October 2009 arXiv papers — page 27

Yongzhi Cao, Guoqing Chen

Motivated by Zadeh's paradigm of computing with words rather than numbers, several formal models of computing with words have recently been proposed. These models are based on automata and thus are not well-suited for concurrent computing. In this paper, we incorporate the well-known model of concurrent computing, Petri nets, together with fuzzy set theo

V. N. Melnikov

Gravitation as a fundamental interaction that governs all phenomena at large and very small scales, but still not well understood at a quantum level, is a cardinal missing link in unification of all physical interactions. Discovery of the present acceleration of the Universe, the dark matter and dark energy problems are also a great challenge to modern physi

Satyam Mukherjee, Gautam Mukherjee, Neelima Gupte

We study message transport on a $1-d$ ring of nodes and randomly distributed hubs. Messages are deposited on the network at a constant rate. When the rate at which messages are deposited on the lattice is very high, messages start accumulating after a critical time and the average load per node starts increasing. The power-spectrum of the load time-series sh

O. Karpenkov, A. Vershik

How to find "best rational approximations" of maximal commutative subgroups of GL(n,R)? In this paper we pose and make first steps in the study of this problem. It contains both classical problems of Diophantine and simultaneous approximations as a particular subcases but in general is much wider. We prove estimates for n=2 for both totaly real and c

A. Just, H. Jahreiss

We present a fully consistent evolutionary disc model of the solar cylinder. The model is based on a sequence of stellar sub-populations described by the star formation history (SFR) and the dynamical heating law (given by the age-velocity dispersion relation AVR). The combination of kinematic data from Hipparcos and the finite lifetimes of main sequence (MS

L. Coney

Muon ionization cooling provides the only practical solution for preparing high brightness beams necessary for a neutrino factory or muon collider. The Muon Ionization Cooling Experiment (MICE) is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line designed to generate a range of input emittances and momenta with

Zhenhua Qiao, Yanxia Xing, Jian Wang

We report a theoretical investigation on conductance fluctuation of mesoscopic systems. Extensive numerical simulations on quasi-one dimensional, two dimensional, and quantum dot systems with different symmetries (COE, CUE, and CSE) indicate that the conductance fluctuation can reach a new universal value in the crossover regime for systems with CUE and CSE

Zhong-Qi Ma, C. N. Yang

In these two papers, we solve the N body 1D harmonically trapped spinless Boson or spin 1/2 Fermions with repulsive delta function interaction in the limit $N\to \infty$.

Masaaki Nakamura, Eduardo V. Castro, Balazs Dora

Physical properties reflecting valley asymmetry of Landau levels in a biased bilayer graphene under magnetic field are discussed. Within the $4-$band continuum model with Hartree-corrected self-consistent gap and finite damping factor we predict the appearance of anomalous steps in quantized Hall conductivity due to the degeneracy lifting of Landau levels. M

J. Marteau

The aim of the OPERA experiment is to search for the appearance of the tau neutrino in the quasi pure muon neutrino beam produced at CERN (CNGS). The detector, installed in the Gran Sasso underground laboratory 730 km away from CERN, consists of a lead/emulsion target complemented with electronic detectors. After a short pilot run in 2007, a first physics ru

E. J. Chung, M. -H. Rhee, H. Kim, M. S. Yun

We have performed an On-The-Fly (OTF) mapping survey of ${\rm ^{12}{CO(J=1-0)}}$ emission in 28 Virgo cluster spiral galaxies using the Five College Radio Astronomy Observatory (FCRAO) 14-m telescope. This survey aims to characterize the CO distribution, kinematics, and luminosity of a large sample of galaxies covering the full extents of stellar disks, rath

Partha Goswami

We investigate a chiral d-density wave (CDDW) mean field Hamiltonian in momentum space, which also includes the in-plane hopping anisotropy parameter e, for the under-doped YBCO to explore the possibility of quantum oscillations (QO) in the specific heat in the presence of a changing magnetic field (B). The inclusion is motivated by the experimental signatur

V. Roman'kov, E. Ventura

An algorithm is constructed that, when given an explicit presentation of a finitely generated nilpotent group $G,$ decides for any pair of endomorphisms $φ, ψ: G \to G$ and any pair of elements $u, v \in G,$ whether or not the equation $(xφ)u = v (xψ)$ has a solution $x \in G.$ Thus it is shown that the problem of the title is decidable. Also we present an a

H. Kleinert

At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the second and fourth moments of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.

G. Chaudhuri, F. Gulminelli, S. Das Gupta

Different formulas relying measurable fragment isotopic observables to the symmetry energy of excited nuclei have been proposed and applied to the analysis of heavy ion collision data in the recent literature. In this paper we examine the quality of the different expressions in the framework of the McGill Canonical Thermodynamic Model. We show that even in t

V. V. Flambaum, S. G. Porsev

Our calculations have shown that the 5f_5/2-7s_1/2 23131 cm^{-1} transition from the ground state in the ion Th^{3+} is very sensitive to the temporal variation of the fine structure constant alpha (q=-75300 cm^{-1}). The line is very narrow, the ion has been trapped and laser cooled and the positive shifter line 5f_5/2-5f_7/2 4325 cm^{-1} (q=+2900 cm^{-1})

Ilana Feain, Ronald Ekers, Tara Murphy, Bryan Gaensler

We present the results of an Australia Telescope Compact Array 1.4 GHz spectropolarimetric aperture synthesis survey of 34 square degrees centred on Centaurus A - NGC 5128. A catalogue of 1005 extragalactic compact radio sources in the field to a continuum flux density of 3 mJy/beam is provided along with a table of Faraday rotation measures (RMs) and linear

D. C. Peets, Ruixing Liang, Mati Raudsepp, W. N. Hardy

Highly-perfect platelet single crystals of Tl_2Ba_2CuO_{6+d} (Tl-2201) were grown by a self-flux technique. A novel encapsulation scheme allowed the precursors to react prior to the sealing required to contain volatile thallium oxides, and permitted the removal of melt at the conclusion of growth, reproducibly producing high yields of clean crystals. The cry

V. B. Bobrov, S. A. Trigger

Model of the degenerated weakly non-ideal Bose gas is considered without suggestion on C-number representation of the creation and annihilation operators with zero momentum. The "density-density" correlation function and the one-particle Green function are calculated on basis of the suggestion about C-number representation of the operator of particle

Jeffrey S. Bary, Jarron M. Leisenring, Michael F. Skrutskie

Using the Infrared Spectrograph aboard the Spitzer Space Telescope, we observed multiple epochs of 11 actively accreting T Tauri stars in the nearby Taurus-Auriga star forming region. In total, 88 low-resolution mid-infrared spectra were collected over 1.5 years in Cycles 2 and 3. The results of this multi-epoch survey show that the 10 um silicate complex in

David Saintillan, Amir Alizadeh Pahlavan

Suspensions of self-propelled particles, such as swimming micro-organisms, are known to undergo complex dynamics as a result of hydrodynamic interactions. This fluid dynamics video presents a numerical simulation of such a suspension, based on a kinetic theory recently developed by Saintillan and Shelley (Physics of Fluids, 20, 123403, 2008). Starting from a

Atushi Tanaka, Kae Nemoto

The parametric deformations of quasienergies and eigenvectors of unitary operators are applied to the design of quantum adiabatic algorithms. The conventional, standard adiabatic quantum computation proceeds along eigenenergies of parameter-dependent Hamiltonians. By contrast, discrete adiabatic computation utilizes adiabatic passage along the quasienergies

C. Weeks, M. Franz

We explore the possible particle-hole instabilities that can arise in a system of massless Dirac fermions on both the honeycomb and pi-flux square lattices with short range interactions. Through analytical and numerical studies we show that these instabilities can result in a number of interesting phases. In addition to the previously identified charge and s

German Kälbermann

A model of nuclear fusion consisting of a wave packet impinging into a well located between square one dimensional barriers is treated analytically. The wave function inside the well is calculated exactly for the assisted tunneling induced by a perturbation mimicking a constant electric field with arbitrary time dependence. Conditions are found for the enhan

Sanjoy Biswas, Biswarup Mukhopadhyaya

We consider a supersymmetric (SUSY) scenario including right-handed neutrinos, one of whose scalar superpartners is the lightest SUSY particle (LSP). The distinguishing feature in the collider signal of SUSY in such a case is not missing energy but a pair of charged tracks corresponding to the next-to- lightest SUSY particle, when it is, as in the case consi

Zhen Hou, A. J. Banday, K. M. Gorski, N. E. Groeneboom

We present local extrema studies of two models that introduce a preferred direction into the observed cosmic microwave background (CMB) temperature field. In particular, we make a frequentist comparison of the one- and two-point statistics for the dipole modulation and ACW models with data from the five-year Wilkinson Microwave Anisotropy Probe (WMAP). This

S. W. Kong, A. Y. L. Wong, Y. F. Huang, K. S. Cheng

Conventionally, long GRBs are thought to be caused by the core collapses of massive stars. During the lifetime of a massive star, a stellar wind bubble environment should be produced. Furthermore, the microphysics shock parameters may vary along with the evolution of the fireball. Here we investigate the variation of the microphysics shock parameters under t

Yulij Ilyashenko, Jaume Llibre

The restricted version of the Hilbert 16th problem for quadratic vector fields requires an upper estimate of the number of limit cycles through a vector parameter that characterizes the vector fields considered and the limit cycles to be counted. In this paper we give an upper estimate of the number of limit cycles of quadratic vector fields $"σ$--distan

Hoda Bidkhori, Shaunak Kishore

The line graph LG of a directed graph G has a vertex for every edge of G and an edge for every path of length 2 in G. In 1967, Knuth used the Matrix-Tree Theorem to prove a formula for the number of spanning trees of LG, and he asked for a bijective proof. In this paper, we give a bijective proof of a generating function identity due to Levine which generali

Amir Farbin

While in the early 90s High Energy Physics (HEP) lead the computing industry by establishing the HTTP protocol and the first web-servers, the long time-scale for planning and building modern HEP experiments has resulted in a generally slow adoption of emerging computing technologies which rapidly become commonplace in business and other scientific fields. I

Istvan Danko

We report the first direct observation of muon antineutrinos in the MINOS Far Detector in the current muon-neutrino dominated beam. The magnetic field of the detector is utilized to separate muon neutrinos and antineutrinos event-by-event by identifying the charge sign of the muon created in charged-current interactions. We present preliminary results on the

Manikandan Mathur, Matthieu Mercier, Thierry Dauxois, Thomas Peacock

In this fluid dynamics video, we demonstrate the experimental generation of various internal wave fields using a novel wave generator. Specifically, uni-directional internal wave beams and vertical modes 1 and 2 are generated and visualized using Particle Image Velocimetry. Further details and analysis of these experiments can be found in [1].

Christian Sturm

We discuss the concepts and the framework of the renormalization procedure in regularization-invariant momentum subtraction schemes. These schemes are used in the context of lattice simulations for the determination of physical quantities like light quark masses. We focus on the renormalization procedure with a symmetric subtraction point of a quark mass and

Yongsheng Jiang, Huan-Song Zhou

We study the following Schrödinger-Poisson system (P_λ)\{ll} -Δu + (1+μg(x))u+λϕ(x) u =|u|^{p-1}u, x\in \mathbb{R}^3,

X. -H. Guo, B. Liu, M. -H. Weng

The vacuum fluctuation (VF) effects on asymmetric nuclear matter are investigated. Masses of nucleons and mesons are modified in the nuclear medium by calculating the loop-diagram corrections and the density dependence of hadron masses is obtained. The relativistic Lagrangian density with the isovector scalar $δ$ meson is used to calculate the nuclear equati

I. C. Kim, H. K. Lei

We introduce a notion of viscosity solutions for a nonlinear degenerate diffusion equation with a drift potential. We show that our notion of solutions coincide with the weak solutions defined via integration by parts. As an application of the viscosity solutions theory, we show that the free boundary uniformly converges to the equilibrium as time grows. In

J. Krticka, A. Feldmeier, L. M. Oskinova, J. Kubat

Hot stars are sources of X-ray emission originating in their winds. Although hydrodynamical simulations that are able to predict this X-ray emission are available, the inclusion of X-rays in stationary wind models is usually based on simplifying approximations. To improve this, we use results from time-dependent hydrodynamical simulations of the line-driven

Mumtaz Hussain, Jason Levesley

In this paper we investigate the metrical theory of Diophantine approximation associated with linear forms that are simultaneously small for infinitely many integer vectors; i.e. forms which are close to the origin. A complete Khintchine--Groshev type theorem is established, as well as its Hausdorff measure generalization. The latter implies the complete Hau

Karl-Olof Lindahl

We give lower bounds for the size of linearization discs for power series over $\mathbb{C}_p$. For quadratic maps, and certain power series containing a `sufficiently large' quadratic term, we find the exact linearization disc. For finite extensions of $\mathbb{Q}_p$, we give a sufficient condition on the multiplier under which the corresponding lineariz

M. N. Kiselev, K. Kikoin, J. Richert

We show how the charge input signal applied to the gate electrode in a double and triple quantum dot may be converted to a pulse in the Kondo cotunneling current being a spin response of a nano-device under a strong Coulomb blockade. The stochastic component of the input signal results in the infrared cutoff of Kondo transmission. The stochastization of the

Janusz Kaluzny, Ian B. Thompson

We report time-series photometry for 16 variable stars located in the central part of the globular cluster NGC 6752. The sample includes 13 newly identified objects. The precision of our differential photometry ranges from 1 mmag at V=14.0 to 10 mmag at V=18.0. We detected 4 low amplitude variables located on the extended horizontal branch (EHB) of the clust

Wei Cui, Wolfram Helwig, Hoi-Kwong Lo

For a tripartite pure state of three qubits, it is well known that there are two inequivalent classes of genuine tripartite entanglement, namely the GHZ-class and the W-class. Any two states within the same class can be transformed into each other with stochastic local operations and classical communication (SLOCC) with a non-zero probability. The optimal co

D. Bernard

I review the recent efforts to improve the precision of the prediction of the anomalous moment of the muon, in particular of the hadronic contribution of the vacuum polarization, which is the contribution with the largest uncertainty. Focus is given to the recent result for e+e- -> pi+pi- by the BaBar collaboration, obtained using events with radiation in th

Youjun Lu, Fupeng Zhang, Qingjuan Yu

Hypervelocity stars (HVSs) escaping away from the Galactic halo are dynamical products of interactions of stars with the massive black hole(s) (MBH) in the Galactic Center (GC). They are mainly B-type stars with their progenitors unknown. OB stars are also populated in the GC, with many being hosted in a clockwise-rotating young stellar (CWS) disk within hal

Antina Ghosh, Vijayakumar K. Chikkadi, Peter Schall, Jorge Kurchan

Glasses are structurally liquid-like, but mechanically solid-like. Most attempts to understand glasses start from liquid state theory. Here we take the opposite point of view, and use concepts from solid state physics. We determine the vibrational modes of a colloidal glass experimentally, and find soft low-frequency modes that are very different in nature f

Patrick Wils, Boris T. Gaensicke, Andrew J. Drake, John Southworth

By cross matching blue objects from SDSS with GALEX and the astrometric catalogues USNO-B1.0, GSC2.3 and CMC14, 64 new dwarf nova candidates with one or more observed outbursts have been identified. 14 of these systems are confirmed as cataclysmic variables through existing and follow-up spectroscopy. A study of the amplitude distribution and an estimate of

Alastair J. R. Sanderson, Trevor J. Ponman

We present a parametric analysis of the intracluster medium and gravitating mass distribution of a statistical sample of 20 galaxy clusters using the phenomenological cluster model of Ascasibar and Diego. We describe an effective scheme for the estimation of errors on model parameters and derived quantities using bootstrap resampling. We find that the model

Brando Bellazzini, Csaba Csaki, Adam Falkowski, Andreas Weiler

We present a simple supersymmetric model where the dominant decay mode of the lightest Higgs boson is h->2eta->4c where eta is a light pseudoscalar and c is the charm quark. For such decays the Higgs mass can be smaller than 100 GeV without conflict with experiment. Together with the fact that both the Higgs and the pseudoscalar eta are pseudo-Goldstone boso

Laura A. Lopez, Enrico Ramirez-Ruiz, Carles Badenes, Daniela Huppenkothen

We present a new observational method to type the explosions of young supernova remnants (SNRs). By measuring the morphology of the Chandra X-ray line emission in seventeen Galactic and Large Magellanic Cloud SNRs with a multipole expansion analysis (using power ratios), we find that the core-collapse SNRs are statistically more asymmetric than the Type Ia S

A. Ahmad

The study of W or Z boson with accompanying hadronic jets in final states is of high importance at hadron colliders both to understand Standard Model processes and to measure background to Beyond Standard Model physics searches. The presence of one or more jets in the final state increases the complexity for the reconstruction of leptons and of missing trans

Ernst Martin Witte, Filippo Borlenghi, Gerd Ascheid, Rainer Leupers

Multiple-input multiple-output (MIMO) wireless transmission imposes huge challenges on the design of efficient hardware architectures for iterative receivers. A major challenge is soft-input soft-output (SISO) MIMO demapping, often approached by sphere decoding (SD). In this paper, we introduce the - to our best knowledge - first VLSI architecture for SISO S

V. D. Ivashchuk

A (n + 1)-dimensional Einstein-Gauss-Bonnet (EGB) model is considered. For diagonal cosmological-type metrics, the equations of motion are reduced to a set of Lagrange equations. The effective Lagrangian contains two "minisuperspace" metrics on R^n. The first one is the well-known 2-metric of pseudo-Euclidean signature and the second one is the Finsl

Gennady Gorelik

Do physical laws limit the speed of "all data processing systems, manmade as well as biological"? This question proposed and positively answered by H. J. Bremermann in 1962, should be corrected to make it compatible with Einstein's theory of gravity (aka General Relativity, or GR). As a result, the Bremermann's limit, proportional to mass M of any computer,

Gyu-Boong Jo, Ye-Ryoung Lee, Jae-Hoon Choi, Caleb A. Christensen

Ho claims in his comment that our experiment is direct evidence that itinerant ferromagnetism does not exist in ultracold Fermi gases. This claim is incorrect and based on an invalid estimate of relaxation times and an erroneous interpretation of the detectability of ferromagnetic domains. We point out that the experimental evidence is consistent with the ex

Ricardo Conceição

We construct isotrivial and non-isotrivial elliptic curves over $\mathbb{F}_q(t)$ with an arbitrarily large set of separable integral points. As an application of this construction, we prove that there are isotrivial log-general type varieties over $\mathbb_{F}_q(t)$ with a Zariski dense set of separable integral points. This provides a counterexample to a n

A. Kucinskas, H. -G. Ludwig, E. Caffau, M. Steffen

We present synthetic broad-band photometric colors of a late-type giant located close to the RGB tip (T_eff = 3640 K, log g = 1.0 and [M/H] = 0.0). Johnson-Cousins-Glass BVRIJHK colors were obtained from the spectral energy distributions calculated using 3D hydrodynamical and 1D classical stellar atmosphere models. The differences between photometric magnitu

Stephen Godfrey

There have been numerous developments in hadron spectroscopy over the past year. In this brief review I focus on two general areas. In the first I give an update on hadrons with b-quarks. Their properties are in textbook agreement with QCD motivated constituent quark models. The second topic is the Charmonium-like $XYZ$ states above open charm threshold that

Constantine Yannouleas, Uzi Landman

A description of neutral and multiply charged fullerenes is proposed based on a stabilized jellium (structureless pseudopotential) approximation for the ionic background and the local density approximation for the sigma and pi valence electrons. A recently developed shell-correction method is used to calculate total energies and properties of both the neutra

B. Doubrov, E. V. Ferapontov

Let u be a function of n independent variables x^1, ..., x^n, and U=(u_{ij}) the Hessian matrix of u. The symplectic Monge-Ampere equation is defined as a linear relation among all possible minors of U. Particular examples include the equation det U=1 governing improper affine spheres and the so-called heavenly equation, u_{13}u_{24}-u_{23}u_{14}=1, describi

R. Armillis, C. Coriano, L. Delle Rose

We compute in linearized gravity all the contributions to the gravitational effective action due to a virtual Dirac fermion, related to the conformal anomaly. This requires, in perturbation theory, the identification of the gauge-gauge-graviton vertex off mass shell, involving the correlator of the energy-momentum tensor and two vector currents ($TJJ$), whic

Wei-tian Deng, Xin-Nian Wang

Within the framework of generalized factorization of higher-twist contributions to semi-inclusive cross section of deeply inelastic scattering off a large nucleus, multiple parton scattering leads to an effective medium-modified fragmentation function and the corresponding medium-modified DGLAP evolution equations. We extend the study to include gluon multip

George Pal, Yaroslav Pavlyukh, Wolfgang Hübner, Hans Christian Schneider

We present a method for computing optical absorption spectra by means of a Bethe-Salpeter equation approach, which is based on a conserving linear response calculation for electron-hole coherences in the presence of an external electromagnetic field. This procedure allows, in principle, for the determination of the electron-hole correlation function self-con

K. Kutak

We report on application of QCD in calculations of forward jet and W, Z boson production cross sections at the Large Hadron Collider. In particular in case of jet production we emphasize dynamical features of the matrix elements controlling the resummation of logarithmically enhanced corrections in $\sqrt{s}/E_T$, where $E_T$ is the jet production transverse

P. D. Smith, R. E. Hughes, B. L. Winer, T. W. Wood

The Fermi Gamma-Ray Space Telescope was launched in June 2008 and the onboard Large Area Telescope (LAT) has been collecting data since August of that same year. The LAT is currently being used to study a wide range of science topics in high-energy astrophysics, one of which is the study of high-energy cosmic rays. The LAT has recently demonstrated its abili

Aymeric Sadoc, Bernard Mercey, Charles Simon, Dominique Grebille

Using first principle calculations we showed that the Curie temperature of manganites thin films can be increased by far more than an order of magnitude by applying appropriate strains. Our main breakthrough is that the control of the orbital ordering responsible for the spectacular $T_C$ increase cannot be imposed by the substrate only. Indeed, the strains,

M. Longo, V. Rotger, S. Vigni

The main goal of this article is to give an explicit rigid analytic uniformization of the maximal toric quotient of the Jacobian of a Shimura curve over the field of rational numbers at a prime dividing exactly the level. This result can be viewed as complementary to the classical theorem of Cerednik and Drinfeld which provides rigid analytic uniformizations

Y. Daikoku, H. Okada

We propose a E_6 inspired supersymmetric model with a non-Abelian discrete flavor symmetry (S_4 group); that is, SU(3)_c x SU(2)_W x U(1)_Y x U(1)_X x S_4 x Z_2. In our scenario, the additional abelian gauge symmetry; U(1)_X, not only solves the mu-problem in the minimal Supersymmetric Standard Model(MSSM), but also requires new exotic fields which play an i

E. N. Thompson, S. Willocq, K. M. Black

The Standard Model has been successful in describing many fundamental aspects of particle physics. However, there are some remaining puzzles that are not explained within the context of its present framework. We discuss the possibility to discover new physics in the ATLAS Detector via a four-fermion contact interaction, much in the same way Fermi first descr

Shaun Hotchkiss, Subir Sarkar

Multiple inflation is a model based on N=1 supergravity wherein there are sudden changes in the mass of the inflaton because it couples to 'flat direction' scalar fields which undergo symmetry breaking phase transitions as the universe cools. The resulting brief violations of slow-roll evolution generate a non-gaussian signal which we find to be osci

Julio C. Fabris, Bernardo Fraga, Nelson Pinto-Neto, Winfried Zimdahl

Recent investigations seem to favor a cosmological dynamics according to which the accelerated expansion of the Universe may have already peaked and is now slowing down again \cite{sastaro}. As a consequence, the cosmic acceleration may be a transient phenomenon. We investigate a toy model that reproduces such a background behavior as the result of a time-de

J. Ferrando

Recent results from the HERA ep collider are reviewed in these proceedings. The results are from measurements that probe QCD at high-energy scales, as defined by $Q^2$, the four-momentum-transfer squared of the collisions. These cross-section measurements provide information about the parton distribution functions (PDFs) of the proton and can be used to cons

Ewa Pawluszewicz, Delfim F. M. Torres

We consider dynamic systems on time scales under the control of two agents. One of the agents desires to keep the state of the system out of a given set regardless of the other agent's actions. Leitmann's avoidance conditions are proved to be valid for dynamic systems evolving on an arbitrary time scale.

Andrew Drucker, Ronald de Wolf

Alongside the development of quantum algorithms and quantum complexity theory in recent years, quantum techniques have also proved instrumental in obtaining results in classical (non-quantum) areas. In this paper we survey these results and the quantum toolbox they use.

Miao Li, Rong-Xin Miao, Yi Pang

We compute the Casimir energy of the photon field in a de Sitter space and find it to be proportional to the size of the horizon, the same form of the holographic dark energy. We suggest to make metamaterials to mimic de Sitter space in laboratory and measure the predicted Casimir energy.

Marcelo Arenas, Jorge Perez, Juan Reutter, Cristian Riveros

In the recent years, a lot of attention has been paid to the development of solid foundations for the composition and inversion of schema mappings. In this paper, we review the proposals for the semantics of these crucial operators. For each of these proposals, we concentrate on the three following problems: the definition of the semantics of the operator, t

A. S. Rapinchuk, I. A. Rapinchuk

We address the problem of when two finite dimensional central division algebras over the same field are necessarily isomorphic given that they have the same maximal subfields.

M. Pallavicini

Borexino is a solar neutrino experiment running at the Laboratori Nazionali del Gran Sasso, Italy. The radioactive background levels in the liquid scintillator target meet or even exceed design goals, opening unanticipated opportunities. The main results, so far, are the measurement of the $^7$Be solar neutrino flux (the first ever done) and the measurement

Sang Pyo Kim, Hyun Kyu Lee, Yongsung Yoon

We find the Bogoliubov coefficient from the tunneling boundary condition on a charged particle coupled to a static electric field $E_0 sech^2 (z/L)$ and, using the regularization scheme in Phys. Rev. D 78, 105013 (2008), obtain the exact one-loop effective action in scalar and spinor QED. It is shown that the effective action satisfies the general relation b

Pandeng Dong, Song Shao, Xiangdong Ye

Let $\F$ be a collection of subsets of $\Z_+$ and $(X,T)$ be a dynamical system. $x\in X$ is $\F$-recurrent if for each neighborhood $U$ of $x$, $\{n\in\Z_+:T^n x\in U\}\in \F$. $x$ is $\F$-product recurrent if $(x,y)$ is recurrent for any $\F$-recurrent point $y$ in any dynamical system $(Y,S)$. It is well known that $x$ is $\{infinite\}$-product recurrent

D. E. Kharzeev, E. M. Levin

N=4 Super-symmetric Yang-Mills theory (N=4 SYM) in the strong coupling regime has been successfully applied (through the AdS/CFT correspondence) to the description of strongly coupled plasma which is a multiparticle state. Yet, the high-energy scattering in the strong coupling limit of N=4 SYM is purely elastic, so this multiparticle final state can never be

Naoyuki Haba, Kin-ya Oda, Ryo Takahashi

We propose a simple five-dimensional extension of the Standard Model (SM) without any Higgs potential nor any extra fields. A Higgs doublet lives in the bulk of a flat line segment and its boundary condition is Dirichlet at the ends of the line, which causes the electroweak symmetry breaking without Higgs potential. The vacuum expectation value of the Higgs

Adam Larios, Edriss S. Titi

We prove higher-order and a Gevrey class (spatial analytic) regularity of solutions to the Euler-Voigt inviscid $α$-regularization of the three-dimensional Euler equations of ideal incompressible fluids. Moreover, we establish the convergence of strong solutions of the Euler-Voigt model to the corresponding solution of the three-dimensional Euler equations f

Mikhail Zaidenberg

The classical Floquet theory deals with Floquet-Bloch solutions of periodic PDEs (see e.g., P. Kuchment. Floquet Theory for Partial Differential Equations. Basel: Birkhauser, 1993). Peter Kuchment developed as well a discrete version of this theory for difference vector equations on lattices, including the Floquet theory on infinite periodic graphs. Here we

Ameur Dhahri

We prove that the quadratic second quantization of an operator p on $L^2(\mathbb{R}^d)\cap L^\infty (\mathbb{R}^d)$ is an orthogonal projection on the quadratic Fock space if and only if p =MI, where MI is a multiplication operator by a characteristic function I.

Ivan C. Christov

Recent numerical work on the Zabusky--Kruskal experiment has revealed, amongst other things, the existence of hidden solitons in the wave profile. Here, using Osborne's nonlinear Fourier analysis, which is based on the periodic, inverse scattering transform, the hidden soliton hypothesis is corroborated, and the \emph{exact} number of solitons, their amp

J. Köplinger, V. Dzhunushaliev

This paper follows recent steps towards a nonassociative quantum theory and points out the mathematical structure behind the proposed modifications to conventional quantum theory. An N=1 supersymmetry model and a strong force glueball ansatz is highlighted. Using nonassociative complex octonion algebra, it is shown how the Lorentz Lie algebra can be understo

Hai Qing Zhou, Chung Wen Kao, Shin Nan Yang, Keitaro Nagata

The details of the calculation of the two-boson exchange effects in the parity-violating elastic $ep$ scattering within a simple hadronic model, including both the nucleon and $Δ(1232)$-resonance intermediate states, are presented. We examine the sensitivity of our results with respect to choice of form factors. We emphasize the importance to use correct rel

Selda Esen, CMS Collaboration

We present a search for extra dimensions in the diphoton channel using the CMS detector at the Large Hadron Collider. The search is focused on the forthcoming 2009--2010 run at 10 TeV center$-$of$-$mass energy and $\sim 100$ pb$^{-1}$ of data. We discuss event selection and optimization, as well as data-driven methods of estimating various backgrounds and ef

M. Soderberg

Liquid Argon Time Projection Chamber detectors are ideally suited for studying neutrino interactions and probing the parameters that characterize neutrino oscillations. The ability to drift ionization particles over long distances in purified argon and to trigger on abundant scintillation light allows for excellent particle identification and triggering capa

Dilip Jana

Due to the large $t\bar{t}$ production cross-section at the LHC energies, the ATLAS experiment is expected to have enough statistics to measure $t\bar{t}$ cross-section even at initial luminosities. Recent studies performed in ATLAS on the development of $t\bar{t}$ cross-section measurements in the lepton+jets channel at $\sqrt{s}$=10 TeV using the likelihoo

Yakir Aharonov, Pawel O. Mazur

We study a simple exactly solvable 2D model describing the interaction of a localized particle with an impurity. The localization potential $V(x)=-αδ(x)$ causes the particle to be trapped in the y-axis, and the `impurity' is modeled by a straight impenetrable edge extending along the positive x-axis. We show that the problem described can be treated as t

L. Raul Abramo, Patrick Peter, Ivan Yasuda

We investigate bouncing solutions in the framework of the non-singular gravity model of Brandenberger, Mukhanov and Sornborger. We show that a spatially flat universe filled with ordinary matter undergoing a phase of contraction reaches a stage of minimal expansion factor before bouncing in a regular way to reach the expanding phase. The expansion can be con

K. Mukai, E. Zietsman, M. Still

V893 Sco is an eclipsing dwarf nova that had attracted little attention from X-ray astronomers until it was proposed as the identification of an RXTE all-sky slew survey (XSS) source. Here we report on the pointed X-ray observations of this object using Suzaku. V893 Sco was in quiescence at the time, as indicated by the coordinated optical photometry we obta

Darren D. Price

We present a search for the Standard Model Higgs boson produced in association with a W boson in $p\bar{p}$ collisions at a center-of-mass energy of $\sqrt{s} = 1.96$ TeV. The search is performed in the $WH\to \ellνb\bar{b}$ channel using 2.7 fb$^{-1}$ of data collected by both the CDF detector and by the $DØ$ detector, at the Fermilab Tevatron. The searches

P. G. Freeman, S. M. Hayden, C. D. Frost, M. Enderle

Polarized- and unpolarized-neutron scattering measurements of the spin excitation spectrum in the stripe-ordered phase of La2NiO4+d (d = 0.11) are presented. At low energies, the magnetic spectral weight is found to shift anomalously towards the two-dimensional antiferromagnetic wave vector, similar to the low-energy dispersions observed in cuprate supercond

A. Ferrari, M. V. Garzelli, P. R. Sala

From an experimental point of view, clear signatures of multifragmentation have been detected by different experiments. On the other hand, from a theoretical point of view, many different models, built on the basis of totally different and often even contrasting assumptions, have been provided to explain them. In this contribution we show the capabilities an

D. Kotschick, S. Morita

In the early 1970's, Gelfand, Kalinin and Fuks found an exotic characteristic class of degree 7 in the Gelfand-Fuks cohomology of the Lie algebra of formal Hamiltonian vector fields on the plane. We prove that this cohomology class can be decomposed as a product of a certain leaf cohomology class of degree 5 and the transverse symplectic class. This is s

J. Páramos, O. Bertolami

We consider the impact of a power-law correction to the Newtonian potential, inspired by ungravity or $f(R)$ extensions of the Standard Model, and draw conclusions on the possibility of measuring the relevant parameters through observables made available by the Galileo satellite positioning system.

V. I. Gerasimenko, V. O. Shtyk, A. G. Zagorodny

The problem of description of the evolution of the microscopic phase density and its generalizations is discussed. With this purpose, the sequence of marginal microscopic phase densities is introduced, and the appropriate BBGKY hierarchy for these microscopic distributions and their average values is formulated. The microscopic derivation of the generalized

Sergey Siparov

In this paper the basic model for the anisotropic geometrodynamics (AGD) is introduced and used to discuss the classical GRT tests - orbit precession, light bending and gravitational red shift - on the galactic scale. It is shown that the corresponding effects could be used for the interpretation of the observed phenomena. Moreover, the AGD approach provides