December 2008 arXiv papers — page 2

Jonathan Brundan, Alexander Kleshchev

We explain how to deduce the degenerate analogue of Ariki's categorification theorem over the ground field C as an application of Schur-Weyl duality for higher levels and the Kazhdan-Lusztig conjecture in finite type A. We also discuss some supplementary topics, including Young modules, tensoring with sign, tilting modules and Ringel duality.

Koji Fujiwara, Jason Fox Manning

We give new examples of hyperbolic and relatively hyperbolic groups of cohomological dimension $d$ for all $d\geq 4$. These examples result from applying CAT$(0)$/CAT$(-1)$ filling constructions (based on singular doubly warped products) to finite volume hyperbolic manifolds with toral cusps. The groups obtained have a number of interesting properties, which

Guocai Liu, Ping Zhang, Zhigang Wang, Shu-Shen Li

We study the spin Hall effect in the kagomé lattice with Rashba spin-orbit coupling. The conserved spin Hall conductance $σ_{xy}^{s}$ (see text) and its two components, i.e., the conventional term $σ_{xy}^{s0}$ and the spin-torque-dipole term $σ_{xy}^{sτ}$, are numerically calculated, which show a series of plateaus as a function of the electron Fermi energy

Mikhail V. Medvedev

Radiation from GRBs in the prompt phase, flares and an afterglow is thought to be produced by accelerated electrons in magnetic fields. Such emission may be produced at collisionless shocks of baryonic outflows or at reconnection sites (at least for the prompt and flares) of the magnetically dominated (Poynting flux driven) outflows, where no shocks presumab

Ningning Hao, Ping Zhang, Zhigang Wang, Wei Zhang

We study the topological edge states of the Haldane's graphene model with zigzag/armchair lattice edges. The Harper equation for solving the energies of the edge states is derived. The results show that there are two edge states in the bulk energy gap, corresponding to the two zero points of the Bloch function on the complex-energy Riemann surface. The e

Rob van Glabbeek, Ursula Goltz, Jens-Wolfhard Schicke

When considering distributed systems, it is a central issue how to deal with interactions between components. In this paper, we investigate the paradigms of synchronous and asynchronous interaction in the context of distributed systems. We investigate to what extent or under which conditions synchronous interaction is a valid concept for specification and im

Roman Ya. Kezerashvili, Gregory L. Matloff

Near-sun space-environment effects on metallic thin films solar sails as well as hollow-body sails with inflation fill gas are considered. Analysis of interaction of the solar radiation with the solar sail materials is presented. This analysis evaluates worst-case solar radiation effects during solar-radiation-pressure acceleration. The dependence of the thi

Cristinel Diaconu

Recent progress in the understanding of the nucleon is presented. The unpolarised structure functions are obtained with unprecedented precision from the combined H1 and ZEUS data and are used to extract proton parton distribution functions via NLO QCD fits. The obtained parametrisation displays an improved precision, in particular at low Bjorken x, and leads

N. -E. Raouafi

Multi-instrument data sets of NOAA AR10938 on Jan. 16, 2007, (e.g., {\emph{Hinode}}, {\it{STEREO}}, {\it{GOES}}, {\it{MLSO}} and {\it{ISOON}} H$α$) are utilized to study the fine structure and evolution of a magnetic loop system exhibiting multiple crossing threads, whose arrangement and individual shapes are very suggestive of individual field lines in a fl

Rob van Glabbeek, Ursula Goltz, Jens-Wolfhard Schicke

We investigate classes of systems based on different interaction patterns with the aim of achieving distributability. As our system model we use Petri nets. In Petri nets, an inherent concept of simultaneity is built in, since when a transition has more than one preplace, it can be crucial that tokens are removed instantaneously. When modelling a system whic

Zhuo Li, Li-Juan Xing, Xin-Mei Wang

We explicitly construct an infinite family of asymptotically good concatenated quantum stabilizer codes where the outer code uses CSS-type quantum Reed-Solomon code and the inner code uses a set of special quantum codes. In the field of quantum error-correcting codes, this is the first time that a family of asymptotically good quantum codes is derived from b

Jonathan Grindlay

Observations of a long-lasting Gamma-ray burst, one that has the brightest optical counterpart yet discovered, challenge theoretical understanding of these bursts but may enhance their usefulness as cosmic probes.

J. L. Han

The magnetic fields of our Milky Way galaxy are the main agent for cosmic rays to transport. In the last decade, much new knowledge has been gained from measurements of the Galactic magnetic fields. In the Galactic disk, from the RMs of a large number of newly discovered pulsars, the large-scale magnetic fields along the spiral arms have been delineated in a

Z. Brzezniak, B. Goldys

The Landau-Lifshitz-Gilbert equation perturbed by a multiplicative space-dependent noise is considered for a ferromagnet filling a bounded three-dimensional domain. We show the existence of weak martingale solutions taking values in a sphere $\mathbb S^2$. The regularity of weak solutions is also discussed. Some of the regularity results are new even for the

A. G. Kosovichev

Magnetic fields emerging from the Sun's interior carry information about physical processes of magnetic field generation and transport in the convection zone. Soon after appearance on the solar surface the magnetic flux gets concentrated in sunspot regions and causes numerous active phenomena on the Sun. This paper discusses some properties of the emergi

Abel Rodriguez, Enrique ter Horst

Extracting market expectations has always been an important issue when making national policies and investment decisions in financial markets. In option markets, the most popular way has been to extract implied volatilities to assess the future variability of the underlying with the use of the Black and Scholes formula. In this manuscript, we propose a novel

Dacheng Lin, Ronald A. Remillard, Jeroen Homan

We have analyzed 866 RXTE observations of the 2006-2007 outburst of the accreting neutron star XTE J1701-462, during which the source evolves from super-Eddington luminosities to quiescence. The X-ray color evolution first resembles the Cyg X-2 subgroup of Z sources, with frequent excursions on the horizontal and normal branches (HB/NB). The source then deca

Lev Birbrair, Alexandre Fernandes, Walter D Neumann

We construct examples of complex algebraic surfaces not admitting normal embeddings (in the sense of semialgebraic or subanalytic sets) with image a complex algebraic surface.

J. J. Rehr, J. P. Gardner, M. Prange, L. Svec

We investigate the feasibility of high performance scientific computation using cloud computers as an alternative to traditional computational tools. The availability of these large, virtualized pools of compute resources raises the possibility of a new compute paradigm for scientific research with many advantages. For research groups, cloud computing provid

John M. Bulava, Robert G. Edwards, Eric Engelson, Justin Foley

Highly excited states for isospin 1/2 baryons are calculated for the first time using lattice QCD with two flavors of dynamical quarks. Anisotropic lattices are used with two pion masses: 416(36) MeV and 578(29) MeV. The lowest four energies are reported in each of the six irreducible representations of the octahedral group at each pion mass. The lattices us

Keun-Young Kim, Ismail Zahed

In the holographic model of QCD, baryons are chiral solitons sourced by D4 flavor instantons in bulk of size 1/\sqrtλ with λ=g^2*N_c. Using the ADHM construction we explicit the exact two-instanton solution in bulk. We use it to construct the core NN potential to order N_c/λ. The core sources meson fields to order \sqrt{N_c/λ} which are shown to contribute t

Bedřich Sousedík, Jan Mandel

After a short historical review, we present four popular substructuring methods: FETI-1, BDD, FETI-DP, BDDC, and derive the primal versions to the two FETI methods, called P-FETI-1 and P-FETI-DP, as proposed by Fragakis and Papadrakakis. The formulation of the BDDC method shows that it is the same as P-FETI-DP and the same as a preconditioner introduced by C

Zdzisław Brzeźniak, Jerzy Zabczyk

The paper is concerned with spatial and time regularity of solutions to linear stochastic evolution equation perturbed by Lévy white noise "obtained by subordination of a Gaussian white noise". Sufficient conditions for spatial continuity are derived. It is also shown that solutions do not have in general \cadlag modifications. General results are ap

Stéphane Chrétien, Alfred Hero, Hervé Perdry

The EM algorithm is a widely used methodology for penalized likelihood estimation. Provable monotonicity and convergence are the hallmarks of the EM algorithm and these properties are well established for smooth likelihood and smooth penalty functions. However, many relaxed versions of variable selection penalties are not smooth. The goal of this paper is to

Francesco Bartolucci, Ivonne L. Solis-Trapala

We demonstrate the use of a multidimensional extension of the latent Markov model to analyse data from studies with correlated binary responses in developmental psychology. In particular, we consider an experiment based on a battery of tests which was administered to pre-school children, at three time periods, in order to measure their inhibitory control and

Jose Iraides Belandria

This article presents a heuristic combination of the local and global formulations of the second law of thermodynamics that suggests the possibility of theoretical existence of thermodynamics processes with positive and negative entropy production.Such processes may exhibit entropy couplings that reveal an unusual behavior from the point of view of conventio

Christopher D. Sogge, Chengbo Wang

We obtain KSS, Strichartz and certain weighted Strichartz estimate for the wave equation on $(\R^d, \mathfrak{g})$, $d \geq 3$, when metric $\mathfrak{g}$ is non-trapping and approaches the Euclidean metric like $ x ^{- ρ}$ with $ρ>0$. Using the KSS estimate, we prove almost global existence for quadratically semilinear wave equations with small initial data

Rafe Mazzeo, Julie Rowlett

Let $\Omega_0$ be a polygon in $\RR^2$, or more generally a compact surface with piecewise smooth boundary and corners. Suppose that $\Omega_\e$ is a family of surfaces with $\calC^\infty$ boundary which converges to $\Omega_0$ smoothly away from the corners, and in a precise way at the vertices to be described in the paper. Fedosov \cite{Fe}, Kac \cite{K} a

A. Anokhina, A. Morozov, Sh. Shakirov

A linear map between two vector spaces has a very important characteristic: a determinant. In modern theory two generalizations of linear maps are intensively used: to linear complexes (the nilpotent chains of linear maps) and to non-linear mappings. Accordingly, determinant of a linear map has two generalizations: to determinants of complexes and to resulta

R. K. Kaul, D. Ullmo, G. Zarand, S. Chandrasekharan

We consider an "impurity" with a spin degree of freedom coupled to a finite reservoir of non-interacting electrons, a system which may be realized by either a true impurity in a metallic nano-particle or a small quantum dot coupled to a large one. We show how the physics of such a spin impurity is revealed in the many-body spectrum of the entire fini

Alessandro Mirizzi, Javier Redondo, Guenter Sigl

Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using

Patrick Rice, Jim Harrington

Decoy state protocols are a useful tool for many quantum key distribution systems implemented with weak coherent pulses, allowing significantly better secret bit rates and longer maximum distances. In this paper we present a method to numerically find optimal three-level protocols, and we examine how the secret bit rate and the optimized parameters are depen

Peter Harremoes

On a compact group the Haar probability measure plays the role of uniform distribution. The entropy and rate distortion theory for this uniform distribution is studied. New results and simplified proofs on convergence of convolutions on compact groups are presented and they can be formulated as entropy increases to its maximum. Information theoretic techniqu

Alexey Boyarsky, Oleg Ruchayskiy, Mikhail Shaposhnikov

We present a comprehensive overview of an extension of the Standard Model that contains three right-handed (sterile) neutrinos with masses below the electroweak scale [the Neutrino Minimal Standard Model, (nuMSM)]. We consider the history of the Universe from the inflationary era through today and demonstrate that most of the observed phenomena beyond the St

J. Brannlund, S. Kloster, A. DeBenedictis

Using the improved quantization technique to the mini-superspace approximation of loop quantum gravity, we study the evolution of black holes supported by a cosmological constant. The addition of a cosmological constant allows for classical solutions with planar, cylindrical, toroidal and higher genus black holes. Here we study the quantum analog of these sp

A. Hamilton, J. Murugan, A. Prinsloo, M. Strydom

We study some of the properties of dual giant gravitons - D2-branes wrapped on an $S^{2}\subset AdS_{4}$ - in type IIA string theory on $AdS_{4}\times \mathbb{CP}^{3}$. In particular we confirm that the spectrum of small fluctuations about the giant is both real and independent of the size of the graviton. We also extend previously developed techniques for a

Gero von Gersdorff, Mariano Quiros

We analyze a scenario where the right-handed neutrinos make part of a strongly coupled conformal field theory and acquire an anomalous dimension γ<1 at a large scale Λ. Their Yukawa couplings to the Higgs become irrelevant at the fixed point and they are suppressed at low scales giving rise naturally to a small (sub-meV) Dirac neutrino mass which breaks the

Christos Kokorelis

We examine the issue of generating the perturbatively absent ${\bf 10} \cdot {\bf 10} \cdot {\bf 5}^H$ SU(5)/flipped SU(5)Yukawa couplings in type II D-brane orientifold compactifications of string theory both at the perturbative (PER) and the non-perturbative (NP) level. We find at the PER level, higher order terms like $ {\bf 10} \cdot {\bf 10} \cdot {\bf{

Heng-Yu Chen, Jinn-Ouk Gong

We present a detailed systematics for comparing warped brane inflation with the observations, incorporating the effects of both moduli stabilization and ultraviolet bulk physics. We explicitly construct an example of the inflaton potential governing the motion of a mobile D3 brane in the entire warped deformed conifold. This allows us to precisely identify t

Andrea De Simone, Mark P. Hertzberg, Frank Wilczek

An interacting scalar field with largish coupling to curvature can support a distinctive inflationary universe scenario. Previously this has been discussed for the Standard Model Higgs field, treated classically or in a leading log approximation. Here we investigate the quantum theory using renormalization group methods. In this model the running of both the

Tatsuo Azeyanagi, Noriaki Ogawa, Seiji Terashima

The Kerr/CFT correspondence is a holographic duality between a two dimensional chiral conformal field theory (CFT) and the very near horizon limit of an extremal black hole, which includes an AdS2 structure. To understand the dual chiral CFT2, we apply the Kerr/CFT correspondence to a certain class of black holes embedded in string theory, which include the

Joshua Erlich, Christopher Westenberger

Estimates of the light hadron masses, decay constants and couplings in AdS/QCD models are generally more accurate than should have been expected. Certain predictions based on the AdS/CFT correspondence, such as the ratio of the equilibrium viscosity to entropy density, are universal and therefore provide firm experimental tests of these models. Other observa

Jan de Boer, Veronika E. Hubeny, Mukund Rangamani, Masaki Shigemori

We study Brownian motion and the associated Langevin equation in AdS/CFT. The Brownian particle is realized in the bulk spacetime as a probe fundamental string in an asymptotically AdS black hole background, stretching between the AdS boundary and the horizon. The modes on the string are excited by the thermal black hole environment and consequently the stri

Rodrigo Fernández, Christopher Thompson

We investigate the effects of neutrino heating and alpha-particle recombination on the hydrodynamics of core-collapse supernovae. Our focus is on the non-linear dynamics of the shock wave that forms in the collapse, and the assembly of positive energy material below it. To this end, we perform time-dependent hydrodynamic simulations with FLASH2.5 in spherica

J. T. Firouzjaee, Reza Mansouri

Application of concepts like black hole and event horizon in cosmological context are not trivial, as has been shown in the last decade. We introduce special solutions of the LTB family representing collapsing over-dense regions extending to an expanding closed, open, or flat FRW model asymptotically. We study the dynamics of the collapsing region, and its d

Yan-Qing Ma, Yu-Jie Zhang, Kuang-Ta Chao

In heavy quarkonium production, the measured ratio $R_{c \bar c}=σ[J/ψ+ c\bar c + X]/σ[J/ψ+X]$ at B factories is much larger than existing theoretical predictions. To clarify this discrepancy, in nonrelativistic QCD (NRQCD) we find the next-to-leading-order (NLO) QCD correction to $e^+ e^- \to J/ψ+gg$ can enhance the cross section by about 20%. Together with

Yu. V. Bludov, V. V. Konotop, M. Salerno

Inter-band Rabi oscillations of gap soliton matter waves induced by time dependent periodic forces in combined linear and nonlinear optical lattices are for the first time demonstrated. It is shown that under suitable conditions these oscillations can become long-lived. By switching off the external force at proper time it is possible to create either pure (

Heath Emerson, Ralf Meyer

We use correspondences to define a purely topological equivariant bivariant K-theory for spaces with a proper groupoid action. Our notion of correspondence differs slightly from that of Connes and Skandalis. We replace smooth K-oriented maps by a class of K-oriented normal maps, which are maps together with a certain factorisation. Our construction does not

Michael J. Biercuk, Hermann Uys, Aaron P. VanDevender, Nobuyasu Shiga

We present experimental measurements on a model quantum system that demonstrate our ability to dramatically suppress qubit error rates by the application of optimized dynamical decoupling pulse sequences in a variety of experimentally relevant noise environments. We provide the first demonstration of an analytically derived pulse sequence developed by Uhrig,

Selman Akbulut, Kouichi Yasui

It is known that every exotic smooth structure on a simply connected closed 4-manifold is determined by a codimention zero compact contractible Stein submanifold and an involution on its boundary. Such a pair is called a cork. In this paper, we construct infinitely many knotted imbeddings of corks in 4-manifolds such that they induce infinitely many differen

Frank Wilczek

I review the quantum kinematics of identical particles, which suggests new possibilities, beyond bosons and fermions, in 2+1 dimensions; and how simple flux-charge constructions embody the new possibilities, leading to both abelian and nonabelian anyons. I briefly allude to experimental realizations, and also advertise a spinor construction of nonabelian sta

Sean M. O&#39;Neill, M. Coleman Miller, Tamara Bogdanovic, Christopher S. Reynolds

The association of an electromagnetic signal with the merger of a pair of supermassive black holes would have many important implications. For example, it would provide new information about gas and magnetic field interactions in dynamical spacetimes as well as a combination of redshift and luminosity distance that would enable precise cosmological tests. A

Janik Kailasvuori

The intrinsic contribution to the spin Hall effect in a 2DEG with non-magnetic impurities is studied in a quantum Boltzmann approach. It is shown that if the steady state response is perturbative in the spin-orbit coupling parameter $λ$, then the precession term--vital for Dyakonov-Perel relaxation and the key to the spin Hall effect in previous similar Bolt

Igor A. Tanski

In this article we derive two simple solutions of nonlinear Fokker - Planck equation for incompressible fluid and investigate their properties. In the second version errors in coefficients Imn and Jmn values are corrected.

Christian Frønsdal

This first article of a series formulates the thermodynamics of ideal gases in a constant gravitational field in terms of an action principle that is closely integrated with thermodynamics. The theory, in its simplest form, does not deviate from standard practice, but it lays the foundations for a more systematic approach to the various extensions, such as t

Alexey Anisimov, Pasquale Di Bari

We show that, within the see-saw mechanism, an almost decoupled RH neutrino species N_DM with mass M_DM \gtrsim 100 GeV can play the role of Dark Matter (DM). The N_DM&#39;s can be produced from non-adiabatic conversions of thermalized (source) RH neutrinos with mass M_S lower than M_DM. This is possible if a non-renormalizable operator is added to the minim

Craig van Coevering

The author has proved that a crepant resolution Y of a Ricci-flat Kähler cone X admits a complete Ricci-flat Kähler metric asymptotic to the cone metric in every Kähler class in H^2_c(Y,\R). These manifolds are generalizations of the Ricci-flat ALE Kähler spaces known by the work of P. Kronheimer, D. Joyce and others. This article considers further the probl

Orest Hrycyna, Marek Szydlowski

In this publication we investigate dynamics of a flat FRW cosmological model with a non-minimally coupled scalar field with the coupling term $ξR ψ^{2}$ in the scalar field action. The quadratic potential function $V(ψ)\propto ψ^{2}$ is assumed. All the evolutional paths are visualized and classified in the phase plane, at which the parameter of non-minimal

Nikolay Gromov, Vladimir Kazakov, Pedro Vieira

We propose, using the example of the O(4) sigma model, a general method for solving integrable two dimensional relativistic sigma models in a finite size periodic box. Our starting point is the so-called Y-system, which is equivalent to the thermodynamic Bethe ansatz equations of Yang and Yang. It is derived from the Zamolodchikov scattering theory in the cr

Ramesh Kumar Muthumalai

We show some definite integrals connecting to infinite series, studied in Ramanujan&#39;s paper, titled &#34;On question 330 of Professor Sanjana&#34;. We present few recursive methods to evaluate these definite integrals in various cases and we generalize this, to evaluate simliar kind of integrals through infinite series.

A. J. Kanel-Belov, A. V. Dyskin, Y. Estrin, E. Pasternak

We present structures comprised of identical convex polyhedra which are interlocked geometrically. These sets cannot be disassembled by removing individual polyhedra by translations and/or rotations. The shapes that permit interlocking arrangements include all five platonic solids. Criteria for interlocking based on transformations of the cross-sections of t

Alessandro Betti, Gianluca Fiori, Giuseppe Iannaccone

We present a novel method for the evaluation of shot noise in quasi one-dimensional field-effect transistors, such as those based on carbon nanotubes and silicon nanowires. The method is derived by using a statistical approach within the second quantization formalism and allows to include both the effects of Pauli exclusion and Coulomb repulsion among charge

Kunihito Ioka

We propose that a nearby gamma-ray burst (GRB) or GRB-like (old, single and short-lived) pulsar/supernova remnant/microquasar about 10^{5-6} years ago may be responsible for the excesses of cosmic-ray positrons and electrons recently observed by the PAMELA, ATIC/PPB-BETS, Fermi and HESS experiments. We can reproduce the smooth Fermi/HESS spectra as well as t

Ulf H. Danielsson, Larus Thorlacius

A model of 3+1 dimensional gravity with negative cosmological constant coupled to abelian gauge fields has been proposed as a gravity dual for Lifshitz like critical phenomena in 2+1 dimensions. The finite temperature behavior is described by black holes that are asymptotic to the Lifshitz fixed point geometry. There is a one-parameter family of charged blac

Mladen Kolar, Le Song, Amr Ahmed, Eric P. Xing

Stochastic networks are a plausible representation of the relational information among entities in dynamic systems such as living cells or social communities. While there is a rich literature in estimating a static or temporally invariant network from observation data, little has been done toward estimating time-varying networks from time series of entity at

T. R. Routray, Jagajjaya Nayak, D. N. Basu

Exotic cluster decay of very heavy nuclei is studied using the microscopic nuclear potentials obtained by folding density dependent M3Y effective interaction with the densities of the cluster and the daughter nuclei. The microscopic nuclear potential, Coulomb interaction and the centrifugal barrier arising out of spin-parity conservation are used to obtain t

Alessandro Ballestrero, Giuseppe Bevilacqua, Ezio Maina

A complete parton level analysis of lv + four jets production at the LHC is presented, including all processes at order O(alpha^6), O(alpha^4*alpha_s^2) and O(alpha^2*alpha_s^4). The infinite Higgs mass scenario, which is considered as a benchmark for strong scattering theories and is the limiting case for composite Higgs models, is confronted with the Stand

L. Sun, Z. -H. Fan, C. Tao, J. -P. Kneib

We study the impact of catastrophic errors occurring in the photometric redshifts of galaxies on cosmological parameter estimates with cosmic shear tomography. We consider a fiducial survey with 9-filter set and perform photo-z measurement simulations. It is found that a fraction of 1% galaxies at z_{spec}~0.4 is misidentified to be at z_{phot}~3.5. We then

Sergei P. Maydanyuk

In the paper the closed Friedmann--Robertson--Walker model with quantization in the presence of the positive cosmological constant and radiation is studied. For analysis of tunneling probability for birth of an asymptotically deSitter, inflationary Universe as a function of the radiation energy a new definition of a &#34;free&#34; wave propagating inside str

Leonid Lantsman

We argue that BPS ansatzes, entering manifestly vacuum BPS monopole solutions to equations of motion in the (Minkowskian) non-Abelian Higgs model play the role of some electric form-factors and that this implies (soft) violating the CP-invariance of the mentioned model, similar to taking place in the Euclidian Yang-Mills (YM) theory with instantons, generati

Sarbari Guha, Subenoy Chakraborty

In the braneworld scenario ordinary standard model matter and on-gravitational fields are confined by some trapping mechanism to the 4-dimensional universe constituting the D3-branes which are embedded in a (4 + n)-dimensional manifold referred to as the bulk (n being the number of extra dimensions). The notion of particle confinement is necessary for theori

Toan Nguyen

We extend our recent work with K. Zumbrun on long-time stability of multi-dimensional noncharacteristic viscous boundary layers of a class of symmetrizable hyperbolic-parabolic systems. Our main improvements are (i) to establish the stability for a larger class of systems in dimensions $d\ge 2$, yielding the result for certain magnetohydrodynamics (MHD) laye

Alioscia Hamma, Claudio Castelnovo, Claudio Chamon

We discuss the existence of stable topological quantum memory at finite temperature. At stake here is the fundamental question of whether it is, in principle, possible to store quantum information for macroscopic times without the intervention from the external world, that is, without error correction. We study the toric code in two dimensions with an additi

Qiang Li, Zhuo Chen, Yan He, Jing-ping Jiang

This paper introduces a model based upon games on an evolving network, and develops three clustering algorithms according to it. In the clustering algorithms, data points for clustering are regarded as players who can make decisions in games. On the network describing relationships among data points, an edge-removing-and-rewiring (ERR) function is employed t

Avraham Aizenbud, Dmitry Gourevitch, Eitan Sayag

In the first part of the paper we generalize a descent technique due to Harish-Chandra to the case of a reductive group acting on a smooth affine variety both defined over an arbitrary local field F of characteristic zero. Our main tool is the Luna Slice Theorem. In the second part of the paper we apply this technique to symmetric pairs. In particular we pro

Yiyuan She

This paper discusses a class of thresholding-based iterative selection procedures (TISP) for model selection and shrinkage. People have long before noticed the weakness of the convex $l_1$-constraint (or the soft-thresholding) in wavelets and have designed many different forms of nonconvex penalties to increase model sparsity and accuracy. But for a nonortho

Gouranga C Nayak

We solve renormalization group equation in QCD in the presence of SU(3) constant chromo-electric field E^a with arbitrary color index a=1,2,...8 and find that the QCD coupling constant α_s depends on two independent casimir/gauge invariants C_1=[E^aE^a] and C_2=[d_{abc}E^aE^bE^c]^2 instead of one gauge invariant C_1=[E^aE^a]. The βfunction is derived from th

Michael Gronau, Jonathan L. Rosner

A doubly CKM-suppressed amplitude in $B^0\to J/ψK_S$ leads to corrections in CP asymmetries $S = \sin 2β, C=0$, which may be enhanced by long-distance rescattering. It has been suggested that this enhancement may lead to several percent corrections. We calculate an upper bound of order $10^{-3}$ on rescattering corrections using measured branching ratios for

Armin Lühr, Alejandro Saenz

The stopping power of antiprotons in atomic and molecular hydrogen as well as helium was calculated in an impact-energy range from 1 keV to 6.4 MeV. In the case of H2 and He the targets were described with a single-active electron model centered on the target. The collision process was treated with the close-coupling formulation of the impact-parameter metho

A. A. Golubov, A. Brinkman, O. V. Dolgov, I. I. Mazin

The theory of Andreev conductance is formulated for junctions involving normal metals (N) and multiband superconductors (S) and applied to the case of superconductors with nodeless extended $s_{\pm}$-wave order parameter symmetry, as possibly realized in the recently discovered ferro pnictides. We find qualitative differences from tunneling into s-wave or d-

Alberto S. Cattaneo, Giovanni Felder, Thomas Willwacher

Recently the first two authors constructed an L-infinity morphism using the S^1-equivariant version of the Poisson Sigma Model (PSM). Its role in deformation quantization was not entirely clear. We give here a "good" interpretation and show that the resulting formality statement is equivalent to formality on cyclic chains as conjectured by Tsygan and proved

J. J. Sławianowski, V. Kovalchuk

Considered is the Schrödinger equation in a finite-dimensional space as an equation of mathematical physics derivable from the variational principle and treatable in terms of the Lagrange-Hamilton formalism. It provides an interesting example of &#34;mechanics&#34; with singular Lagrangians, effectively treatable within the framework of Dirac formalism. We d

J. X. de Carvalho, Sarika Jalan, M. S. Hussein

The study of spectral behavior of networks has gained enthusiasm over the last few years. In particular, Random Matrix Theory (RMT) concepts have proven to be useful. In discussing transition from regular behavior to fully chaotic behavior it has been found that an extrapolation formula of the Brody type can be used. In the present paper we analyze the regul

Neven Bilic

Thermodynamic properties of dark energy are discussed assuming that dark energy is described in terms of a selfinteracting complex scalar. We first show that, under certain assumptions, selfinteracting complex scalar field theories are equivalent to purely kinetic k-essence models. Then we analyze the themal properties of k-essence and in particular we show

Benito Santos, Elena Loginova, Arantzazu Mascaraque, Andreas K Schmid

We have grown epitaxial films a few atomic layers thick of iron oxides on ruthenium. We characterize the growth by low energy electron microscopy. Using selected area diffraction and intensity vs. voltage spectroscopy, we detect two distinct phases which are assigned to wustite and magnetite. Spin polarized low energy electron microscopy shows magnetic domai

Abhijit Samanta

In the atmospheric neutrino experiments the primary problems are the huge uncertainties of flux, very rapid fall of flux with increase of energy, the energy dependent wide resolutions of energy and zenith angle between true neutrinos and reconstructed neutrinos. These all in together make the choice of binning of the data for chi-square analysis complicated.

Jeong-Bo Shim, Mahir S. Hussein, Martina Hentschel

We study the validity of the Born-Oppenheimer approximation in chaotic dynamics. Using numerical solutions of autonomous Fermi accelerators, we show that the general adiabatic conditions can be interpreted as the narrowness of the chaotic region in phase space.

Abhijit Samanta

We have analyzed the atmospheric neutrino data to study the octant of $θ_{23}$ and the precision of the oscillation parameters for a large Iron CALorimeter (ICAL) detector. The ICAL being a tracking detector has the ability to measure the energy and the direction of the muon with high resolution. From bending of the track in magnetic field it can also distin

Concetta Nobile, Luigi Carbone, Angela Fiore, Roberto Cingolani

We deposit droplets of nanorods dispersed in solvents on substrate surfaces and let the solvent evaporate. We find that strong contact line pinning leads to dense nanorod deposition inside coffee stain fringes, where we observe large-scale lateral ordering of the nanorods with the long axis of the rods oriented parallel to the contact line. We observe birefr

Stephen D. Bartlett, Terry Rudolph, Robert W. Spekkens, Peter S. Turner

Typical quantum communication schemes are such that to achieve perfect decoding the receiver must share a reference frame with the sender. Indeed, if the receiver only possesses a bounded-size quantum token of the sender&#39;s reference frame, then the decoding is imperfect, and we can describe this effect as a noisy quantum channel. We seek here to characte

Boris Bukh, Jiří Matoušek, Gabriel Nivasch

A set N is called a &#34;weak epsilon-net&#34; (with respect to convex sets) for a finite set X in R^d if N intersects every convex set that contains at least epsilon*|X| points of X. For every fixed d>=2 and every r>=1 we construct sets X in R^d for which every weak (1/r)-net has at least Omega(r log^{d-1} r) points; this is the first superlinear lower boun

Xue-Qian Li

The experimental observation indicates that the branching ratio of $ψ&#39;\to ρπ$ is very small while the $ρ-π$ channel is a main one in $J/ψ$ decays. To understand the puzzle, various interpretations have been proposed. Meanwhile according to the hadronic helicity selection rule the decay mode $J/ψ\toρπ$ should be suppressed, but definitely, numerical compu

Hiroto Kuninaka, Hisao Hayakawa

Impact phenomena of nanoclusters subject to thermal fluctuations are numerically investigated. From the molecular dynamics simulation for colliding two identical clusters, it is found that the restitution coefficient for head-on collisions has a peak at a colliding speed due to the competition between the cohesive interaction and the repulsive interaction of

Daniel Kane, Gregory N. Price, Erik D. Demaine

Alexandrov&#39;s Theorem states that every metric with the global topology and local geometry required of a convex polyhedron is in fact the intrinsic metric of a unique convex polyhedron. Recent work by Bobenko and Izmestiev describes a differential equation whose solution leads to the polyhedron corresponding to a given metric. We describe an algorithm bas

Jorge Galindo, Sergio Macario

We show that every Abelian group satisfying a mild cardinal inequality admits a pseudocompact group topology from which all countable subgroups inherit the maximal totally bounded topology (we say that such a topology satisfies property $\h$). Every pseudocompact Abelian group $G$ with cardinality $|G|\leq 2^{2^\cc}$ satisfies this inequality and therefore a

Hajime Ishimori, Yusuke Shimizu, Morimitsu Tanimoto

We have presented a $S_4$ flavor model to unify quarks and leptons in the framework of the SU(5) GUT. Three generations of $\bar5$-plets in SU(5) are assigned $3_1$ of $S_4$ while the first and the second generations of 10-plets in SU(5) are assigned to be 2 of $S_4$, and the third generation of 10-plet is to be $1_1$ of $S_4$. The right-handed neutrinos are

Raka Dasgupta

We investigate the phenomenon of fermionic pairing with mismatched Fermi surfaces in a two-species system in the presence of Feshbach resonance, where the resonantly-paired fermions combine to form bosonic molecules. We observe that the Feshbach parameters control the critical temperature of the gapped BCS superfluid state, and also determine the range over

Aleks Kleyn

Based on twin representations of division ring in an Abelian group I consider $D$\Hyph vector spaces over division ring. Morphism of $D$\Hyph vector spaces is linear map of $D$\Hyph vector spaces. I consider derivative of function $f$ of continuous division ring as linear map the most close to function $f$. I explore expansion of map into Taylor series and m

Jun Li, Wen Yang, Kai Chang

We investigate theoretically the spin states in InAs/AlSb/GaSb broken-gap quantum wells by solving the Kane model and the Poisson equation self-consistently. The spin states in InAs/AlSb/GaSb quantum wells are quite different from those obtained by the single-band Rashba model due to the electron-hole hybridization. The Rashba spin-splitting of the lowest co

Ji-Haeng Huh, Jihn E. Kim, Bumseok Kyae

We present the dark matter extension of the minimal supersymmetric standard model by one more two component stable fermion N toward explaining the recent rising high energy positron spectrum of the PAMELA data. The needed coupling can arise in the flipped-SU(5) GUT.