May 2008 arXiv papers — page 12
Showing 1,101–1,200 of 4,900 papers
Cohen-Macaulay clutters with combinatorial optimization properties and parallelizations of normal edge ideals
math.ACLuis A. Dupont, Enrique Reyes-Espinoza, Rafael H. Villarreal
Let C be a uniform clutter and let I=I(C) be its edge ideal. We prove that if C satisfies the packing property (resp. max-flow min-cut property), then there is a uniform Cohen-Macaulay clutter C1 satisfying the packing property (resp. max-flow min-cut property) such that C is a minor of C1. For arbitrary edge ideals of clutters we prove that the normality pr
Sanjay Kumar
A large conformational change in the reaction co-ordinate and the role of the solvent in the formation of base-pairing are combined to settle a long standing issue {\it i.e.} prediction of re-entrance in the force induced transition of DNA. A direct way to observe the re-entrance, i.e a strand goes to the closed state from the open state and again to the ope
Marc Henneaux, Daniel Persson, Daniel H. Wesley
We present a systematic study of the cosmological billiard structures of Einstein-p-form systems in which all spatial directions are compactified on a manifold of nontrivial topology. This is achieved for all maximally oxidised theories associated with split real forms, for all possible compactifications as defined by the de Rham cohomology of the internal m
Note on recent measurements of the $ψ(1S)\to\ga η_C(1S)$ and $ψ(2S)\to\ga η_C(1S)$ branching ratios
hep-phStanley F. Radford, Wayne W. Repko
Recently published measurements of the branching ratios ${\cal B}(ψ(1S)\to\ga η_C(1S))$ and ${\cal B}(ψ(2S)\to\ga η_C(1S))$ by the CLEO collaboration are examined in the context of a potential model that includes both relativistic and one-loop QCD corrections to the quark-antiquark interaction. The prediction for the width $Γ(ψ(1S)\to\ga η_C(1S))$ is in exce
Danilo Silva, Frank R. Kschischang
The problem of error correction in both coherent and noncoherent network coding is considered under an adversarial model. For coherent network coding, where knowledge of the network topology and network code is assumed at the source and destination nodes, the error correction capability of an (outer) code is succinctly described by the rank metric; as a cons
Gui-Jun Ding, Wei Huang, Jia-Feng Liu, Mu-Lin Yan
The proximity of ${\rm Z}^+(4430)$ to the ${\rm D^{*}\bar{D}_1}$ threshold suggests that it may be a ${\rm D^{*}\bar{D}_1}$ molecular state. The ${\rm D^{*}\bar{D}_1}$ system has been studied dynamically from quark model, and state mixing effect is taken into account by solving the multichannel Schr$\ddot{\rm o}$dinger equation numerically. We suggest the mo
A Classical Analogue to the Standard Model, Chapter 3: Standard Model particle spectrum from scalar fields on $\mathbb{C}^{\wedge 18}$
physics.gen-phR. N. C. Pfeifer
The $\mathbb{C}^{\wedge 2\mathfrak{n}}$ models are analogue models which generate Lagrangians for quasiparticles on $\mathbb{R}^{1,3}$ from antisymmetric vector products on Grassmann manifolds. This paper introduces $\mathbb{C}^{\wedge 18}$, the smallest member of this series which is capable of hosting a quasiparticle spectrum analogous to the Standard Mode
Masato Minamitsuji
We discuss the comsological evolution of a brane in the $D(>6)$-dimensional black brane spacetime in the context of the Kaluza-Klein (KK) braneworld scheme, i.e., to consider KK compactification on the brane. The bulk spacetime is composed of two copies of a patch of $D$-dimensional black three-brane solution. The near-horizon geometry is given by $AdS_{5}\t
G. Lamer, M. Hoeft, J. Kohnert, A. Schwope
In the distant universe X-ray luminous clusters of galaxies are rare objects. Large area surveys are therefore needed to probe the high luminosity end of the cluster population at redshifts z >= 1. We correlated extended X-ray sources from the second XMM-Newton source catalogue (2XMM) with the SDSS in order to identify new clusters of galaxies. Distant clust
An Imprint of Super-Structures on the Microwave Background due to the Integrated Sachs-Wolfe Effect
astro-phBenjamin R. Granett, Mark C. Neyrinck, István Szapudi
We measure hot and cold spots on the microwave background associated with supercluster and supervoid structures identified in the Sloan Digital Sky Survey Luminous Red Galaxy catalog. The structures give a compelling visual imprint, with a mean temperature deviation of 9.6 +/- 2.2 microK, i.e. above 4 sigma. We interpret this as a detection of the late-time
I. Bezsudnov, A. Snarskii
Introduced and investigated new kind of percolation problem - so called internal percolation problem (IP). In usual percolation problem current flows from top to bottom of the system and here it can be called as external percolation problem (EP) despite of the IP case when voltage is applied to the system through bars which are inside of the hole in system.
Gabriella Böhm
This is a preprint version of a chapter for Handbook of Algebra.
Tuning the effective fine structure constant in graphene: opposing effects of dielectric screening on short- and long-range potential scattering
cond-mat.mtrl-sciC. Jang, S. Adam, J. -H. Chen, E. D. Williams
We reduce the dimensionless interaction strength in graphene by adding a water overlayer in ultra-high vacuum, thereby increasing dielectric screening. The mobility limited by long-range impurity scattering is increased over 30 percent, due to the background dielectric constant enhancement leading to reduced interaction of electrons with charged impurities.
Ilya Berdnikov, P. Coleman, Steven H. Simon
We propose an experiment to explore the magnetic phase transitions in interacting fermionic Hubbard systems, and describe how to obtain the ferromagnetic phase diagram of itinerant electron systems from these observations. In addition signatures of ferromagnetic correlations in the observed ground states are found: for large trap radii (trap radius $R_T > 4$
David Dunn, James P. Crutchfield
Rapidly expanding insect populations, deforestation, and global climate change threaten to destabilize key planetary carbon pools, especially the Earth's forests which link the micro-ecology of insect infestation to climate. To the extent mean temperature increases, insect populations accelerate deforestation. This alters climate via the loss of active c
A. Lewis Licht
We consider the unparticle action that is made gauge invariant by inclusion of an open Wilson line factor. In deriving vertexes from such an action it has been customary to use a form of differentiating the Wilson line originally proposed by Mandelstam. Using a simple example, we show that the Mandelstam derivative is mathematically inconsistent. We show tha
Nikolaos Kidonakis, Ramona Vogt
We present results for the top quark pair cross section at the Tevatron and the LHC. We use the resummed double differential cross section, employing the fully kinematics-dependent soft anomalous dimension matrices, to calculate the soft-gluon contributions at next-to-next-to-leading order (NNLO). We improve and update our previous estimates by refining our
Muyoung Heo, Konstantin B. Zeldovich, Eugene I. Shakhnovich
How does immune system evolve functional proteins - potent antibodies - in such a short time? We address this question using a microscopic, protein-level, sequence-based model of humoral immune response with explicitly defined interactions between Immunoglobulins, host and pathogen proteins. Potent Immunoglobulins are discovered in this model via clonal sele
Impact ionization fronts in semiconductors: superfast propagation due to "nonlocalized" preionization
cond-mat.mtrl-sciPavel Rodin, Andey Minarsky, Igor Grekhov
We discuss a new mode of ionization front passage in semiconductor structures. The front of avalanche ionization propagates into an intrinsic semiconductor with a constant electric field $E_{\rm m}$ in presence of a small concentration of free nonequilibrium carriers - so called preionization. We show that if the profile of these initial carriers decays in t
The Use of Labeled Cortical Distance Maps for Quantization and Analysis of Anatomical Morphometry of Brain Tissues
stat.COE. Ceyhan, M. Hosakere, T. Nishino, J. Alexopoulos
Anatomical shape differences in cortical structures in the brain can be associated with various neuropsychiatric and neuro-developmental diseases or disorders. Labeled Cortical Distance Map (LCDM), can be a powerful tool to quantize such morphometric differences. In this article, we investigate various issues regarding the analysis of LCDM distances in relat
Kun-Feng Shie, James M. Nester, Hwei-Jang Yo
Investigations of the dynamic modes of the Poincare gauge theory of gravity found only two good propagating torsion modes; they are effectively a scalar and a pseudoscalar. Cosmology affords a natural situation where one might see observational effects of these modes. Here we consider only the ``scalar torsion'' mode. This mode has certain distinctiv
H. Bercovici, R. G. Douglas, C. Foias
A new functional model for pairs of commuting isometries is described. Intertwining operators between such models are then studied in order to approach the classification of invariant subspaces of such pairs.
K. Triantafyllopoulos
Bayesian inference is developed for matrix-variate dynamic linear models (MV-DLMs), in order to allow missing observation analysis, of any sub-vector or sub-matrix of the observation time series matrix. We propose modifications of the inverted Wishart and matrix $t$ distributions, replacing the scalar degrees of freedom by a diagonal matrix of degrees of fre
Nicola Garofalo, Niko Marola
We establish sharp estimates for the $p$-capacity of metric rings with unrelated radii in metric measure spaces equipped with a doubling measure and supporting a Poincaré inequality. These estimates play an essential role in the study of the local behavior of \p-harmonic Green's functions.
Adriano Mosca Conte, Emiliano Ippoliti, Rodolfo Del Sole, Paolo Carloni
Spectral properties of chromophores are used to probe complex biological processes in vitro and in vivo, yet how the environment tunes their optical properties is far from being fully understood. Here we present a method to calculate such properties on large scale systems, like biologically relevant molecules in aqueous solution. Our approach is based on man
Metin Gurses, Ismagil Habibullin, Kostyantyn Zheltukhin
The concept of integrable boundary conditions is applied to hydrodynamic type systems. Examples of such boundary conditions for dispersionless Toda systems are obtained. The close relation of integrable boundary conditions with integrable reductions of multi-field systems is observed. The problem of consistency of boundary conditions with the Hamiltonian for
Jae-Weon Lee, Sooil Lim, Dale Choi
We suggest that the dark matter model based on Bose Einstein condensate or scalar field can resolve the apparently contradictory behaviors of dark matter in the Abell 520 and the Bullet cluster. During a collision of two galaxies in the cluster, if initial kinetic energy of the galaxies is large enough, two dark matter halos pass each other in a soliton-like
Marco Luca Rossi
The activities carried out by Italian physicists in the field of semiconductor physics during the period spanning from 1945 to the foundation of the National Group of Structure of the Matter (GNSM, 1965) are reviewed within their historical context. Until the fifties, the Italian research was only marginally involved, if at all, in the main streams of advanc
Rudolf Gorenflo, Francesco Mainardi
We introduce the linear operators of fractional integration and fractional differentiation in the framework of the Riemann-Liouville fractional calculus. Particular attention is devoted to the technique of Laplace transforms for treating these operators in a way accessible to applied scientists, avoiding unproductive generalities and excessive mathematical r
Jochen Rau
In this didactical note I review in depth the rationale for using generalised canonical distributions in quantum statistics. Particular attention is paid to the proper definitions of quantum entropy and quantum relative entropy, as well as to quantum state reconstruction on the basis of incomplete data. There are two appendices in which I outline how general
B. S. Acharya, F. Cavallari, G. Corcella, R. Di Sipio
The large ttbar production cross-section at the LHC suggests the use of top quark decays to calibrate several critical parts of the detectors, such as the trigger system, the jet energy scale and b-tagging.
A. V. Volotka, D. A. Glazov, G. Plunien, V. M. Shabaev
The effect of finite nuclear mass on the magnetic-dipole transition probabilities between fine-structure levels of the same term is investigated. Based on a rigorous QED approach a nonrelativistic formula for the recoil correction to first order in m_e/M is derived. Numerical results for transitions of experimental interest are presented.
tsachik gelander
The purpose of this note is to present two elementary, but useful, facts concerning actions on uniformly convex spaces. We demonstrate how each of them can be used in an alternative proof of the triviality of the first $L_p$-cohomology of higher rank simple Lie groups, proved in [BFGM].
Jean-Louis Tane
The first part of this paper is a summary of a hypothesis previously advanced, suggesting the existence of a close link between thermodynamics and relativity. The second part is a preliminary comment about some possible consequences in the fields of physics, astronomy and biology.
Zhibin Yan
Convergence of the solutions of nonhomogeneous linear singularly perturbed systems to that of the corresponding reduced singular system on the half-line [0, $\infty $) is considered. To include the situation on a neighborhood of initial instant, a boundary layer, a distributional approach to convergence is adopted. An explicit analytical expression for the l
Francesca Astengo, Bianca Di Blasio, Fulvio Ricci
Let $\Hn$ be the $(2n+1)$-dimensional Heisenberg group and $K$ a compact group of automorphisms of $\Hn$ such that $(K\ltimes \Hn,K)$ is a Gelfand pair. We prove that the Gelfand transform is a topological isomorphism between the space of $K$-invariant Schwartz functions on $\Hn$ and the space of Schwartz function on a closed subset of $\R^s$ homeomorphic to
Xiaoyu Fu
This paper is addressed to a study of the null controllability for the semilinear parabolic equation with a complex principal part. For this purpose, we establish a key weighted identity for partial differential operators $(\a+i\b)\pa_t+\sum\limits_{j,k=1}^n\pa_k(a^{jk}\pa_j)$ (with real functions $\a$ and $\b$), by which we develop a universal approach, bas
Using Chandra to Unveil the High-Energy Properties of the High-Magnetic Field Radio Pulsar J1119-6127
astro-phSamar Safi-Harb, Harsha S. Kumar
(shortened) PSR J1119-6127 is a high magnetic field (B=4.1E13 Gauss), young (<=1,700 year-old), and slow (P=408 ms) radio pulsar associated with the supernova remnant (SNR) G292.2-0.5. In 2003, Chandra allowed the detection of the X-ray counterpart of the radio pulsar, and provided the first evidence for a compact pulsar wind nebula (PWN). We here present ne
I. Cabrera-Munguia, V. S. Manko
We show that any magnetostatic axially symmetric solution of the Einstein-Maxwell equations can be endowed with a specific charged fluid source of the Polanco et al type via a simple procedure requiring the knowledge of exclusively the magnetostatic seed spacetime. Using this procedure we construct yet another exact solution for a massive magnetic dipole sur
L. Jakaite, V. Schetinin
In the last year more than 70,000 people have been brought to the UK hospitals with serious injuries. Each time a clinician has to urgently take a patient through a screening procedure to make a reliable decision on the trauma treatment. Typically, such procedure comprises around 20 tests; however the condition of a trauma patient remains very difficult to b
Craig Calcaterra, Axel Boldt
Linear combinations of translations of a single Gaussian, e^{-x^2}, are shown to be dense in L^2(R). Two algorithms for determining the coefficients for the approximations are given, using orthogonal Hermite functions and least squares. Taking the Fourier transform of this result shows low-frequency trigonometric series are dense in L^2 with Gaussian weight
A. del Campo
The momentum distribution of an expanding cloud of one-dimensional hard-core anyons is studied by an exact numerical approach, and shown to become indistinguishable from that of a non-interacting spin-polarized Fermi gas for large enough times (dynamical fermionization). We also consider the expansion of one-dimensional anyons with strongly attractive short-
T. Antal, P. L. Krapivsky, S. Redner
We investigate the collision cascade that is generated by a single moving incident particle on a static hard-sphere gas. We argue that the number of moving particles at time t grows as t^{xi} and the number collisions up to time t grows as t^{eta}, with xi=2d/(d+2) and eta=2(d+1)/(d+2) and d the spatial dimension. These growth laws are the same as those from
J. M. Ancochea Bermudez, J. Fresan, Juan Margalef-Bentabol
In this paper we classify the laws of three-dimensional and four-dimensional nilpotent Jordan algebras over the field of complex numbers. We describe the irreducible components of their algebraic varieties and extend contractions and deformations among them. In particular, we prove that J2 and J3 are irreducible and that J4 is the union of the Zariski closur
A. Arcones, G. Martinez-Pinedo, E. O'Connor, A. Schwenk
We study the composition of the outer layers of a protoneutron star and show that light nuclei are present in substantial amounts. The composition is dominated by nucleons, deuterons, tritons and alpha particles; 3He is present in smaller amounts. This composition can be studied in laboratory experiments with new neutron-rich radioactive beams that can repro
V. Ya. Kravchenko
E. M. Chudnovsky has recently posted on the ArXive his Reply (arXiv:0805.2918) to my Comment (Phys. Rev. Lett. 100, 199703 (2008)) on his recent Letter (E. M. Chudnovsky, Phys. Rev. Lett. 99, 206601 (2007)). In order to avoid possible misunderstandings in the evaluation of his Letter, I am posting my Comment with some remarks on the contents of his Reply.
S. Wallentowitz, A. B. Klimov
A model of photo-detection using a Bose--Einstein condensate in an atom-chip based micro trap is analyzed. Atoms absorb photons from the incident light field, receive part of the photon momentum and leave the trap potential. Upon counting of escaped atoms within predetermined time intervals, the photon statistics of the incident light is mapped onto the atom
Slow-roll, acceleration, the Big Rip and WKB approximation in NLS-type formulation of scalar field cosmology
gr-qcBurin Gumjudpai
Aspects of non-linear Schrödinger-type (NLS) formulation of scalar (phantom) field cosmology on slow-roll, acceleration, WKB approximation and Big Rip singularity are presented. Slow-roll parameters for the curvature and barotropic density terms are introduced. We reexpress all slow-roll parameters, slow-roll conditions and acceleration condition in NLS form
Theerakarn Phetnora, Roongtum Sooksan, Burin Gumjudpai
We describe non-flat standard Friedmann cosmology of canonical scalar field with barotropic fluid in form of non-linear Schrödinger-type (NLS) formulation in which all cosmological dynamical quantities are expressed in term of Schrödinger quantities as similar to those in time-independent quantum mechanics. We assume the expansion to be superfast, i.e. phant
J. F. Leandro, F. L. Semião
In this paper, we use the Weisskopf-Wigner theory to study the entanglement in the state of the free-space radiation field produced from vacuum due to atomic decay. We show how bipartite entanglement is shared between different partitions of the radiation modes. We investigate the role played by the size of the partitions and their detuning with the decaying
O. Sergijenko, B. Novosyadlyj
The features of a homogeneous scalar field $ϕ$ with classical Lagrangian $L=ϕ_{;i}ϕ^{;i}/2-V(ϕ)$ and tachyon field Lagrangian $L=-V(ϕ)\sqrt{1-ϕ_{;i}ϕ^{;i}}$ causing the observable accelerated expansion of the Universe are analyzed. The models with constant equation-of-state parameter $w_{de}=p_{de}/ρ_{de}<-1/3$ are studied. For both cases the fields $ϕ(a)$ a
Steven Weinberg
It is shown that the generating function for tree graphs in the "in-in" formalism may be calculated by solving the classical equations of motion subject to certain constraints. This theorem is illustrated by application to the evolution of a single inflaton field in a Robertson--Walker background.
Muon Spin Rotation Measurements of Heterogeneous Field Response in Overdoped La2-xSrxCuO4
cond-mat.str-elG. J. MacDougall, A. A. Aczel, R. J. Birgeneau, T. Ito
Transverse-field muon spin rotation measurements of overdoped La2-xSrxCuO4 reveal a large broadening of the local magnetic field distribution in response to applied field, persisting to high temperatures. The field-response is approximately Curie-Weiss like in temperature and is largest for the highest doping investigated. Such behaviour is contrary to the c
M. Deak, F. Schwennsen
We calculate and analyze Z and W production in association with quark-antiquark pair in k_T-factorization. Numerical calculations are performed using the Monte Carlo generator CASCADE for proton proton collisions at LHC energy. We compare total and differential cross sections calculated in k_T-factorization approach with total differential cross sections obt
M. Fujikawa, H. Hayashii, S. Eidelman
We report a high-statistics measurement of the branching fraction for tau^- --> pi^- pi^0 nu_tau and the invariant mass spectrum of the produced pi^- pi^0 system using 72.2 fb^-1 of data recorded with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider. The branching fraction obtained is (25.24 +/- 0.01 +/- 0.39)%, where the first error is stat
W. -M. Wang
We prove that in 1-D the growth of Sobolev norms for time-dependent linear Schrödinger equations is at most logarithmic in time for any (fixed) potential which is analytic (or Gevrey). Recently it was proven in [N] that almost surely the Sobolev norms are unbounded, which indicates that the log is almost surely necessary. In [W], the author showed that the S
Róbert Juhász
A class of cubic networks composed of a regular one-dimensional lattice and a set of long-range links is introduced. Networks parametrized by a positive integer k are constructed by starting from a one-dimensional lattice and iteratively connecting each site of degree 2 with a $k$th neighboring site of degree 2. Specifying the way pairs of sites to be connec
Abraham Broer, Victor Reiner, Larry Smith, Peter Webb
We extend in several directions invariant theory results of Chevalley, Shephard and Todd, Mitchell and Springer. Their results compare the group algebra for a finite reflection group with its coinvariant algebra, and compare a group representation with its module of relative coinvariants. Our extensions apply to arbitrary finite groups in any characteristic.
Nils Dencker
The paper studies the local solvability and subellipticity for square systems of principal type. These are the systems for which the principal symbol vanishes of first order on its kernel. For systems of principal type having constant characteristics, local solvability is equivalent to condition (PSI) on the eigenvalues, see arXiv:0801.4043. This is a condit
Lionel Mason, Arman Taghavi-Chabert
We show that the Euclidean Kerr-NUT-(A)dS metric in $2m$ dimensions locally admits $2^m$ hermitian complex structures. These are derived from the existence of a non-degenerate closed conformal Killing-Yano tensor with distinct eigenvalues. More generally, a conformal Killing-Yano tensor, provided its exterior derivative satisfies a certain condition, algebra
Anton Gerasimov, Dimitri Lebedev, Sergey Oblezin
We identify q-deformed gl(l+1)-Whittaker functions with a specialization of Macdonald polynomials. This provides a representation of q-deformed gl(l+1)-Whittaker functions in terms of Demazure characters of affine Lie algebra \hat{gl(l+1)}. We also define a system of dual Hamiltonians for q-deformed gl(l+1)-Toda chains and give a new integral representation
Bruno Kahn, R. Sujatha
This version corrects a wrong proof of Proposition 6.3.2 and simplifies the exposition in Section 6.
Henrik Bäärnhielm
This thesis contains a collection of algorithms for working with the twisted groups of Lie type known as Suzuki groups, and small and large Ree groups. The two main problems under consideration are constructive recognition and constructive membership testing. We also consider problems of generating and conjugating Sylow and maximal subgroups. The algorithms
Huy Tai Ha, Susan Morey
An ideal I in a Noetherian ring R is normally torsion-free if Ass(R/I^t)=Ass(R/I) for all natural numbers t. We develop a technique to inductively study normally torsion-free square-free monomial ideals. In particular, we show that if a square-free monomial ideal I is minimally not normally torsion-free then the least power t such that I^t has embedded prime
E. Berg, D. Orgad, S. A. Kivelson
Apparently, some form of local superconducting pairing persists to temperatures well above the maximum observed $T_c$ in underdoped cuprates, \textit{i.e.} $T_c$ is suppressed due to the small phase stiffness. With this in mind, we consider the following question -- Given a system with a high pairing scale $Δ_0 $ but with $T_c$ reduced by phase fluctuations,
Stochastic time-dependent current-density functional theory: a functional theory of open quantum systems
cond-mat.str-elR. D'Agosta, M. Di Ventra
The dynamics of a many-body system coupled to an external environment represents a fundamentally important problem. To this class of open quantum systems pertains the study of energy transport and dissipation, dephasing, quantum measurement and quantum information theory, phase transitions driven by dissipative effects, etc. Here, we discuss in detail an ext
Vitaly Schetinin, Dayou Li, Carsten Maple
The use of multiple Decision Models (DMs) enables to enhance the accuracy in decisions and at the same time allows users to evaluate the confidence in decision making. In this paper we explore the ability of multiple DMs to learn from a small amount of verified data. This becomes important when data samples are difficult to collect and verify. We propose an
Fionn Murtagh, Adam Ganz, Stewart McKie
We analyze the style and structure of story narrative using the case of film scripts. The practical importance of this is noted, especially the need to have support tools for television movie writing. We use the Casablanca film script, and scripts from six episodes of CSI (Crime Scene Investigation). For analysis of style and structure, we quantify various c
Matthew L. Terraciano, Mark Bashkansky, Fredrik Fatemi
We demonstrate Faraday spectroscopy with high duty cycle and sampling rate using atoms confined to a blue-detuned optical trap. Our trap consists of a crossed pair of high-charge-number hollow laser beams, which forms a dark, box-like potential. We have used this to measure transient magnetic fields in a 500-micron-diameter spot over a 400 ms time window wit
Stanislaw J. Szarek, Nicole Tomczak-Jaegermann
The Nontrivial Projection Problem asks whether every finite-dimensional normed space of dimension greater than one admits a well-bounded projection of non-trivial rank and corank or, equivalently, whether every centrally symmetric convex body (of arbitrary dimension greater than one) is approximately affinely equivalent to a direct product of two bodies of n
R. S. D. Thomas
This paper continues the refinement of Richard Roth's taxonomy of isonemal weaving designs through types 11--32 of the 39 in order to solve three problems for those designs: which designs exist in various sizes, which prefabrics can be doubled and remain isonemal, and which can be halved and remain isonemal.
Moshe Marcus, Laurent Veron
We construct and study the properties of the precise boundary trace of positive solutions of $-Δu+u^q=0$ in a smooth bounded domain of $\mathbb R^N$, in the supercritical case $q\geq q_c=(N+1)/(N-1)$
Andrey Shishkov, Laurent Veron
Let $h:[0,\infty)\mapsto [0,\infty)$ be continuous and nondecreasing, $h(t)>0$ if $t>0$, and $m,q$ be positive real numbers. We investigate the behavior when $k\to\infty$ of the fundamental solutions $u=u_{k}$ of $\prt_{t} u-Δu^m+h(t)u^q=0$ in $Ω\ti (0,T)$ satisfying $u_{k}(x,0)=kδ_0$. The main question is wether the limit is still a solution of the above eq
Steven Dale Cutkosky, Bernard Teissier
Given a noetherian local domain $R$ and a valuation $ν$ of its field of fractions which is non negative on $R$, we derive some very general bounds on the growth of the number of distinct valuation ideals of $R$ corresponding to values lying in certain parts of the value group $Γ$ of $ν$. We show that this growth condition imposes restrictions on the semigrou
Moshe Marcus, Laurent Veron
We prove bilateral capacitary estimates for the maximal solution $U_F$ of $-Δu+u^q=0$ in the complement of an arbitrary closed set $F\subset\mathbb R^N$, involving the Bessel capacity $C_{2,q'}$, for $q$ in the supercritical range $q\geq q_{c}:=N/(N-2)$. We derive a pointwise necessary and sufficient condition, via a Wiener type criterion, in order that
Patrick T. Underhill, Juan P. Hernández-Ortiz, Michael D. Graham
Populations of swimming microorganisms produce fluid motions that lead to dramatically enhanced diffusion of tracer particles. Using simulations of suspensions of swimming particles in a periodic domain, we capture this effect and show that it depends qualitatively on the mode of swimming: swimmers ``pushed'' from behind by their flagella show greate
Measurement of the Casimir force between a gold sphere and silicon surface with nanoscale trench arrays
quant-phH. B. Chan, Y. Bao, J. Zou, R. A. Cirelli
We report measurements of the Casimir force between a gold sphere and a silicon surface with an array of nanoscale, rectangular corrugations using a micromechanical torsional oscillator. At distance between 150 nm and 500 nm, the measured force shows significant deviations from the pairwise additive formulism, demonstrating the strong dependence of the Casim
Gholamreza Rashedi
In this paper, a dc Josephson junction between two singlet superconductors (d-wave and s-wave) with arbitrary reflection coefficient has been investigated theoretically following the famous paper [ Y. Tanaka and S. Kashiwaya 1996 \textit{Phys. Rev. B} {\bf 53}, R11957]. For the case of High $T_c$ superconductors, the $c$-axes are parallel to an interface wit
Zhibin Yan
Analyzing the order of unobservable impulse in descriptor system leads to a new testing criterion for impulse observability, both the statement and the proof of which use only the original system data.
David Andrieux, Pierre Gaspard
A universal quantum work relation is proved for isolated time-dependent Hamiltonian systems in a magnetic field as the consequence of microreversibility. This relation involves a functional of an arbitrary observable. The quantum Jarzynski equality is recovered in the case this observable vanishes. The Green-Kubo formula and the Casimir-Onsager reciprocity r
Theoretical study of phonon-assisted singlet-singlet relaxation in two-electron semiconductor quantum dot molecules
cond-mat.mes-hallA. Grodecka, P. Machnikowski, J. Förstner
Phonon-assisted singlet-singlet relaxation in semiconductor quantum dot molecules is studied theoretically. Laterally coupled quantum dot structures doped with two electrons are considered. We take into account interaction with acoustic phonon modes via deformation potential and piezoelectric coupling. We show that piezoelectric mechanism for the considered
W. -M. Wang
We prove that the Sobolev norm for a 1-D periodic Schroedinger equation remain bounded under small resonant perturbations.
M. Pasquato, G. Bertin
The globular clusters (GC) of our Galaxy have been found to lie close to a plane in the log(R_e), log(sigma), SB_e space, on the continuation of the Fundamental Plane (FP) known to characterize the properties of early-type galaxies. We reexamine the issue on a sample of 48 GCs selected in terms of homogeneity criteria for the photometric data available from
Rui A. C. Ferreira, Delfim F. M. Torres
We establish some linear and nonlinear integral inequalities of Gronwall-Bellman-Bihari type for functions with two independent variables on general time scales. The results are illustrated with examples, obtained by fixing the time scales to concrete ones. An estimation result for the solution of a partial delta dynamic equation is given as an application.
Pure Point Spectrum of the Floquet Hamiltonian for the Quantum Harmonic Oscillator Under Time Quasi- Periodic Perturbations
math.SPW. -M. Wang
We prove that the $1-d$ quantum harmonic oscillator is stable under spatially localized, time quasi-periodic perturbations on a set of Diophantine frequencies of positive measure. This proves a conjecture raised by Enss-Veselic in their 1983 paper \cite{EV} in the general quasi-periodic setting. The motivation of the present paper also comes from constructio
Bodo Lampe
After a prologue which clarifies some issues left open in my last paper, the main features of the tetron model of elementary particles are discussed in the light of recent developments, in particular the formation of strong and electroweak vector bosons and a microscopic understanding of how the observed tetrahedral symmetry of the fermion spectrum may arise
Period problems for mean curvature one surfaces in $H^3$ (with application to surfaces of low total curvature)
math.DGWayne Rossman, Masaaki Umehara, Kotaro Yamada
We review recent results on classifying complete constant mean curvature 1 (CMC 1) surfaces in hyperbolic 3-space with low total curvature. There are two natural notions of "total curvature" -- one is the total absolute curvature, which is the integral over the surface of the absolute value of the Gaussian curvature, and the other is the dual total a
Wayne Rossman, Masaaki Umehara, Kotaro Yamada
With the developments of the last decade on complete constant mean curvature 1 (CMC 1) surfaces in the hyperbolic 3-space $H^3$, many examples of such surfaces are now known. However, most of the known examples have regular ends. (An end is irregular, resp. regular, if the hyperbolic Gauss map of the surface has an essential singularity, resp. at most a pole
Redouane Al Fakir, William G. Unruh
In light of the discovery of the first-ever double pulsar system, PSR J0737-3039, we re-examine an earlier proposal to directly detect gravity waves from neutron stars, which was predicated on a hypothetical system almost identical to the later discovered double pulsar. We re-derive the effect in more detail, and confirm the initial estimate--sometimes doubt
Hiroyuki Yoshida, Sascha Ahlert, Martin Jansen, Yoshihiko Okamoto
Ag2MnO2 is studied as a possible candidate compound for an antiferromagnetic XY spin model on a triangular lattice. In spite of the large Curie-Weiss temperature of -430 K found in magnetic susceptibi-lity, Mn3+ spins with S = 2 do not undergo a conventional long-range order down to 2 K probably owing to the geometrical frustration and two dimensionality in
T Fukumura, H Toyosaki, K Ueno, M Nakano
Electric and magnetic properties of a high temperature ferromagnetic oxide semiconductor, cobalt-doped rutile TiO2, are summarized. The cobalt-doped rutile TiO2 epitaxial thin films with different electron densities and cobalt contents were grown on r-sapphire substrates with laser molecular beam epitaxy. Results of magnetization, magnetic circular dichroism
Anon Plangprasopchok, Kristina Lerman
Many social Web sites allow users to publish content and annotate with descriptive metadata. In addition to flat tags, some social Web sites have recently began to allow users to organize their content and metadata hierarchically. The social photosharing site Flickr, for example, allows users to group related photos in sets, and related sets in collections.
Bixiang Wang
The existence of a pullback attractor is established for the singularly perturbed FitzHugh-Nagumo system defined on the entire space $R^n$ when external terms are unbounded in a phase space. The pullback asymptotic compactness of the system is proved by using uniform a priori estimates for far-field values of solutions. Although the limiting system has no gl
E. M. Foard, A. J. Wagner
Phase-separation fronts leave in their wakes morphologies that are substantially different from the morphologies formed in homogeneous phase-separation. In this paper we focus on fronts in binary mixtures that are enslaved phase-separation fronts, i.e. fronts that follow in the wake of a control-parameter front. In the one-dimensional case, which is the focu
Yutaka Baba, Nobuyuki Ishibashi, Koichi Murakami
In the OSp invariant closed string field theory, we construct the states corresponding to parallel D-branes that are located at different points in the space-time. Using these states, we evaluate annulus amplitudes. We show that the results coincide with those of first quantized string theory.
Sherry H. F. Yan
This note provide bijective proofs of two combinatorial identities involving generalized Catalan number $C_{m,5}(n)={m\over 5n+m}{5n+m\choose n}$ recently proposed by Sun.
L. Jacoutot, A. G. Kosovichev, A. Wray, N. N. Mansour
The goal of this research is to investigate how magnetic field affects the dynamics of granular convection and excitation of solar oscillations by means of realistic numerical simulations. We have used a 3D, compressible, non-linear radiative magnetohydrodynamics code developed at the NASA Ames Research Center. This code takes into account several physical p
Krzysztof Burdzy, John M. Lee
We prove that a sequence of semi-discrete approximations converges to a multiplicative functional for reflected Brownian motion, which intuitively represents the Lyapunov exponent for the corresponding stochastic flow. The method of proof is based on a study of the deterministic version of the problem and the excursion theory.
Infrared Passbands for Precise Photometry of Variable Stars by Amateur and Professional Astronomers
astro-phEugene F. Milone, Andrew T. Young
The Infrared spectral region is a rich one for variable star work, especially of cooler stars, but it has been hard to do IR photometry because of high, variable background, and specialized telescopic equipment that is usually required to obtain meaningful data. Typically telescopes with IR detectors have been at high elevations, to minimize water vapor abso
Jianhui Wang, A. Iyengar, H. A. Fertig, L. Brey
We investigate integer and half-integer filling states (uniform and unidimensional stripe states respectively) for graphene using the Hartree-Fock approximation. For fixed filling factor, the ratio between the scales of the Coulomb interaction and Landau level spacing $g=(e^2/ε\ell)/(\hbar v_F/\ell)$, with $\ell$ the magnetic length, is a field-independent c