February 2007 arXiv papers — page 11
Showing 1,001–1,100 of 4,165 papers
Fokker-Planck and Chapman-Kolmogorov equations for Ito processes with finite memory
cond-mat.stat-mechJoseph L. McCauley
The usual derivation of the Fokker-Planck partial differential eqn. assumes the Chapman-Kolmogorov equation for a Markov process. Starting instead with an Ito stochastic differential equation we argue that finitely many states of memory are allowed in Kolmogorov's two pdes, K1 (the backward time pde) and K2 (the Fokker-Planck pde), and show that a Chapma
Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation
quant-phToshiki Ide, Holger F. Hofmann
The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally pr
Hee-Jung Lee, N. I. Kochelev
We perform a QCD sum rule analysis for the $f_0$ light tetraquark taking into account the contribution arising from the two pion intermediate state. With the interpolating currents of the different chiral combinations of scalar and pseudoscalar diquarks, it is demonstrated that the interpolating current with maximum chirality has a large coupling to the two
C. E. Rodríguez Torres, A. F. Cabrera, L. A. Errico, S. Duhalde
In this work we present an X-ray Absorption Spectroscopy characterization of the local environment of the impurity in room temperature ferromagnetic anatase TiO2 thin films doped with Co, Ni, Cu, or Zn, deposited on LaAlO3 substrate by Pulsed Laser Deposition. It was found that there is a considerable amount of impurity atoms substituting Ti in TiO2 anatase,
Stephen J. Howard, R. D. Horton, D. Q. Hwang, R. W. Evans
We present a method of analyzing a set of N time signals f_i(t) that consist of local measurements of the same physical observable taken at N sequential locations Z_i along the length of an experimental device. The result is an algorithm for reconstructing an approximation F(z,t) of the field f(z,t) in the inaccessible regions between the points of measureme
Raanan Schul
We prove a quantitative version of the following statement. Given a Lipschitz function f from the k-dimensional unit cube into a general metric space, one can decomposed f into a finite number of BiLipschitz functions f|_{F_i} so that the k-Hausdorff content of f([0,1]^k\setminus \cup F_i) is small. We thus generalize a theorem of P. Jones (1988) from the se
Hoi-Kwong Lo, Norbert Lütkenhaus
Quantum cryptography can, in principle, provide unconditional security guaranteed by the law of physics only. Here, we survey the theory and practice of the subject and highlight some recent developments.
Slobodan N. Simić
Oseledets regularity functions quantify the deviation of the growth associated with a dynamical system along its Lyapunov bundles from the corresponding uniform exponential growth. Precise degree of regularity of these functions is unknown. We show that for every invariant Lyapunov bundle of a volume preserving Anosov flow on a closed smooth Riemannian manif
D. E. Browne, E. Kashefi, M. Mhalla, S. Perdrix
We extend the notion of quantum information flow defined by Danos and Kashefi for the one-way model and present a necessary and sufficient condition for the deterministic computation in this model. The generalized flow also applied in the extended model with measurements in the X-Y, X-Z and Y-Z planes. We apply both measurement calculus and the stabiliser fo
Eduardo Flores, Ernst Knoesel
In an analysis of the Afshar experiment R.E. Kastner points out that the selection system used in this experiment randomly separates the photons that go to the detectors, and therefore no which-way information is obtained. In this paper we present a modified but equivalent version of the Afshar experiment that does not contain a selection device. The double-
Earl T. Campbell, Joseph Fitzsimons, Simon C. Benjamin, Pieter Kok
Given a suitably large and well connected (complex) graph state, any quantum algorithm can be implemented purely through local measurements on the individual qubits. Measurements can also be used to create the graph state: Path erasure techniques allow one to entangle multiple qubits by determining only global properties of the qubits. Here, this powerful ap
Vitalij Garber
We propose a bimetric space-time consisting of two vierbein bundles, in which a superluminal S-field mediates a causal exchange of quantum information associated with quantum entanglement. The resulting theory leaves the usual quantum field interactions, as well as the speed of light unchanged, but introduces quantum information effects related to the S-fiel
M. Merkli, I. M. Sigal, G. P. Berman
We present a rigorous analysis of the phenomenon of decoherence for general $N-$level systems coupled to reservoirs. The latter are described by free massless bosonic fields. We apply our general results to the specific cases of the qubit and the quantum register. We compare our results with the explicitly solvable case of systems whose interaction with the
A. Delgado, C. Saavedra, J. C. Retamal
We propose a scheme for the transfer of quantum information among distant qutrits. We apply this scheme to the distribution of entanglement among distant nodes and to the generation of multipartite antisymmetric states. We also discuss applications to quantum secret sharing.
Samir Lipovaca
The LH-II of purple bacteria Rhodospirillum (Rs.) molischianum and Rhodopseudomonas (Rps.) acidophila adopts a highly symmetrical ring shape, with a radius of about 7 nm. In the case of Rps. acidophila the ring has a ninefold symmetry axis, and in LH-II from Rs. molischianum the ring has an eightfold symmetry axis. These rings are found to exibit two bands o
Correctly validating results from single molecule data: the case of stretched exponential decay in the catalytic activity of single lipase B molecules
q-bio.SCOphir Flomenbom, Johan Hofkens, Kelly Velonia, Frans C. de Schryver
The question of how to validate and interpret correctly the waiting time probability density functions (WT-PDFs) from single molecule data is addressed. It is shown by simulation that when a stretched exponential WT-PDF, with a stretched exponent alfa and a time scale parameter tau, generates the off periods of a two-state trajectory, a reliable recovery of
Rishi L. Khan, Rajanikanth Vadigepalli, Guang Gao, James S. Schwaber
Motivation: In microarray analysis, special consideration must be given to the issues of multiple statistical tests and typically p-values are adjusted to control family-wise error rate (FWER) or false discovery rate (FDR). FDR metrics have been suggested for controlling false positives, however, genes with p-values close to the threshold typically have a hi
E. Lunasin, S. Kurien, M. Taylor, E. Titi
For wavenumbers k such that k * alpha > 1, corresponding to spatial scales smaller than alpha, there are three candidate power laws for the energy spectrum of the Navier-Stokes-alpha model, corresponding to three possible dynamical eddy turnover time scales in the model equations: one from the smoothed field, the second from the rough field and the third fro
Bruno Macke, Bernard Ségard
We examine how the interference of a coherent light-pulse with its slightly time-delayed copy may generate a pulse nearly identical to the original one and ahead of it. The simplicity of this 2-pulse system enabled us to obtain exact analytic expressions of the pulse distortion, valid for a wide class of pulse shapes. Explicit results are given for the pulse
Ferenc Sikler
The pixel detector of CMS can be used to reconstruct very low pT charged particles down to about 0.1 GeV/c. This can be achieved with high efficiency, good resolution and a negligible fake rate for elementary collisions. In the case of central PbPb collisions the fake rate can be kept low for pT > 0.4 GeV/c. In addition, the detector can be employed for iden
A simple derivation of the Lorentz transformation and of the related velocity and acceleration formulae
physics.gen-phJean-Michel Levy
The Lorentz transformation is entirely derived from length contraction, itself established through the known light-clock thought experiment . This makes the derivation accessible to beginning students once Eintein's two postulates have been admitted. The formula derived for the space part of the general rotation-free Lorentz transformation is very compac
P. Abbon, S. Andriamonje, S. Aune, T. Dafni
A low background Micromegas detector has been operating in the CAST experiment at CERN for the search of solar axions during the first phase of the experiment (2002-2004). The detector, made out of low radioactivity materials, operated efficiently and achieved a very low level of background rejection (5 x 10^-5 counts/keV/cm^2/s) without shielding.
D. Autiero, B. Beltran, J. M. Carmona, S. Cébrian
One of the three X-ray detectors of the CAST experiment searching for solar axions is a Time Projection Chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity X-ray signal expected in the CAST experiment. A low hardware threshold of 0.
V. K. Magas, L. P. Csernai, E. Molnar
The freeze out (FO) of the expanding systems, created in relativistic heavy ion collisions, is discussed. We start with kinetic FO model, which realizes complete physical FO in a layer of given thickness, and then combine our gradual FO equations with Bjorken type system expansion into a unified model. We shall see that the basic FO features, pointed out in
M. Isse, T. Hirano, R. Mizukawa, A. Ohnishi
We propose a new hadronization mechanism, jet-fluid string (JFS) formation and decay, to understand observables in intermediate to high-$p_{T}$ regions comprehensively. In the JFS model, hard partons produced in jet lose their energy in traversing the QGP fluid, which is described by fully three-dimensional hydrodynamic simulations. When a jet parton escapes
K. Watanabe, Y. Tsue
We investigate the time evolution of the quantum meson modes in the late time of chiral phase transition. In particular, it is shown that there exists a possible solution to the equation of motion for the quantum meson modes, which reveals a parametric resonance and/or resonance through forced oscillation induced by the small oscillation of the chiral conden
Debasish Das
The influence of Bose-Einstein statistics on multi-particle production characterized for various systems and energies by the STAR collaboration provides interesting information about the space-time dynamics of relativistic heavy-ion collisions at RHIC. We present the centrality and transverse mass dependence measurements of the two-pion interferometry in Au+
Measurement of the multi-hadron decays of omega, Ks and eta-mesons in heavy ion collisions at $\sqrt{s_{NN}}=200 GeV in the PHENIX experiment at RHIC
nucl-exV. Riabov
The PHENIX experiment at RHIC measured $ω$, $η$ and $K_{S}^{0}$-meson production at high $p_{T}$ in $p+p$, $d+Au$ and $Au+Au$ collisions at $\sqrt{s_{NN}}=200$ $GeV$. Measurements performed in different hadronic decay channels give consistent results. The measured ratios of all three mesons to $π^{0}$ are found to be flat as a function of $p_{T}$ in $p+p$ co
W. Sommer
A Large Ion Collider Experiment - ALICE will become operational with the startup of the Large Hadron Collider - LHC at the end of 2007. One focus of the physics program is the measurement of quarkonia in proton-proton and lead-lead collisions. Quarkonia states will be measured in two kinematic regions and channels: di-muonic decays will be measured in the fo
J. Smyrski, H. -H. Adam, A. Budzanowski, E. Czerwinski
Total and differential cross sections for the dp --> 3He eta reaction have been measured near threshold for 3He center-of-mass momenta in the range from 17.1 MeV/c to 87.5 MeV/c. The data were taken during a slow ramping of the COSY internal deuteron beam scattered on a proton target detecting the 3He ejectiles with the COSY-11 facility. The forward-backward
Renato Mirollo, Steven H. Strogatz
We solve a longstanding stability problem for the Kuramoto model of coupled oscillators. This system has attracted mathematical attention, in part because of its applications in fields ranging from neuroscience to condensed-matter physics, and also because it provides a beautiful connection between nonlinear dynamics and statistical mechanics. The model cons
Yoji Kawamura, Hiroya Nakao, Yoshiki Kuramoto
We demonstrate that nonlocally coupled limit-cycle oscillators subject to spatiotemporally white Gaussian noise can exhibit a noise-induced transition to turbulent states. After illustrating noise-induced turbulent states with numerical simulations using two representative models of limit-cycle oscillators, we develop a theory that clarifies the effective dy
Matthias Schork
It is shown how some of the recent results of de Souza et al. [1] can be generalized to describe Hamiltonians whose eigenvalues are given as k-generalized Fibonacci numbers. Here k is an arbitrary integer and the cases considered by de Souza et al. corespond to k=2.
Bruce Allison, John Faulkner, Yoji Yoshii
The classification of structurable tori with nontrivial involution, which was begun by Allison and Yoshii, is completed. New examples of structurable tori are obtained using a construction of structurable algebras from a semilinear version of cubic forms satisfying the adjoint identity. The classification uses techniques borrowed from quadratic forms over Z_
Ronald Brown
We use the n-globe with its skeletal filtration to define the fundamental globular omega--groupoid of a filtered space; the proofs use an analogous fundamental cubical omega--groupoid due to the author and Philip Higgins. This method also relates the construction to the fundamental crossed complex of a filtered space, and this relation allows the proof that
Oleg Chalykh
We consider one-dimensional elliptic Ruijsenaars model of type $BC_1$. It is given by a three-term difference Schrödinger operator $L$ containing 8 coupling constants. We show that when all coupling constants are integers, $L$ has meromorphic eigenfunctions expressed by a variant of Bethe ansatz. This result generalizes the Bethe ansatz formulas known in the
Sébastien Boyaval
We consider the computation of averaged coefficients for the homogenization of elliptic partial differential equations. In this problem, like in many multiscale problems, a large number of similar computations parametrized by the macroscopic scale is required at the microscopic scale. This is a framework very much adapted to model order reduction attempts. T
Doug Pickrell
The universal covering of the group PSU(1,1) acts naturally on H^m(δ), the space of holomorphic differentials of order m on the Poincare disk. The purpose of this paper is to survey, as broadly as I am able, the basic sources and examples of invariant measures for this action.
Marcy Barge, Beverly Diamond
Anderson and Putnam showed that the cohomology of a substitution tiling space may be computed by collaring tiles to obtain a substitution which ``forces its border.'' One can then represent the tiling space as an inverse limit of an inflation and substitution map on a cellular complex formed from the collared tiles; the cohomology of the tiling space
Marcel Morales
In the first part of this paper we study scrollers and linearly joined varieties. A particular class of varieties, of important interest in classical Geometry are Cohen--Macaulay varieties of minimal degree. They appear naturally studying the fiber cone of of a codimension two toric ideals. Let $I\subset S$ be an ideal defining a linearly joined arrangement
Sharp semiclassical estimates for the number of eigenvalues below a degenerate critical level
math.SPLech Zielinski
We consider the semiclassical asymptotic behaviour of the number of eigenvalues smaller than $E$ for elliptic operators in $L\sp 2 ({\bf R}\sp d)$. We describe a method of finding remainder estimates related to the volume of the region of the phase space in which the principal symbol takes values belonging to the interval $[E'-h; E'+h]$, where $E'
Gianpasquale Martelli
The response to a setpoint change in PID controlled feedback systems plays an important role for the tuning methods. This response may be easily evaluated in linear systems without delay by solving the related ordinary differential equations. These equations are also obtained for system with delay, if the delay exponential term is approximated to a polynomia
Yi Lin, Hao Helen Zhang
We propose a new method for model selection and model fitting in multivariate nonparametric regression models, in the framework of smoothing spline ANOVA. The ``COSSO'' is a method of regularization with the penalty functional being the sum of component norms, instead of the squared norm employed in the traditional smoothing spline method. The COSSO
Enno Mammen, Byeong U. Park
In this paper a new smooth backfitting estimate is proposed for additive regression models. The estimate has the simple structure of Nadaraya--Watson smooth backfitting but at the same time achieves the oracle property of local linear smooth backfitting. Each component is estimated with the same asymptotic accuracy as if the other components were known.
Rémi Carles
Solutions of semi-classical Schrodinger equation with isotropic harmonic potential focus periodically in time. We study the perturbation of this equation by a nonlinear term. If the scaling of this perturbation is critical, each focus crossing is described by a nonlinear scattering operator, which is therefore iterated as many times as the solution passes th
Yijun Zuo
As estimators of location parameters, univariate trimmed means are well known for their robustness and efficiency. They can serve as robust alternatives to the sample mean while possessing high efficiencies at normal as well as heavy-tailed models. This paper introduces multidimensional trimmed means based on projection depth induced regions. Robustness of t
From $ε$-entropy to KL-entropy: Analysis of minimum information complexity density estimation
math.STTong Zhang
We consider an extension of $ε$-entropy to a KL-divergence based complexity measure for randomized density estimation methods. Based on this extension, we develop a general information-theoretical inequality that measures the statistical complexity of some deterministic and randomized density estimators. Consequences of the new inequality will be presented.
Konrad Waldorf
Usually bundle gerbes are considered as objects of a 2-groupoid, whose 1-morphisms, called stable isomorphisms, are all invertible. I introduce new 1-morphisms which include stable isomorphisms, trivializations and bundle gerbe modules. They fit into the structure of a 2-category of bundle gerbes, and lead to natural definitions of surface holonomy for close
Embeddings into Free Heyting Algebras and Translations into Intuitionistic Propositional Logic
math.LOMichael O'Connor
We find a translation with particularly nice properties from intuitionistic propositional logic in countably many variables to intuitionistic propositional logic in two variables. In addition, the existence of a possibly-not-as-nice translation from any countable logic into intuitionistic propositional logic in two variables is shown. The nonexistence of a t
T. Tony Cai, Peter Hall
There has been substantial recent work on methods for estimating the slope function in linear regression for functional data analysis. However, as in the case of more conventional finite-dimensional regression, much of the practical interest in the slope centers on its application for the purpose of prediction, rather than on its significance in its own righ
Pressure Regularity Criterion for the Three-dimensional Navier-Stokes Equations in Infinite Channel
math.APChongsheng Cao, Edriss S. Titi
In this paper we consider the three-dimensional Navier-Stokes equations in an infinite channel. We provide a sufficient condition, in terms of $\partial_z p$, where $p$ is the pressure, for the global existence of the strong solutions to the three-dimensional Navier-Stokes equations.
Bilateral Canonical Cascades: Multiplicative Refinement Paths to Wiener's and Variant Fractional Brownian Limits
math.PRJulien Barral, Benoit Mandelbrot
The original density is 1 for $t\in (0,1)$, $b$ is an integer base ($b\geq 2$%), and $p\in (0,1)$ is a parameter. The first construction stage divides the unit interval into $b$ subintervals and multiplies the density in each subinterval by either 1 or -1 with the respective frequencies of $\frac{1% }{2}+\frac{p}{2}$ and ${1/2}-\frac{p}{2}$. It is shown that
Ying Wei, Xuming He
Rejoinder: Conditional Growth Charts [math.ST/0702634]
Mary Lou Thompson
Discussion of Conditional growth charts [math.ST/0702634]
Matias Salibian-Barrera, Ruben H. Zamar
Discussion of Conditional growth charts [math.ST/0702634]
Anneli Pere
Discussion of Conditional growth charts [math.ST/0702634]
S. Gerhold
We show that the probability mass function of the riff-shuffle distribution, also known as the minimum negative binomial distribution, is unimodal, but in general not log-concave.
Emeric Deutsch, Luca Ferrari, Simone Rinaldi
We translate the concept of succession rule and the ECO method into matrix notation, introducing the concept of a production matrix. This allows us to combine our method with other enumeration techniques using matrices, such as the method of Riordan matrices. Finally we treat the case of rational production matrices, i.e. those leading to rational generating
Ilse Fischer
Monotone triangles are certain triangular arrays of integers, which correspond to $n \times n$ alternating sign matrices when prescribing $(1,2,...,n)$ as bottom row of the monotone triangle. In this article we define halved monotone triangles, a specialization of which correspond to vertically symmetric alternating sign matrices. We derive an operator formu
Raymond J. Carroll, David Ruppert
Discussion of Conditional growth charts [math.ST/0702634]
Jean-Luc Marichal, Michael Dorff
We explore the idea that the derivative of the volume, V, of a region in R^d with respect to r equals its surface area, A, where r = d V/A. We show that the families of regions for which this formula for r is valid, which we call homogeneous families, include all the families of similar regions. We determine equivalent conditions for a family to be homogeneo
Ying Wei, Xuming He
Growth charts are often more informative when they are customized per subject, taking into account prior measurements and possibly other covariates of the subject. We study a global semiparametric quantile regression model that has the ability to estimate conditional quantiles without the usual distributional assumptions. The model can be estimated from long
Hebing Rui, Jie Xu
In this paper, we give a necessary and sufficient condition for a cyclotomic Brauer algebra being semisimple. This generalizes previous result for a Brauer algebra.
Rowena Held, Iva Stavrov, Brian VanKoten
We use reduced homogeneous coordinates to study Riemannian geometry of the octonionic (or Cayley) projective plane. Our method extends to the para-octonionic (or split octonionic) projective plane, the octonionic projective plane of indefinite signature, and the hyperbolic dual of the octonionic projective plane; we discuss these manifolds in the later secti
Achilleas Sinefakopoulos
We construct a (shellable) polyhedral cell complex that supports a minimal free resolution of a Borel fixed ideal, which is minimally generated (in the Borel sense) by just one monomial in S=k[x_1,x_2,...,x_n]; this includes the case of powers of the homogeneous maximal ideal (x_1,x_2,...,x_n) as a special case. In our most general result we prove that for a
Achilleas Sinefakopoulos
We define the reduced horseshoe resolution and the notion of conjoined pairs of ideals in order to study the minimal graded free resolution of a class of p-Borel ideals and recover Pardue's regularity formula for them. It will follow from our technique that the graded betti numbers of these ideals do not depend on the characteristic of the base field k.
Sebastian M. Cioabă
Let $G$ be an irregular graph on $n$ vertices with maximum degree $Δ$ and diameter $D$. We show that Δ-λ_1>\frac{1}{nD} where $λ_1$ is the largest eigenvalue of the adjacency matrix of $G$. We also study the effect of adding or removing few edges on the spectral radius of a regular graph.
O. A. Castro-Alvaredo, J. M. Maillet
We present determinant formulae for the form factors of spin operators of general integrable XXX Heisenberg spin chains for arbitrary (finite dimensional) spin representations. The results apply to any "mixed" spin chains, such as alternating spin chains, or to spin chains with magnetic impurities.
Victor M. Villalba, Luis A. Gonzalez-Diaz
We solve the two-component Dirac equation in the presence of a spatially one dimensional symmetric attractive cusp potential. The components of the spinor solution are expressed in terms of Whittaker functions. We compute the bound states solutions and show that, as the potential amplitude increases, the lowest energy state sinks into the Dirac sea becoming
Michael McGuigan
We discuss implications of the large eigenvalue of the cosmological constant seesaw mechanism extending hep-th/0602112 and hep-th/0604108. While the previous papers focused on the small eigenvalue as a cosmological constant associated with the accelerating Universe, here we draw attention to the physical implications of the large eigenvalue. In particular we
Julian B. Berchtold, Gunter Scharf
The massive spin-2 quantum gauge theory previously developed is applied to calculate gravitational bremsstrahlung. It is shown that this theory is unique and free from defects. In particular, there is no strong coupling if the graviton mass becomes small. The cross sections go over smoothly into the ones of the massless theory in the limit of vanishing gravi
Hideki Ishihara, Jiro Soda
We explore the obsevability of extra dimensions through 5-dimensional squashed Kaluza-Klein black holes residing in the Kaluza-Klein spacetime. With the expectation that the Hawking radiation reflects the 5-dimensional nature of the squashed horizon, we study the Hawking radiation of a scalar field in the squashed black hole background. As a result, we show
Alan H. Guth
I summarize the arguments that strongly suggest that our universe is the product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are described. Although the infinity of pocket universes produced by eternal inflation are unobservable, it is argued that eternal inflation has real consequences in terms of the way that
Kari Enqvist, Steen Hannestad, Martin S. Sloth
We propose a novel mechanism for dark energy, based on an extended seesaw for scalar fields, which does not require any new physics at energies below the TeV scale. A very light quintessence mass is usually considered to be technically unnatural, unless it is protected by some symmetry broken at the new very light scale. We propose that one can use an extend
Takeshi Fukuyama, Tatsuru Kikuchi, Nobuchika Okada
This talk consists of two parts. In part I we review how the minimal renormalizable supersymmetric SO(10) model, an SO(10) framework with only one 10 and one 126 Higgs multiplets in the Yukawa sector, is attractive because of its highly predictive power. Indeed it not only gives a consistent predictions on neutrino oscillation data but also gives reasonable
Pedro Costa
Using the SU(3) Nambu-Jona-Lasinio (NJL) model, we study the chiral phase transition at finite $T$ and $μ_B$. Special attention is given to the QCD critical end point (CEP): the study of physical quantities, as the pressure, the entropy, the baryon number susceptibility and the specific heat near the CEP, will provide complementary information concerning the
Phase transitions in quark matter and behaviour of physical observables in the vicinity of the critical end point
hep-phPedro Costa, C. A. de Sousa, M. C. Ruivo, Yu. L. Kalinovsky
We study the chiral phase transition at finite $T$ and $μ_B$ within the framework of the SU(3) Nambu-Jona-Lasinio (NJL) model. The QCD critical end point (CEP) and the critical line at finite temperature and baryonic chemical potential are investigated: the study of physical quantities, such as the baryon number susceptibility near the CEP, will provide comp
Song Shu, Jia-Rong Li
The BEC of charged pions is investigated in the framework of O(4) linear sigma model. By using Cornwall-Jackiw-Tomboulis formalism, we have derived the gap equations for the effective masses of the mesons at finite temperature and finite isospin density. The BEC is discussed in chiral limit and non-chiral limit at Hartree approximation and also at large N ap
Scalar and Spinor Particles with Low Binding Energy in the Strong Stationary Magnetic Field Studied by Means of Two-and Three-Dimensional Models
hep-phV. N. Rodionov
On the basis of analytic solutions of Schrodinger and Pauli equations for a uniform magnetic field and a single attractive $δ({\bf r})$-potential the equations for the bound one-active electron states are discussed. It is vary important that ground electron states in the magnetic field essentially different from the analog state of spin-0 particles that bind
D. Antonov, H. -J. Pirner
Using a parametrization of the Wilson loop with the minimal-area law, we calculate the polarization operator of a valence gluon, which propagates in the confining background. This enables us to obtain the infrared freezing (i.e. finiteness) of the running strong coupling in the confinement phase, as well as in the deconfinement phase up to the temperature of
B. M. Tavares, H. -J. Drescher, T. Kodama
In this work we present a study of the influence of nucleus initializations on the event-by-event elliptic flow coefficient, $v_2$. In most Monte-Carlo models, the initial positions of the nucleons in a nucleus are completely uncorrelated, which can lead to very high density regions. In a simple, yet more realistic model where overlapping of the nucleons is
Reply to "Comment on 'Quantization of FRW spacetimes in the presence of a cosmological constant and radiation'"
gr-qcN. A. Lemos, G. A. Monerat, E. V. Corrêa Silva, G. Oliveira-Neto
The Comment by Amore {\it et al.} [gr-qc/0611029] contains a valid criticism of the numerical precision of the results reported in a recent paper of ours [Phys. Rev. D {\bf 73}, 044022 (2006)], as well as fresh ideas on how to characterize a quantum cosmological singularity. However, we argue that, contrary to what is suggested in the Comment, the quantum co
AICA: a New Pair Force Evaluation Method for Parallel Molecular Dynamics in Arbitrary Geometries
cs.CEGraham B. Macpherson, Jason M. Reese
A new algorithm for calculating intermolecular pair forces in Molecular Dynamics (MD) simulations on a distributed parallel computer is presented. The Arbitrary Interacting Cells Algorithm (AICA) is designed to operate on geometrical domains defined by an unstructured, arbitrary polyhedral mesh, which has been spatially decomposed into irregular portions for
Syndrome Decoding of Reed-Solomon Codes Beyond Half the Minimum Distance based on Shift-Register Synthesis
cs.ITGeorg Schmidt, Vladimir R. Sidorenko, Martin Bossert
In this paper, a new approach for decoding low-rate Reed-Solomon codes beyond half the minimum distance is considered and analyzed. Unlike the Sudan algorithm published in 1997, this new approach is based on multi-sequence shift-register synthesis, which makes it easy to understand and simple to implement. The computational complexity of this shift-register
Slavcho Shtrakov
We introduce and study the essential inputs (variables) for terms (trees) and tree automata.
V. Nicosia, G. Mangioni, V. Carchiolo, M. Malgeri
In this paper we present a formal description of PROSA, a P2P resource management system heavily inspired by social networks. Social networks have been deeply studied in the last two decades in order to understand how communities of people arise and grow. It is a widely known result that networks of social relationships usually evolves to small-worlds, i.e.
V. Nicosia, G. Mangioni, V. Carchiolo, M. Malgeri
Retrieving resources in a distributed environment is more difficult than finding data in centralised databases. In the last decade P2P system arise as new and effective distributed architectures for resource sharing, but searching in such environments could be difficult and time-consuming. In this paper we discuss efficiency of resource discovery in PROSA, a
Philipp Pluch, Samo Wakounig
The aim of this technical report is to give a short overview of known techniques for network tomography (introduced in the paper of Vardi (1996)), extended by a Bayesian approach originating Tebaldi and West (1998). Since the studies of A.K. Erlang (1878-1929) on telephone networks in the last millennium, lots of needs are seen in todays applications of netw
Slavcho Shtrakov, Vladimir Shtrakov
We consider the computational complexity of tree transducers, depending on their separable sets of input variables.
Thomas Michel, Gerhard Wunder
The downlink of a multiple-input multiple output (MIMO) broadcast channel (BC) is considered, where each receiver is equipped with a single antenna and the transmitter performs nonlinear Dirty-Paper Coding (DPC). We present an efficient algorithm that finds the optimum transmit filters and power allocation as well as the optimum precoding order(s) possibly a
Margaret E. Johnson, Teresa Head-Gordon, Ard A. Louis
The use of an effective intermolecular potential often involves a compromise between more accurate, complex functional forms and more tractable simple representations. To study this choice in detail, we systematically derive coarse-grained isotropic pair potentials that accurately reproduce the oxygen-oxygen radial distribution function of the TIP4P-Ew water
Mladen Georgiev
We consider the magnetostatic response to an external magnetic field of a crystal containing off-center ions, such as Li^+ in KCl and KBr or the apical oxygens O(A) in the LaSCO family of layered perovskites. Magnetic dipoles are deduced from the matrix elements of the energy operator of a spinning particle in a magnetic field which particle also satisfies t
First-principles calculation of mechanical properties of Si <001> nanowires and comparison to nanomechanical theory
cond-mat.mtrl-sciByeongchan Lee, Robert E. Rudd
We report the results of first-principles density functional theory calculations of the Young's modulus and other mechanical properties of hydrogen-passivated Si <001> nanowires. The nanowires are taken to have predominantly {100} surfaces, with small {110} facets according to the Wulff shape. The Young's modulus, the equilibrium length and the const
Magnetization reversal in the orthovanadate RVO3 compounds (R = La, Nd, Sm, Gd, Er and Y): Inhomogeneities caused by defects in the orbital sector of quasi-one-dimensional orbital systems
cond-mat.str-elL D Tung, M R Lees, G Balakrishnan, D McK Paul
We report on a study of various RVO3 single-crystal samples (R = La, Nd, Sm, Gd, Er and Y) which show temperature-induced magnetization reversal. For compounds with lighter rare-earths (R = La, Nd and Sm), magnetization reversal can be observed for magnetic field applied in the ab plane and along the c axis, whereas for the heavy rare-earths (R = Gd, Er) mag
Sandro Stringari
The purpose of this paper is to review some of the dynamic and superfluid features exhibited by ultracold Fermi gases with special emphasis on the effects of the external confinement which will be assumed in most cases of harmonic shape.
Ferromagnetism in Fe-doped ZnO Nanocrystals: Experimental and Theoretical investigations
cond-mat.mtrl-sciDebjani Karmakar, S. K. Mandal, R. M. Kadam, P. L. Paulose
Fe-doped ZnO nanocrystals are successfully synthesized and structurally characterized by using x-ray diffraction and transmission electron microscopy. Magnetization measurements on the same system reveal a ferromagnetic to paramagnetic transition temperature > 450 K with a low-temperature transition from ferromagnetic to spin-glass state due to canting of th
Jorg Behler, Sonke Lorenz, Karsten Reuter
The accurate description of molecule-surface interactions requires a detailed knowledge of the underlying potential-energy surface (PES). Recently, neural networks (NNs) have been shown to be an efficient technique to accurately interpolate the PES information provided for a set of molecular configurations, e.g. by first-principles calculations. Here, we fur
Static dielectric response and Born effective charge of BN nanotubes from {\it ab initio} finite electric field calculations
cond-mat.mtrl-sciG. Y. Guo, S. Ishibashi, T. Tamura, K. Terakura
{\it Ab initio} investigations of the full static dielectric response and Born effective charge of BN nanotubes (BN-NTs) have been performed for the first time using finite electric field method. It is found that the ionic contribution to the static dielectric response of BN-NTs is substantial and also that a pronounced chirality-dependent oscillation is sup
Adrianne R. T. van Eerd, Wouter G. Ellenbroek, Martin van Hecke, Jacco H. Snoeijer
We numerically study the distribution P(f) of contact forces in frictionless bead packs, by averaging over the ensemble of all possible force network configurations. We resort to umbrella sampling to resolve the asymptotic decay of P(f) for large f, and determine P(f) down to values of order 10^{-45} for ordered and disordered systems in two and three dimens
Bhavtosh Bansal, V. K. Dixit, V. Venkataraman, H. L. Bhat
InAs_{x}Sb_{1-x} alloys show a strong bowing in the energy gap, the energy gap of the alloy can be less than the gap of the two parent compounds. We demonstrate that a consequence of this alloying is a systematic degradation in the sharpness of the absorption edge. The alloy disorder induced band-tail (Urbach tail) characteristics are quantitatively studied