June 2006 arXiv papers — page 10

Volker Braun, Evgeny I. Buchbinder, Burt A. Ovrut

We study a new mechanism to dynamically break supersymmetry in the E8xE8 heterotic string. As discussed recently in the literature, a long-lived, meta-stable non-supersymmetric vacuum can be achieved in an N=1 SQCD whose spectrum contains a sufficient number of light fundamental flavors. In this paper, we present, within the context of the hidden sector of t

W. C. Jones, T. E. Montroy, B. P. Crill, C. R. Contaldi

We discuss instrumental and analytic methods that have been developed for the first generation of bolometric cosmic microwave background (CMB) polarimeters. The design, characterization, and analysis of data obtained using Polarization Sensitive Bolometers (PSBs) are described in detail. This is followed by a brief study of the effect of various polarization

Chengpu Wang

A new deterministic floating-point arithmetic called precision arithmetic is developed to track precision for arithmetic calculations. It uses a novel rounding scheme to avoid excessive rounding error propagation of conventional floating-point arithmetic. Unlike interval arithmetic, its uncertainty tracking is based on statistics and the central limit theore

S. Kabbaj, A. Mimouni

The t-class semigroup of an integral domain is the semigroup of the isomorphy classes of the t-ideals with the operation induced by ideal t-multiplication. This paper investigates ring-theoretic properties of an integral domain that reflect reciprocally in the Clifford or Boolean property of its t-class semigroup. Contexts (including Lipman and Sally-Vasconc

Guang-Liang Li, Victor O. K. Li

We show that some mathematical results and their negations are both deducible. The derived contradictions indicate the inconsistency of current mathematics. This paper is an updated version of arXiv:math/0606635v3 with additional results and proofs.

Hajime Tsuji

In this paper, I give a new construction of a Kähler-Einstein metrics on a smooth projective variety with ample canonical bundle. This result can be generalized to the construction of a singular Kähler-Einstein metric on a smooth projective variety of general type which gives an AZD of the canonical bundle. Also the variation of Bergman kernels and Kähler-Ei

Masato Minamitsuji, Wade Naylor, Misao Sasaki

We investigate the stability of the extra dimensions in a warped, codimension two braneworld that is based upon an Einstein-Maxwell-dilaton theory with a non-vanishing scalar field potential. The braneworld solution has two 3-branes, which are located at the positions of the conical singularities. For this type of brane solution the relative positions of the

G. Gokhroo, G. Majumder

We report the first observation of a near-threshold enhancement in the $D^0\bar{D}^0\pi^0$ system from $B \to D^0\bar{D}^0\pi^0 K$ decays using a 414 $\mathrm{fb}^{-1}$ data sample collected at the $\Upsilon(4S)$ resonance. The enhancement peaks at a mass $M=3875.4 \pm 0.7_{-2.0}^{+1.2}$ MeV/$c^2$ and the branching fraction for events in the peak is \Br ($B

T. Schrabback, T. Erben, P. Simon, J. -M. Miralles

This is the first paper of a series describing our measurement of weak lensing by large-scale structure using archival observations from the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). In this work we present results from a pilot study testing the capabilities of the ACS for cosmic shear measurements with early parallel obser

A. G. Aksenov, M. Milgrom, V. V. Usov

We present the results of numerical simulations of stationary, spherically outflowing, electron-positron pair winds, with total luminosities in the range 10^{34}- 10^{42} ergs/s. In the concrete example described here, the wind injection source is a hot, bare, strange star, predicted to be a powerful source of electron-positron pairs created by the Coulomb b

Elena Kartashova, Victor S. L'vov

We suggest a way of rationalizing an intra-seasonal oscillations (IOs) of the Earth atmospheric flow as four meteorological relevant triads of interacting planetary waves, isolated from the system of all the rest planetary waves. Our model is independent of the topography (mountains, etc.) and gives a natural explanation of IOs both in the North and South He

Alex W. Wilber, Jonathan P. K. Doye, Ard A. Louis, Eva G. Noya

We systematically study the design of simple patchy sphere models that reversibly self-assemble into monodisperse icosahedral clusters. We find that the optimal patch width is a compromise between structural specificity (the patches must be narrow enough to energetically select the desired clusters) and kinetic accessibility (they must be sufficiently wide t

M. ~Kozlov, E. ~Levin, A. ~Prygarin

In this paper we continue to pursue a goal of finding the effective theory for high energy interaction in QCD based on the colour dipole approach, for which the BFKL Pomeron Calculus gives a low energy limit. The two key problems, that we consider are the following: the probabilistic interpretation of the BFKL Pomeron Calculus and the possible scenario for t

A. Sheykhi, M. H. Dehghani, N. Riazi, J. Pakravan

We construct a class of charged, rotating solutions of (n+1)-dimensional Einstein-Maxwell-dilaton gravity with Liouville-type potentials and investigate their properties. These solutions are neither asymptotically flat nor (anti)-de Sitter. We find that these solutions can represent black brane, with two inner and outer event horizons, an extreme black brane

Chung-Pin Chou, T. K. Lee, Chang-Ming Ho

The spectral weights (SW's) for adding and removing an electron of the Gutzwiller projected d-wave superconducting (SC) state of the t-J-type models are studied numerically on finite lattices. Restrict to the uniform system but treat exactly the strong correlation between electrons, we show that the product of weights is equal to the pairing amplitude sq

Daris Samart

In this paper, we investigate and analyze the cosmological dynamics of the universe, with an effect of modified $f(R)$ gravity emerging at cosmological scale. We choose the Einstein frame as a physical frame. We consider phase portraits of the universe at the late time from modified $f(R)$ gravity model. This result gives our universe an acceleration phase e

Liam Watson

We give a recipe for constructing families of distinct knots that have identical Khovanov homology and give examples of pairs of prime knots, as well as infinite families, with this property.

Lev Vaidman

The basic concept of the two-state vector formalism, which is the time symmetric approach to quantum mechanics, is the backward evolving quantum state. However, due to the time asymmetry of the memory's arrow of time, the possible ways to manipulate a backward evolving quantum state differ from those for a standard, forward evolving quantum state. The si

Jun-Liang Song, Shi-Jian Gu, Hai-Qing Lin

In this paper we study the concurrence and the block-block entanglement in the $S=1/2$ spin ladder with four-spin ring exchange by the exact diagonalization method of finite cluster of spins. The relationship between the global phase diagram and the ground-state entanglement is investigated. It is shown that the block-block entanglement of different block si

K. Evlampiev, H. Isambert

Successive whole genome duplications have recently been firmly established in all major eukaryote kingdoms. It is not clear, however, how such dramatic evolutionary process has contributed to shape the large scale topology of protein-protein interaction (PPI) networks. We propose and analytically solve a generic model of PPI network evolution under successiv

M. Cortesi, R. Chechik, A. Breskin, G. Guedes

The thick GEM (THGEM) [1] is an "expanded" GEM, economically produced in the PCB industry by simple drilling and etching in G-10 or other insulating materials (fig. 1). Similar to GEM, its operation is based on electron gas avalanche multiplication in sub-mm holes, resulting in very high gain and fast signals. Due to its large hole size, the THGEM is

J. F. C. A. Veloso, F. D. Amaro, J. M. F. dos Santos, A. Breskin

We present a Photon-Assisted Cascaded Electron Multipliers (PACEM) which has a potential for ion back-flow blocking in gaseous radiation detectors: the avalanche from a first multiplication stage propagates to the successive one via its photons, which in turn induce photoelectron emission from a photocathode deposited on the second multiplier stage; the mult

Dimitri Chikhladze

We show that the class of separable morphisms in the sense of G. Janelidze and W. Tholen in the case of Galois structure of second order coverings of simplicial sets due to R. Brown and G. Janelidze coincides with the class of covering maps of simplicial sets.

Jozef H. Przytycki

It is a natural question to ask whether two links are equivalent by the following moves -- parallel parts of a link are changed to k-times half-twisted parts and if they are, how many moves are needed to go from one link to the other. In particular if k=2 and the second link is a trivial link it is the question about the unknotting number. The new polynomial

landon rabern

We outline some ongoing work related to a conjecture of Reed \cite{reed97} on $ω$, $Δ$, and $χ$. We conjecture that the complement of a counterexample $G$ to Reed's conjecture has connectivity on the order of $\log(|G|)$. We prove that this holds for a family (parameterized by $ε> 0$) of relaxed bounds; the $ε= 0$ limit of which is Reed's upper bound

Alex E. Bernardini

By reporting to the Dirac wave-packet prescription where it is formally assumed the {\em fermionic} nature of the particles, we shall demonstrate that chiral oscillations implicitly aggregated to the interference between positive and negative frequency components of mass-eigenstate wave-packets introduce some small modifications to the standard neutrino flav

Alex E. Bernardini

We proceed with the construction of normalizable Dirac wave packets for treating chiral oscillations in the presence of an external magnetic field. Both chirality and helicity quantum numbers correspond to variables of fundamental importance in the study of chiral interactions, in particular, in the context of neutrino physics. In order to clarify a subtle a

A. A. Zheltukhin

A new type of supersymmetric twistors is proposed and they are called $θ$-twistors versus the supertwistors. The $θ$-twistor is a triple of spinors including the spinor superspace coordinate $θ$ instead of the Grassmannian scalar in the supertwistor triple. The superspace of the $θ$-twistors is closed under the superconformal group transformations except the

U. Baur, A. Juste, L. H. Orr, D. Rainwater

We discuss possibilities to measure the tt-gamma and ttZ couplings at hadron and lepton colliders. We also briefly describe how these measurements can be used to constrain the parameter space of models of new physics, in particular Little Higgs models.

Vittorio Del Duca

In this talk I review some challenges which await perturbative QCD at the Large Hadron Collider. In particular, I consider the underlying event, Monte Carlo methods and next-to-leading order (NLO) calculations.

A. V. Kuznetsov, N. V. Mikheev

The conversion nu_L -> nu_R gamma^* of a neutrino with a magnetic moment is considered, caused by the additional Wolfenstein energy acquired by a left-handed neutrino in medium, with an accurate taking account of the photon γ^* dispersion in medium. It is shown that the threshold arises in the process, caused by the photon (plasmon) effective mass. This thre

A. V. Kuznetsov, N. V. Mikheev

The neutrino chirality-flip process under the conditions of the supernova core is investigated in detail with the plasma polarization effects in the photon propagator taken into account. It is shown that the contribution of the proton fraction of plasma is essential. New upper bounds on the neutrino magnetic moment are obtained: mu_nu < (0.5 - 1.1) 10^{-12}

A. V. Kuznetsov, N. V. Mikheev

Neutrino dispersion properties in an active medium consisting of magnetic field and plasma are analysed. We consider in detail the contribution of a magnetic field into the neutrino self-energy operator Sigma (p). The results for this contribution were contradictory in the previous literature. For the conditions of the early universe where the background med

Ghulam Shabbir

A study of proper Weyl collineations in Kantowski-Sachs and Bianchi type III space-times is given by using the rank of the 6X6 Weyl matrix and direct integration techniques. Studying proper Weyl collineations in each of the above space-times, it is shown that there exists no such possibility when the above space-times admit proper Weyl collineations.

Gretchen K. Campbell, Jongchul Mun, Micah Boyd, Patrick Medley

Microwave spectroscopy was used to probe the superfluid-Mott Insulator transition of a Bose-Einstein condensate in a 3D optical lattice. Using density dependent transition frequency shifts we were able to spectroscopically distinguish sites with different occupation numbers, and to directly image sites with occupation number n=1 to n=5 revealing the shell st

C. Pfleiderer, J. A. Mydosh, M. Vojta

The ground state of URu2Si2 changes from so-called hidden order (HO) to large-moment antiferromagnetism (LMAF) upon applying hydrostatic pressure in excess of 14 kbar. We report the dc-magnetization M(B,T,p) of URu2Si2 for magnetic fields B up to 12 T, temperatures T in the range 2 to 100 K, and pressure p up to 17 kbar. Remarkably, characteristic scales suc

J. B. Neaton, Mark S. Hybertsen, Steven G. Louie

The electronic structure of benzene on graphite (0001) is computed using the GW approximation for the electron self-energy. The benzene quasiparticle energy gap is predicted to be 7.2 eV on graphite, substantially reduced from its calculated gas-phase value of 10.5 eV. This decrease is caused by a change in electronic correlation energy, an effect completely

J. M. McNamara, T. Jeltes, A. S. Tychkov, W. Hogervorst

We report the observation of simultaneous quantum degeneracy in a dilute gaseous Bose-Fermi mixture of metastable atoms. Sympathetic cooling of helium-3 (fermion) by helium-4 (boson), both in the lowest triplet state, allows us to produce ensembles containing more than 10^6 atoms of each isotope at temperatures below 1 micro-Kelvin, and achieve a fermionic d

Jang-ik Park, SangGap Lee, Insuk Yu, Yongho Seo

We have developed an inductive method to detect the magnetostrictive resonance signal and applied it to an ultrasonic magnetostrictive transducer sample. Slab shaped ferrite samples are mounted in an RF coil and actuated by pulse modulated RF magnetic field. A DC magnetic field is also applied and the resonance signal from the sample is detected by the same

J. A. Ludlow, O. P. Sushkov

Using numerical simulations we investigate dynamical quantum chaos in isolated nuclear spin systems. We determine the structure of quantum states, investigate the validity of the Curie law for magnetic susceptibility and find the spectrum of magnetic noise. The spectrum is the same for positive and negative temperatures. The study is motivated by recent inte

O. S. Barisic

The polaron formation is investigated in the intermediate regime of the Holstein model by using an exact diagonalization technique for the one-dimensional infinite lattice. The numerical results for the electron and phonon propagators are compared with the nonadiabatic weak- and strong-coupling perturbation theories, as well as with the harmonic adiabatic ap

I. V. Tokatly

We propose a hydrodynamics theory of collective quantum Hall states, which describes incompressible liquids, hexatic liquid crystals, a bubble solid and a Wigner crystal states within a unified framework. The structure of the theory is uniquely determined by the space-time symmetry, and a symmetry with respect to static shear deformations. In agreement with

Jeremy D. Schnittman, Julian H. Krolik, John F. Hawley

We use a relativistic ray-tracing code to calculate the light curves observed from a global general relativistic magneto-hydrodynamic simulation of an accretion flow onto a Schwarzschild black hole. We apply three basic emission models to sample different properties of the time-dependent accretion disk. With one of these models, which assumes thermal blackbo

Chengpu Wang

The concept of functionality oriented programming is proposed, and some of its aspects are discussed, such as: (1) implementation independent basic types and generic collection types; (2) syntax requirements and recommendations for implementation independence; (3) unified documentation and code; (4) cross-module interface; and (5) cross-language program maki

Charles Bordenave

We study the spectral measure of large Euclidean random matrices. The entries of these matrices are determined by the relative position of $n$ random points in a compact set $Ω_n$ of $\R^d$. Under various assumptions we establish the almost sure convergence of the limiting spectral measure as the number of points goes to infinity. The moments of the limiting

K. Maaz, Arif Mumtaz, S. K. Hasanain, Abdullah Ceylan

Magnetic nanoparticles of cobalt ferrite have been synthesized by wet chemical method using stable ferric and cobalt salts with oleic acid as the surfactant. X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) confirmed the formation of single phase cobalt ferrite nanoparticles in the range 15-48nm depending on the annealing temperature and ti

David Fattal, Ray Beausoleil, Yoshihisa Yamamoto

We study analytically the dynamics of cavity QED nodes in a practical quantum network. Given a single 3-level $Λ$-type atom or quantum dot coupled to a micro-cavity, we derive several necessary and sufficient criteria for the coherent trapping and generation of a single photon pulse with a given waveform to be realizable. We prove that these processes can be

Elmas Irmak, John D. McCarthy

In this paper, we prove that each injective simplicial map of the arc complex of a compact, connected, orientable surface with nonempty boundary is induced by a homeomorphism of the surface. We deduce, from this result, that the group of automorphisms of the arc complex is naturally isomorphic to the extended mapping class group of the surface, provided the

Jordan Kyriakidis, Guido Burkard

We propose a universal quantum computing scheme in which the orthogonal qubit states $|0>$ and $|1>$ are identical in their single-particle spin and charge properties. Each qubit is contained in a single quantum dot and gate operations are induced all-electrically by changes in the confinement potential. Within the computational space, these qubits are robus

Philip S. Amanik, George M. Fuller

We perform one-zone simulations of the infall epoch of a pre-supernova stellar core in the presence of neutrino flavor changing scattering interactions. Our calculations give a self-consistent assessment of the relationship between flavor changing rates and the reduction in electron fraction and re-distribution of initial electron lepton number among the neu

Peter C. Richter

Many classical randomized algorithms (e.g., approximation algorithms for #P-complete problems) utilize the following random walk algorithm for {\em almost uniform sampling} from a state space $S$ of cardinality $N$: run a symmetric ergodic Markov chain $P$ on $S$ for long enough to obtain a random state from within $ε$ total variation distance of the uniform

Amit Bhar, Indrani Chattopadhyay, Debasis Sarkar

No-Cloning and No-Deleting theorems are verified with the constraint on local state transformations via the existence of incomparable states. Assuming the existence of exact cloning or deleting operation defined on a minimum number of two arbitrary states, an incomparable pair of states of the joint system between two parties can be made to compare under det

X. X. Yi, D. M. Tong, L. C. Kwek, C. H. OH

The adiabatic approximation in open systems is formulated through the effective Hamiltonian approach. By introducing an ancilla, we embed the open system dynamics into a non-Hermitian quantum dynamics of a composite system, the adiabatic evolution of the open system is then defined as the adiabatic dynamics of the composite system. Validity and invalidity co

Benjamin Ribba, Thierry Colin, Santiago Schnell

Background: Radiotherapy outcomes are usually predicted using the Linear Quadratic model. However, this model does not integrate complex features of tumor growth, in particular cell cycle regulation. Methods: In this paper, we propose a multiscale model of cancer growth based on the genetic and molecular features of the evolution of colorectal cancer. The mo

Marcelo Samuel Berman, Fernando de Mello Gomide

After the introduction to the subject, we review the Machian relations involving the different kinds of energy densities in the Universe. By suposing that dark-matter is composed by Neutrino&#39;s massive energy, we hint that the Neutrino&#39;s masses should be proportional to the inverse of R, while the total number of Neutrinos in the Universe increases wi

D. Korobkin, Y. A. Urzhumov, B. Neuner, G. Shvets

We experimentally and theoretically study electromagnetic properties of optically thin silicon carbide (SiC) membranes perforated by an array of sub-wavelength holes. Giant absorption and transmission is found using Fourier Transformed Infrared (FTIR) microscopy and explained by introducing a frequency-dependent effective permittivity $ε_{\rm eff}(ω)$ of the

Gennady Shvets

A chirality-based approach to making a one-way waveguide that can be used as an optical isolator or a polarizer is described. The waveguide is rectangular, and chirality is introduced by making slanted rectangular grooves on the waveguide walls. Chirality of the waveguide manifests as a strong circular dichroism, and is responsible for transmitting one circu

H. C. Ho, W. R. Johnson, S. A. Blundell, M. S. Safronova

Relativistic third-order MBPT is applied to obtain energies of ions with two valence electrons in the no virtual-pair approximation (NVPA). A total of 302 third-order Goldstone diagrams are organized into 12 one-body and 23 two-body terms. Only third-order two-body terms and diagrams are presented here, owing to the fact that the one-body terms are identical

Yu Meiling, Du Jiaxin, Liu Lianshou

The hadronization scheme for parton transport in relativistic heavy ion collisions is considered in detail. It is pointed out that the traditional scheme for particles being freezed out one by one leads to serious problem on unreasonable long lifetime for partons. A super-cooling of the parton system followed by a collective phase transition is implemented i

Oren Ben-Bassat

We introduce a new method for ``twisting&#39;&#39; relative equivalences of derived categories of sheaves on two spaces over the same base. The first aspect of this is that the derived categories of sheaves on the spaces are twisted. They become derived categories of sheaves on gerbes living over spaces that are locally (on the base) isomorphic to the origin

J. -F. Lafont

In this paper, we prove a version of the classical Cartan-Hadamard theorem for negatively curved manifolds, of dimension $n\neq 5$, with non-empty totally geodesic boundary. More precisely, if $M_1^n,M_2^n$ are any two such manifolds, we show that (1) $\partial ^\infty \tilde M_1^n$ is homeomorphic to $\partial ^\infty \tilde M_2^n$, and (2) $\tilde M_1^n$ i

Keqin Liu

We introduce two classes of nonassociative algebras and define the building blocks in the context of the new nonassociative algebras.

John Bowman

We prove a bijection between finite-dimensional irreducible modules for an arbitrary quantum affine algebra $U_q(g)$ and finite-dimensional irreducible modules for its Borel subalgebra $U_q(g)^{\geq 0}$.

Yuval Peres, Ofer Zeitouni

Let ${\cal T}$ be a rooted Galton-Watson tree with offspring distribution $\{p_k\}$ that has $p_0=0$, mean $m=\sum kp_k>1$ and exponential tails. Consider the $λ$-biased random walk $\{X_n\}_{n\geq 0}$ on ${\cal T}$; this is the nearest neighbor random walk which, when at a vertex $v$ with $d_v$ offspring, moves closer to the root with probability $λ/(λ+d_v)

Zenghu Li

This is a survey on recent progresses in the study of branching processes with immigration, generalized Ornstein-Uhlenbeck processes and affine Markov processes. We mainly focus on the applications of skew convolution semigroups and the connections in those processes.

Zenghu Li, Hao Wang, Jie Xiong

A non-critical branching immigration superprocess with dependent spatial motion is constructed and characterized as the solution of a stochastic equation driven by a time-space white noise and an orthogonal martingale measure. A representation of its conditional log-Laplace functionals is established, which gives the uniqueness of the solution and hence its

Donald A. Dawson, Zenghu Li, Xiaowen Zhou

A superprocess with coalescing spatial motion is constructed in terms of one-dimensional excursions. Based on this construction, it is proved that the superprocess is purely atomic and arises as scaling limit of a special form of the superprocess with dependent spatial motion studied in Dawson {\it et al.} (2001) and Wang (1997, 1998).

Donald A. Dawson, Zenghu Li

It is proved that a general non-differentiable skew convolution semigroup associated with a strongly continuous semigroup of linear operators on a real separable Hilbert space can be extended to a differentiable one on the entrance space of the linear semigroup. A cadlag strong Markov process on an enlargement of the entrance space is constructed from which

Donald A. Dawson, Zenghu Li, Byron Schmuland, Wei Sun

Skew convolution semigroups play an important role in the study of generalized Mehler semigroups and Ornstein-Uhlenbeck processes. We give a characterization for a general skew convolution semigroup on real separable Hilbert space whose characteristic functional is not necessarily differentiable at the initial time. A connection between this subject and cata

Donald A. Dawson, Zenghu Li

A superprocess with dependent spatial motion and interactive immigration is constructed as the pathwise unique solution of a stochastic integral equation carried by a stochastic flow and driven by Poisson processes of one-dimensional excursions.

Zeng-Hu Li

A special type of immigration associated with measure-valued branching processes is formulated by using skew convolution semigroups. We give characterization for a general inhomogeneous skew convolution semigroup in terms of probability entrance laws. The related immigration process is constructed by summing up measure-valued paths in the Kuznetsov process d

Donald A. Dawson, Luis G. Gorostiza, Zenghu Li

A new formulation of non-local branching superprocesses is given from which we derive as special cases the rebirth, the multitype, the mass-structured, the multilevel and the age-reproduction-structured superprocesses and the superprocess-controlled immigration process. This unified treatment simplifies considerably the proof of existence of the old classes

Donald A. Dawson, Zenghu Li, Hao Wang

We construct a class of superprocesses by taking the high density limit of a sequence of interacting-branching particle systems. The spatial motion of the superprocess is determined by a system of interacting diffusions, the branching density is given by an arbitrary bounded non-negative Borel function, and the superprocess is characterized by a martingale p

J. Delenclos, A. Leroy

Let K,S,D be a division ring, an endomorphism and a S-derivation of K, respectively. In this setting we introduce generalized noncommutative symmetric functions and obtain Vieta formula and decompositions of differential operators. W-polynomials show up naturally, their connections with P-independency, Vandermonde and Wronskian matrices are briefly studied.

Monica Visan, Xiaoyi Zhang

We prove global well-posedness and scattering for the nonlinear Schrödinger equation with power-type nonlinearity \begin{equation*} \begin{cases} i u_t +Δu = |u|^p u, \quad \frac{4}{n}<p<\frac{4}{n-2}, u(0,x) = u_0(x)\in H^s(\R^n), \quad n\geq 3, \end{cases} \end{equation*} below the energy space, i.e., for $s<1$. In \cite{ckstt:low7}, J. Colliander, M. Keel

Hans J. H. Tuenter

In the Frobenius problem we are given a set of coprime, positive integers $a_1, a_2,...,a_k$, and are interested in the set of positive numbers NR that have no representation by the linear form $\sum_i a_ix_i$ in nonnegative integers $x_1, x_2,...,x_k$. We give a functional relationship that completely characterizes the set NR, and apply it to the case when

Steven N. Evans, Tye Lidman

We investigate a possible definition of expectation and conditional expectation for random variables with values in a local field such as the $p$-adic numbers. We define the expectation by analogy with the observation that for real-valued random variables in $L^2$ the expected value is the orthogonal projection onto the constants. Previous work has shown tha

Wladimir G. Boskoff, Marian G. Ciuca, Bogdan D. Suceava

Several authors have pointed out the connection between Barbilian&#39;s metric introduced in 1934 and the recent study of Apollonian metrics. We provide examples of various distances that can be obtained by Barbilian&#39;s metrization procedure and we discuss the relation between this metrization procedure and important Riemannian and generalized Lagrangian

Monica Visan

We obtain global well-posedness, scattering, and global $L^{\frac{2(n+2)}{n-2}}_{t,x}$ spacetime bounds for energy-space solutions to the energy-critical nonlinear Schrödinger equation in $\R_t\times \R^n_x$, $n\geq 5$.

Toby Bartels

I categorify the definition of fibre bundle, replacing smooth manifolds with differentiable categories, Lie groups with coherent Lie 2-groups, and bundles with a suitable notion of 2-bundle. To link this with previous work, I show that certain 2-categories of principal 2-bundles are equivalent to certain 2-categories of (nonabelian) gerbes. This relationship

Taejin Lee

We propose an alternative interpretation of the boundary state for the rolling tachyon, which may depict the time evolution of unstable D-branes in string theory. Splitting the string variable in the temporal direction into the classical part, which we may call "time" and the quantum one, we observe the time dependent behaviour of the boundary. Using the fer

Jean Alexandre, Nick E. Mavromatos

We develop an exact functional method applied to the bosonic string on a shperical world sheet, in graviton and dilaton backgrounds, consistent with conformal invariance. In this method, quantum fluctuations are controled by the amplitude of the kinetic term of the corresponding stringy sigma-model, and we exhibit a novel non-perturbative non-critical string

M. B. Voloshin

Two-pion transitions in charmonium and bottomonium are considered with the leading relativistic effects taken into account. The contribution of the chromo- magnetic interaction of the charmed quarks to the amplitude of the decay $ψ(2S) \to ππJ/ψ$ is estimated from the available data. This contribution is enhanced by a factor of three in the decay $η_c(2S) \t

Yu Meiling, Xu Mingmei, Liu Lianshou

The possible application of boosted neural network to particle classification in high energy physics is discussed. A two-dimensional toy model, where the boundary between signal and background is irregular but not overlapping, is constructed to show how boosting technique works with neural network. It is found that boosted neural network not only decreases t

Fizuli Mamedov

A possible original $SU(2)_{L} \times SU(2)_{R}$ symmetry of the elementary particles and the mechanism of its breaking is discussed. It is concluded that it is the broken symmetry states of the particles which induce the interactions among the particles.

C. P. Burgess

This article provides a cartoon of the quantization of General Relativity using the ideas of effective field theory. These ideas underpin the use of General Relativity as a theory from which precise predictions are possible, since they show why quantum corrections to standard classical calculations are small. Quantum corrections can be computed controllably

H. Mohseni Sadjadi

We show that, in contrast to the flat case, the Maxwell theory is not confining in the background of the three dimensional BTZ black-hole (covering space). We also study the effect of the curvature on screening behavior of Maxwell-Chern-Simons model in this space-time.

Bertrand Mesot, Christof Teuscher

It has been shown that uniform as well as non-uniform cellular automata (CA) can be evolved to perform certain computational tasks. Random Boolean networks are a generalization of two-state cellular automata, where the interconnection topology and the cell&#39;s rules are specified at random. Here we present a novel analytical approach to find the local rule

Alexander Punnoose

A closed-form analytic formula for the magnetoconductivity in the diffusive regime is derived in the presence of Bychkov-Rashba spin-orbit interaction in two dimensions. It is shown that at low fields B << B_{so}, where B_{so} is the characteristic field associated with spin precession, D&#39;yakonov-Perel&#39; mechanism leads to spin relaxation, while for B

P. Zhang, M. Murakami

Three dimensionality of 3D pulsed second sound wave in He II emitted from a finite size heater is experimentally investigated and theoretically studied based on two-fluid model in this study. The detailed propagation of 3D pulsed second sound wave is presented and reasonable agreement between the experimental and theoretical results is obtained. Heater size

Erkan Tuzel, Thomas Ihle, Daniel M. Kroll

The dynamic structure factor, vorticity and entropy density dynamic correlation functions are measured for Stochastic Rotation Dynamics (SRD), a particle based algorithm for fluctuating fluids. This allows us to obtain unbiased values for the longitudinal transport coefficients such as thermal diffusivity and bulk viscosity. The results are in good agreement

Z. P. Yin, W. E. Pickett

The evolution of the magnetic moment and various features of the electronic structure of fcc Gd are followed to reduced volume V/Vo = 0.125 using the LDA+U correlated band method. The stability of the moment is substantial; crude estimates of this signature of a possible ``Mott transition&#39;&#39; in the 4f system suggest a critical pressure Pc 500 GPa. The

Noriyuki Matsunaga, Hinako Fukushi, Yoshikazu Nakada, Toshihiko Tanabe

We report the result of our near-infrared observations (JHKs) for type II Cepheids (including possible RV Tau stars) in galactic globular clusters. We detected variations of 46 variables in 26 clusters (10 new discoveries in seven clusters) and present their light curves. Their periods range from 1.2 d to over 80 d. They show a well-defined period-luminosity

Joon Hyeop Lee, Myung Gyoon Lee, Ho Seong Hwang

We present a study of the nature of the blue early-type galaxies (BEGs) in the GOODS north and south fields using the GOODS HST/ACS archival data. Using visual inspection, we have selected 58 BEGs and 113 normal red early-type galaxies (REGs) in the sample of 1,949 galaxies with spectroscopic redshifts. We find that the BEGs are generally bluer, fainter, and

Tae-Soo Pyo, Masahiko Hayashi, Naoto Kobayashi, Alan T. Tokunaga

We present new results of [Fe II] 1.644-micron spectroscopy toward the jets from HL Tau and RW Aur carried out with the Subaru Telescope combined with the adaptive optics system. We observed the regions within 2&#34; - 3&#34; from the stars with the sub-arcsecond resolutions of 0.&#34;5 and 0.&#34;2 for HL Tau and RW Aur, respectively. In addition to the str

Stanislaw D. Glazek, Jaroslaw Mlynik

Light-front Hamiltonian formulation of QCD with only one flavor of quarks is used in its simplest approximate version to calculate masses and boost-invariant wave functions of c-anti-c or b-anti-b mesons. It is shown that in the Hamiltonian approach in its simplest version the strong coupling constant alpha and quark mass m (for suitable values of the renorm

M. Iskin, C. A. R. Sa de Melo

We analyze the zero temperature phase diagram for an asymmetric two-component Fermi gas as a function of mass anisotropy and population imbalance. We identify regions corresponding to normal, or uniform/non-uniform superfluid phases, and discuss topological quantum phase transitions in the Bardeen-Cooper-Schrieffer (BCS), unitarity and Bose-Einstein condensa

Mohammed Abouzaid

We construct the Fukaya category of a closed surface equipped with an area form using only elementary (essentially combinatorial) methods. We also compute the Grothendieck group of its derived category.

S. S. Kancharla, E. Dagotto

Motivated by experiments on atomically smooth layers of LaTiO$_3$, a Mott insulator, sandwiched between layers of SrTiO$_3$, a band insulator, a simple model for such heterostructures is studied using quasi one-dimensional lattices and the Lanczos method. Taking both the local and long-range Coulomb interactions into account, and computing the layer dependen

Preston Jones

A time varying space-time metric is shown to be a source of electromagnetic radiation. The post-Newtonian approximation is used as a realistic model of the connection between the space-time metric and a time varying gravitational potential. Large temporal variations in the metric from the coalescence of colliding black holes and neutron stars are shown to be