S. N. Lobo
In this work, we explore the possibility of evolving (2+1) and (3+1)-dimensional wormhole spacetimes, conformally related to the respective static geometries, within the context of nonlinear electrodynamics. For the (3+1)-dimensional spacetime, it is found that the Einstein field equation imposes a contracting wormhole solution and the obedience of the weak
Miguel Mostafa
The Pierre Auger Observatory detects ultra-high energy cosmic rays by implementing two complementary air-shower techniques. The combination of a large ground array and fluorescence detectors, known as the "hybrid" concept, means that a rich variety of measurements can be made on a single shower, providing much improved information over what is possible with
Possible Constraints on the Duration of Inflationary Expansion from Quantum Stress Tensor Fluctuations
gr-qcChun-Hsien Wu, Kin-Wang Ng, L. H. Ford
We discuss the effect of quantum stress tensor fluctuations in deSitter spacetime upon the expansion of a congruence of timelike geodesics. We treat a model in which the expansion fluctuations begin on a given hypersurface in deSitter spacetime, and find that this effect tends to grow, in contrast to the situation in flat spacetime. This growth potentially l
Scaling property and the generalized entropy uniquely determined by a fundamental nonlinear differential equation
cond-mat.stat-mechHiroki Suyari, Tatsuaki Wada
We derive a scaling property from a fundamental nonlinear differential equation whose solution is the so-called q-exponential function. A scaling property has been believed to be given by a power function only, but actually more general expression for the scaling property is found to be a solution of the above fundamental nonlinear differential equation. In
C. A. Bonin, J. T. Lunardi, L. A. Manzoni, B. M. Pimentel
This paper has been withdrawn by the authors
Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
astro-phB. T. Draine, Aigen Li
Infrared (IR) emission spectra are calculated for dust composed of mixtures of amorphous silicate and graphitic grains, including varying amounts of polycyclic aromatic hydrocarbon (PAH) particles. The models are constrained to reproduce the average Milky Way extinction curve. The calculations include the effects of single-photon heating. Updated IR absorpti
Time-dependent universal conductance fluctuations in mesoscopic Au wires: implications
cond-mat.mes-hallA. Trionfi, S. Lee, D. Natelson
In cold, mesoscopic conductors, two-level fluctuators lead to time-dependent universal conductance fluctuations (TDUCF) manifested as $1/f$ noise. In Au nanowires, we measure the magnetic field dependence of TDUCF, weak localization (WL), and magnetic field-driven (MF) UCF before and after treatments that alter magnetic scattering and passivate surface fluct
Mirjam Cvetic, Paul Langacker
We construct new supersymmetric SU(5) Grand Unified Models based on Z4 x Z2 orientifolds with intersecting D6-branes. Unlike constructions based on Z2 x Z2 orientifolds, the orbifold images of the three-cycles wrapped by D6-branes correspond to new configurations and thus allow for models in which, in addition to the chiral sector in 10 and 5-bar representat
Branching Fraction Measurements of Charged B Decays to K*+K+K-, K*+pi+K-, K*+K+pi- and K*+pi+pi- Final States
hep-exThe BABAR Collaboration, B. Aubert
Branching fraction and asymmetry measurements of charmless $B^+\to K^{*+}h^+_1h^-_2$ (where $h_{1,2}$ = $K$, $π$) decays are presented, using a data sample of 232 million $Υ(4S) \to$ $BB$ decays collected with the BaBar detector at the SLAC PEP-II asymmetric-energy $B$ factory. Using a maximum likelihood fit, the following branching fraction results were obt
Sucharit Sarkar, Jiajun Wang
In this paper, we give an algorithm to compute the hat version of the Heegaard Floer homology of a closed oriented three-manifold. This method also allows us to compute the filtrations coming from a null-homologous link in a three-manifold.
E. Boulat, P. Mehta, N. Andrei, E. Shimshoni
We study the low-temperature heat transport in clean two-leg spin ladder compounds coupled to three-dimensional phonons. We argue that the very large heat conductivities observed in such systems can be traced back to the existence of approximate symmetries and corresponding weakly violated conservation laws of the effective (gapful) low--energy model, namely
T. Rozek, D. Grzonka, H. -H. Adam, A. Budzanowski
Sigma+ hyperon production was measured at the COSY-11 spectrometer via the p p --> n K+ Sigma+ reaction at excess energies of Q = 13 MeV and Q = 60 MeV. These measurements continue systematic hyperon production studies via the p p --> p K+ Lambda/Sigma0 reactions where a strong decrease of the cross section ratio close-to-threshold was observed. In order to
John B. Etnyre
In this note we observe, answering a question of Eliashberg and Thurston, that all contact structures on a closed oriented 3-manifold are $C^\infty$-deformations of foliations.
A. D. Kennedy
This is the write-up of three lectures on algorithms for dynamical fermions that were given at the ILFTN workshop 'Perspectives in Lattice QCD' in Nara during November 2005. The first lecture is on the fundamentals of Markov Chain Monte Carlo methods and introduces the Hybrid Monte Carlo (HMC) algorithm and symplectic integrators; the second lecture
Yusuke Nishida, Dam Thanh Son
We construct systematic expansions around four and two spatial dimensions for a Fermi gas near the unitarity limit. Near four spatial dimensions such a Fermi gas can be understood as a weakly interacting system of fermionic and bosonic degrees of freedom. To the leading and next-to-leading orders in the expansion over epsilon=4-d, with d being the dimensiona
Steve Blanchet, Pasquale Di Bari
Flavor effects in leptogenesis reduce the region of the see-saw parameter space where the final predictions do not depend on the initial conditions, the strong wash-out regime. In this case we show that the lowest bounds holding on the lightest right-handed (RH) neutrino mass and on the reheating temperature for hierarchical heavy neutrinos, do not get relax
Interference between doubly-Cabibbo-suppressed and Cabibbo-favored amplitudes in $D^0 \to K_S(π^0,η,η')$ decays
hep-phJonathan L. Rosner
A definite relative phase and amplitude exists between the doubly-Cabibbo-% suppressed amplitude for $D^0 \to \ko M^0$ and the Cabibbo-favored amplitude for $D^0 \to \ok M^0$, where $M^0 = (π^0,η,η')$: $A(D^0 \to \ko M^0) = - \tan^2 θ_C A(D^0 \to \ok M^0)$. Here $θ_C$ is the Cabibbo angle. This relation, although previously recognized (for $M^0 = π^0$) a
Gautam Rupak, Thomas Schaefer, Andrei Kryjevski
We consider a polarized Fermi gas in the unitarity limit. Results are calculated analytically up to next-to-leading order in an expansion about d=4 spatial dimensions. We find a first order transition from superfluid to normal phase. The critical chemical potential asymmetry for this phase transition is delta_mu_c= 2/(mu epsilon)*(1-0.467ε), where epsilon=4-
Yannis Bakopoulos, Theophanis Raptis, Doxaras Ioannis
The Divider set, as an innovative alternative concept to maximal disks, Voronoi sets and cut loci, is presented with a formal definition based on topology and differential geometry. The relevant mathematical theory by previous authors and a comparison with other medial axis definitions is presented. Appropriate applications are proposed and examined.
D. A. Mazurenko, X. Shan, J. C. P. Stiefelhagen, C. M. Graf
Coherent acoustic radial oscillations of thin spherical gold shells of submicron diameter excited by an ultrashort optical pulse are observed in the form of pronounced modulations of the transient reflectivity on a subnanosecond time scale. Strong acousto-optical coupling in a photonic crystal enhances the modulation of the transient reflectivity up to 4%. T
Jonathan E. Moussa, Marvin L. Cohen
Two simple bounds on the $T_c$ of conventional, phonon-mediated superconductors are derived within the framework of Eliashberg theory in the strong coupling regime. The first bound is set by the total electron-phonon coupling available within a material given the hypothetical ability to arbitrarily dope the material. This bound is studied by deriving a gener
V. V. Shokurov
To construct a resulting model in LMMP is sufficient to prove existence of log flips and their termination for certain sequences. We prove that LMMP in dimension $d-1$ and termination of terminal log flips in dimension $d$ imply, for any log pair of dimension $d$, the existence of a {\em resulting} log model: a strictly log minimal model or a strictly log te
For what number of cars must self organization occur in the Biham-Middleton-Levine traffic model from any possible starting configuration?
math.COTim D. Austin, Itai Benjamini
For any initial configuration of fewer than N/2 cars the BML model will self organize to attain speed one. On the other hand, there is a configuration of size m in which no car can move if and only if m is at least 2N.
Florentin Smarandache, Jean Dezert
This paper introduces the notion of qualitative belief assignment to model beliefs of human experts expressed in natural language (with linguistic labels). We show how qualitative beliefs can be efficiently combined using an extension of Dezert-Smarandache Theory (DSmT) of plausible and paradoxical quantitative reasoning to qualitative reasoning. We propose
P. Deuar, P. D. Drummond
The quantum dynamics of colliding Bose-Einstein condensates with 150 000 atoms are simulated directly from the Hamiltonian using the stochastic positive-P method. Two-body correlations between the scattered atoms and their velocity distribution are found for experimentally accessible parameters. Hanbury Brown-Twiss or thermal-like correlations are seen for c
Shing-Tung Yau
This is lecture notes of a talk I gave at the Morningside Center of Mathematics on June 20, 2006. In this talk, I survey on Poincare and geometrization conjecture.
Andre Joyal, Myles Tierney
We show that complete Segal spaces and Segal categories are Quillen equivalent to quasi-categories.
Joseph Y. Halpern, Riccardo Pucella
Logics for security protocol analysis require the formalization of an adversary model that specifies the capabilities of adversaries. A common model is the Dolev-Yao model, which considers only adversaries that can compose and replay messages, and decipher them with known keys. The Dolev-Yao model is a useful abstraction, but it suffers from some drawbacks:
F. Clementi, M. Gallegati, G. Kaniadakis
Starting from the generalized exponential function $\exp_κ(x)=(\sqrt{1+κ^{2}x^{2}}+κx)^{1/κ}$, with $\exp_{0}(x)=\exp(x)$, proposed in Ref. [G. Kaniadakis, Physica A \textbf{296}, 405 (2001)], the survival function $P_{>}(x)=\exp_κ(-βx^α)$, where $x\in\mathbf{R}^{+}$, $α,β>0$, and $κ\in[0,1)$, is considered in order to analyze the data on personal income dis
Thomas Holenstein
Consider a game where a refereed a referee chooses (x,y) according to a publicly known distribution P_XY, sends x to Alice, and y to Bob. Without communicating with each other, Alice responds with a value "a" and Bob responds with a value "b". Alice and Bob jointly win if a publicly known predicate Q(x,y,a,b) holds. Let such a game be given a
BEC-BCS crossover, phase transitions and phase separation in polarized resonantly-paired superfluids
cond-mat.supr-conDaniel E. Sheehy, Leo Radzihovsky
We study resonantly-paired s-wave superfluidity in a degenerate gas of two species (hyperfine states labeled by $\uparrow,\downarrow$) of fermionic atoms when the numbers $N_{\uparrow}$ and $N_{\downarrow}$ of the two species are {\it unequal}, i.e., the system is "polarized". We find that the continuous crossover from the Bose-Einstein condensate (B
Ivan V. Arzhantsev, Juergen Hausen
Given a multigraded algebra $A$, it is a natural question whether or not for two homogeneous components $A_u$ and $A_v$, the product $A_{nu}A_{nv}$ is the whole component $A_{nu+nv}$ for $n$ big enough. We give combinatorial and geometric answers to this question.
Test of a universality ansatz for the contact values of the radial distribution functions of hard-sphere mixtures near a hard wall
cond-mat.stat-mechMariano Lopez de Haro, Santos B. Yuste, Andres Santos
Recent Monte Carlo simulation results for the contact values of polydisperse hard-sphere mixtures at a hard planar wall are considered in the light of a universality assumption made in approximate theoretical approaches. It is found that the data seem to fulfill the universality ansatz reasonably well, thus opening up the possibility of inferring properties
James Graber
LISA may make it possible to test the black-hole uniqueness theorems of general relativity, also called the no-hair theorems, by Ryan's method of detecting the quadrupole moment of a black hole using high-mass-ratio inspirals. This test can be performed more robustly by observing inspirals in earlier stages, where the simplifications used in making inspi
Nicolai Kuntze, Dominique Maehler, Andreas U. Schmidt
Reputation and recommendation systems are fundamental for the formation of community market places. Yet, they are easy targets for attacks which disturb a market's equilibrium and are often based on cheap pseudonyms used to submit ratings. We present a method to price ratings using trusted computing, based on pseudonymous tickets.
B. Enriquez, G. Halbout
We introduce the notion of Gamma-Lie bialgebra, where Gamma is a group. These objects give rise to cocommutative co-Poisson algebras, for which we construct quantization functors. This enlarges the class of co-Poisson algebras for which a quantization is known. Our result relies on our earlier work, where we showed that twists of Lie bialgebras can be quanti
Sophonie Blaise Tchapnda
Some future global properties of cosmological solutions for the Einstein-Vlasov-Maxwell system with surface symmetry are presented. Global existence is proved, the homogeneous spacetimes are future complete for causal trajectories, and the same is true for inhomogeneous plane-symmetric solutions with small initial data. In the latter case some decay properti
The BABAR Collaboration, B. Aubert
We present an observation of $B\toη^\prime K^*$. The data sample corresponds to 232 million $B\bar{B}$ pairs collected with the BABAR detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We measure the branching fractions (in units of $10^{-6}$) $\mathcal{B}(B^0\toη^\prime K^{*0}) = 3.8\pm1.1\pm0.5$ and $\mathcal{B}(B^+\toη^\prime K^{*+}) = 4.9^{+1.
J. Zhou, G. Li, J. L. Luo, Y. C. Ma
Dimension reduction due to the orbital ordering has recently been proposed to explain the exotic charge, magnetic and structural transitions in some three-dimensional (3D) transitional metal oxides. We present optical measurement on a spinel compound MgTi$_2$O$_4$ which undergoes a sharp metal-insulator transition at 240 K, and show that the spectral change
R. Parwani, G. Tabia
Using perturbative methods, we analyse a nonlinear generalisation of Schrodinger's equation that had previously been obtained through information-theoretic arguments. We obtain analytical expressions for the leading correction, in terms of the nonlinearity scale, to the energy eigenvalues of the linear Schrodinger equation in the presence of an external
Mauro Spreafico
We study the spectral functions, and in particular the zeta function, associated to a class of sequences of complex numbers, called of spectral type. We investigate the decomposability of the zeta function associated to a double sequence with respect to some simple sequence, and we provide a technique for obtaining the first terms in the Laurent expansion at
A. Fotopoulos, K. L. Panigrahi, M. Tsulaia
In this short note we present a Lagrangian formulation for free bosonic Higher Spin fields which belong to massless reducible representations of D-dimensional Anti de Sitter group using an ambient space formalism.
Denis Krotov
An n-ary operation q:A^n->A is called an n-ary quasigroup of order |A| if in x_0=q(x_1,...,x_n) knowledge of any n elements of x_0,...,x_n uniquely specifies the remaining one. An n-ary quasigroup q is permutably reducible if q(x_1,...,x_n)=p(r(x_{s(1)},...,x_{s(k)}),x_{s(k+1)},...,x_{s(n)}) where p and r are (n-k+1)-ary and k-ary quasigroups, s is a permuta
Chris Connell, Nets Hawk Katz
The radius of the star-shaped set need not have been continuous.
V. D'Odorico, M. Viel, F. Saitta, S. Cristiani
We study the three-dimensional distribution of non virialised matter at z~2 using high resolution spectra of QSO pairs and simulated spectra drawn from cosmological hydrodynamical simulations. We have collected the largest sample of QSO pairs ever observed with UVES at the ESO-VLT, with angular separations between ~1 and 14 arcmin. The observed correlation f
Tom Coates
In the approach to Gromov-Witten theory developed by Givental, genus-zero Gromov-Witten invariants of a manifold X are encoded by a Lagrangian cone in a certain infinite-dimensional symplectic vector space. We give a construction of this cone, in the spirit of S^1-equivariant Floer theory, in terms of S^1-equivariant Gromov-Witten theory of the product X \ti
Influence of temperature gradients on tunnel junction thermometry below 1 K: cooling and electron-phonon coupling
cond-mat.mes-hallJ. T. Karvonen, L. J. Taskinen, I. J. Maasilta
We have studied thermal gradients in thin Cu and AlMn wires, both experimentally and theoretically. In the experiments, the wires were Joule heated non-uniformly at sub-Kelvin temperatures, and the resulting temperature gradients were measured using normal metal-insulator-superconducting tunnel junctions. The data clearly shows that even in reasonably well c
Quasi-stationary Electromagnetic Effects in Conductors and Superconductors in Schwarzchild Space-time
astro-phB. J. Ahmedov, F. J. Fattoyev
The general principles needed to compute the effect of a stationary gravitational field on the quasistationary electromagnetic phenomena in normal conductors and superconductors are formulated from general relativistic point of view. Generalization of the skin effect, that is the general relativistic modification of the penetration depth (of the time-depende
Yu. B. Ivanov, V. N. Russkikh
Transverse-mass spectra in Au+Au and Pb+Pb collisions in incident energy range from 2A to 160A GeV are analyzed within the model of 3-fluid dynamics. It is shown that dynamical description of freeze-out, accepted in this model, naturally explains the incident energy behavior of inverse-slope parameters of these spectra observed in experiment. Simultaneous re
Self-induced spontaneous transport of water molecules through a symmetrical nanochannel by ratchetlike mechanism
physics.bio-phRongzheng Wan, Hangjun Lu, Jinyuan Li, Jingdong Bao
Water molecules, confined in a carbon nanotube, were monitored using molecular dynamics simulation. Spontaneous directional transportation during a long timescale was observed in the symmetrical nanochannel by a ratchet-like mechanism. This ratchet-like system was without any asymmetrical structure or external field, while the asymmetric ratchet-like potenti
Electronic properties of correlated metals in the vicinity of a charge order transition: optical spectroscopy of $α$-(BEDT-TTF)$_2M$Hg(SCN)$_4$ ($M$ = NH$_4$, Rb, Tl)
cond-mat.str-elN. Drichko, M. Dressel, C. A. Kuntscher, A. Pashkin
The infrared spectra of the quasi-two-dimensional organic conductors $α$-(BEDT-TTF)$_2$$M$Hg(SCN)$_4$ ($M$ = NH$_4$, Rb, Tl) were measured in the range from 50 to 7000 \cm down to low temperatures in order to explore the influence of electronic correlations in quarter-filled metals. The interpretation of electronic spectra was confirmed by measurements of pr
Pietro Caputo, Alessandra Faggionato
We consider the random walk on a simple point process on $\Bbb{R}^d$, $d\geq2$, whose jump rates decay exponentially in the $α$-power of jump length. The case $α=1$ corresponds to the phonon-induced variable-range hopping in disordered solids in the regime of strong Anderson localization. Under mild assumptions on the point process, we show, for $α\in(0,d)$,
Julius Wess
Deformed gauge transformations on deformed coordinate spaces are considered for any Lie algebra. The representation theory of this gauge group forces us to work in a deformed Lie algebra as well. This deformation rests on a twisted Hopf algebra, thus we can represent a twisted Hopf algebra on deformed spaces. That leads to the construction of Lagrangian inva
M. Baldo, G. F. Burgio, P. Castorina, S. Plumari
The quark matter equation of state (EOS) derived from the standard Nambu - Jona-Lasinio (NJL) model is soft enough to render neutron stars (NS) unstable at the onset of the deconfined phase, and no pure quark matter can be actually present in its interior. Since this is a peculiarity of the NJL model, we have studied a modified NJL model with a momentum cut-
Lukas Pichl, Taisei Kaizoji, Takuya Yamano
Universal features in stock markets and their derivative markets are studied by means of probability distributions in internal rates of return on buy and sell transaction pairs. Unlike the stylized facts in log normalized returns, the probability distributions for such single asset encounters encorporate the time factor by means of the internal rate of retur
R. Anglani, M. Mannarelli, G. Nardulli, M. Ruggieri
We discuss specific heat and neutrino emissivity due to direct Urca processes for quark matter in the color superconductive Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phase of Quantum-Chromodynamics. We assume that the three light quarks $u, d, s$ are in a color and electrically neutral state and interact by a four fermion Nambu-Jona Lasinio coupling. We study
I. Travenec
Quantum site percolation as a limiting case of binary alloy is studied numerically in 2D within the tight-binding model. We address the transport properties in all regimes - ballistic, diffusive (metallic), localized and crossover between the latter two. Special attention is given to the region close to the conduction band center, but even there the Anderson
Andrea Cavagna, Tomas S. Grigera, Paolo Verrocchio
According to the mosaic scenario, relaxation in supercooled liquids is ruled by two competing mechanisms: surface tension, opposing the creation of local excitations, and entropy, providing the drive to the configurational rearrangement of a given region. We test this scenario through numerical simulations well below the Mode Coupling temperature. For an equ
Keh-Shin Lii, Murray Rosenblatt
Processes with almost periodic covariance functions have spectral mass on lines parallel to the diagonal in the two-dimensional spectral plane. Methods have been given for estimation of spectral mass on the lines of spectral concentration if the locations of the lines are known. Here methods for estimating the intercepts of the lines of spectral concentratio
Jukka P. Pekola, Francesco Giazotto, Olli-Pentti Saira
We propose a cyclic refrigeration principle based on mesoscopic electron transport. Synchronous sequential tunnelling of electrons in a Coulomb-blockaded device, a normal metal-superconductor single-electron box, results in a cooling power of $\sim k_{\rm B}T \times f$ at temperature $T$ over a wide range of cycle frequencies $f$. Electrostatic work, done by
A. Chervov, D. Talalaev
The Lax operator of the Gaudin type models is a 1-form on the classical level. In virtue of the quantization scheme proposed in [Talalaev04] (hep-th/0404153) it is natural to treat the quantum Lax operator as a connection; this connection is a particular case of the Knizhnik-Zamolodchikov connection [ChervovTalalaev06] (hep-th/0604128). In this paper we find
Alejandro Corichi, Jeronimo Cortez, Guillermo A. Mena Marugan, Jose M. Velhinho
Modulo a homogeneous degree of freedom and a global constraint, the linearly polarised Gowdy $T^3$ cosmologies are equivalent to a free scalar field propagating in a fixed nonstationary background. Recently, a new field parameterisation was proposed for the metric of the Gowdy spacetimes such that the associated scalar field evolves in a flat background in 1
Kazem Bitaghsir-Fadafan, Mohammad R. Garousi
We apply the prescription proposed in hep-th/0307197 for non-abelian expansion of S-matrix elements, to the S-matrix element of four tachyons and one gauge field in superstring theory. We show that the leading order terms of the expansion are in perfect agreement with the non-abelian generalization of the tachyon DBI action in which the tachyon potential is
Gersende Fort, Sean Meyn, Eric Moulines, Pierre Priouret
Fluid limit techniques have become a central tool to analyze queueing networks over the last decade, with applications to performance analysis, simulation and optimization. In this paper, some of these techniques are extended to a general class of skip-free Markov chains. As in the case of queueing models, a fluid approximation is obtained by scaling time, s
D. V. Savin, O. Legrand, F. Mortessagne
In a two-dimensional microwave chaotic cavity ohmic losses located at the contour of the cavity result in different broadenings of different modes. We provide an analytic description and establish the link between such an inhomogeneous damping and the complex (non-real) character of biorthogonal wave functions. This substantiates the corresponding recent exp
Y. Tabata, H. Kadowaki, K. Matsuhira, Z. Hiroi
We have investigated the kagomé ice behavior of the dipolar spin-ice compound Dy_{2}Ti_{2}O_{7} in magnetic field along a [111] direction using neutron scattering and Monte Carlo simulations. The spin correlations show that the kagomé ice behavior predicted for the nearest-neighbor (NN) interacting model, where the field induces dimensional reduction and spi
Kalvis M. Jansons
We consider the stochastic Stokes drift of a flexible dumbbell. The dumbbell consists of two isotropic Brownian particles connected by a linear spring with zero natural length, and is advected by a sinusoidal wave. We find an asymptotic approximation for the Stokes drift in the limit of a weak wave, and find good agreement with the results of a Monte Carlo s
S. Fournais, B. Helffer
We consider the Neumann Laplacian with constant magnetic field on a regular domain. Let $B$ be the strength of the magnetic field, and let $λ_1(B)$ be the first eigenvalue of the magnetic Neumann Laplacian on the domain. It is proved that $B \mapsto λ_1(B)$ is monotone increasing for large $B$. Combined with the results of \cite{FournaisHelffer3}, this impli
Chyh-Hong Chern, Dung-Hai Lee
Through Haldane's construction, the fractional quantum Hall states on a two-sphere was shown to be the ground states of {\it one-dimensional} SU(2) spin Hamiltonians. In this Letter we generalize this construction to obtain a new class of SU(N) spin Hamiltonians. These Hamiltonians describes center-of-mass-position conserving pair hopping fermions in spa
Takahiro Ohta
Generalizing Pisier's idea, we introduce a Hilbertian matrix cross normed space associated with a pair of symmetric normed ideals. When the two ideals coincide, we show that our construction gives an operator space if and only if the ideal is the Schatten class. In general, a pair of symmetric normed ideals that are not necessarily the Schatten class may
Alexander Stoimenow, Toshifumi Tanaka
We show examples of knots with the same polynomial invariants and hyperbolic volumes, with variously coinciding 2-cable polynomials and colored Jones polynomials, which are not mutants.
Ryota Okazaki, Kohji Yanagawa
Let $S = K[x_1, ..., x_n ]$ be a polynomial ring over a field $K$, and $E = K < y_1, ..., y_n >$ an exterior algebra. The "linearity defect" $ld_E(N)$ of a finitely generated graded $E$-module $N$ measures how far $N$ departs from "componentwise linear". It is known that $ld_E(N) < \infty$ for all $N$. But the value can be arbitrary large, wh
Hunter Monroe
Because no closed timelike curve (CTC) on a Lorentzian manifold can be deformed to a point, any such manifold containing a CTC must have a topological feature, to be called a timelike wormhole, that prevents the CTC from being deformed to a point. If all wormholes have horizons, which typically seems to be the case in space-times without exotic matter, then
Maximally Symmetric Minimal Unification Model SO(32) with Three Families in Ten Dimensional Space-time
hep-phYue-Liang Wu
Based on a maximally symmetric minimal unification hypothesis and a quantum charge-dimension correspondence principle, it is demonstrated that each family of quarks and leptons belongs to the Majorana-Weyl spinor representation of 14-dimensions that relate to quantum spin-isospin-color charges. Families of quarks and leptons attribute to a spinor structure o
Inelastic X-Ray Scattering Study of Exciton Properties in an Organic Molecular crystal
cond-mat.otherK. Yang, L. P. Chen, Y. Q. Cai, N. Hiraoka
Excitons in a complex organic molecular crystal were studied by inelastic x-ray scattering (IXS) for the first time. The dynamic dielectric response function is measured over a large momentum transfer region, from which an exciton dispersion of 130 meV is observed. Semiempirical quantum chemical calculations reproduce well the momentum dependence of the meas
Chen Wang, Dong Lai, JinLin Han
Recent observations of pulsar wind nebulae and radio polarization profiles revealed a tendency of the alignment between the spin and velocity directions in neutron stars. We study the condition for spin-kick alignment using a toy model, in which the kick consists of many off-centered, randomly-oriented thrusts. Both analytical considerations and numerical si
Xiongfeng Ma
By simulating four quantum key distribution (QKD) experiments and analyzing one decoy-state QKD experiment, we compare two data post-processing schemes based on security against individual attack by Lütkenhaus, and unconditional security analysis by Gottesman-Lo-Lütkenhaus-Preskill. Our results show that these two schemes yield close performances. Since the
Marcelo O Terra Cunha, Vlatko Vedral
We review how to obtain spin entangled pairs of fermions from a Fermi gas. An experiment with neutrons is proposed in order to get such pairs.
Nagalakshmi A Rao, B. A. Kagali
While Klein paradox is often encountered in the context of scattering of relativistic particles at a potential barrier, we presently discuss a puzzling situation that arises with the Klein-Gordon equation for bound states. With the usual minimal coupling procedure of introducing the interaction potential, a paradoxical situation arises when the 'hill'
Nonadiabatic Transitions for a Decaying Two-Level-System: Geometrical and Dynamical Contributions
quant-phR. Schilling, Mark Vogelsberger, D. A. Garanin
We study the Landau-Zener Problem for a decaying two-level-system described by a non-hermitean Hamiltonian, depending analytically on time. Use of a super-adiabatic basis allows to calculate the non-adiabatic transition probability P in the slow-sweep limit, without specifying the Hamiltonian explicitly. It is found that P consists of a ``dynamical''
Entanglement by linear SU(2) transformations: generation and evolution of quantum vortex states
quant-phG. S. Agarwal, J. Banerji
We consider the evolution of a two-mode system of bosons under the action of a Hamiltonian that generates linear SU(2) transformations. The Hamiltonian is generic in that it represents a host of entanglement mechanisms, which can thus be treated in a unified way. We start by solving the quantum dynamics analytically when the system is initially in a Fock sta
F. Benatti, R. Floreanini, S. Breteaux
Non-positive Markov approximations are sometimes used to describe the dynamics of qubits in weak interaction with suitable environments; the appearance of negative probabilities is avoided by assuming that the transient regime eliminates from the possible initial conditions those qubit states which would otherwise be mapped out of the Bloch sphere by the sub
Hysteresis and bi-stability by an interplay of calcium oscillations and action potential firing
q-bio.CBJ. M. A. M. Kusters, J. M. Cortes, W. P. M. van Meerwijk, D. L. Ypey
Many cell types exhibit oscillatory activity, such as repetitive action potential firing due to the Hodgkin-Huxley dynamics of ion channels in the cell membrane or reveal intracellular inositol triphosphate (IP$_3$) mediated calcium oscillations (CaOs) by calcium-induced calcium release channels (IP$_3$-receptor) in the membrane of the endoplasmic reticulum
Subwavelength fractional Talbot effect in layered heterostructures of composite metamaterials
physics.opticsSimin Feng, Klaus Halterman, Pamela L. Overfelt
We demonstrate that under certain conditions, fractional Talbot revivals can occur in heterostructures of composite metamaterials, such as multilayer positive and negative index media, metallodielectric stacks, and one-dimensional dielectric photonic crystals. Most importantly, without using the paraxial approximation we obtain Talbot images for the feature
Krisztian Peters
Most of the physics analyses at a hadron collider rely on a precise measurement of the energy of jets in the final state. This requires a precise in situ calibration of the calorimeter with the final detector setup. We present the basic procedure and results of the in situ gain calibration of the D0 HCAL in Run II. The gain calibration works on top of the pu
J. A. O. Matos, S. M. A. Gama, H. J. Ruskin, A. Sharkasi
We use a new method of studying the Hurst exponent with time and scale dependency. This new approach allow us to recover the major events affecting worldwide markets (such as the September 11th terrorist attack) and analyze the way those effects propagate through the different scales. The time-scale dependence of the referred measures demonstrates the releva
Glauber T. Silva
The present study concerns the dynamic radiation force on solid elastic spheres exerted by a plane wave with two frequencies (bichromatic wave) considering the nonlinearity of the fluid. Our approach is based on solving the wave scattering for the sphere in the quasilinear approximation within the preshock wave range. The dynamic radiation force is then obta
Y. Miroshnychenko, W. Alt, I. Dotsenko, L. Förster
We have recently demonstrated the creation of regular strings of neutral caesium atoms in a standing wave optical dipole trap using optical tweezers [Y. Miroshnychenko et al., Nature, in press (2006)]. The rearrangement is realized atom-by-atom, extracting an atom and re-inserting it at the desired position with sub-micrometer resolution. We describe our exp
Iwo Bialynicki-Birula, Zofia Bialynicka-Birula
We show that in addition to well known Bessel, Hermite-Gauss, and Laguerre-Gauss beams of electromagnetic radiation, one may also construct exponential beams. These beams are characterized by a fall-off in the transverse direction described by an exponential function of rho. Exponential beams, like Bessel beams, carry definite angular momentum and are period
K. Malarz
We modify the model of Deffuant et al. to distinguish true opinion among others in the fashion of Hegselmann and Krause <http://jasss.soc.surrey.ac.uk/9/3/10.html>. The basic features of both models modified to account for truth seekers are qualitatively the same.
R. Cross, M. Grinfeld, H. Lamba, T. Seaman
A class of heterogeneous agent models is investigated where investors switch trading position whenever their motivation to do so exceeds some critical threshold. These motivations can be psychological in nature or reflect behaviour suggested by the efficient market hypothesis (EMH). By introducing different propensities into a baseline model that displays EM
Time interval measurements by uniformly accelerating observers (non-longitudinal case)
physics.gen-phStefan Popescu, Bernhard Rothenstein
We consider two non-longitudinal Doppler Effect experiments. The first one involves a stationary source of monochromatic light located at the origin O of the K(XOY) inertial reference frame and an observer R who performs the hyperbolic motion at a constant altitude. The second involves a stationary observer located at the origin O and a monochromatic source
Yuichi Ikeda, Hideaki Aoyama, Hiroshi Iyetomi, Yoshi Fujiwara
This paper describes an agent-based model of interacting firms, in which interacting firm agents rationally invest capital and labor in order to maximize payoff. Both transactions and production are taken into account in this model. First, the performance of individual firms on a real transaction network was simulated. The simulation quantitatively reproduce
Zubin Jacob, Leonid V. Alekseyev, Evgenii Narimanov
We propose an approach to far-field optical imaging beyond the diffraction limit. The proposed system allows image magnification, is robust with respect to material losses and can be fabricated by adapting existing metamaterial technologies in a cylindrical geometry.
Lia Leon Chachanidze-Margolin, Shalva Tsiklauri
The kinematical rotations of N-partical Hyperspherical basis are considered. The recurrence relation method of determination of transformation coefficients for arbitrary N-values is demonstrated.