March 2009 arXiv papers — page 36
Showing 3,501–3,600 of 5,470 papers
Ben Freivogel, Matthew Kleban
We study a statistical model defined by a conformally invariant distribution of overlapping spheres in arbitrary dimension d. The model arises as the asymptotic distribution of cosmic bubbles in d+1 dimensional de Sitter space, and also as the asymptotic distribution of bubble collisions with the domain wall of a fiducial "observation bubble" in d+2 dimensio
F. Breitling
This work reports on the discovery of HESS J1514-591, a VHE gamma-ray source found at the pulsar wind nebula (PWN) MSH 15-52 and its associated pulsar PSR B1509-58. The discovery was made with the High Energy Stereoscopic System (H.E.S.S.), which currently provides the most sensitive measurement in the energy range of about 0.2-100 TeV. This analysis is the
N. Tobias Jacobson, Silvano Garnerone, Stephan Haas, Paolo Zanardi
The phase diagram of a quantum XY spin chain with Gaussian-distributed random anisotropies and transverse fields is investigated, with focus on the fidelity susceptibility, a recently introduced quantum information theoretical measure. Monitoring the finite-size scaling of the probability distribution of this quantity as well as its average and typical value
Einstein's unpublished opening lecture for his course on relativity theory in Argentina, 1925
physics.hist-phAlejandro Gangui, Eduardo L. Ortiz
In 1922 the University of Buenos Aires (UBA) Council approved a motion to send an invitation to Albert Einstein to visit Argentina and give a course of lectures on his theory of relativity. The motion was proposed by Jorge Duclout (1856-1927), who had been educated at the Eidgenossische Technische Hochschule, Zurich (ETH). This proposal was the culmination o
Martin Elvis, Francesca Civano, Cristian Vignali, Simonetta Puccetti
The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra} program that has imaged the central 0.5 sq.deg of the COSMOS field (centered at 10h, +02deg) with an effective exposure of ~160ksec, and an outer 0.4sq.deg. area with an effective exposure of ~80ksec. The limiting source detection depths are 1.9e-16 erg cm(-2) s(-1) in the Soft (0.5-2 keV) ban
Constraining the Black Hole Mass Spectrum with Gravitational Wave Observations I: The Error Kernel
astro-ph.COJoseph E. Plowman, Daniel C. Jacobs, Ronald W. Hellings, Shane L. Larson
Many scenarios have been proposed for the origin of the supermassive black holes (SMBHs) that are found in the centres of most galaxies. Many of these formation scenarios predict a high-redshift population of intermediate-mass black holes (IMBHs), with masses in the range 100 to 100000 times that of the Sun. A powerful way to observe these IMBHs is via gravi
Tolga Guver, Feryal Ozel
A linear relation between the hydrogen column density (N_H) and optical extinction (A_V) in the Galaxy has long been observed. A number of studies found differing results in the slope of this relation. Here, we utilize the data on 22 supernova remnants that have been observed with the latest generation X-ray observatories and for which optical extinction and
G. Ghisellini, L. Maraschi, F. Tavecchio
Flat Spectrum Radio Quasars (FSRQs) and BL Lac objects detected in the first three months of the Fermi survey neatly separate in the gamma-ray spectral index vs gamma-ray luminosity plane. BL Lac objects are less luminous and have harder spectra than broad line blazars. We suggest that this division has its origin in the different accretion regimes of the tw
Michal Bregman, Tal Alexander
The maser disk around the massive black hole (MBH) in active galaxy NGC 4258 exhibits an O(10 deg) warp on the O(0.1 pc) scale. The physics driving the warp are still debated. Suggested mechanisms include torquing by relativistic frame dragging or by radiation pressure. We propose here a new warping mechanism: resonant torquing of the disk by stars in the de
A sharp bound on eigenvalues of Schroedinger operators on the halfline with complex-valued potentials
math.SPRupert L. Frank, Ari Laptev, Robert Seiringer
We derive a sharp bound on the location of non-positive eigenvalues of Schroedinger operators on the halfline with complex-valued potentials.
G. Kowal, A. Lazarian, E. T. Vishniac, K. Otmianowska-Mazur
We study the effects of turbulence on magnetic reconnection using 3D numerical simulations. This is the first attempt to test a model of fast magnetic reconnection in the presence of weak turbulence proposed by Lazarian & Vishniac (1999). This model predicts that weak turbulence, generically present in most of astrophysical systems, enhances the rate of reco
Bradley A. Chase, Ben Q. Baragiola, Heather L. Partner, Brigette D. Black
We argue that it is possible in principle to reduce the uncertainty of an atomic magnetometer by double-passing a far-detuned laser field through the atomic sample as it undergoes Larmor precession. Numerical simulations of the quantum Fisher information suggest that, despite the lack of explicit multi-body coupling terms in the system's magnetic Hamilto
Valeri N. Kotov, Bruno Uchoa, A. H. Castro Neto
We examine the 1/N expansion, where N is the number of two-component Dirac fermions, for Coulomb interactions in graphene with a gap of magnitude $\Delta = 2 m$. We find that for $N\alpha\gg1$, where $\alpha$ is graphene's "fine structure constant", there is a crossover as a function of distance $r$ from the usual 3D Coulomb law, $V(r) \sim 1/r$, to a 2D Cou
L. DiCarlo, J. M. Chow, J. M. Gambetta, Lev S. Bishop
By harnessing the superposition and entanglement of physical states, quantum computers could outperform their classical counterparts in solving problems of technological impact, such as factoring large numbers and searching databases. A quantum processor executes algorithms by applying a programmable sequence of gates to an initialized register of qubits, wh
Delio Mugnolo, Robin Nittka
A well-known result going back to the 1930s states that all bounded linear operators mapping scalar-valued $L^1$-spaces into $L^\infty$-spaces are kernel operators and that in fact this relation induces an isometric isomorphism between the space of such operators and the space of all bounded kernels. We extend this result to the case of spaces of vector-valu
Sylvie Corteel, Cyrille Savelief, Mirjana Vuletić
Generating functions for plane overpartitions are obtained using various methods such as nonintersecting paths, RSK type algorithms and symmetric functions. We extend some of the generating functions to cylindric partitions. Also, we show that plane overpartitions correspond to certain domino tilings and we give some basic properties of this correspondence.
Nail Ussembayev
This paper has been withdrawn by the author for further investigation.
V. Koukouloyannis, I. Kourakis
The occurrence of single- or multisite localized vibrational modes, also called Discrete Breathers (DBs), in 2D hexagonal dusty plasma (DP) lattices is investigated. The system is described by a Klein-Gordon hexagonal lattice characterized by a negative coupling parameter $\e$ in account of its inverse dispersive behavior. A theoretical analysis is performed
Samuel Lundqvist
We introduce the concept of multiplication matrices for ideals of projective dimension zero. We discuss various applications and in particular, we give a new algorithm to compute the variety of an ideal of projective dimension zero.
Kavan Modi
We study preparation of states for open quantum mechanics. For non-Markovian systems that are initially correlated with the environment, the affects of the preparation procedure are nontrivial. This is due to the indirect affects on the state of the environment induced via the correlations with the system and the act of preparation on the system. We give thr
Alain Connes, Caterina Consani
We determine the {\em real} counting function $N(q)$ ($q\in [1,\infty)$) for the hypothetical "curve" $C=\overline {\Sp \Z}$ over $\F_1$, whose corresponding zeta function is the complete Riemann zeta function. Then, we develop a theory of functorial $\F_1$-schemes which reconciles the previous attempts by C. Soulé and A. Deitmar. Our construction fi
Victor Martin-Mayor, David Yllanes
We propose a cluster simulation algorithm for statistical ensembles with fixed order parameter. We use the tethered ensemble, which features Helmholtz's effective potential rather than Gibbs's free energy, and in which canonical averages are recovered with arbitrary accuracy. For the D = 2,3 Ising model our method's critical slowing down is compa
Nayereh Majd, D. Momeni
The main goal of this paper is deriving Density of states $g(ε)$ (degeneracy function) per volume for an equation of state (EOS) $p=-ρ$ (we called it dark energy(DE)).We have concluded that thermodynamic quantities such as pressure and energy density are simple functions of temperature, fugacity, curvature and mass of Bosons. Our work has been expressed the
Temperature-dependent transport in a sixfold degenerate two-dimensional electron system on a H-Si(111) surface
cond-mat.mes-hallRobert N. McFarland, Tomasz M. Kott, Luyan Sun, K. Eng
Low-field magnetotransport measurements on a high mobility (mu=110,000 cm^2/Vs) two-dimensional (2D) electron system on a H-terminated Si(111) surface reveal a sixfold valley degeneracy with a valley splitting <= 0.1 K. The zero-field resistivity rho_{xx} displays strong temperature dependence for 0.07 < T < 25 K as predicted for a system with high degenerac
Mark Hindmarsh, Huiquan Li
We investigate the spacetime-dependent condensation of the tachyon in effective field theories. Previous work identified singularities in the field which appear in finite time: infinite gradients at the kinks, and (in the eikonal approximation) caustics near local minima. By performing a perturbation analysis, and with numerical simulations, we demonstrate a
Quantum distillation: dynamical generation of low-entropy states of strongly correlated fermions in an optical lattice
cond-mat.quant-gasF. Heidrich-Meisner, S. R. Manmana, M. Rigol, A. Muramatsu
Correlations between particles can lead to subtle and sometimes counterintuitive phenomena. We analyze one such case, occurring during the sudden expansion of fermions in a lattice when the initial state has a strong admixture of double occupancies. We promote the notion of quantum distillation: during the expansion, and in the presence of strongly repulsive
Proof of a Conjecture on the Sequence of Exceptional Numbers, Classifying Cyclic Codes and APN Functions
cs.ITFernando Hernando, Gary McGuire
We prove a conjecture that classifies exceptional numbers. This conjecture arises in two different ways, from cryptography and from coding theory. An odd integer $t\geq 3$ is said to be exceptional if $f(x)=x^t$ is APN (Almost Perfect Nonlinear) over $\mathbb{F}_{2^n}$ for infinitely many values of $n$. Equivalently, $t$ is exceptional if the binary cyclic c
Kang Ning
The problem of finding the longest common subsequence (LCS) for a set of sequences is a very interesting and challenging problem in computer science. This problem is NP-complete, but because of its importance, many heuristic algorithms have been proposed, such as Long Run algorithm and Expansion algorithm. However, the performance of many current heuristic a
Effects of QCD radiation on inclusive variables for determining the scale of new physics at hadron colliders
hep-phAndreas Papaefstathiou, Bryan Webber
We examine the effects of QCD initial-state radiation on a class of quantities, designed to probe the mass scale of new physics at hadron colliders, which involve longitudinal as well as transverse final-state momenta. In particular, we derive universal functions that relate the invariant mass and energy distribution of the visible part of the final state to
Ph. von Doetinchem
This thesis discusses two different approaches for the measurement of cosmic-ray antiparticles in the GeV to TeV energy range. The first part of this thesis discusses the prospects of antiparticle flux measurements with the proposed PEBS detector. The project allots long duration balloon flights at one of Earth's poles at an altitude of 40 km. GEANT4 sim
NMR investigation of superconductivity and antiferromagnetism in CaFe$_2$As$_2$ under pressure
cond-mat.supr-conS. -H. Baek, H. Lee, S. E. Brown, N. J. Curro
We report $^{75}$As NMR measurements in CaFe$_2$As$_2$, made under applied pressures up to 0.83 GPa produced by a standard clamp pressure cell. Our data reveal phase segregation of paramagnetic (PM) and antiferromagnetic (AFM) phases over a range of pressures, with the AFM phase more than 90 % dominant at low temperatures. In situ RF susceptibility measureme
Andreas Schulz, Alex Zazunov, Reinhold Egger
We compute the critical Josephson current through a single-molecule junction. As a model for a molecule with a bistable conformational degree of freedom, we study an interacting single-level quantum dot coupled to a two-level system and weakly connected to two superconducting electrodes. We perform a lowest-order perturbative calculation of the critical curr
Solution of the Crow-Kimura and Eigen models for alphabets of arbitrary size by Schwinger spin coherent states
q-bio.PEEnrique Munoz, Jeong-Man Park, Michael W. Deem
To represent the evolution of nucleic acid and protein sequence, we express the parallel and Eigen models for molecular evolution in terms of a functional integral representation with an $h$-letter alphabet, lifting the two-state, purine/pyrimidine assumption often made in quasi-species theory. For arbitrary $h$ and a general mutation scheme, we obtain the s
Feature selection in omics prediction problems using cat scores and false nondiscovery rate control
stat.APMiika Ahdesmäki, Korbinian Strimmer
We revisit the problem of feature selection in linear discriminant analysis (LDA), that is, when features are correlated. First, we introduce a pooled centroids formulation of the multiclass LDA predictor function, in which the relative weights of Mahalanobis-transformed predictors are given by correlation-adjusted $t$-scores (cat scores). Second, for featur
Carlos A. Cardona, Carmen A. Núñez
We consider R and NS spectral flow sectors of type IIB superstring theory on AdS(3)xS(3)xT(4) in the context of the AdS(3)/CFT(2) correspondence. We present a derivation of the vertex operators creating spectral flow images of chiral primary states previously proposed in the literature. We compute spectral flow conserving three-point functions involving thes
M. H. Albert, M. D. Atkinson, R. Brignall, N. Ruskuc
Pattern classes which avoid 321 and other patterns are shown to have the same growth rates as similar (but strictly larger) classes obtained by adding articulation points to any or all of the other patterns. The method of proof is to show that the elements of the latter classes can be represented as bounded merges of elements of the original class, and that
S. Bauch, K. Balzer, C. Henning, M. Bonitz
An analysis of the quantum breathing behavior of few-particle Coulomb systems in one- and two-dimensional harmonic traps is presented. We report the existence of \emph{two independent breathing modes} and present exact numerical results for two particles at any coupling strength which smoothly connect the two known limits of an \emph {ideal} quantum and a st
Francesco De Martini
Two quantum Macro-states and their Macroscopic Quantum Superpositions (MQS) localized in two far apart, space - like separated sites can be non-locally correlated by any entangled couple of single-particles having interacted in the past. This novel Macro - Macro paradigm is investigated on the basis of a recent study on an entangled Micro-Macro system involv
Xiang-Fei Meng, Gang Li, Ying Chen, Chuan Liu
Thermal properties of glueballs in SU(3) Yang-Mills theory are investigated in a large temperature range from $0.3T_c$ to $1.9T_c$ on anisotropic lattices. The glueball operators are optimized for the projection of the ground states by the variational method with a smearing scheme. Their thermal correlators are calculated in all 20 symmetry channels. It is f
Jan Essert
Wagoner complexes are simplicial complexes associated to groups of Kac-Moody type. They admit interesting homotopy groups which are related to integral group homology if the root datum is of 2-spherical type. We give a general definition of Wagoner complexes, exhibit some simple properties and calculate low dimensional homotopy groups. In addition, we give a
Cecile Monthus, Thomas Garel
At Anderson critical points, the statistics of the two-point transmission $T_L$ for disordered samples of linear size $L$ is expected to be multifractal with the following properties [Janssen {\it et al} PRB 59, 15836 (1999)] : (i) the probability to have $T_L \sim 1/L^κ$ behaves as $L^{Φ(κ)}$, where the multifractal spectrum $Φ(κ)$ terminates at $κ=0$ as a
Fermions Tunneling from Higher-Dimensional Reissner-Nordström Black Hole: Semiclassical and Beyond Semiclassical Approximation
gr-qcShu-Zheng Yang, Dan Wen, Kai Lin
Based on semiclassical tunneling method, we focus on charged fermions tunneling from higher-dimensional Reissner-Nordström black hole. We first simplify the Dirac equation by semiclassical approximation, and then a semiclassical Hamilton-Jacobi equation is obtained. Using the Hamilton-Jacobi equation, we study the Hawking temperature and fermions tunneling r
Radiative and Semileptonic B Decays Involving the Tensor Meson K_2^*(1430) in the Standard Model and Beyond
hep-phHisaki Hatanaka, Kwei-Chou Yang
We study semileptonic and radiative B decays involving the strange tensor meson K_2^*(1430) in the final state. Using the large energy effective theory (LEET) techniques, we formulate the B \to K_2^* transition form factors in large recoil region. All the form factors can be parametrized in terms of two independent LEET parameters ζ_\perp and ζ_\parallel. Th
Periodic billiard orbits on $n$--dimensional ellipsoids with impacts on confocal quadrics and isoperiodic deformations
nlin.SISimonetta Abenda, Petr G. Grinevich
In our paper we study periodic geodesic motion on multidimensional ellipsoids with elastic impacts along confocal quadrics. We show that the method of isoperiodic deformation is applicable.
Timothy Trudgian
This paper refines the argument of Lehman by reducing the size of the constants in Turing's method. This improvement is given in Theorem 1 and scope for further improvements is also given. Analogous improvements to Dirichlet L-functions and Dedekind zeta-functions are also included.
Lester Ingber
Previous papers have developed a statistical mechanics of neocortical interactions (SMNI) fit to short-term memory and EEG data. Adaptive Simulated Annealing (ASA) has been developed to perform fits to such nonlinear stochastic systems. An N-dimensional path-integral algorithm for quantum systems, qPATHINT, has been developed from classical PATHINT. Both fol
Ofer Aharony, Eyal Karzbrun
We study the low-energy effective action on confining strings (in the fundamental representation) in SU(N) gauge theories in D space-time dimensions. We write this action in terms of the physical transverse fluctuations of the string. We show that for any D, the four-derivative terms in the effective action must exactly match the ones in the Nambu-Goto actio
H. Zhang, D. Y. Tang, L. M. Zhao, X. Wu
We report on the experimental observation of stable dark solitons in an all normal dispersion fiber laser. We found experimentally that dark soliton formation is a generic feature of the fiber laser under strong continuous wave (CW) emission. However, only under appropriate pump strength and negative cavity feedback, stable single or multiple dark soliton co
K. Prasad, B. Sundar Rajan
A single source network is said to be memory-free if all of the internal nodes (those except the source and the sinks) do not employ memory but merely send linear combinations of the symbols received at their incoming edges on their outgoing edges. In this work, we introduce network-error correction for single source, acyclic, unit-delay, memory-free network
Horacio E. Camblong, Carlos R. Ordonez
The near-horizon conformal symmetry of nonextremal black holes is shown to be a mandatory ingredient for the holographic scaling of the scalar-field contribution to the black hole entropy. This conformal tightness is revealed by semiclassical first-principle scaling arguments through an analysis of the multiplicative factors in the entropy due to the radial
Michal Malinsky, Tommy Ohlsson, He Zhang
We analyze the structure of the non-unitary leptonic mixing matrix in the inverse seesaw model with heavy singlets accessible at the LHC. In this model, unlike in the usual TeV seesaw scenarios, thelow-scale right-handed neutrinos do not suffer from naturalness issues. Underlying correlations among various parameters governing the non-unitarity effects are e
J. J. Halliwell, J. M. Yearsley
In the arrival time problem in quantum mechanics, a standard formula that frequently emerges as the probability for crossing the origin during a given time interval is the current integrated over that time interval. This is semiclassically correct but can be negative due to backflow. Here, we show that this formula naturally arises in a decoherent histories
E. del Valle, D. Sanvitto, A. Amo, F. P. Laussy
We study the dynamics of formation and decay of a condensate of microcavity polaritons. We investigate the relationship between the number of particles, the emission's linewidth and its degree of linear polarization which serves as the order parameter. Tracking the condensate's formation, we show that, even when interactions are negligible, coherence
Jérôme Dedecker, Florence Merlevède, Magda Peligrad
In this paper, we prove maximal inequalities and study the functional central limit theorem for the partial sums of linear processes generated by dependent innovations. Due to the general weights, these processes can exhibit long-range dependence and the limiting distribution is a fractional Brownian motion. The proofs are based on new approximations by a li
QCD with and in nuclei: color transparency and short-range correlations in nuclei - theory, observations, directions for further studies
hep-phMark Strikman
We summarize basic theoretical ideas which let to the observation of the short-range correlations (SRC) in nuclei using hard probes and outline directions for probing quark-gluon structure of SRCs. Implications of the observations of color transparency for processes involving pions are reviewed. Open questions and directions for further studies of color tran
G. Altarelli, F. Feruglio, L. Merlo
In view of the fact that the data on neutrino mixing are still compatible with a situation where Bimaximal mixing is valid in first approximation and it is then corrected by terms of order of the Cabibbo angle, arising from the diagonalization of the charged lepton masses, we construct a model based on the discrete group S4 where those properties are natural
On the energetics of stratified turbulent mixing, irreversible thermodynamics, Boussinesq models, and the ocean heat engine controversy
physics.flu-dynRemi Tailleux
A key issue in stratified turbulence theory concerns the nature of the link between D(APE), the dissipation rate of available potential energy APE, and W_{r,turbulent}, the turbulent rate of change of background gravitational potential energy GPE_r, which are both controlled by molecular diffusion. For Boussinesq fluids with a linear equation of state, this
Carles Bivià-Ausina, Santiago Encinas
We show an effective method to compute the Łojasiewicz exponent of an arbitrary sheaf of ideals of $\OO_X$, where $X$ is a non-singular scheme. This method is based on the algorithm of resolution of singularities.
Cosmological Alfvén waves in the recent CMB data, and the observational bound on the primordial vector perturbation
astro-ph.COJaiseung Kim, Pavel Naselsky
In the presence of the primordial magnetic field, initial vector (vorticity) perturbations produce cosmological Alfven waves and leave imprints on cosmic microwave background (CMB) temperature and polarization anisotropy. We have investigated imprints of cosmological Alfven waves in CMB anisotropy. For data constraints, we have used the power spectrum of the
Csaba Szántó
We deduce using the Ringel-Hall algebra approach explicit formulas for the cardinalities of some Grassmannians over a finite field associated to the Kronecker quiver. We realize in this way a quantification of the formulas obtained by Caldero and Zelevinsky for the Euler characteristics of these Grassmannians. We also present a recursive algorithm for comput
Thilo Henrich
We give a complete description of the cluster-mutation classes of diagrams of Dynkin types \mathbb{A},\mathbb{B},\mathbb{D} and of affine Dynkin types \mathbb{B}^{(1)},\mathbb{C}^{(1)},\mathbb{D}^{(1)} via certain families of diagrams.
Yuji Koike, Tetsuya Tomita
We study the single transverse spin asymmetry for the inclusive pion production in the nucleon-nucleon collision, p^\uparrow p\toπX, based on the twist-3 mechanism in the collinear factorization. We derive the soft-fermion-pole (SFP) contribution to the twist-3 single-spin-dependent cross section associated with the twist-3 quark-gluon correlation functions
Xian Gao, Bin Hu
We investigate the primordial trispectra of the general multifield DBI inflationary model. In contrast with the single field model, the entropic modes can source the curvature perturbations on the super horizon scales, so we calculate the contributions from the interaction of four entropic modes mediating one adiabatic mode to the trispectra, at the large tr
Nonsingular plane filling curves of minimum degree over a finite field and their automorphism groups: Supplements to a work of Tallini
math.AGMasaaki Homma, Seon Jeong Kim
Our concern is a nonsingular plane curve defined over a finite field of q elements which includes all the rational points of the projective plane over the field. The possible degree of such a curve is at least q+2. We prove that nonsingular plane curves of degree q+2 having the property actually exist. More precisely, we write down explicitly all of those cu
An-Ping Li
In this paper, we will continue to estmate g_1(n|m) for general n and m.
Low-Temperature Heat Transport in the Low-Dimensional Quantum Magnet NiCl_{2}-4SC(NH_{2})_{2}
cond-mat.str-elX. F. Sun, W. Tao, X. M. Wang, C. Fan
We report a study of the low-temperature thermal conductivity of NiCl_{2}-4SC(NH_{2})_{2}, which is a spin-1 chain system exhibiting the magnon Bose-Einstein condensation (BEC) in magnetic field. It is found that the low-T thermal conductivity along the spin-chain direction shows strong anomalies at the lower and upper critical fields of the magnon BEC state
Oleg R. Musin
The classical Hurwitz theorem says that if n first "harmonics" (2n + 1 Fourier coefficients) of a continuous function f(x) on the unit circle are zero, then f(x) changes sign at least 2n + 1 times. We show that similar facts and its converse hold for any function that are orthogonal to a Chebyshev system. These theorems can be extended for convex cur
Zeyong Wei, Hongqiang Li, Chao Wu, Zhihong Hang
We show that a hybrid metamaterial slab comprising of an one-dimensional array of two different types of cavities exhibits ferrimagnetic-like surface resonances which can be used to realize interesting phenomena such as directive emission as a consequence of strong angle-dependent reflection phase and the selective coupling of a Gaussian incident beam into a
A proposed experimental method to determine $α$-sensitivity of splitting between ground and 7.6 eV isomeric states in Th-229
physics.atom-phJ. C. Berengut, V. A. Dzuba, V. V. Flambaum, S. G. Porsev
The 7.6 eV electromagnetic transition between the nearly degenerate ground state and first excited state in the Th-229 nucleus may be very sensitive to potential changes in the fine-structure constant, $α= e^2/\hbar c$. However, the sensitivity is not known, and nuclear calculations are currently unable to determine it. We propose measurements of the differe
Jian Song, Ben Weinkove
We investigate the metric behavior of the Kahler-Ricci flow on the Hirzebruch surfaces, assuming the initial metric is invariant under a maximal compact subgroup of the automorphism group. We show that, in the sense of Gromov-Hausdorff, the flow either shrinks to a point, collapses to $\mathbb{P}^1$ or contracts an exceptional divisor, confirming a conjectur
Test of Universal Rise of Hadronic Total Cross Sections based on pi p, Kp and pbar p,pp Scatterings
hep-phMuneyuki Ishida, Keiji Igi
Recently there are several evidences of the hadronic total cross section sigma(tot) to be proportional to B (log s)2 consistent with the Froissart unitarity bound. The COMPETE collaborations have further assumed sigma(tot) = B (log s/s0)2 + Z to extend its universal rise with the common value of B and s0 for all hadronic scatterings to reduce the number of a
Transverse momentum distributions of quarks in the nucleon from the Chiral Quark Soliton Model
hep-phM. Wakamatsu
We report the first calculation of the simplest but most fundamental transverse momentum dependent (TMD) distribution of quarks in the nucleon, i.e. the time-reversal-even unpolarized TMD quark and antiquark distribution with isoscalar combination, within the framework of the chiral quark soliton model. The nonperturbative account of the deformed Dirac-sea q
Jean-Marie Barbaroux, Thomas Chen, Semjon Vugalter, Vitali Vougalter
In this paper, we determine the exact expression for the hydrogen binding energy in the Pauli-Fierz model up to the order $O(α^5\logα^{-1})$, where $α$ denotes the finestructure constant, and prove rigorous bounds on the remainder term of the order $o(α^5\logα^{-1})$. As a consequence, we prove that the binding energy is not a real analytic function of $α$,
S. C. Tripathy, K. Jain, F. Hill
We investigate the variation of high-degree mode frequencies as a local response to the active regions in two different phases of the solar activity cycle. We find that the correlation between frequency shifts and the surface magnetic activity measured locally are significantly different during the two activity periods.
V. Golyshev
We introduce a canonical strip hypothesis for Fano varieties. We show that the canonical strip hypothesis for a Fano variety implies that the zeros of the Hilbert polynomial of embedded Calabi--Yau and general type hypersurfaces are located on a vertical line. This extends, in particular, Villegas's `polynomial RH' for intersections in projective spa
Different mechanisms for efficient optical transmission through bilayered subwavelength patterned metal films
physics.opticsJian Wang, Yong Zeng, Xiaoshuang Chen, Wei Lu
Light transmission through bilayered thin metal films perforated with subwavelength hole arrays are numerically studied based on a full-vector finite-difference time-domain approach. A variety of transmission peaks originating from different physical mechanisms are observed. In addition to the direct tunnelling and Fabry-Pèrot resonances, generally possessed
Variation of Oscillation Mode Parameters over the Solar Cycle 23: An Analysis on Different Time Scales
astro-ph.SRS. C. Tripathy, F. Hill, K. Jain, J. W. Leibacher
We investigate the variation in the mode parameters obtained from time series of length 9, 36, 72 and 108 days to understand the changes occurring on different time-scales. The regression analysis between frequency shifts and activity proxies indicates that the correlation and slopes are correlated and both increase in going from time series of 9 to 108 days
Juan Carlos Degollado, Dario Nunez, Carlos Palenzuela
The explicit form of perturbation equation for the $Ψ_4$ Weyl scalar, containing the matter source terms, is derived for general type D spacetimes. It is described in detail the particular case of the Schwarzschild spacetime using in-going penetrating coordinates. As a practical application, we focused on the emission of gravitational waves when a black hole
A lack of close binaries among hot horizontal branch stars in globular clusters - M80 and NGC5986
astro-ph.GAC. Moni Bidin, S. Moehler, G. Piotto, Y. Momany
Recent investigations have revealed a surprising lack of close binaries among extreme horizontal branch (EHB) stars in the globular cluster NGC6752, at variance with the analogous sdB field stars. Another puzzling result concerns the derived spectroscopic masses for some EHB stars. The present paper extends our study of NGC6752 to M80 and NGC5986. Twenty-one
Jia Shao, Sergey V. Buldyrev, Lidia A. Braunstein, Shlomo Havlin
In a network, we define shell $\ell$ as the set of nodes at distance $\ell$ with respect to a given node and define $r_\ell$ as the fraction of nodes outside shell $\ell$. In a transport process, information or disease usually diffuses from a random node and reach nodes shell after shell. Thus, understanding the shell structure is crucial for the study of th
N. Cardiel
In many astronomical problems one often needs to determine the upper and/or lower boundary of a given data set. An automatic and objective approach consists in fitting the data using a generalised least-squares method, where the function to be minimized is defined to handle asymmetrically the data at both sides of the boundary. In order to minimise the cost
Valery Borovikov, Andrew Zangwill
We use kinetic Monte Carlo simulations to understand growth- and etching-induced step bunching of 6H-SiC{0001} vicinal surfaces oriented towards [1-100] and [11-20]. By taking account of the different rates of surface diffusion on three inequivalent terraces, we reproduce the experimentally observed tendency for single bilayer height steps to bunch into half
A. Curioni, B. T. Fleming, W. Jaskierny, C. Kendziora
A filter system for removing electronegative impurities from liquid argon is described. The active components of the filter are adsorbing molecular sieve and activated-copper-coated alumina granules. The system is capable of purifying liquid argon to an oxygen-equivalent impurity concentration of better than 30 parts per trillion, corresponding to an electro
Yuriy E. Kuzovlev
An universal exact description of kinetics of open quantum systems in terms of random wave functions and stochastic Schrödinger equation is suggested. It is shown that evolution of random quantum states of an open system is unitary on average, and this implies validity of the optical theorem for any inelastic scattering.
The CDF collaboration, T. Aaltonen
We report a search for narrow resonances, produced in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV, that decay into muon pairs with invariant mass between 6.3 and 9.0 GeV/c^2. The data, collected with the CDF~II detector at the Fermilab Tevatron collider, correspond to an integrated luminosity of 630 pb$^{-1}$. We use the dimuon invariant mass distribution t
Bin Zhang
Kinetic equilibration during the early stage of a relativistic heavy ion collision is studied using a radiative transport model. Thermalization is found to dominate over expansion with medium regulated cross sections. Pressure anisotropy shows an approximate alpha_s scaling when radiative processes are included. It approaches an asymptotic time evolution on
Andreas Karch, Piotr Surowka, Ethan G. Thompson
We study defects in non-relativistic conformal field theories. As in the well-studied case of relativistic conformal defects, we find that a useful tool to organize correlation functions is the defect operator expansion (dOPE). We analyze how the dOPE is implemented in theories with a holographic dual, highlighting some interesting aspects of the operator/st
M. Cantiello, N. Langer, I. Brott, A. de Koter
We study the convection zones in the outer envelope of hot massive stars which are caused by opacity peaks associated with iron and helium ionization. We determine the occurrence and properties of these convection zones as function of the stellar parameters. We then confront our results with observations of OB stars. A stellar evolution code is used to compu
Photoproduction of J/psi and of high mass e+e- in ultra-peripheral Au+Au collisions at sqrt(s_NN) = 200 GeV
nucl-exPHENIX Collaboration, A. Afanasiev
We present the first measurement of photoproduction of J/psi and of two-photon production of high-mass e+e- pairs in electromagnetic (or ultra-peripheral) nucleus-nucleus interactions, using Au+Au data at sqrt(s_NN) = 200 GeV. The events are tagged with forward neutrons emitted following Coulomb excitation of one or both Au^{star} nuclei. The event sample co
Kevork N. Abazajian
There exists considerable interest in dark matter candidates that can reduce cosmological structure at sub-galactic scales through a suppression of the power spectrum of primordial perturbations as well as have a primordial velocity distribution to produce cores in the smallest-scale dwarf halos. Light keV-mass-scale sterile neutrinos can be such a "warm
Joseph F. Traub
This paper was presented on the occasion of an honorary doctoral degree for Henryk Wozniakowski at Friedrich Schiller University in Jena, Germany on June 6, 2008. Information-based complexity (IBC) is the study of algorithms and computational complexity of continuous problems. Examples of such problems include partial differential equations (in particular, t
Dephasing by electron-electron interactions in a ballistic Mach-Zehnder interferometer
cond-mat.mes-hallClemens Neuenhahn, Florian Marquardt
We consider a ballistic Mach-Zehnder interferometer for electrons propagating chirally in one dimension (such as in an integer Quantum Hall effect edge channel). In such a system, dephasing occurs when the finite range of the interaction potential is taken into account. Using the tools of bosonization, we discuss the decay of coherence as a function of propa
Hilário Alencar, Walcy Santos, Detang Zhou
We consider the integrals of $r$-mean curvatures $S_r$ of a complete hypersurface $M$ in space forms $\mathcal{Q}_c^{n+1}$ which generalize volume $(r=0)$, total mean curvature $(r=1)$, total scalar curvature $(r=2)$ and total curvature $(r=n)$. Among other results we prove that a complete properly immersed hypersurface of a space form with $S_r\geq 0$, $S_r
E. Carquin, M. E. Gomez, J. Rodriguez-Quintero, S. Lola
The WMAP dark matter constraints on b-$\tau$ Yukawa Unification in the presence of massive neutrinos is revisited. The predictions for the bottom quark mass are observed to be modified by the large neutrino mixing suggested by the data. This enables Yukawa unification also for large $\tan\beta$, and for positive $\mu$ that were previously disfavoured. Conseq
Eliana Zoque
We study the variety of n by n matrices with commutator of rank at most one. We describe its irreducible components; two of them correspond to the pairs of commuting matrices, and n-2 components of smaller dimension corresponding to the pairs of rank one commutator. In our proof we define a map to the zero fiber of the Hilbert scheme of points and study the
Victor Tapia
We obtain the evolution equations for the Riemann tensor, the Ricci tensor and the scalar curvature induced by the mean curvature flow. The evolution for the scalar curvature is similar to the Ricci flow, however, negative, rather than positive, curvature is preserved. Our results are valid in any dimension.
Classification of All Noncommutative Polynomials Whose Hessian Has Negative Signature One and A Noncommutative Second Fundamental Form
math.FAHarry Dym, Jeremy M. Greene, J. William Helton, Scott A. McCullough
Every symmetric polynomial p(x)=p(x_1,...,x_g) (with real coefficients) in g noncommuting variables x_1, ..., x_g can be written as a sum and difference of squares of noncommutative polynomials. Let s(p), the negative signature of p, denote the minimum number of negative squares used in this representation, and let the noncommutative Hessian of p be defined
Alexander Stroeer, Jordan Camp
The Ninja data analysis challenge allowed the study of the sensitivity of data analysis pipelines to binary black hole numerical relativity waveforms in simulated Gaussian noise at the design level of the LIGO observatory and the VIRGO observatory. We analyzed NINJA data with a pipeline based on the Hilbert Huang Transform, utilizing a detection stage and a
Kangjun Seo, Chen Fang, B. Andrei Bernevig, Jiangping Hu
We show that features of the dynamical spin susceptibility can unambiguously distinguish between different pairing symmetries of the superconducting state in iron-based superconductors. A magnetic resonance is a unique feature for the extended $s_{x^2y^2}$-wave $\cos k_x\cos k_y$ pairing symmetry. It is present in the pure superconducting (SC) state, but wea
Roman Gielerak, Marek Sawerwain
The canonical Schmidt decomposition of quantum states is discussed and its implementation to the Quantum Computation Simulator is outlined. In particular, the semiorder relation in the space of quantum states induced by the lexicographic semiorder of the space of the Schmidt coefficients is discussed. The appropriate sorting algorithms on the corresponding P