August 2010 arXiv papers — page 25

Yu. D. Fomin, V. N. Ryzhov, E. N. Tsiok

We report a detailed simulation study of the phase behavior of core softened system with attractive well. Different repulsive shoulder widthes and attractive well depthes are considered which allows to monitor the influence of repulsive and attractive forces on the phase diagram of the system. Thermodynamic anomalies in the systems are also studied. It is sh

Fëdor Nazarov, Ekaterina Shulman

\noindent In [1] L. Polterovich and Z. Rudnick considered the behavior of a one-parameter subgroup of a Lie group under the influence of a sequence of kicks. Among others they raise the following problem: {\it is the horocycle flow stably quasi-mixing on $SL(2,\mathbb{R})/Γ$?} Equivalently it can be reformulated in terms of boundedness of the sequences of pr

L. Lesniak, A. Furman, R. Kaminski, P. Zenczykowski

Rare B decays to three charged kaons are analysed. The weak decay amplitudes are derived in the QCD factorization approach. The strong final state interactions between pairs of kaons are described using the kaon scalar and vector form factors. The scalar form factors at low K+K- effective mass distributions are constrained by chiral symmetry and are related

Eugen Hellmann

We show that the Kisin varieties associated to simple $ϕ$-modules of rank $2$ are connected in the case of an arbitrary cocharacter. This proves that the connected components of the generic fiber of the flat deformation ring of an irreducible $2$-dimensional Galois representation of a local field are precisely the components where the multiplicities of the H

H. B. Cao, I. Mirebeau, A. Gukasov, P. Bonville

We have measured neutron diffraction patterns in a single crystal sample of the pyrochlore compound Er$_2$Ti$_2$O$_7$ in the antiferromagnetic phase (T=0.3\,K), as a function of the magnetic field, up to 6\,T, applied along the [110] direction. We determine all the characteristics of the magnetic structure throughout the quantum critical point at $H_c$=2\,T.

Nigel B. Wilding, Peter Sollich

The statistical mechanics of phase transitions in dense systems of polydisperse particles presents distinctive challenges to computer simulation and analytical theory alike. The core difficulty, namely dealing correctly with particle size fractionation between coexisting phases, is set out in the context of a critique of previous simulation work on such syst

Youssef Maliki

we study on compact Riemannian manifolds with boundary, the problems of existence and multiplicity of solutions to a Neumann problem involving the p-Laplacian operator and critical Sobolev exponents.

C. M. S. Gannarelli, D. M. Silevitch, T. F. Rosenbaum, G. Aeppli

We simulate the dc magnetic response of the diluted dipolar-coupled Ising magnet LiHo\(_{0.045}\)Y\(_{0.955}\)F\(_4\) in a transverse field, using exact diagonalization of a two-spin Hamiltonian averaged over nearest-neighbour configurations. The pairwise model, incorporating hyperfine interactions, accounts for the observed drop-off in the longitudinal (c-a

I. Mirebeau, G. Parette

We have performed new neutron diffuse scattering measurements in Fe$_{1-x}$Cr$_x$ solid solutions, in a concentration range 0$<$x$<$0.15, where the atomic distribution shows an inversion of the short range order. By optimizing the signal-background ratio, we obtain an accurate determination of the concentration of inversion x$_0$ =0.110(5). We determine the

L. Fricke, S. Serrano-Guisan, H. W. Schumacher

We numerically study ultra fast resonant spin torque (ST) magnetization reversal in magnetic tunnelling junctions (MTJ) driven by current pulses having a direct current (DC) and a resonant alternating current (AC) component. The precessional ST dynamics of the single domain MTJ free layer cell are modelled in the macro spin approximation. The energy efficien

Yupeng Chen, Shu Zhang, Diego F. Torres, Jianmin Wang

We analyze the RXTE observations of the 2009 outburst of H~1743-322, as well as the observations of the previous five outbursts for comparison. The hardness-intensity diagram (HID) shows a complete counter-clockwise q-track for the 2009 outburst and, interestingly, the track falls in} between a huge one in 2003, with a complete transition to high/soft state,

G. Ciaramicoli, I. Marzoli, P. Tombesi

The new generation of planar Penning traps promises to be a flexible and versatile tool for quantum information studies. Here, we propose a fully controllable and reversible way to change the typical trapping harmonic potential into a double-well potential, in the axial direction. In this configuration a trapped particle can perform coherent oscillations bet

Tilman Zibold, Eike Nicklas, Christian Gross, Markus K. Oberthaler

We report on the experimental realization of an internal bosonic Josephson junction in a Rubidium spinor Bose-Einstein condensate. The measurement of the full time dynamics in phase space allows the characterization of the theoretically predicted $π$-phase modes and quantitatively confirms analytical predictions, revealing a classical bifurcation. Our result

Ying-Chang Liang, Guangming Pan, Yonghong Zeng

In recent years, some spectrum sensing algorithms using multiple antennas, such as the eigenvalue based detection (EBD), have attracted a lot of attention. In this paper, we are interested in deriving the asymptotic distributions of the test statistics of the EBD algorithms. Two EBD algorithms using sample covariance matrices are considered: maximum eigenval

S. Campana, R. Salvaterra, G. Tagliaferri, C. Kouveliotou

Gamma-Ray Bursts (GRBs) are the most violent explosions in the Universe. Long duration GRBs are associated with the collapse of massive stars, rivaling their host galaxies in luminosity. The discovery of the most distant spectroscopically confirmed object in the Universe, GRB090423, opened a new window on the high redshift Universe, making it possible to stu

L. L. Ma, Y. X. Bai, Z. Cao, M. J. Chen

The Large High Altitude Air Shower Observatory project is proposed to study high energy gamma ray astronomy ( 40 GeV-1 PeV ) and cosmic ray physics ( 20 TeV-1 EeV ). The wide field of view Cherenkov telescope array, as a component of the LHAASO project, will be used to study energy spectrum and compositions of cosmic ray by measuring the total Cherenkov ligh

John W. Barrett, Endre Süli

We show the existence of global-in-time weak solutions to a general class of coupled Hookean-type bead-spring chain models that arise from the kinetic theory of dilute solutions of polymeric liquids with noninteracting polymer chains. The class of models involves the unsteady incompressible Navier-Stokes equations in a bounded domain in two or three space di

P. Vielva

The report of a significant deviation of the CMB temperature anisotropies distribution from Gaussianity (soon after the public release of the WMAP data in 2003) has become one of the most solid WMAP anomalies. This detection grounds on an excess of the kurtosis of the Spherical Mexican Hat Wavelet coefficients at scales of around 10 degrees. At these scales,

Mirek Giersz, Douglas C. Heggie

We describe Monte Carlo models for the dynamical evolution of the massive globular cluster 47 Tuc (NGC 104). The code includes treatments of two-body relaxation, most kinds of three- and four-body interactions involving primordial binaries and those formed dynamically, the Galactic tide, and the internal evolution of both single and binary stars. We arrive a

Jonathan C. Tan, Britton D. Smith, Brian W. O&#39;Shea

We review theoretical models of Population III.1 star formation, focusing on the protostellar feedback processes that are expected to terminate accretion and thus set the mass of these stars. We discuss how dark matter annihilation may modify this standard feedback scenario. Then, under the assumption that dark matter annihilation is unimportant, we predict

H. Bouy, J. Girard, E. L. Martin, N. Huelamo

With a spectral type of T10, UGPS J072227.51-054031.2 is one of the coolest objects known to date in the solar neighborhood. Multiple systems are relatively common among early and mid-T dwarfs. We search for faint and close companions around UGPSJ072227.51-054031.2. We have obtained high spatial resolution images in the H and Ks bands using adaptive optics a

Alexandra S. Gibbs, Kevin S. Knight, Philip Lightfoot

We report a detailed high-resolution powder neutron diffraction investigation of the structural behaviour of the multiferroic hexagonal polymorph of YMnO3 between room temperature and 1403 K. The study was aimed at resolving previous uncertainties regarding the nature of the paraelectric- ferroelectric transition and the possibilities of any secondary struct

G. Pietrzynski, W. Gieren, M. Hamuy, G. Pignata

We have detected, for the first time, Cepheid variables in the Sculptor Group spiral galaxy NGC 7793. From wide-field images obtained in the optical V and I bands on 56 nights in 2003-2005, we have discovered 17 long-period (24-62 days) Cepheids whose periods and mean magnitudes define tight period-luminosity relations. We use the (V-I) Wesenheit index to de

Jouko Mickelsson, Sylvie Paycha

We show that the residue density of the logarithm of a generalised Laplacian on a closed manifold defines an invariant polynomial valued differential form. We express it in terms of a finite sum of residues of classical pseudodifferential symbols. In the case of the square of a Dirac operator, these formulae provide a pedestrian proof of the Atiyah-Singer fo

Gia-Wei Chern

We investigate the nature of phase transitions induced by Dzyaloshinskii-Moriya (DM) interactions on a classical pyrochlore antiferromagnet. For both symmetry-allowed antisymmetric exchange interactions, the macroscopic degeneracy due to geometrical frustration is relieved and a long-range magnetic order appears in the ground state. We find an Ising-like pha

Gianluca Geloni, Vitali Kocharyan, Evgeni Saldin

This paper discusses the potential for enhancing the LCLS hard X-ray FEL capabilities. In the hard X-ray regime, a high longitudinal coherence will be the key to such performance upgrade. The method considered here to obtain high longitudinal coherence is based on a novel single-bunch self-seeding scheme exploiting a single crystal monochromator, which is ex

Frederic Knabe, Aydin Sezgin

For two-user interference channels, the capacity is known for the case where interference is stronger than the desired signal. Moreover, it is known that if the interference is above a certain level, it does not reduce the capacity at all. To achieve this capacity, the channel inputs need to be Gaussian distributed. However, Gaussian signals are continuous a

Pierre Del Moral, Peng Hu, Nadia Oudjane

We analyze the Snell envelope with path dependent multiplicative optimality criteria. Especially for this case, we propose a variation of the Snell envelope backward recursion which allows to extend some classical approxima- tion schemes to the multiplicatively path dependent case. In this framework, we propose an importance sampling particle approximation s

M. Jagadesh Kumar, C. Linga Reddy

We report a novel method to reduce the collector-emitter offset-voltage of the wide bandgap SiC-P-emitter lateral HBTs using a dual-bandgap emitter. In our approach, the collector-emitter offset-voltage VCE(offset) is reduced drastically by eliminating the built-in potential difference between the emitter-base (EB) junction and collector-base (CB) junction b

F. J. Fattoyev, C. J. Horowitz, J. Piekarewicz, G. Shen

Nuclear effective interactions are useful tools in astrophysical applications especially if one can guide the extrapolations to the extremes regions of isospin and density that are required to simulate dense, neutron-rich systems. Isospin extrapolations may be constrained in the laboratory by measuring the neutron skin thickness of a heavy nucleus, such as 2

M. Jagadesh Kumar, C. Linga Reddy

In this paper, we demonstrate that the performance of silicon Schottky rectifiers on SOI can be significantly improved using a Lateral Dual Sidewall Schottky (LDSS) concept. Our results based on numerical simulation show that the LDSS structure on SOI has low forward voltage drop and low reverse leakage current while its breakdown voltage is significantly la

Cosimo Bambi

On the basis of the Carter-Israel conjecture, today we believe that some compact and massive objects in the Galaxy and in the Universe are Kerr black holes. However, this idea cannot yet be confirmed by observations. We can currently obtain reliable estimates of the masses of these objects, but we do not know if the space-time around them is described by the

Bahodir B. Ahmedov

The general-relativistic Ohm&#39;s law for a two-component plasma which includes the gravitomagnetic force terms even in the case of quasi-neutrality has been derived. The equations that describe the electromagnetic processes in a plasma surrounding a neutron star are obtained by using the general relativistic form of Maxwell equations in a geometry of slow

M. Jagadesh Kumar, Amit Sharma

Basic SiC bipolar transistors have been studied in the past for their applications where high power or high temperature operation is required. However since the current gain in SiC bipolar transistors is very low and therefore, a large base drive is required in high current applications. Therefore, it is important to enhance the current gain of SiC bipolar t

Raghvendra S. Saxena, M. Jagadesh Kumar

In this work, we propose a new Stepped Oxide Hetero-Material Trench (SOHMT) power MOSFET with three sections in the trench gate (an N+ poly gate sandwiched between two P+ poly gates) and having different gate oxide thicknesses (increasing from source side to drain side). The different gate oxide thickness serves the purpose of simultaneously achieving (i) a

Sigbjorn Hervik, Alan Coley

We consider arbitrary-dimensional pseudo-Riemannian spaces of signature $(k,k+m)$. We introduce a boost-weight decomposition and define a number of algebraic properties (e.g., the ${\bf S}_i$- and ${\bf N}$-properties) and present a boost-weight decomposition to classify the Weyl tensors of arbitrary signature and discuss degenerate algebraic types (e.g., VS

Raghvendra S. Saxena, M. Jagadesh Kumar

In this paper, we propose a new trench power MOSFET with strained Si channel that provides lower on resistance than the conventional trench MOSFET. Using a 20% Ge mole fraction in the Si1-xGex body with a compositionally graded Si1-xGex buffer in the drift region enables us to create strain in the channel along with graded strain in the accumulation region.

Vivek Venkataraman, Susheel Nawal, M. Jagadesh Kumar

For nanoscale CMOS applications, strained-silicon devices have been receiving considerable attention owing to their potential for achieving higher performance and compatibility with conventional silicon processing. In this work, an analytical model for the output current characteristics (I-V) of nanoscale bulk strained-Si/SiGe MOSFETs, suitable for analog ci

M. Jagadesh Kumar, Vinod Parihar

In this paper we report a new PNP Surface Accumulation Layer Transistor (SALTran) on SOI which uses the concept of surface accumulation of holes near the emitter contact to significantly improve the current gain. Using two-dimensional simulation, we have evaluated the performance of the proposed device in detail by comparing its characteristics with those of

M. Jagadesh Kumar, G. V. Reddy

In this letter we discuss how the short channel behavior in sub 100 nm channel range can be improved by inducing a step surface potential profile at the back gate of an asymmetrical double gate (DG) Silicon-On-Insulator (SOI) Metal-Oxide-Semiconductor Field-Effect- Transistor (MOSFET) in which the front gate consists of two materials with different work func

Amir Daneshgar, Ali Reza Rahimi, Siamak Taati

We prove that every partial function with finite domain and range can be effectively simulated through sequential colorings of graphs. Namely, we show that given a finite set $S=\{0,1,\ldots,m-1\}$ and a number $n \geq \max\{m,3\}$, any partial function $φ:S^{^p} \to S^{^q}$ (i.e. it may not be defined on some elements of its domain $S^{^p}$) can be effectiv

M. Jagadesh Kumar, Harsh Bahl

A new Schottky-gate Bipolar Mode Field Effect Transistor (SBMFET) is proposed and verified by two-dimensional simulation. Unlike in the case of conventional BMFET, which uses deep diffused p+-regions as the gate, the proposed device uses the Schottky gate formed on the silicon planar surface for injecting minority carriers into the drift region. The SBMFET i

Deepak Dhar, Joel L. Lebowitz

We investigate the thermodynamic properties of a toy model of glasses: a hard-core lattice gas with nearest neighbor interaction in one dimension. The time-evolution is Markovian, with nearest-neighbor and next-nearest neighbor hoppings, and the transition rates are assumed to satisfy detailed balance condition, but the system is non-ergodic below a glass te

Shigefumi Hata, Takeaki Shimokawa, Kensuke Arai, Hiroya Nakao

Nonlinear oscillators can mutually synchronize when they are driven by common external impulses. Two important scenarios are (i) synchronization resulting from phase locking of each oscillator to regular periodic impulses and (ii) noise-induced synchronization caused by Poisson random impulses, but their difference has not been fully quantified. Here we anal

G. Venkateshwar Reddy, M. Jagadesh Kumar1

In this paper, we present the unique features exhibited by modified asymmetrical Double Gate (DG) silicon on insulator (SOI) MOSFET. The proposed structure is similar to that of the asymmetrical DG SOI MOSFET with the exception that the front gate consists of two materials. The resulting modified structure, Dual Material Double Gate (DMDG) SOI MOSFET, exhibi

M. Jagadesh Kumar, Sumeet Kumar Gupta, Vivek Venkataraman

A compact model for the effect of parasitic internal fringe capacitance on threshold voltage in high-K gate dielectric SOI MOSFETs is developed. Our model includes the effects of the gate dielectric permittivity, spacer oxide permittivity, spacer width, gate length and width of MOS structure. A simple expression for parasitic internal fringe capacitance from

Vijay Sai Patnaik, Ankit Gheedia, M. Jagadesh Kumar

After more than 30 years of validation of Moore&#39;s law, the CMOS technology has already entered the nanoscale (sub-100nm) regime and faces strong limitations. The nanowire transistor is one candidate which has the potential to overcome the problems caused by short channel effects in SOI MOSFETs and has gained signifi - cant attention from both device and

Huai-Qiang Gu, Jun-Hong An, Kang Jin

We study the Bloch oscillations (BOs) of two-component Bose-Einstein condensates (BECs) trapped in spin-dependent optical lattices. Based on the derived equations of motion of the wave packet in the basis of localized wave functions of the lattice sites, the damping effect induced by the intercomponent and intracomponent interactions to the BOs is explored a

Cam McLeman

The modern theory of class field towers has its origins in the study of the p-class field tower over a quadratic imaginary number field, so it is fitting that this problem be the first in the discipline to be nearing a solution. We survey the state of the subject and present a new cohomological condition for a quadratic imaginary number field to have an infi

Cam McLeman

All current techniques for showing that a number field has an infinite p-class field tower depend on one of various forms of the Golod-Shafarevich inequality. Such techniques can also be used to restrict the types of p-groups which can occur as Galois groups of finite p-class field towers. In the case that the base field is a quadratic imaginary number field

Wei Liu, Wei-Lu Wang, C. S. Liu, Q. F. Fang

Proposed as blanket structural materials for fusion power reactors, reduced activation ferritic/martensitic (RAFM) steel undergoes volume expanding and contracting in a cyclic mode under service environment. Particularly, being subjected to significant fluxes of fusion neutrons RAFM steel suffers considerable local volume variations in the radiation damage i

T. Zigdon, A. D. Wilson-Gordon, S. Guttikonda, E. J. Bahr

We report measurements of nonlinear magneto-optical rotation (NMOR) for the D2 line of $^{87}$Rb atoms in an antirelaxation-coated vapor cell in the presence of a radio-frequency (rf) field. The experimental NMOR signals as a function of rf field frequency for various rf field powers are compared to a theoretical model based on the density-matrix formalism.

Jinzhao Yuan

The CCD photometric observations of the eclipsing binary PS Persei (PS Per) were obtained on two consecutive days in 2009. The 2003 version Wilson-Devinney code was used to analyze the first complete light curves in $V$ and $R$ bands. It is found that PS Per is a short-period Algol-type binary with the less massive component accurately filling its inner crit

Hao Zhu, Geert Leus, Georgios B. Giannakis

Solving linear regression problems based on the total least-squares (TLS) criterion has well-documented merits in various applications, where perturbations appear both in the data vector as well as in the regression matrix. However, existing TLS approaches do not account for sparsity possibly present in the unknown vector of regression coefficients. On the o

Andrei Semenov

I review recently conducted measurements of $\gen$ as well as precision form factor experiments at high momentum transfer that will be performed with the 11 GeV electron beam at Jefferson Lab.

Xavier Vidaux

Büchi&#39;s problem asks whether there exists a positive integer $M$ such that any sequence $(x_n)$ of at least $M$ integers, whose second difference of squares is the constant sequence $(2)$, satisifies $x_n^2=(x+n)^2$ for some $x\in\Z$. A positive answer to Büchi&#39;s problem would imply that there is no algorithm to decide whether or not an arbitrary sys

Jun Ma, Zhenyu Wu, Song Wang, Zhou Fan

M31 globular cluster B379 is the first extragalactic cluster, the age of which was determined by main-sequence photometry. In this method, the age of a cluster is obtained by fitting its CMD with stellar evolutionary models. However, different stellar evolutionary models use different parameters of stellar evolution, such as range of stellar masses, differen

S. Rumyantsev, G. Liu, W. Stillman, M. Shur

We fabricated a large number of single and bilayer graphene transistors and carried out a systematic experimental study of their low-frequency noise characteristics. A special attention was given to determining the dominant noise sources in these devices and the effect of aging on the current-voltage and noise characteristics. The analysis of the noise spect

Attila~Pór, David R. Wood

The big-line-big-clique conjecture states that for all $k,\ell\geq2$ there is an integer $n$ such that every finite set of at least $n$ points in the plane contains $\ell$ collinear points or $k$ pairwise visible points. We show that this conjecture is false for infinite point sets, by constructing a countably infinite point set with no 4 collinear points an

Meghann Agarwal, Milos Milosavljevic

Photometrically distinct nuclear star clusters (NSCs) are common in late-type-disk and spheroidal galaxies. The formation of NSCs is inevitable in the context of normal star formation in which a majority of stars form in clusters. A young, mass-losing cluster embedded in an isolated star-forming galaxy remains gravitationally bound over a period determined b

Janet Conrad, Andre de Gouvea, Shashank Shalgar, Joshua Spitz

An ultra-large Liquid Argon Time Projection Chamber-based neutrino detector will have the uncommon ability to detect atmospheric tau neutrino events. This paper discusses the most promising modes for identifying charged current tau neutrino interactions, and shows that, with simple kinematic cuts, ~30 tau neutrinos can be isolated in a 100 kt*yr exposure, wi

Florin P. Boca, Joseph Vandehey

We prove results concerning the joint limiting distribution of the renewal time of denominators and consecutive digits of random irrational numbers in the case of continued fractions with even partial quotients, with odd partial quotients, and for Nakada&#39;s α-expansions.

Lev Lokutsievskiy

The author proposes a method for investigating actions of finite groups on aspherical spaces. Complete homotopy classification of free actions of finite groups on aspherical spaces is obtained. Also there are some results about non-free actions. For example a relation between the cohomology of finite groups and the lattice structure of its subgroups is obtai

A. P. Sazonov, A. Gukasov, I. Mirebeau, H. Cao

We studied the field-induced magnetic structures of the Tb2Ti2O7 pyrochlore by single-crystal neutron diffraction with a magnetic field applied along a [110] axis, focusing on the influence of a small misalignment. Both induced magnetic structures with k=0 and k=(0,0,1) propagation vectors are found to be sensitive to the misalignment, which controls the mag

Gregory R. Brady, A. Robert Ellis, David L. Moehring, Daniel Stick

We have successfully demonstrated an integrated optical system for collecting the fluorescence from a trapped ion. The system, consisting of an array of transmissive, dielectric micro-optics and an optical fiber array, has been intimately incorporated into the ion-trapping chip without negatively impacting trapping performance. Epoxies, vacuum feedthrough, a

C. R. Rotundu, B. Freelon, T. R. Forrest, S. D. Wilson

Heat-capacity, X-ray diffraction, and resistivity measurements on a high-quality BaFe$_{2}$As$_{2}$ sample show an evolution of the magneto-structural transition with successive annealing periods. After a 30-day anneal the resistivity in the (ab) plane decreases by more than an order of magnitude, to 12 $μΩ$cm, with a residual resistance ratio $\sim$36; the

Saurish Chakrabarty, Zohar Nussinov

We derive a universal form for the correlation function of general n component systems in the limit of high temperatures or weak coupling. This enables the extraction of effective microscopic interactions from measured high temperature correlation functions. We find that in systems with long range interactions, there exist diverging correlation lengths with

Mark Hannam, Sascha Husa, Frank Ohme, P. Ajith

One way to produce complete inspiral-merger-ringdown gravitational waveforms from black-hole-binary systems is to connect post-Newtonian (PN) and numerical-relativity (NR) results to create &#34;hybrid&#34; waveforms. Hybrid waveforms are central to the construction of some phenomenological models for GW search templates, and for tests of GW search pipelines

Nima Arkani-Hamed, Jacob L. Bourjaily, Freddy Cachazo, Simon Caron-Huot

We give an explicit recursive formula for the all L-loop integrand for scattering amplitudes in N=4 SYM in the planar limit, manifesting the full Yangian symmetry of the theory. This generalizes the BCFW recursion relation for tree amplitudes to all loop orders, and extends the Grassmannian duality for leading singularities to the full amplitude. It also pro

Kazunori Nakayama, Fuminobu Takahashi

We study a recently proposed running kinetic inflation model in which the inflaton potential becomes flat due to rapid growth of the kinetic term at large inflaton field values. As concrete examples, we build a variety of chaotic inflation models in supergravity with e.g. quadratic, linear, and fractional-power potentials. The power of the potential generica

Alexei V. Penskoi

Extremal spectral properties of the Lawson tori are studied. A Lawson torus carries an extremal metric for some eigenvalue of the Laplace-Beltrami operator. The main result of this paper is that the number of this eigenvalue is expressed in terms of fundamental tones of auxiliary periodic Sturm-Liouville problems.

Richard Froese, Florina Halasan, David Hasler

We prove the almost sure existence of absolutely continuous spectrum at low disorder for the Anderson model on the simplest example of a product of a regular tree with a finite graph. This graph contains loops of unbounded size.

Philipp Hauke, Fernando M. Cucchietti, Alexander Müller-Hermes, Mari-Carmen Bañuls

Systems with long-range interactions show a variety of intriguing properties: they typically accommodate many meta-stable states, they can give rise to spontaneous formation of supersolids, and they can lead to counterintuitive thermodynamic behavior. However, the increased complexity that comes with long-range interactions strongly hinders theoretical studi

Sachin Jain

It is known from earlier work of Iqbal, Liu (arXiv:0809.3808) that the boundary transport coefficients such as electrical conductivity (at vanishing chemical potential), shear viscosity etc. at low frequency and finite temperature can be expressed in terms of geometrical quantities evaluated at the horizon. In the case of electrical conductivity, at zero che

Koenraad M. R. Audenaert

According to a celebrated result by Löwner, a real-valued function $f$ is operator monotone if and only if its Löwner matrix, which is the matrix of divided differences $L_f=(\frac{f(x_i)-f(x_j)}{x_i-x_j})_{i,j=1}^N$, is positive semidefinite for every integer $N>0$ and any choice of $x_1,x_2,...,x_N$. In this paper we answer a question of R. Bhatia, who ask

Sergio Ferrara, Renata Kallosh, Andrei Linde, Alessio Marrani

We identify a particularly simple class of supergravity models describing superconformal coupling of matter to supergravity. In these models, which we call the canonical superconformal supergravity (CSS) models, the kinetic terms in the Jordan frame are canonical, and the scalar potential is the same as in the global theory. The pure supergravity part of the

Iulia Ghiu

The paper [Phys. Lett. A 373 (2009) 3610] by D.-C. Li analyzes the transformation between two-qubit mixed states by local operations and classical communication. We show that the proof of the main theorem, Theorem 2.6 in [Phys. Lett. A 373 (2009) 3610] is not complete. Therefore the generalization of Nielsen&#39;s theorem to mixed states still remains an ope

Nicolas Crampé, Frank Göhmann, Andreas Klümper

We calculate the low temperature asymptotics of a function $γ$ that generates the temperature dependence of all static correlation functions of the isotropic Heisenberg chain.

Pavel Rytíř

We say that a linear code C over a field F is triangular representable if there exists a two dimensional simplicial complex $Δ$ such that C is a punctured code of the kernel ker $Δ$ of the incidence matrix of $Δ$ over F and there is a linear mapping between C and ker $Δ$ which is a bijection and maps minimal codewords to minimal codewords. We show that the l

Géza Kós

The 6th problem of the 50th International Mathematical Olympiad (IMO), held in Germany, 2009, was the following. Let $a_1,a_2,...,a_n$ be distinct positive integers and let $M$ be a set of $n-1$ positive integers not containing $s=a_1+a_2+...+a_n$. A grasshopper is to jump along the real axis, starting at the point 0 and making $n$ jumps to the right with le

Ingrid Beltita, Daniel Beltita

We develop our earlier approach to the Weyl calculus for representations of infinite-dimensional Lie groups by establishing continuity properties of the Moyal product for symbols belonging to various modulation spaces. For instance, we prove that the modulation space of symbols $M^{\infty,1}$ is an associative Banach algebra and the corrresponding operators

I. Nandori

Known results on two-dimensional quantum electrodynamics (QED_2) have been used to study the dependence of functional renormalization group equations on renormalization schemes and approximations applied for its bosonized version. It is demonstrated that the singularity of flow equations can be avoided in the optimized and power-law schemes for the bosonized

Sönke Hansen

Rayleigh-type surface waves correspond to the characteristic variety, in the elliptic boundary region, of the displacement-to-traction map. In this paper, surface quasimodes are constructed for the reduced elastic wave equation, anisotropic in general, with traction-free boundary. Assuming a global variant of a condition of Barnett and Lothe, the constructio

Moe S. Khalil, F. C. Wellstood, Kevin D. Osborn

The loss in superconducting microwave resonators at low-photon number and low temperatures is not well understood but has implications for achievable coherence times in superconducting qubits. We have fabricated single-layer resonators with a high quality factor by patterning a superconducting aluminum film on a sapphire substrate. Four resonator geometries

Adrian Popescu

Let $I$ be an intersection of three monomial prime ideals of a polynomial algebra $S$ over a field. We give a special Stanley decomposition of $I$ which provides a lower bound of the Stanley depth of $I$, greater than or equal to $\depth\ (I)$, that is, Stanley&#39;s Conjecture holds for $I$.

Edinah K. Gnang, Ahmed Elgammal, Vladimir Retakh

In this paper we propose a general spectral theory for tensors. Our proposed factorization decomposes a tensor into a product of orthogonal and scaling tensors. At the same time, our factorization yields an expansion of a tensor as a summation of outer products of lower order tensors . Our proposed factorization shows the relationship between the eigen-objec

Laurent Duchemin, Christophe Josserand

We study the influence of the surrounding gas in the dynamics of drop impact on a smooth surface. We use an axisymmetric 3D model for which both the gas and the liquid are incompressible; lubrication regime applies for the gas film dynamics and the liquid viscosity is neglected. In the absence of surface tension a finite time singularity whose properties are

Richard A. Wentworth

We present gluing formulas for zeta regularized determinants of Dolbeault laplacians on Riemann surfaces. These are expressed in terms of determinants of associated operators on surfaces with boundary satisfying local elliptic boundary conditions. The conditions are defined using the additional structure of a framing, or trivialization of the bundle near the

Vlasios Vasileiou

One of the cornerstones of special relativity is the postulate that all observers measure exactly the same photon speeds independently on the photon energies. However, a hypothesized structure of spacetime may alter this conclusion at ultra-small length scales. Even a tiny energy-dependent variation in the speed of light may be revealed, when accumulated ove

Uri Bader, Pierre-Emmanuel Caprace, Tsachik Gelander, Shahar Mozes

We show that the group of almost automorphisms of a d-regular tree does not admit lattices. As far as we know this is the first such example among (compactly generated) simple locally compact groups.

Tanja Eisner, David Kunszenti-Kovacs

We study the convergence of the so-called entangled ergodic averages $\frac{1}{N^k}\sum_{n_1,...,n_k=1}^{N}T_m^{n_{α(m)}}A_{m-1}T_{m-1}^{n_{α(m-1)}}A_{m-2}...A_1T_1^{n_{α(1)}},$ where $k\leq m$ and $α:\{1,...,m\}\to\{1,...,k\}$ is a surjective map. We show that, on general Banach spaces and without any restriction on the partition $α$, the above averages con

Hoernisa Iminniyaz, Mitsuru Kakizaki

We propose an analytic treatment for computing the relic abundances of non-relativistic particles whose annihilation rate at chemical decoupling is increased by Sommerfeld enhancement. We find approximate rational functions that closely fit the thermal average of Sommerfeld-enhanced cross sections in the massless limit of force carriers for s- and p-wave ann

Michael E. Cuffaro

A growing number of commentators have, in recent years, noted the important affinities in the views of Immanuel Kant and Niels Bohr. While these commentators are correct, the picture they present of the connections between Bohr and Kant is painted in broad strokes; it is open to the criticism that these affinities are merely superficial. In this essay, I pro

Stuart I. Muldrew, Frazer R. Pearce, Chris Power

With the ever increasing resolution of N-body simulations, accurate subhalo detection is becoming essential in the study of the formation of structure, the production of merger trees and the seeding of semi-analytic models. To investigate the state of halo finders, we compare two different approaches to detecting subhaloes; the first based on overdensities i

Piotr Trocha

Orbital Kondo effect in a system of two single-level quantum dots attached to external electron reservoirs is considered theoretically. The dots are coupled via direct hoping term and Coulomb interaction. The Kondo temperature is evaluated from the scaling approach and slave boson technique. The later method is also used to calculate linear conductance of th

Géza Kós, Lajos Rónyai

Alon&#39;s combinatorial Nullstellensatz (Theorem 1.1 from \cite{Alon1}) is one of the most powerful algebraic tools in combinatorics, with a diverse array of applications. Let $\F$ be a field, $S_1,S_2,..., S_n$ be finite nonempty subsets of $\F$. Alon&#39;s theorem is a specialized, precise version of the Hilbertsche Nullstellensatz for the ideal of all po

Ludovic Berthier, Pinaki Chaudhuri, Corentin Coulais, Olivier Dauchot

We analyze the large scale structure and fluctuations of jammed packings of size disperse spheres, produced in a granular experiment as well as numerically. While the structure factor of the packings reveals no unusual behavior for small wavevectors, the compressibility displays an anomalous linear dependence at low wavectors and vanishes when q -> 0. We sho

Yu. S. Kalashnikova, A. V. Nefediev

The 1D2 charmonium assignment for the X(3872) meson is considered, as prompted by a recent result from the BABAR Collaboration, favouring 2-+ quantum numbers for the X. It is shown that established properties of the X(3872) are in a drastic conflict with the 1D2 c-anti-c assignment.

Victor J. W. Guo, Jiang Zeng

The Apéry numbers $A_n$ and central Delannoy numbers $D_n$ are defined by $$A_n=\sum_{k=0}^{n}{n+k\choose 2k}^2{2k\choose k}^2, \quad D_n=\sum_{k=0}^{n}{n+k\choose 2k}{2k\choose k}. $$ Motivated by some recent work of Z.-W. Sun, we prove the following congruences: \sum_{k=0}^{n-1}(2k+1)^{2r+1}A_k &\equiv \sum_{k=0}^{n-1}\varepsilon^k (2k+1)^{2r+1}D_k \equiv

Sofiane Bourouaine, Eckart Marsch, Fritz M. Neubauer

We show the evidence of ion-cyclotron dissipation mechanism in solar wind plasma using Helios data. From our statistical analysis we found that the wave power of high-frequency transverse waves (having frequencies between 0.01 and 1 normalized to the proton gyrofrequency in the plasma frame) correlates with both, the proton temperature anisotropy, $T_{\perp}