August 2010 arXiv papers — page 19

Bendong Lou

We study a two-point free boundary problem in a sector for a quasilinear parabolic equation. The boundary conditions are assumed to be spatially and temporally "self-similar" in a special way. We prove the existence, uniqueness and asymptotic stability of an expanding solution which is self-similar at discrete times. We also study the existence and u

R. Percacci, G. P. Vacca

There seems to be a common prejudice that asymptotic safety is either incompatible with, or at best unrelated to, the other topics in the title. This is not the case. In fact, we show that 1) the existence of a fixed point with suitable properties is a promising way of deriving emergent properties of gravity, and 2) there is a sense in which asymptotic safet

Marco Mamone-Capria

The concept of an objective spatial direction in special relativity is investigated and theories assuming light-speed isotropy while accepting the existence of a privileged spatial direction are classified. A natural generalization of the proper time principle is introduced which makes it possible to devise experimental tests of spatial isotropy. Several com

Jonathan Barrett, Nicolas Gisin

If nonlocality is to be inferred from a violation of Bell's inequality, an important assumption is that the measurement settings are freely chosen by the observers, or alternatively, that they are random and uncorrelated with the hypothetical local variables. We study the case where this assumption is weakened, so that measurement settings and local vari

Guangbin Zhuang

Let $H$ be a pointed Hopf algebra over an algebraically closed field of characteristic zero. If $H$ is a domain with finite Gelfand-Kirillov dimension greater than or equal to two, then $H$ contains a Hopf subalgebra of Gelfand-Kirillov dimension two.

Genqian Liu

In this paper, by a new method we establish the Weyl-type asymptotic formula for the counting function of biharmonic Stekloff eigenvalues with Neumann boundary condition in a bounded domain of an $n$-dimensional Riemannian manifold.

Ariel R. Zhitnitsky

The violation of local P and CP invariance in QCD, as it is observed at RHIC, has been a subject of intense discussions for the last couple of years.Separately, a new thermalization scenario for heavy ion collisions through the event horizon as a manifestation of the Unruh effect, has been also suggested. In this paper we argue that these two, naively unrela

Jonathan A. Kelner, James R. Lee, Gregory N. Price, Shang-Hua Teng

We present a method for proving upper bounds on the eigenvalues of the graph Laplacian. A main step involves choosing an appropriate "Riemannian" metric to uniformize the geometry of the graph. In many interesting cases, the existence of such a metric is shown by examining the combinatorics of special types of flows. This involves proving new inequal

N. M. Chtchelkatchev, A. A. Golubov, T. I. Baturina, V. M. Vinokur

We discuss fluctuations near the second order phase transition where the free energy has an additional non-Hermitian term. The spectrum of the fluctuations changes when the odd-parity potential amplitude exceeds the critical value corresponding to the PT-symmetry breakdown in the topological structure of the Hilbert space of the effective non-Hermitian Hamil

Marshall Williams

We prove the equivalence between geometric and analytic definitions of quasiconformality for a homeomorphism $f\colon X\rightarrow Y$ between arbitrary locally finite separable metric measure spaces, assuming no metric hypotheses on either space. When $X$ and $Y$ have locally $Q$-bounded geometry and $Y$ is contained in an Alexandrov space of curvature bound

Victor Ivrii

We consider 2- and 3-dimensional Schrödinger or generalized Schrödinger-Pauli operators with the non-degenerating magnetic field in the open domain under certain non-degeneracy assumptions we derive pointwise spectral asymptotics. We also consider asymptotics of some related expressions (see below). For all asymptotics loops rather than periodic trajectories

Matthew Brunner, J. M. Deutsch

The statistical mechanics of a linear non-interacting polymer chain with a large number of monomers is considered with fixed angular momentum. The radius of gyration for a linear polymer is derived exactly by functional integration. This result is then compared to simulations done with a large number of non-interacting rigid links at fixed angular momentum.

Ishanu Chattopadhyay, Yicheng Wen, Asok Ray

We propose a technique for pattern classification in symbolic streams via selective erasure of observed symbols, in cases where the patterns of interest are represented as Probabilistic Finite State Automata (PFSA). We define an additive abelian group for a slightly restricted subset of probabilistic finite state automata (PFSA), and the group sum is used to

K. A. Al-Hassanieh, Yi-feng Yang, Ivar Martin, C. D. Batista

We consider a Periodic Anderson Model (PAM) with a momentum-dependent inter-band hybridization that is strongly suppressed near the Fermi level. Under these conditions, we reduce the PAM to an effective low-energy Hamiltonian, $H_{\rm eff}$, by expanding in the small parameter $V_0/t$ ( $V_0$ is the maximum inter-band hybridization amplitude and $t$ is the h

Cynthia Aku-Leh, Florent Perez, Bernard Jusserand, David Richards

We have measured dispersions of spin-flip waves and spin-flip single-particle excitations of a spin polarized two-dimensional electron gas in a CdMnTe quantum well using resonant Raman scattering. We find the energy of the spin-flip wave to be below the spin-flip single particle excitation continuum, a contradiction to the theory of spin waves in diluted mag

Iegor Reznikoff

We give a purely logical proof of the J. Conway and S. Kochen Free Will theorem concerning undeterminacy in Quantum Mechanics (Notices of the AMS, February 2009, Vol. 56/2, p. 226). The logical method seems to be very powerful.

Guyslain Naves, Christophe Weibel

We give an algorithm to route a multicommodity flow in a planar graph $G$ with congestion $O(\log k)$, where $k$ is the maximum number of terminals on the boundary of a face, when each demand edge lie on a face of $G$. We also show that our specific method cannot achieve a substantially better congestion.

Guyslain Naves

We give an algorithm with complexity $O(f(R)^{k^2} k^3 n)$ for the integer multiflow problem on instances $(G,H,r,c)$ with $G$ an acyclic planar digraph and $r+c$ Eulerian. Here, $f$ is a polynomial function, $n = |V(G)|$, $k = |E(H)|$ and $R$ is the maximum request $\max_{h \in E(H)} r(h)$. When $k$ is fixed, this gives a polynomial algorithm for the arc-di

Joseph H. Silverman

A number of authors have proven explicit versions of Lehmer's conjecture for polynomials whose coefficients are all congruent to 1 modulo m. We prove a similar result for polynomials f(X) that are divisible in (Z/mZ)[X] by a polynomial of the form 1+X+...+X^n for some n > ε*deg(f). We also formulate and prove an analogous statement for elliptic curves.

Leticia Zarate

We calculate the annihilator of the ku-toral class for the p-groups Z_{p^2} X Z_{p^k}$ with k > 2. This allows us to give a description of the ku-homology of these groups.

Timour Ten, Joaquín E. Drut, Timo A. Lähde

Preconditioning is at the core of modern many-fermion Monte Carlo algorithms, such as Hybrid Monte Carlo, where the repeated solution of a linear problem involving an ill-conditioned matrix is needed. We report on a performance comparison of three preconditioning strategies, namely Chebyshev polynomials, strong-coupling approximation and weak-coupling expans

Waldemar Ulmer, Evangelos Matsinos

The well-known Bragg-Kleeman rule RCSDA = A dot E0p has become a pioneer work in radiation physics of charged particles and is still a useful tool to estimate the range RCSDA of approximately monoenergetic protons with initial energy E0 in a homogeneous medium. The rule is based on the continuous-slowing-down-approximation (CSDA). It results from a generaliz

Yang Li, Aria Nosratinia

Unlike point-to-point cognitive radio, where the constraint imposed by the primary rigidly curbs the secondary throughput, multiple secondary users have the potential to more efficiently harvest the spectrum and share it among themselves. This paper analyzes the sum throughput of a multiuser cognitive radio system with multi-antenna base stations, either in

Steve K. Lamoreaux

Several new experiments have extended studies of the Casimir force into new and interesting regimes. This recent work will be briefly reviewed. With this recent progress, new issues with background electrostatic effects have been uncovered. The myriad of problems associated with both patch potentials and electrostatic calibrations are discussed and the remai

G. Savini, Y. J. Dappe, S. Öberg, J. -C. Charlier

The thermodynamic and mechanical properties of graphitic systems are strongly dependent on the shear elastic constant C44. Using state-of-the-art density functional calculations, we provide the first complete determination of their elastic constants and exfoliation energies. We show that stacking misorientations lead to a severe lowering of C44 of at least o

D. Antonov, J. E. F. T. Ribeiro, A. V. Nefediev

We suggest the possibility of creation in the early Universe of stable domains of radius a few kilometers wide, formed by coherently excited states of $π$-mesons. Such domains appear dark to an external observer, since the decay rate of the said coherent pionic states into photons is vanishingly small. The related thermal insulation of the domains from the o

Alexander Reznikov, Vasiliy Vasyunin, Alexander Volberg

We consider weights $w$ and their cut-offs: $w_a(t)=w(t)$ if $w(t)\le a$ and $w_a(t)=a$ if $w(t)> a$. We consider a generalized $A_p$-``norm'' and prove that the ``norm'' of $w_a$ is not greater then the ``norm'' of $w$. Our proof in the case $w\in A_2$ is especially simple.

Chengbo Li

The curvature and the reduced curvature are basic differential invariants of the pair (Hamiltonian system, Lagrange distribution) on the symplectic manifold. It is shown that the negativity of the reduced curvature implies the hyperbolicity of any compact invariant set of the Hamiltonian flow restricted to a prescribed energy level. We consider the Hamiltoni

Veysel Celik, Hatice Unal, Ersen Mete, Sinasi Ellialtioglu

The adsorption profiles and electronic structures of Pt$_n$ (n = 1--4) clusters on stoichiometric, reduced and reconstructed rutile TiO$_2$(110) surfaces were systematically studied using on site d-d Coulomb interaction corrected hybrid density functional theory calculations. The atomic structure of small Pt cluster adsorbates mainly depend on the stoichiome

Dhouha Grissa, Sylvie Guillaume, Engelbert Mephu Nguifo

Formal Concept Analysis "FCA" is a data analysis method which enables to discover hidden knowledge existing in data. A kind of hidden knowledge extracted from data is association rules. Different quality measures were reported in the literature to extract only relevant association rules. Given a dataset, the choice of a good quality measure remains a

Ahmed M. El-Mezeini, Alaa I. Ibrahim

We present evidence for Quasi Periodic Oscillations (QPOs) in the recurrent outburst activity from SGR 1806-20 using Rossi X-ray Timing Explorer (RXTE) observations during November 1996. Searching for QPOs in a sample of 30 bursts at similar frequencies to those previously reported in the December 27, 2004 giant flare, we find evidence for a QPO in a burst a

Mu'awya Naser, Pedro Peris-Lopez, Mohammd Rafie, Jan van der Lubbe

In this paper, we analyze the security of an RFID authentication protocol proposed by Liu and Bailey [1], called Privacy and Authentication Protocol (PAP), and show its vulnerabilities and faulty assumptions. PAP is a privacy and authentication protocol designed for passive tags. The authors claim that the protocol, being resistant to commonly assumed attack

R. Cassano, S. Ettori, S. Giacintucci, G. Brunetti

The frequently observed association between giant radio halos and merging galaxy clusters has driven present theoretical models of non-thermal emission from galaxy clusters, which are based on the idea that the energy dissipated during cluster-cluster mergers could power the formation of radio halos. To quantitatively test the merger-halo connection we prese

Jan Roden, Alexander Eisfeld, John S. Briggs

The validity of the CES approximation is investigated by comparison with direct diagonalisation of a model vibronic Hamiltonian of $N$ identical monomers interacting electronically. Even for quite short aggregates (N\gtrsim 6) the CES approximation is shown to give results in agreement with direct diagonalisation, for all coupling strengths, except that of i

Suk Kim, Soo-Chang Rey, Thorsten Lisker, Sangmo Tony Sohn

We present ultraviolet (UV) color-magnitude relations (CMRs) of early-type dwarf galaxies in the Virgo cluster, based on Galaxy Evolution Explorer (GALEX) UV and Sloan Digital Sky Survey (SDSS) optical imaging data. We find that dwarf lenticular galaxies (dS0s), including peculiar dwarf elliptical galaxies (dEs) with disk substructures and blue centers, show

M. Silarski

In this article we present studies of the near threshold pp-->ppK+K- reaction in view of the K+K- final state interaction. The investigations include analysis of both the low-energy K+K- invariant mass distributions measured by COSY-11 collaboration at excess energies of Q = 10 MeV and Q = 28 MeV and the near threshold excitation function for the pp-->ppK+K-

Hadi Zayyani, Massoud Babaie-Zadeh, Christian Jutten

In this paper, we propose a Bayesian Hypothesis Testing Algorithm (BHTA) for sparse representation. It uses the Bayesian framework to determine active atoms in sparse representation of a signal. The Bayesian hypothesis testing based on three assumptions, determines the active atoms from the correlations and leads to the activity measure as proposed in Iterat

Elizabeth Wulcan

We use residue currents on toric varieties to obtain bounds on the support of solutions to polynomial ideal membership problems. Our bounds depend on the Newton polytopes of the polynomial systems and are therefore well adjusted to sparse systems of polynomials. We present variants of classical results due to Macaulay and Max Noether.

V. V. Lehtola, K. Kaski, R. P. Linna

We present a numerical study of forced polymer translocation by using two separate pore models. Both of them have been extensively used in previous forced translocation studies. We show that variations in the pore model affect the forced translocation characteristics significantly in the biologically relevant pore force, i.e. driving force, range. Details of

M. Bigdeli, G. H. Bordbar, A. Poostforush

The lowest order constrained variational (LOCV) technique has been used to investigate some of the thermodynamic properties of spin polarized hot asymmetric nuclear matter, such as the free energy, symmetry energy, susceptibility and equation of state. We have shown that the symmetry energy of the nuclear matter is substantially sensitive to the value of spi

Iordanis Koutsopoulos, Leandros Tassiulas

The smart power grid aims at harnessing information and communication technologies to enhance reliability and enforce sensible use of energy. Its realization is geared by the fundamental goal of effective management of demand load. In this work, we envision a scenario with real-time communication between the operator and consumers. The grid operator controll

Doris Arzoumanian, Moira Jardine, Jean-François Donati, Julien Morin

Significant progress has been made recently in our understanding of the structure of stellar magnetic fields, thanks to advances in detection methods such as Zeeman-Doppler Imaging. The extrapolation of this surface magnetic field into the corona has provided 3D models of the coronal magnetic field and plasma. This method is sensitive mainly to the magnetic

Jan Roden, Walter T. Strunz, Alexander Eisfeld

Absorption spectra of small molecular aggregates (oligomers) are considered. The dipole-dipole interaction between the monomers leads to shifts of the oligomer spectra with respect to the monomer absorption. The line-shapes of monomer as well as oligomer absorption depend strongly on the coupling to vibrational modes. Using a recently developed approach [Rod

Stefaan Vaes

We give a survey of recent classification results for crossed product von Neumann algebras arising from measure preserving group actions on probability spaces. This includes II_1 factors with uncountable fundamental groups and the construction of W*-superrigid actions where the crossed product entirely remembers the initial group action that it was construct

Y. T. Tanaka, J. P. Raulin, F. C. P. Bertoni, P. R. Fagundes

We report on the first detection of ionospheric disturbances caused by short repeated gamma-ray bursts from the magnetar SGR J1550-5418. Very low frequency (VLF) radio wave data obtained in South America clearly show sudden amplitude and phase changes at the corresponding times of eight SGR bursts. Maximum amplitude and phase changes of the VLF signals appea

Mohamad Charafeddine, Zhu Han, Arogyaswami Paulraj, John Cioffi

Treating the interference as noise in the n-user interference channel, the paper describes a novel approach to the rates region, composed by the time-sharing convex hull of 2^n-1 corner points achieved through On/Off binary power control. The resulting rates region is denoted crystallized rates region. By treating the interference as noise, the n-user rates

D. J. Champion, G. B. Hobbs, R. N. Manchester, R. T. Edwards

High-precision pulsar timing relies on a solar-system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantl

Shyam K. Choudhury, Anjan K. Gupta

We report on tip induced doping in local tunnel spectra of single layer graphene (SLG) with tunable back-gate using room temperature scanning tunneling microscopy and spectroscopy (STM/S). The SLG samples, prepared on silicon dioxide surface by exfoliation method and verified by Raman spectra, show atomically resolved honeycomb lattice. Local tunnel spectra

Hiroyuki Hata, Toru Kikuchi

We consider constructing the relativistic system of collective coordinates of a field theory soliton on the basis of a simple principle: The collective coordinates must be introduced into the static solution in such a way that the equation of motion of the collective coordinates ensures that of the original field theory. As an illustration, we apply this pri

M. Jagadesh Kumar, C. Linga Reddy

In this paper, we report a new 4H-SiC Lateral Dual Sidewall Schottky (LDSS) rectifier on a highly doped drift layer consisting of a high-barrier sidewall Schottky contact on top of the low-barrier Schottky contact. Using two-dimensional device simulation, the performance of the proposed device has been evaluated in detail by comparing its characteristics wit

Yanchao Wang, Jian Lv, Li Zhu, Yanming Ma

We have developed a powerful method for crystal structure prediction from "scratch" through particle swarm optimization (PSO) algorithm within the evolutionary scheme. PSO technique is dramatically different with the genetic algorithm and has apparently avoided the use of evolution operators (e.g., crossover and mutation). The approach is based on a

M. Jagadesh Kumar

We report a new structure, called the Shielded Ohmic Contact (ShOC) rectifier which utilizes trenches filled with a high barrier metal to shield an Ohmic contact during the reverse bias. When the device is forward biased, the Ohmic contact conducts with a low forward drop. However, when reverse biased, the Ohmic contact is completely shielded by the high bar

Sneh Saurabh, M. Jagadesh Kumar

Tunnel field effect transistor (TFET) devices are attractive as they show good scalability and have very low leakage current. However they suffer from low on-current and high threshold voltage. In order to employ the TFET for circuit applications, these problems need to be tackled. In this paper, a novel lateral strained double-gate TFET (SDGTFET) is present

Yuriy A. Reznik

We study the problem of quantization of discrete probability distributions, arising in universal coding, as well as other applications. We show, that in many situations this problem can be reduced to the covering problem for the unit simplex. This setting yields precise asymptotic characterization in the high-rate regime. We also describe a simple and asympt

Yong Feng, Wenyuan Wu, Jingzhong Zhang

Factorization of polynomials is one of the foundations of symbolic computation. Its applications arise in numerous branches of mathematics and other sciences. However, the present advanced programming languages such as C++ and J++, do not support symbolic computation directly. Hence, it leads to difficulties in applying factorization in engineering fields. I

Craig Cowan

We examine a Gelfand type system and show the extremal solutions are bounded provided we are close enough to the scalar case.

Anatol N. Kirillov, Toshiaki Maeno

We construct a model of the affine nil-Hecke algebra as a subalgebra of the Nichols-Woronowicz algebra associated to a Yetter-Drinfeld module over the affine Weyl group. We also discuss the Peterson isomorphism between the homology of the affine Grassmannian and the small quantum cohomology ring of the flag variety in terms of the braided differential calcul

V. Ravi, G. Hobbs, D. Wickramasinghe, D. J. Champion

The magnetic chemically peculiar star CU Virginis is a unique astrophysical laboratory for stellar magnetospheres and coherent emission processes. It is the only known main sequence star to emit a radio pulse every rotation period. Here we report on new observations of the CU Virginis pulse profile in the 13 and 20\,cm radio bands. The profile is known to be

J. Davy Kirkpatrick, Dagny L. Looper, Adam J. Burgasser, Steven D. Schurr

We have conducted a 4030-square-deg near-infrared proper motion survey using multi-epoch data from the Two Micron All-Sky Survey (2MASS). We find 2778 proper motion candidates, 647 of which are not listed in SIMBAD. After comparison to DSS images, we find that 107 of our proper motion candidates lack counterparts at B-, R-, and I-bands and are thus 2MASS-onl

Alessandro Cerioni, Robert H. Brandenberger

We study linear cosmological perturbations in the ``healthy extension'' of Horava-Lifshitz gravity which has recently been analyzed \cite{BPS2}. We find that there are two degrees of freedom for scalar metric fluctuations, but that one of them decouples in the infrared limit. Also, for appropriate choices of the parameters defining the Lagrangian, th

Seppo Laine, Marita Krause, Fatemeh S. Tabatabaei, Christos Siopis

We obtained Spitzer/IRAC 3.6-8 micron images of the nearby spiral galaxy NGC 4258 to study possible interactions between dust and the radio jet. In our analysis we also included high-resolution radio continuum, H-alpha, CO, and X-ray data. Our data reveal that the 8 micron emission, believed to originate largely from PAH molecules and hot dust, is an excelle

Lin Lin, Jianfeng Lu, Lexing Ying

We develop a hierarchical matrix construction algorithm using matrix-vector multiplications, based on the randomized singular value decomposition of low-rank matrices. The algorithm uses $\mathcal{O}(\log n)$ applications of the matrix on structured random test vectors and $\mathcal{O}(n \log n)$ extra computational cost, where $n$ is the dimension of the un

Elias Gravanis

Spherically symmetric shock waves are shown to exist in Lovelock gravity. They amount to a change of branch of the spherically symmetric solutions across a null hypersurface. The implications of their existence for the status of Birkhoff's theorem in the theory is discussed.

Khalid Bou-Rabee, Tasho Kaletha

The normal Farb growth of a group quantifies how well-approximated the group is by its finite quotients. We show that any S-arithmetic subgroup of a higher rank Chevalley group G has normal Farb growth n^dim(G).

Yanir A. Rubinstein, Steve Zelditch

The Cauchy problem for the homogeneous (real and complex) Monge-Ampere equation (HRMA/HCMA) arises from the initial value problem for geodesics in the space of Kahler metrics. It is an ill-posed problem. We conjecture that, in its lifespan, the solution can be obtained by Toeplitz quantizing the Hamiltonian flow defined by the Cauchy data, analytically conti

Eric Cockayne, Gregory M. Rutter, Nathan P. Guisinger, Jason N. Crain

Topological defects can affect the physical properties of graphene in unexpected ways. Harnessing their influence may lead to enhanced control of both material strength and electrical properties. Here we present a new class of topological defects in graphene composed of a rotating sequence of dislocations that close on themselves, forming grain boundary loop

Alexey Zatelepin, Lev Shchur

We report on numerical investigation of fractal properties of critical interfaces in two-dimensional Potts models. Algorithms for finding percolating interfaces of Fortuin-Kasteleyn clusters, their external perimeters and interfaces of spin clusters are presented. Fractal dimensions are measured and compared to exact theoretical predictions.

Frederick A. Harris

Results based on 106 M $\psi'$ events and about 226 M $J/\psi$ events acquired with the BESIII detector at BEPCII are reported, including a confirmation of the BESII $p\bar{p}$ threshold enhancement in $J/\psi \to \gamma p\bar{p}$, branching ratios for $\chi_{cJ} \to \pi^0 \pi^0$ and $\eta \eta$, and first measurements of the branching ratios for $\psi' \to

J. A. Aguilar-Saavedra

We write down a minimal basis for dimension-six gauge-invariant four-fermion operators, with some operator replacements with respect to previous ones which make it simpler for calculations. Using this basis we classify all four-fermion operator contributions involving one or two top quarks. Taking into account the different fermion chiralities, possible colo

Igor Rumanov

Tracy-Widom (TW) equations for one-matrix unitary ensembles (UE) (equivalent to a particular case of Schlesinger equations for isomonodromic deformations) are rewritten in a general form which allows one to derive all the lowest order equations (PDE) for spectral gap probabilities of UE without intermediate higher-order PDE. This is demonstrated on the examp

Su-Yang Xu, L. A. Wray, Y. Xia, R. Shankar

A topological insulator is characterized by spin-momentum locking on its boundary. The spin momentum locking on the surface of a three dimensional topological insulator leads to the existence of a non-trivial Berry's phase which leads to exotic transport phenomena on topological surfaces. Using spin-sensitive probes (Mott polarimetry), we observe the spi

A. A. Zharov, I. S. Beloborodov

We study the dynamic electronic polarizability of a single nano-scale spherical metallic grain using quantum mechanical approach. We introduce the model for interacting electrons bound in the grain allowing us numerically to calculate the frequency dependence of the polarizability of grains of different sizes. We show that within this model the main resonanc

R. Mikulevicius, B. L. Rozovskii

A random perturbation of a deterministic Navier-Stokes equation is considered in the form of an SPDE with Wick type nonlinearity. The nonlinear term of the perturbation can be characterized as the highest stochastic order approximation of the original nonlinear term u\nabla u. This perturbation is unbiased in that the expectation of a solution of the perturb

F. T. Hioe, David Kuebel

A new parameter space is used to classify circular orbits in the Schwarzschild metric.

Pearl Sandick, Juerg Diemand, Katherine Freese, Douglas Spolyar

10 to 10^5 solar mass black holes with dark matter spikes that formed in early minihalos and still exist in our Milky Way Galaxy today are examined in light of recent data from the Fermi Gamma-Ray Space Telescope (FGST). The dark matter spikes surrounding black holes in our Galaxy are sites of significant dark matter annihilation. We examine the signatures o

Michael Hochman

A Borel system consists of a measurable automorphism of a standard Borel space. We consider Borel embeddings and isomorphisms between such systems modulo null sets, i.e. sets which have measure zero for every invariant probability measure. For every t>0 we show that in this category there exists a unique free Borel system (Y,S) which is strictly t-universal

Michael Hochman

Let b be an integer and mu a probability measure on [0,1] which is invariant and ergodic multiplication by b mod 1, and 0<dim(mu)<1. Let f be a diffeomorphism between open subsets of the line. We show that if the measures mu and f(mu) are equivalent on f(E), then f&#39;(x) is a rational power of b at mu-a.e. point x in E. In particular, if g is a piecewise-a

D0 Collaboration, V. Abazov

We report results of a search for particles with anomalously high ionization in events with a high transverse energy jet and large missing transverse energy in $2.4$ fb$^{-1}$ of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron $p\bar{p}$ collider. Production of such particles (quirks) is expected in scenarios with extra QCD-like

Graham Smith

We present a novel and comprehensive approach to the study of the parametric Plateau problem for locally strictly convex (LSC) hypersurfaces of prescribed curvature for general convex curvature functions inside general Riemannian manifolds. We prove existence of solutions to the Plateau problem with outer barrier for LSC hypersurfaces of constant or prescrib

L. Ghezzi, K. Cunha, S. C. Schuler, V. V. Smith

This work presents a homogeneous derivation of atmospheric parameters and iron abundances for a sample of giant and subgiant stars which host giant planets, as well as a control sample of subgiant stars not known to host giant planets. The analysis is done using the same technique as for our previous analysis of a large sample of planet-hosting and control s

Kondayya Gundra, Alok Shukla

We present calculations of the optical absorption and electro-absorption spectra of graphene nanoribbons (GNRs) using a $π-$electron approach, incorporating long-range Coulomb interactions within the Pariser-Parr-Pople (PPP) model Hamiltonian. The approach is carefully bench marked by computing quantities such as the band structure, electric-field driven hal

Joerg Jaeckel, Sabyasachi Roy

High precision spectroscopy can provide a sensitive tool to test Coulomb&#39;s law on atomic length scales. This can then be used to constrain particles such as extra &#34;hidden&#34; photons or minicharged particles that are predicted in many extensions of the standard model, and which cause small deviations from Coulomb&#39;s law. In this paper we use a va

Tatsuro Yuge

We derive general properties of the linear response functions of nonequilibrium steady states in Langevin systems. These correspond to extension of the results which were recently found in Hamiltonian systems [A. Shimizu and T. Yuge, J. Phys. Soc. Jpn. {\bf 79}, 013002 (2010)]. We discuss one of the properties, the sum rule for the response function, in part

Jonas A. Kjäll, Frank Pollmann, Joel E. Moore

In a recent experiment on CoNb_2O_6, Coldea et al. [Science 327, 177 (2010)] found for the first time experimental evidence of the exceptional Lie algebra E_8. The emergence of this symmetry was theoretically predicted long ago for the transverse quantum Ising chain in the presence of a weak longitudinal field. We consider an accurate microscopic model of Co

A. Baule, H. Touchette, E. G. D. Cohen

We investigate a model for the dynamics of a solid object, which moves over a randomly vibrating solid surface and is subject to a constant external force. The dry friction between the two solids is modeled phenomenologically as being proportional to the sign of the object&#39;s velocity relative to the surface, and therefore shows a discontinuity at zero ve

Yanki Lekili

We study an explicit construction of planar open books with four binding components on any three-manifold which is given by integral surgery on three component pure braid closures. This construction is general, indeed any planar open book with four binding components is given this way. Using this construction and results on exceptional surgeries on hyperboli

Rafael Sánchez, Markus Buttiker

We present a microscopic discussion of a nano-sized structure which uses the quantization of energy levels and the physics of single charge Coulomb interaction to achieve an optimal conversion of heat flow to directed current. In our structure the quantization of energy levels and the Coulomb blockade lead to the transfer of quantized packets of energy from

Kartick Tarafder, Biplab Sanyal, Peter M. Oppeneer

Electrical injection in organic semiconductors is a key prerequisite for the realization of organic spintronics. Using density-functional theory calculations we report the effect of electron transfer into the organic molecule Alq$_3$. Our first-principles simulations show that electron injection spontaneously spin-polarizes non-magnetic Alq$_3$ with a magnet

Benedict Baur

Given an elliptic differential operator L of second order with smooth coefficients in a bounded domain with smooth boundary. We show that if the coefficients are Hölder-continuous up to the boundary and the boundary is $C^{2,α}$-smooth that on the space of all $C^{2,α}$-smooth (up to the boundary) functions u fulfilling both u=0 and Lu=0 (on the boundary) th

Michael J. Neely

Lyapunov drift and Lyapunov optimization are powerful techniques for optimizing time averages in stochastic queueing networks subject to stability. However, there are various definitions of queue stability in the literature, and the most convenient Lyapunov drift conditions often provide stability and performance bounds only in terms of a time average expect

E. Behnke, J. Behnke, S. J. Brice, D. Broemmelsiek

Data from the operation of a bubble chamber filled with 3.5 kg of CF$_{3}$I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter

G&#34;otz E. Pfander, Peter Rashkov

We report on initial findings on Gabor systems with multivariate Gaussian window. Unlike the existing characterisation for dimension one in terms of lattice density, our results indicate that the behavior of Gaussians in higher-dimensional Gabor systems is intricate and further exploration is a valuable and challenging task.

Sebastien Galtier, Eric Buchlin

Nonlinear diffusion equations of spectral transfer are systematically derived for anisotropic magnetohydrodynamics in the regime of wave turbulence. The background of the analysis is the asymptotic Alfvén wave turbulence equations from which a differential limit is taken. The result is a universal diffusion-type equation in ${\bf k}$-space which describes in

Avraham Gal

Selected topics in Strangeness Nuclear Physics are reviewed: Lambda hypernuclear spectroscopy and structure, multistrangeness, and Kbar mesons in nuclei

Yu-Bo Sheng, Fu-Guo Deng

We present a one-step deterministic entanglement purification protocol with linear optics and postselection. Compared with the Simon-Pan protocol (Phys. Rev. Lett. 89, 257901 (2002)), this one-step protocol has some advantages. First, it can get a maximally entangled pair with only one step, not only improve the fidelity of less-entangled photon pairs by per

Shrihari Gopalakrishna, Tao Han, Ian Lewis, Zong-guo Si

If a TeV-scale charged gauge boson (W&#39;) is discovered at the Large Hadron Collider (LHC), it will become imperative to determine its chiral couplings to standard model (SM) fermions in order to learn about the underlying theory containing the W&#39;. We describe the reconstruction of the t, b decay mode of the W&#39; at the LHC, and identify various kine

Tong-Jie Zhang, Hao-Ran Yu, Joachim Harnois-Déraps, Ilana MacDonald

We develop a purely mathematical tool to recover some of the information lost in the non-linear collapse of large-scale structure. From a set of 141 simulations of dark matter density fields, we construct a non-linear Weiner filter in order to separate Gaussian and non-Gaussian structure in wavelet space. We find that the non-Gaussian power is dominant at sm

J. S. Sanders, A. C. Fabian, R. K. Smith

Using the width of emission lines in XMM-Newton Reflection Grating Spectrometer spectra, we place direct constraints on the turbulent velocities of the X-ray emitting medium in the cores of 62 galaxy clusters, groups and elliptical galaxies. We find five objects where we can place an upper limit on the line-of-sight broadening of 500 km/s (90 per cent confid

Pavel Augustinsky, Vaclav Janis

We extend an approximation earlier developed by us for the single-impurity Anderson model to a full-size impurity solver for models of interacting electrons with multiple orbitals. The approximation is based on parquet equations simplified by separating small and large energy fluctuations justified in the critical region of a pole in the two-particle vertex.

Birger Horstmann, Ralf Schützhold, Benni Reznik, Serena Fagnocchi

This paper discusses a recent proposal for the simulation of acoustic black holes with ions. The ions are rotating on a ring with an inhomogeneous, but stationary velocity profile. Phonons cannot leave a region, in which the ion velocity exceeds the group velocity of the phonons, as light cannot escape from a black hole. The system is described by a discrete