May 2007 arXiv papers — page 5

R. A. Brownlee

The error between appropriately smooth functions and their radial basis function interpolants, as the interpolation points fill out a bounded domain in R^d, is a well studied artifact. In all of these cases, the analysis takes place in a natural function space dictated by the choice of radial basis function -- the native space. The native space contains func

Daniel Fabrycky, Scott Tremaine

At least two arguments suggest that the orbits of a large fraction of binary stars and extrasolar planets shrank by 1-2 orders of magnitude after formation: (i) the physical radius of a star shrinks by a large factor from birth to the main sequence, yet many main-sequence stars have companions orbiting only a few stellar radii away, and (ii) in current theor

R. A. Brownlee, W. A. Light

In this paper we consider the approximation of functions by radial basis function interpolants. There is a plethora of results about the asymptotic behaviour of the error between appropriately smooth functions and their interpolants, as the interpolation points fill out a bounded domain in R^d. In all of these cases, the analysis takes place in a natural fun

Edward Ackad, Marko Horbatsch

The analytic continuation methods of complex scaling (CS), smooth exterior scaling (SES), and complex absorbing potential (CAP) are investigated for the supercritical quasimolecular ground state in the U(92+)-Cf(98+) system at an internuclear separation of R=20 fm. Pade approximants to the complex-energy trajectories are used to perform an extrapolation of t

Brian Nils Lundstrom, Sungho Hong, Matthew H. Higgs, Adrienne L. Fairhall

Recent in vitro data show that neurons respond to input variance with varying sensitivities. Here, we demonstrate that Hodgkin-Huxley (HH) neurons can operate in two computational regimes, one that is more sensitive to input variance (differentiating) and one that is less sensitive (integrating). A boundary plane in the 3D conductance space separates these t

Claudio Nassif

We will look for an implementation of new symmetries in the space-time structure and their cosmological implications. This search will allow us to find a unified vision for electrodynamics and gravitation. We will attempt to develop a heuristic model of the electromagnetic nature of the electron, so that the influence of the gravitational field on the electr

Mark M. Wilde, Hari Krovi, Todd A. Brun

We construct a theory of continuous-variable entanglement-assisted quantum error correction. We present an example of a continuous-variable entanglement-assisted code that corrects for an arbitrary single-mode error. We also show how to implement encoding circuits using passive optical devices, homodyne measurements, feedforward classical communication, cond

M. Mocko, M. B. Tsang, Z. Y. Sun, N. Aoi

We measured fragmentation cross sections produced using the primary beam of $^{86}$Kr at 64 MeV/nucleon on $^9$Be and $^{181}$Ta targets. The cross sections were obtained by integrating the momentum distributions of isotopes with 25<Z<36 measured using the RIPS fragment separator at RIKEN. The cross-section ratios obtained with the $^{181}$Ta and $^{9}$Be ta

F. W. Stecker, S. D. Hunter, D. A. Kniffen

Analysis of data from the EGRET gamma-ray detector on the Compton Gamma Ray Observatory indicated an anomaly in the form of an excess diffuse galactic flux at GeV energies over that which was theoretically predicted. Various explanations for this anomaly have been put forth, including the invocation of supersymmetric dark matter annihilation. We reexamine th

Susan Cox, J. Singleton, R. D. McDonald, A. Migliori

The so-called stripe phase of the manganites is an important example of the complex behaviour of metal oxides, and has long been interpreted as the localisation of charge at atomic sites. Here, we demonstrate via resistance measurements on La_{0.50}Ca_{0.50}MnO_3 that this state is in fact a prototypical charge density wave (CDW) which undergoes collective t

Bohdan Grzadkowski, Jose Wudka

We consider 5 dimensional gauge theories where the 5th direction is compactified on an interval. The Chern-Simons (CS) terms (favored by naive dimensional analysis) are discussed. A simple scenario with an extra U(1)_X gauge field that couples to SU(3)_{color} through a CS term in the bulk is constructed. The extra component of the Abelian gauge field plays

Paolo Benincasa, Freddy Cachazo

We introduce a set of consistency conditions on the S-matrix of theories of massless particles of arbitrary spin in four-dimensional Minkowski space-time. We find that in most cases the constraints, derived from the conditions, can only be satisfied if the S-matrix is trivial. Our conditions apply to theories where four-particle scattering amplitudes can be

Angelo B. Mingarelli

A commutative semigroup of abstract factorials is defined in the context of the ring of integers. We study such factorials for their own sake, whether they are or are not connected to sets of integers. Given a subset X of the positive integers we construct a &#34;factorial set&#34; with which one may define a multitude of abstract factorials on X. We study t

Gregory D. Mack, John F. Beacom, Gianfranco Bertone

We point out a new and largely model-independent constraint on the dark matter scattering cross section with nucleons, applying when this quantity is larger than for typical weakly interacting dark matter candidates. When the dark matter capture rate in Earth is efficient, the rate of energy deposition by dark matter self-annihilation products would grossly

David Milovich

Extending some results of Malykhin, we prove several independence results about base properties of $\beta\omega-\omega$ and its powers, especially the Noetherian type $Nt(\beta\omega-\omega)$, the least $\kappa$ for which $\beta\omega-\omega$ has a base that is $\kappa$-like with respect to containment. For example, $Nt(\beta\omega-\omega)$ is never less tha

A. V. Strelchenko, D. V. Vassilevich

We analyze renormalization and the high temperature expansion of the one-loop effective action of the space-time noncommutative ϕ^4 theory by using the zeta function regularization in the imaginary time formalism (i.e., on S^1 x R^3). Interestingly enough, there are no mixed (non-planar) contributions to the counterterms as well as to the power-law high temp

Hamutal Bary-Soroker, Haim Diamant

Recent measurements of the short-wavelength (~ 1--100 nm) fluctuations in stacks of lipid membranes have revealed two distinct relaxations: a fast one (decay rate of ~ 0.1 ns^{-1}), which fits the known baroclinic mode of bulk lamellar phases, and a slower one (~ 1--10 μs^{-1}) of unknown origin. We show that the latter is accounted for by an overdamped capi

K. Bradler, R. Jauregui

The influence of the relativistic covariance requirement on the optimality of the symmetric state-dependent 1 -> 2 cloning machine is studied. Namely, given a photonic qubit whose basis is formed from the momentum-helicity eigenstates, the change to the optimal cloning fidelity is calculated taking into account the Lorentz covariance unitarily represented by

David Lafreniere, Rene Doyon, Christian Marois, Daniel Nadeau

We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope and angular differential imaging was used to suppress the speckle noise of the central star. Detection

B. Willems, V. Kalogera, A. Vecchio, N. Ivanova

We consider the formation of double white dwarfs (DWDs) through dynamical interactions in globular clusters. Such interactions can give rise to eccentric DWDs, in contrast to the exclusively circular population expected to form in the Galactic disk. We show that for a 5-year Laser Interferometer Space Antenna (LISA) mission and distances as far as the Large

Danilo Marchesini, Pieter van Dokkum

Recent galaxy formation models successfully reproduce the local luminosity function (LF) of galaxies by invoking mechanisms to suppress star formation in low- and high-mass galaxies. As these models are optimized to fit the LF at low redshift, a crucial question is how well they predict the LF at earlier times. Here we compare recently measured rest-frame V-

Mahya Ghandehari, Hamed Hatami, Nico Spronk

For any finite unital commutative idempotent semigroup S, a unital semilattice, we show how to compute the amenability constant of its semigroup algebra l^1(S), which is always of the form 4n+1. We then show that these give lower bounds to amenability constants of certain Banach algebras graded over semilattices. We show that there is no commutative semilatt

Brian E. Forrest, Ebrahim Samei, Nico Spronk

In this note we study two related questions. (1) For a compact group G, what are the ranges of the convolution maps on A(GXG) given for u,v in A(G) by $u X v |-> u*v&#39; ($v&#39;(s)=v(s^{-1})$) and $u X v |-> u*v$? (2) For a locally compact group G and a compact subgroup K, what are the amenability properties of the Fourier algebra of the coset space A(G/K)

AM Semikhatov

We review the properties of quantum groups occurring as Kazhdan--Lusztig dual to logarithmic conformal field theory models. These quantum groups at even roots of unity are not quasitriangular but are factorizable and have a ribbon structure; the modular group representation on their center coincides with the representation on generalized characters of the ch

Kaushik Bhattacharya

In this work we discuss the properties of the solutions of the Dirac equation in presence of an uniform background magnetic field. In particular we focus on the nature of the solutions, their ortho-normality properties and how these solutions depend on the choice of the vector potential giving rise to the magnetic field. We explicitly calculate the spin-sum

Johannes Walcher

Open topological string amplitudes on compact Calabi-Yau threefolds are shown to satisfy an extension of the holomorphic anomaly equation of Bershadsky, Cecotti, Ooguri and Vafa. The total topological charge of the D-brane configuration must vanish in order to satisfy tadpole cancellation. The boundary state of such D-branes is holomorphically captured by a

Brian C. Thomas, Adrian L. Melott, Brian D. Fields, Barbara J. Anthony-Twarog

Recently Supernova 2006gy was noted as the most luminous ever recorded, with a total radiated energy of ~10^44 Joules. It was proposed that the progenitor may have been a massive evolved star similar to eta Carinae, which resides in our own galaxy at a distance of about 2.3 kpc. eta Carinae appears ready to detonate. Although it is too distant to pose a seri

Henk Bruin, Mark Demers, Ian Melbourne

We study two classes of dynamical systems with holes: expanding maps of the interval and Collet-Eckmann maps with singularities. In both cases, we prove that there is a natural absolutely continuous conditionally invariant measure $μ$ (a.c.c.i.m.) with the physical property that strictly positive Hölder continuous functions converge to the density of $μ$ und

Dominic van der Zypen

Let $(P,\leq)$ be a partially ordered set and let $τ$ be a compact topology on $P$ that is finer than the interval topology. Then $τ$ is contained in the order (convergence) topology on $(P,τ)$. So any Priestley topology is contained in the order topology.

Sarah Livia Zerbes

This paper has been withdrawn, as it is superseded by arXiv:0806.2122 (Bloch-Kato exponential maps for local fields with imperfect residue fields), which is a more recent version of the same paper.

Alejandro Gangui

Year 2005 was the World Year of Physics, and it was commemorated worldwide as the 100th anniversary of Albert Einstein's legendary works in which the foundations of at least three areas of modern physics were laid: statistical mechanics, quantum mechanics and special relativity. These works turned year 1905 in what deservedly was called the "miraculous year"

F. del Aguila, J. A. Aguilar-Saavedra

A new leptophobic neutral gauge boson Z&#39; with small mixing to the Z can have a mass as light as M_Z&#39; ~ 350 GeV, and still have escaped detection at LEP and Tevatron. Such a Z&#39; boson can be derived from E6 and, if the new heavy neutrino singlets in the 27 representation are lighter than M_Z&#39;/2, the process p p(pbar) -> Z&#39; -> NN -> l+- l+-

Christian T. Byrnes, Kazuya Koyama, Misao Sasaki, David Wands

We present Feynman type diagrams for calculating the n-point function of the primordial curvature perturbation in terms of scalar field perturbations during inflation. The diagrams can be used to evaluate the corresponding terms in the n-point function at tree level or any required loop level. Rules are presented for drawing the diagrams and writing down the

B. E. Kunyavskii, M. A. Tsfasman

We consider higher-dimensional analogues of the classical Brauer-Siegel theorem focusing on the case of abelian varieties over global function fields. We prove such an analogue in the case of constant families of elliptic curves and abelian varieties.

Derrick Hart, Alex Iosevich

We prove that if $A \subset {\Bbb F}_q$ is such that $$|A|>q^{{1/2}+\frac{1}{2d}},$$ then $${\Bbb F}_q^{*} \subset dA^2=A^2+...+A^2 d \text{times},$$ where $$A^2=\{a \cdot a&#39;: a,a&#39; \in A\},$$ and where ${\Bbb F}_q^{*}$ denotes the multiplicative group of the finite field ${\Bbb F}_q$. In particular, we cover ${\Bbb F}_q^{*}$ by $A^2+A^2$ if $|A|>q^{3

Rafael Bautista-Mena

This paper offers an alternative approach to discussing both the principle of relativity and the derivation of the Lorentz transformations. This approach uses the idea that there may not be a preferred inertial frame through a privileged access to information about events. In classroom discussions, it has been my experience that this approach produces some l

P. Zubko, G. Catalan, A. Buckley, P. R. L. Welche

Piezoelectricity is inherent only in noncentrosymmetric materials, but a piezoelectric response can also be obtained in centrosymmetric crystals if subjected to inhomogeneous deformation. This phenomenon, known as flexoelectricity, affects the functional properties of insulators, particularly thin films of high permittivity materials. We have measured strain

Tijmen G. Euser, Hong Wei, Jeroen Kalkman, Yoonho Jun

We present ultrafast optical switching experiments on 3D photonic band gap crystals. Switching the Si inverse opal is achieved by optically exciting free carriers by a two-photon process. We probe reflectivity in the frequency range of second order Bragg diffraction where the photonic band gap is predicted. We find good experimental switching conditions for

T. Ferrus, R. George, C. H. W. Barnes, N. Lumpkin

We observe a complex change in the hopping exponent value from 1/2 to 1/3 as a function of disorder strength and electron density in a sodium-doped silicon MOSFET. The disorder was varied by applying a gate voltage and thermally drifting the ions to different positions in the oxide. The same gate was then used at low temperature to modify the carrier concent

S. V. Akkelin

Characteristic length of mass density resolution in dynamical reduction models is calculated utilizing energy conservation law and viable cosmological model with decreasing energy density of vacuum (dark energy density). The value found, $ \sim 10^{-5}$ cm, numerically coincides with phenomenological spatial short-length cutoff parameter introduced in the Gh

Nicholas W M Touikan

Using the theory developed by Olga Kharlampovich, Alexei Miasnikov, and, independently, by Zlil Sela to describe the set of homomorphisms of a f.g. group G into a free group F, we describe the solutions to equations with coefficients from F and unknowns x,y of the form w(x,y) = u, where u lies in F and w(x,y) is a word in {x,y}^\{pm 1}. We also give an examp

A. Kurtzmann

Self-interacting diffusions are solutions to SDEs with a drift term depending on the process and its normalized occupation measure $μ_t$ (via an interaction potential and a confinement potential). We establish a relation between the asymptotic behavior of $μ_t$ and the asymptotic behavior of a deterministic dynamical flow (defined on the space of the Borel p

N. Bartolo, S. Matarrese, A. Riotto, A. Vaihkonen

The curvaton scenario for the generation of the cosmological curvature perturbation on large scales represents an alternative to the standard slow-roll scenario of inflation in which the observed density perturbations are due to fluctuations of the inflaton field itself. Its basic assumption is that the initial curvature perturbation due to the inflaton fiel

William R. LeFew, Stephanos Venakides, Daniel J. Gauthier

We study theoretically the propagation of a step-modulated optical field as it passes through a dispersive dielectric made up of a dilute collection of oscillators characterized by a single narrow-band resonance. The propagated field is given in terms of an integral of a Fourier type, which cannot be evaluated even for simple models of the dispersive dielect

Aiyou Chen, Peter J. Bickel

Independent component analysis (ICA) has been widely used for blind source separation in many fields such as brain imaging analysis, signal processing and telecommunication. Many statistical techniques based on M-estimates have been proposed for estimating the mixing matrix. Recently, several nonparametric methods have been developed, but in-depth analysis o

C. Bambi, F. R. Urban

The cosmology of KK gravitinos in models with extra dimensions is considered. The main result is that the production of such KK modes is not compatible with an epoch of non--standard expansion after inflation. This is so because the BBN constraint on the zero mode forces the reduced five dimensional Planck mass $M_5$ down to values much smaller than the usua

T. S. Biro, R. Rosenfeld

In this paper we study the possible microscopic origin of heavy-tailed probability density distributions for the price variation of financial instruments. We extend the standard log-normal process to include another random component in the so-called stochastic volatility models. We study these models under an assumption, akin to the Born-Oppenheimer approxim

M. Trenti, S. Ransom, P. Hut, D. C. Heggie

Though about 80 pulsar binaries have been detected in globular clusters so far, no pulsar has been found in a triple system in which all three objects are of comparable mass. Here we present predictions for the abundance of such triple systems, and for the most likely characteristics of these systems. Our predictions are based on an extensive set of more tha

Jonathan Touboul

In this article we study a controllability problem for a parabolic and a hyperbolic partial differential equations in which the control is the shape of the domain where the equation holds. The quantity to be controlled is the trace of the solution into an open subdomain and at a given time, when the right hand side source term is known. The mapping that asso

Will Dison

Given a right-angled Artin group A, the associated Bestvina-Brady group is defined to be the kernel of the homomorphism A \to \mathbb{Z} that maps each generator in the standard presentation of A to a fixed generator of \mathbb{Z}. We prove that the Dehn function of an arbitrary finitely presented Bestvina-Brady group is bounded above by n^4. This is the bes

Jan De Rydt, Jan Rosseel, Torsten T. Schmidt, Antoine Van Proeyen

The general actions of matter-coupled N=1 supergravity have Peccei-Quinn terms that may violate gauge and supersymmetry invariance. In addition, N=1 supergravity with vector multiplets may also contain generalized Chern-Simons terms. These have often been neglected in the literature despite their importance for gauge and supersymmetry invariance. We clarify

S. Duhot, R. Mélin

We investigate a superconducting quantum interference device (SQUID) based on carbon nanotubes in a fork geometry [J.-P. Cleuziou {\it et al.}, Nature Nanotechnology {\bf 1}, 53 (2006)], involving tunneling of evanescent quasiparticles through a superconductor over a distance comparable to the superconducting coherence length, with therefore ``non local&#39;

Hari K. Kunduri, James Lucietti, Harvey S. Reall

Recent work has demonstrated an attractor mechanism for extremal rotating black holes subject to the assumption of a near-horizon SO(2,1) symmetry. We prove the existence of this symmetry for any extremal black hole with the same number of rotational symmetries as known four and five dimensional solutions (including black rings). The result is valid for a ge

Vincent Lafforgue, Sergey Lysenko

Let k be an algebraically closed field of characteristic >2, F=k((t)) and Mp(F) denote the metaplectic extension of Sp_{2d}(F). In this paper we propose a geometric analog of the Weil representation of Mp(F). This is a category of certain perverse sheaves on some stack, on which Mp(F) acts by functors. This construction will be used in math.RT/0701170 (and s

Stéphane Ancey, Yves Décanini, Antoine Folacci, Paul Gabrielli

We study the interaction of an electromagnetic field with a non-absorbing or absorbing dispersive sphere in the framework of complex angular momentum techniques. We assume that the dielectric function of the sphere presents a Drude-like behavior or an ionic crystal behavior modelling metallic and semiconducting materials. We more particularly emphasize and i

Mauro Sbragaglia, Alisia M. Peters, Christophe Pirat, Bram M. Borkent

In some cases water droplets can completely wet micro-structured superhydrophobic surfaces. The {\it dynamics} of this rapid process is analyzed by ultra-high-speed imaging. Depending on the scales of the micro-structure, the wetting fronts propagate smoothly and circularly or -- more interestingly -- in a {\it stepwise} manner, leading to a growing {\it squ

Abdeslam Mimouni

This paper studies the Ratliff-Rush closure of ideals in integral domains. By definition, the Ratliff-Rush closure of an ideal $I$ of a domain $R$ is the ideal given by $\tilde{I}:=\bigcup(I^{n+1}:_{R}I^{n})$ and an ideal $I$ is said to be a Ratliff-Rush ideal if $\tilde{I}=I$. We completely characterize integrally closed domains in which every ideal is a Ra

Daniel N. Blaschke, Harald Grosse, Manfred Schweda

Inspired by the renormalizability of the non-commutative Phi^4 model with added oscillator term, we formulate a non-commutative gauge theory, where the oscillator enters as a gauge fixing term in a BRST invariant manner. All propagators turn out to be essentially given by the Mehler kernel and the bilinear part of the action is invariant under the Langmann-S

Anirudh Pradhan, G. S. Khadekar, M. K. Mishra, S. Kumbhare

This paper has been withdrawn by arXiv administrators because of an inappropriate amount of overlap with hep-th/0505013.

Wei Wang

In this paper, we prove that for every Finsler $n$-sphere $(S^n, F)$ for $n\ge 3$ with reversibility $λ$ and flag curvature $K$ satisfying $(\fracλ{λ+1})^2<K\le 1$, either there exist infinitely many prime closed geodesics or there exists one elliptic closed geodesic whose linearized Poincaré map has at least one eigenvalue which is of the form $\exp(πi μ)$

B. A. Danilchenko, I. A. Obukhov, T. Paszkiewicz, S. Wolski

The maximal value of thermal conductivity κ_{max} of the perfect wurzite GaN crystal containing isotopes of natural abundance is estimated. Our upper limit of κ=4800 W/Km at T_{max}=32 K is smaller than calculated by Liu and Balandin κ=6000 W/Km and higher than obtained by Slack et al κ=3750 W/Km. The phenomenological dependence κ\propto T^{-1.43} obtained b

A. Klimyk, J. Patera

Four families of special functions, depending on n variables, are studied. We call them symmetric and antisymmetric multivariate sine and cosine functions. They are given as determinants or antideterminants of matrices, whose matrix elements are sine or cosine functions of one variable each. These functions are eigenfunctions of the Laplace operator, satisfy

O. S. Zozulya, M. Haque, K. Schoutens, E. H. Rezayi

We present a detailed analysis of bipartite entanglement entropies in fractional quantum Hall (FQH) states, considering both abelian (Laughlin) and non-abelian (Moore-Read) states. We derive upper bounds for the entanglement between two subsets of the particles making up the state. We also consider the entanglement between spatial regions supporting a FQH st

Spasimir Balev

Recent results from the experiments NA48, NA48/1 and NA48/2 are presented, including: direct CP-violation and Dalitz plot slopes measurements for K+- --> 3 pi decays; pi pi scattering effects in K+- --> pi+- pi0 pi0 and Ke4 decays, as well as Ke4 form factors and branching fraction; measurements on radiative charged kaons and hyperon decays, semileptonic dec

Franco Ferrari, Jaroslaw Paturej, Thomas A. Vilgis

In this work the dynamics of a freely jointed random chain which fluctuates at constant temperature in some viscous medium is studied. The chain is regarded as a system of small particles which perform a brownian motion and are subjected to rigid constraints which forbid the breaking of the chain. For simplicity, all interactions among the particles have bee

Spasimir Balev

A high precision search for direct CP-violation in K+- --> 3 pi decays was performed by the NA48/2 experiment at CERN SPS. The asymmetry in the Dalitz plot linear slopes A_g = (g^+ - g^-)/(g^+ + g^-) is measured to be A^c_g = (-1.3 +- 2.3)x10^-4 by studying ~3.1x10^9 K+- --> pi+- pi+ pi- decays and A^n_g = (2.1 +- 1.9)x10^-4 by studying ~91x10^6 K+- --> pi+-

Olav F. Syljuasen

We apply the Average Spectrum Method to the problem of getting the excitation spectrum from imaginary-time quantum Monte Carlo simulations. We show that with high quality QMC data this method reproduces the dominant spectral features very well. It is also capable of giving information on the spectrum in regions dominated by the many-particle continuum of exc

Stoil Donev, Maria Tashkova

This paper aims to present a general idea for description of spatially finite physical objects with a consistent nontrivial translational-rotational dynamical structure and evolution as a whole, making use of the mathematical concepts and structures connected with the Frobenius integrability/nonintegrability theorems and electromagnetic strain quantities. Th

Edmund J. Copeland, Osamu Seto

We derive a new class of exact time dependent solutions in a warped six dimensional supergravity model. Under the assumptions we make for the form of the underlying moduli fields, we show that the only consistent time dependent solutions lead to all six dimensions evolving in time, implying the eventual decompactification or collapse of the extra dimensions.

D. I. Gurevich, P. A. Saponov

We discuss the consistency of the axioms which the definition of quantum Lie algebras is usually based on.

M. Cencelj, D. Repovš, M. Skopenkov

We present a short proof of the following Pontryagin theorem, whose original proof was complicated and has never been published in details: {\bf Theorem.} Let $M$ be a connected oriented closed smooth 3-manifold. Let $L_1(M)$ be the set of framed links in $M$ up to a framed cobordism. Let $°:L_1(M)\to H_1(M;\Z)$ be the map taking a framed link to its homolog

W. Dür, H. J. Briegel

We give a review on entanglement purification for bipartite and multipartite quantum states, with the main focus on theoretical work carried out by our group in the last couple of years. We discuss entanglement purification in the context of quantum communication, where we emphasize its close relation to quantum error correction. Various bipartite and multip

Rainer Beck

The spiral galaxy NGC 6946 was observed in total intensity and linear polarization in five radio bands between 3cm and 21cm. At the inner edge of the inner gas spiral arm the ordered magnetic field is only mildly compressed and turns smoothly, to become aligned along the gas arm. Hence the field is not shocked and is probably connected to the warm, diffuse g

C. G. Boehmer, T. Harko

We consider the possibility that the dark matter, which is required to explain the dynamics of the neutral hydrogen clouds at large distances from the galactic center, could be in the form of a Bose-Einstein condensate. To study the condensate we use the non-relativistic Gross-Pitaevskii equation. By introducing the Madelung representation of the wave functi

Paul Binding, Branko Ćurgus

We consider a regular indefinite Sturm-Liouville problem with two self-adjoint boundary conditions affinely dependent on the eigenparameter. We give sufficient conditions under which the root vectors of this Sturm-Liouville problem can be selected to form a Riesz basis of a corresponding weighted Hilbert space.

Sander Dommers, Remco van der Hofstad, Gerard Hooghiemstra

In this paper, we investigate the diameter in preferential attachment (PA-) models, thus quantifying the statement that these models are small worlds. The models studied here are such that edges are attached to older vertices proportional to the degree plus a constant, i.e., we consider affine PA-models. There is a substantial amount of literature proving th

Maria Deijfen, Henri van den Esker, Remco van der Hofstad, Gerard Hooghiemstra

In this paper, a random graph process ${G(t)}_{t\geq 1}$ is studied and its degree sequence is analyzed. Let $(W_t)_{t\geq 1}$ be an i.i.d. sequence. The graph process is defined so that, at each integer time $t$, a new vertex, with $W_t$ edges attached to it, is added to the graph. The new edges added at time t are then preferentially connected to older ver

Reginald T Cahill

For some 100 years physics has modelled space and time via the spacetime concept, with space being merely an observer dependent perspective effect of that spacetime - space itself had no observer independent existence - it had no ontological status, and it certainly had no dynamical description. In recent years this has all changed. In 2002 it was discovered

Jingfei Zhang, Xin Zhang, Hongya Liu

In this paper, we investigate the holographic dark energy model with interaction between dark energy and dark matter, from the statefinder viewpoint. We plot the trajectories of the interacting holographic dark energy model for different interaction cases as well as for different values of the parameter $c$ in the statefinder-plane. The statefinder diagrams

Julius Vanko, Miroslav Sukenik, Jozef Sima

Including Vaidya metric into the model of Expansive Nondecelerative Universe allows to localize the energy of gravitational field. A term of effective gravitational range is introduced and classic Newton potential is substituted for Yukawa-type potential. It allows to allocate a typical frequency value to each gravitational field. Derived theoretical conclus

Firas Rassoul-Agha, Timo Seppalainen

We consider a multidimensional random walk in a product random environment with bounded steps, transience in some spatial direction, and high enough moments on the regeneration time. We prove an invariance principle, or functional central limit theorem, under almost every environment for the diffusively scaled centered walk. The main point behind the invaria

Brett McInnes

The &#34;bubble universes&#34; of Coleman and De Luccia play a crucial role in string cosmology. Since our own Universe is supposed to be of this kind, bubble cosmology should supply definite answers to the long-standing questions regarding cosmological initial conditions. In particular, it must explain how an initial singularity is avoided, and also how the

M. Gregor, T. Plecenik, M. Prascak, R. Micunek

A new method of preparation of radio-frequency superconducting quantum interference devices on MgB2 thin films is presented. The variable-thickness bridge was prepared by a combination of optical lithography and of the scratching by an atomic force microscope. The critical current of the nanobridge was 0.35 uA at 4.2 K. Non-contact measurements of the curren

R. Brent Tully, Edward J. Shaya, Igor D. Karachentsev, Helene M. Courtois

The peculiar velocity of the Local Group of galaxies manifested in the Cosmic Microwave Background dipole is found to decompose into three dominant components. The three components are clearly separated because they arise on distinct spatial scales and are fortuitously almost orthogonal in their influences. The nearest, which is distinguished by a velocity d

R. Casini, R. Manso Sainz

We consider a gas of hydrogen atoms illuminated by a broadband, unpolarized radiation with zero anisotropy. In the absence of external fields, the atomic J-levels are thus isotropically populated. While this condition persists in the presence of a magnetic field, we show instead that electric fields can induce the alignment of those levels. We also show that

C. M. Savage, K. V. Kheruntsyan

We perform first-principles quantum simulations of dissociation of trapped, spatially inhomogeneous Bose-Einstein condensates of molecular dimers. Specifically, we study spatial pair correlations of atoms produced in dissociation after time of flight. We find that the observable correlations may significantly degrade in systems with spatial inhomogeneity com

Saharon Shelah

Our aim is to improve the negative results i.e. non-existence of limit models, and the failure of the generic pair property from math.LO/0609636 to inaccessible lambda as promised there. The motivation is that in [Sh:F756] the positive results are for lambda measurable hence inaccessible, whereas in math.LO/0609636 in the negative results obtained only on no

Rodney Van Meter, Thaddeus D. Ladd, W. J. Munro, Kae Nemoto

We present a new control algorithm and system design for a network of quantum repeaters, and outline the end-to-end protocol architecture. Such a network will create long-distance quantum states, supporting quantum key distribution as well as distributed quantum computation. Quantum repeaters improve the reduction of quantum-communication throughput with dis

Saharon Shelah

We prove that e.g. there is no omega_4-sequence in (omega_3)^{omega_3} increasing modulo the ideal of countable sets.

Saharon Shelah

We construct non-isomorphic models M, N, e.g. of cardinality aleph_1 such that in the Ehrenfeucht-Fraisse game of length zeta < omega_1 the isomorphism player wins

N. Chernov, N. Simanyi

The Local Ergodic Theorem (also known as the `Fundamental Theorem&#39;) gives sufficient conditions under which a phase point has an open neighborhood that belongs (mod 0) to one ergodic component. This theorem is a key ingredient of many proofs of ergodicity for billiards and, more generally, for smooth hyperbolic maps with singularities. However the proof

William N. N. Hung, Changjian Gao, Xiaoyu Song, Dan Hammerstrom

We present a CAD framework for CMOL, a hybrid CMOS/ molecular circuit architecture. Our framework first transforms any logically synthesized circuit based on AND/OR/NOT gates to a NOR gate circuit, and then maps the NOR gates to CMOL. We encode the CMOL cell assignment problem as boolean conditions. The boolean constraint is satisfiable if and only if there

Bhaskar Dutta, Yukihiro Mimura, Dimitri V. Nanopoulos

We show that the little hierarchy problem can be solved in the no-scale supergravity framework. In this model the supersymmetry breaking scale is generated when the electroweak symmetry breaking condition is satisfied and therefore, unlike usual supersymmetric models, the correlation between the electroweak symmetry breaking scale and the average stop mass s

Alberto Piatti, Marco Zaffalon, Fabio Trojani, Marcus Hutter

It is well known that complete prior ignorance is not compatible with learning, at least in a coherent theory of (epistemic) uncertainty. What is less widely known, is that there is a state similar to full ignorance, that Walley calls near-ignorance, that permits learning to take place. In this paper we provide new and substantial evidence that also near-ign

E. costa-Reyes, A. Aldroubi, I. Krishtal

A useful sampling-reconstruction model should be stable with respect to different kind of small perturbations, regardless whether they result from jitter, measurement errors, or simply from a small change in the model assumptions. In this paper we prove this result for a large class of sampling models. We define different classes of perturbations and quantif

Yitang Zhang

We provide a proof of a variant of the Landau-Siegel Zeros conjecture.

A. Aldroubi, A. Baskakov, I. Krishtal

In this paper we present a rare combination of abstract results on the spectral properties of slanted matrices and some of their very specific applications to frame theory and sampling problems. We show that for a large class of slanted matrices boundedness below of the corresponding operator in $\ell^p$ for some $p$ implies boundedness below in $\ell^p$ for

Ahmed Younes

Manipulating a database system on a quantum computer is an essential aim to benefit from the promising speed-up of quantum computers over classical computers in areas that take a vast amount of storage and processing time such as in databases. In this paper, the basic operations for manipulating the data in a quantum database will be defined, e.g. INSERT, UP

Jens Oehlschlägel

Cluster matching by permuting cluster labels is important in many clustering contexts such as cluster validation and cluster ensemble techniques. The classic approach is to minimize the euclidean distance between two cluster solutions which induces inappropriate stability in certain settings. Therefore, we present the truematch algorithm that introduces two

Robert S. Hoy, Mark O. Robbins

Simulations are used to examine the microscopic origins of strain hardening in polymer glasses. While traditional entropic network models can be fit to the total stress, their underlying assumptions are inconsistent with simulation results. There is a substantial energetic contribution to the stress that rises rapidly as segments between entanglements are pu