April 2008 arXiv papers — page 36

Driss Gretete

Dans cet article nous démontrons un théorème de stabilité des probabilités de retour sur un groupe localement compact unimodulaire, séparable et compactement engendré. Nous démontrons que le comportement asymptotique de $F^{*(2n)}(e)$ ne dépend pas de la densité $F$ sous des hypothèses naturelles. A titre d'exemple nous établissons que la probabilité de

Gabriella Böhm, Tomasz Brzezinski, Robert Wisbauer

Let $A$ be a ring and $\M_A$ the category of $A$-modules. It is well known in module theory that for any $A $-bimodule $B$, $B$ is an $A$-ring if and only if the functor $-\otimes_A B: \M_A\to \M_A$ is a monad (or triple). Similarly, an $A $-bimodule $\C$ is an $A$-coring provided the functor $-\otimes_A\C:\M_A\to \M_A$ is a comonad (or cotriple). The relate

Yasuo Fukui, Akiko Kawamura, Tetsuhiro Minamidani, Yoji Mizuno

The second survey of the molecular clouds in 12CO (J = 1-0) was carried out in the Large Magellanic Cloud by NANTEN. The sensitivity of this survey is twice as high as that of the previous NANTEN survey, leading to a detection of molecular clouds with M_CO > 2 x 10^4 M_sun. We identified 272 molecular clouds, 230 of which are detected at three or more observ

Frithjof B. Anders

We investigate the dynamics of a large anisotropic spin whose easy-axis component is coupled to a bosonic bath with a spectral function $J(\w)\propto ω^s$. Such a spin complex might be realized in a single-molecular magnet. Using the non-perturbative renormalization group, we calculate the line of quantum-phase transitions in the sub-ohmic regime ($s<1$). Th

Francesco S. Cataliotti, Francesco De Martini

The multiphoton quantum superposition generated by a quantum-injected optical parametric amplifier (QI-OPA) seeded by a single-photon belonging to an EPR entangled pair is made to interact with a Mirror-BEC shaped as a Bragg interference structure. The effect can be greatly enhanced if the mirror is part of a cavity structure or is used within an optical int

Eduardo S. Fraga, Ana Júlia Mizher

The presence of a strong magnetic background can modify the nature and the dynamics of the chiral phase transition at finite temperature. We compute the modified effective potential in the linear sigma model with quarks to one loop in the $\bar{MS}$ scheme for $N_{f}=2$. For fields $eB\sim 5 m_π^{2}$ and larger a crossover is turned into a weak first-order t

Juan Carlos Garcia-Escartin, Pedro Chamorro-Posada

We put forward a new CNOT gate scheme with atoms and ions based on quantum interrogation and a bosonic particle extension of the models of linear optics quantum computation. We show how the possibility of particle collision can provide the strong interaction that is needed for universal quantum gates. Two atom optics proposals are provided. Unlike previous s

Adan Cabello, Stefan Filipp, Helmut Rauch, Yuji Hasegawa

We show that an experimental demonstration of quantum contextuality using 2 degrees of freedom of single neutrons based on a violation of an inequality derived from the Peres-Mermin proof of the Kochen-Specker theorem would be more conclusive than those obtained from previous experiments involving pairs of ions [M. A. Rowe et al., Nature (London) 409, 791 (2

Vincent Garcia, Eric Debreuve, Michel Barlaud

The recent improvements of graphics processing units (GPU) offer to the computer vision community a powerful processing platform. Indeed, a lot of highly-parallelizable computer vision problems can be significantly accelerated using GPU architecture. Among these algorithms, the k nearest neighbor search (KNN) is a well-known problem linked with many applicat

M. S. Marsh, J. Ireland, T. Kucera

A Bayesian probability based approach is applied to the problem of detecting and parameterizing oscillations in the upper solar atmosphere for the first time. Due to its statistical origin, this method provides a mechanism for determining the number of oscillations present, gives precise estimates of the oscillation parameters with a self-consistent statisti

Alberto Carpinteri, Nicola M. Pugno

In this paper the new concept of super-bridges, i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of 3.

Paolo Lipparini

We find many conditions equivalent to the model-theoretical property $λ\stackrelκ{\Rightarrow} μ$ introduced in [L1]. Our conditions involve uniformity of ultrafilters, compactness properties of products of topological spaces and the existence of certain infinite matrices.

Jeffrey M. Rosenbluth

We take the point of view of the particle in a multidimensional nearest neighbor random walk in random environment (RWRE). We prove a quenched large deviation principle and derive a variational formula for the quenched rate function. Most of the previous results in this area rely on the subadditive ergodic theorem. We employ a different technique which is ba

Jaroslav Hruby

In the paper it is shown the connection between spacetime and quantum information using an information spacetime as superspace. The connection of quantum information with anticommuting variables is given . Also a solitonic bag is presented where the information is confined.

Pacal Koiran, Jürgen Landes, Natacha Portier, Penghui Yao

We present general methods for proving lower bounds on the query complexity of nonadaptive quantum algorithms. Our results are based on the adversary method of Ambainis.

Oleg Gutik, Dušan Repovš

We give a criterium when a linearly ordered topological semilattice is $H$-closed. We also prove that any linearly ordered $H$-closed topological semilattice is absolutely $H$-closed and we show that every linearly ordered semilattice is a dense subsemilattice of an $H$-closed topological semilattice.

Oleg Gutik, Dušan Repovš

We describe the structure of 0-simple countably compact topological inverse semigroups and the structure of congruence-free countably compact topological inverse semigroups.

Marc de Falco

The Geometry of Interaction purpose is to give a semantic of proofs or programs accounting for their dynamics. The initial presentation, translated as an algebraic weighting of paths in proofnets, led to a better characterization of the lambda-calculus optimal reduction. Recently Ehrhard and Regnier have introduced an extension of the Multiplicative Exponent

A. Ya. Helemskii

We show in this paper that a certain class of normed modules over the algebra of all bounded operators on a Hilbert space possesses a homological property which is a kind of a functional-analytic version of the standard algebraic property of flatness. We mean the preservation, under projective tensor multiplication of modules, of the property of a given morp

Oded Farago

Solvent-free coarse grained models represent one of the most promising approaches for molecular simulations of mesoscopically large membranes. In these models, the size of the simulated membrane is limited by the slow relaxation time of longest bending mode. Here, we present a Monte Carlo algorithm with update moves in which all the lipids are displaced simu

Thomas Mountford, Pierre Tarrès

We consider a model of the shape of a growing polymer introduced by Durrett and Rogers (Probab. Theory Related Fields 92 (1992) 337--349). We prove their conjecture about the asymptotic behavior of the underlying continuous process $X_t$ (corresponding to the location of the end of the polymer at time $t$) for a particular type of repelling interaction funct

M. Kunze, L. Lorenzi, A. Lunardi

We study a class of elliptic operators $A$ with unbounded coefficients defined in $I\times\CR^d$ for some unbounded interval $I\subset\CR$. We prove that, for any $s\in I$, the Cauchy problem $u(s,\cdot)=f\in C_b(\CR^d)$ for the parabolic equation $D_tu=Au$ admits a unique bounded classical solution $u$. This allows to associate an evolution family $\{G(t,s)

V. D. Rusov

Using Chetaev&#39;s theorem on stable trajectories in dynamics in the presence of perturbation forces we obtain a generalized stability condition for Hamiltonian systems that has the form of the Schrodinger equation. We show that the energy of the perturbation forces generating generalized Chetaev&#39;s stability condition is of electromagnetic nature and ex

Gary Froyland, Simon Lloyd, Anthony Quas

We present an analysis of one-dimensional models of dynamical systems that possess &#39;coherent structures&#39;; global structures that disperse more slowly than local trajectory separation. We study cocycles generated by expanding interval maps and the rates of decay for functions of bounded variation under the action of the associated Perron-Frobenius coc

Jason Covey, Christopher Homan

We provide deterministic, polynomial-time computable voting rules that approximate Dodgson&#39;s and (the ``minimization version&#39;&#39; of) Young&#39;s scoring rules to within a logarithmic factor. Our approximation of Dodgson&#39;s rule is tight up to a constant factor, as Dodgson&#39;s rule is $\NP$-hard to approximate to within some logarithmic factor.

Alexander Studenikin

We present quite a powerful method in investigations of different phenomena that can appear when neutrinos and electrons propagate in background matter. This method implies use of exact solutions of modified Dirac equations that contain the correspondent effective potentials accounting for the matter influence on particles. For several particular cases the e

Christian Bonatti, Sylvain Crovisier, Amie Wilkinson

Answering a question of Smale, we prove that the space of C1 diffeomorphisms of a compact manifold contains a residual subset of diffeomorphisms whose centralizers are trivial.

V. V. Yurinsky

This article is dedicated to localization of the principal eigenvalue (PE) of the Stokes operator acting on solenoidal vector fields that vanish outside a large random domain modeling the pore space in a cubic block of porous material with disordered micro-structure. Its main result is an asymptotically deterministic lower bound for the PE of the sum of a lo

Sascha Kurz, Joerg Rambau

We propose the new Top-Dog-Index to quantify the historic deviation of the supply data of many small branches for a commodity group from sales data. On the one hand, the common parametric assumptions on the customer demand distribution in the literature could not at all be supported in our real-world data set. On the other hand, a reasonably-looking non-para

Sascha Kurz, Joerg Rambau, Joerg Schluechtermann, Rainer Wolf

We propose the new Top-Dog-Index, a measure for the branch-dependent historic deviation of the supply data of apparel sizes from the sales data of a fashion discounter. A common approach is to estimate demand for sizes directly from the sales data. This approach may yield information for the demand for sizes if aggregated over all branches and products. Howe

Murat Ali Bayir, Ismail Hakki Toroslu, Ahmet Cosar, Guven Fidan

Web usage mining is a type of web mining, which exploits data mining techniques to discover valuable information from navigation behavior of World Wide Web users. As in classical data mining, data preparation and pattern discovery are the main issues in web usage mining. The first phase of web usage mining is the data processing phase, which includes the ses

Constantin Gaul, Sascha Kurz, Joerg Rambau

We consider the problem of approximating the branch and size dependent demand of a fashion discounter with many branches by a distributing process being based on the branch delivery restricted to integral multiples of lots from a small set of available lot-types. We propose a formalized model which arises from a practical cooperation with an industry partner

Petter Andreas Bergh, Øyvind Solberg

We define relative support varieties with respect to some fixed module over a finite dimensional algebra. These varieties share many of the standard properties of classical support varieties. Moreover, when introducing finite generation conditions on cohomology, we show that relative support varieties contain homological information on the modules involved.

R. M. Guralnick, W. M. Kantor, M. Kassabov, A. Lubotzky

All nonabelian finite simple groups of rank $n$ over a field of size $q$, with the possible exception of the Ree groups $^2G_2(3^{2e+1})$, have presentations with at most $80 $ relations and bit-length $O(\log n +\log q)$. Moreover, $A_n$ and $S_n$ have presentations with 3 generators$,$ 7 relations and bit-length $O(\log n)$, while $\SL(n,q)$ has a presenta

Emmanuel Breuillard

We show that for every integer $d$, there is a constant $N(d)$ such that if $K$ is any field and $F$ is a finite subset of $GL_d(K)$, which generates a non amenable subgroup, then $F^{N(d)}$ contains two elements, which freely generate a non abelian free subgroup. This improves the original statement of the Tits alternative. It also implies a growth gap and

Michael Gittings, Robert Weaver, Michael Clover, Thomas Betlach

We describe RAGE, the ``Radiation Adaptive Grid Eulerian&#39;&#39; radiation-hydrodynamics code, including its data structures, its parallelization strategy and performance, its hydrodynamic algorithm(s), its (gray) radiation diffusion algorithm, and some of the considerable amount of verification and validation efforts. The hydrodynamics is a basic Godunov

Rowena Ball

This note is intended to highlight the important role of black carbon produced from biomass burning in the global carbon cycle, and encourage further research in this area. Consideration of the fundamental physical chemistry of cellulose thermal decomposition suggests that suppression of biomass burning or biasing burning practices to produce soot-free flame

Kenneth R. Davidson, You Qing Ji

We establish a general result about extending a right invertible row over a Banach algebra to an invertible matrix. This is applied to the computation of right topological stable rank of a split exact sequence. We also introduce a quantitative measure of stable rank. These results are applied to compute the right (left) topological stable rank for all nest a

Don Hadwin, Weihua Li

In this paper, we prove approximate lifting results in the C$^{\ast}$-algebra and von Neumann algebra settings. In the C$^{\ast}$-algebra setting, we show that two (weakly) semiprojective unital C*-algebras, each generated by $n$ projections, can be glued together with partial isometries to define a larger (weakly) semiprojective algebra. In the von Neumann

S. K. Leggett, D. Saumon, Loic Albert, Michael. C. Cushing

Luhman and collaborators recently discovered an early-T dwarf companion to the G0 dwarf star HN Peg, using Spitzer Infrared Array Camera (IRAC) images. Companionship was established on the basis of the common proper motion inferred from 1998 Two Micron All Sky Survey images and the 2004 IRAC images. In this paper we present new near-infrared imaging data whi

F. Marchis, P. Descamps, J. Berthier, D. hestroffer

Using 8m-10m class telescopes and their Adaptive Optics (AO) systems, we conducted a long-term adaptive optics campaign initiated in 2003 focusing on four binary asteroid systems: (130) Elektra, (283) Emma, (379) Huenna, and (3749) Balam. The analysis of these data confirms the presence of their asteroidal satellite. We did not detect any additional satellit

Malcolm P. Kennett, Ross. H. McKenzie

Studies of angle-dependent magnetoresistance oscillations (AMRO) in the interlayer conductivity of layered metals have generally considered semi-classical electron transport. We consider a quantum correction to the semi-classical conductivity that arises from what can be described as an interlayer Cooperon. This depends on both the disorder potential within

F. Marchis, P. Descamps, M. Baek, A. W. Harris

In 2003, we initiated a long-term adaptive optics campaign to study the orbit of various main-belt asteroidal systems. Here we present a consistent solution for the mutual orbits of four binary systems: 22 Kalliope, 45 Eugenia, 107 Camilla and 762 Pulcova. With the exception of 45 Eugenia, we did not detect any additional satellites around these systems alth

Xiaojun Tang, Ruoheng Liu, Predrag Spasojevic, H. Vincent Poor

Wireless communication is susceptible to adversarial eavesdropping due to the broadcast nature of the wireless medium. In this paper it is shown how eavesdropping can be alleviated by exploiting the superposition property of the wireless medium. A wiretap channel with a helping interferer (WT-HI), in which a transmitter sends a confidential message to its in

M. L. Trippe, D. M. Crenshaw, R. Deo, M. Dietrich

New spectra of NGC 2992 from the Cerro Tololo Inter-American Observatory show that this nearby AGN has changed its type classification to a Seyfert 2 in 2006. It was originally classified as a Seyfert 1.9, and has been previously seen as a Seyfert 1.5 with strong broad Halpha emission. A comparison of the reddening and equivalent hydrogen column density deri

Olivier Morizot, Laurent Longchambon, Raghavan Kollengode Easwaran, Romain Dubessy

We discuss the quality required for the RF source used to trap neutral atoms in RF-dressed potentials. We illustrate this discussion with experimental results obtained on a Bose-Einstein condensation experiment with different RF sources.

Cullen H. Blake, David Charbonneau, Russel J. White, Guillermo Torres

We report the discovery of a single-lined spectroscopic binary with an Ultra Cool Dwarf (UCD) primary with a spectral type between M8 and L0.5. This system was discovered during the course of an ongoing survey to monitor L dwarfs for radial velocity variations and is the first known small separation (a<1 AU) spectroscopic binary among dwarfs at the M/L trans

Kristian Bredies, Dirk A. Lorenz

In this article a unified approach to iterative soft-thresholding algorithms for the solution of linear operator equations in infinite dimensional Hilbert spaces is presented. We formulate the algorithm in the framework of generalized gradient methods and present a new convergence analysis. As main result we show that the algorithm converges with linear rate

Jacques Distler, Sunil Mukhi, Constantinos Papageorgakis, Mark Van Raamsdonk

We argue that the moduli space for the Bagger-Lambert A_4 theory at level k is (R^8 \times R^8)/D_{2k}, where D_{2k} is the dihedral group of order 4k. We conjecture that the theory describes two M2-branes on a Z_{2k} ``M-fold'', in which a geometrical action of Z_{2k} is combined with an action on the branes. For k=1, this arises as the strong coupling limi

Israel Klich, Leonid Levitov

Entanglement entropy, which is a measure of quantum correlations between separate parts of a many-body system, has emerged recently as a fundamental quantity in broad areas of theoretical physics, from cosmology and field theory to condensed matter theory and quantum information. The universal appeal of the entanglement entropy concept is related, in part, t

Jakub Jȩdrak, Jozef Spałek

We analyze a class of mean-field (MF) lattice-fermion Hamiltonians and construct the corresponding grand-canonical density operator for such system. New terms are introduced, which may be interpreted as local fugacities, molecular fields, etc. The presence of such terms is an unavoidable consequence of a consistent statistical description. Although in some c

Paulo Pires Pacheco, Daniel Waldram

We discuss the structure of &#34;exceptional generalised geometry&#34; (EGG), an extension of Hitchin&#39;s generalised geometry that provides a unified geometrical description of backgrounds in eleven-dimensional supergravity. On a d-dimensional background, as first described by Hull, the action of the generalised geometrical O(d,d) symmetry group is replac

David K. Lai, Michael Bolte, Jennifer A. Johnson, Sara Lucatello

We present the results of an abundance analysis for a sample of stars with $-4<$[Fe/H]$<-2$. The data were obtained with the HIRES spectrograph at Keck Observatory. The set includes 28 stars, with effective temperature ranging from 4800 to 6600 K. For 13 stars with [Fe/H]$<-2.6$, including nine with [Fe/H]$<-3.0$ and one with [Fe/H]$=-4.0$, these are the fir

Paul Krapivsky, Dmitri Krioukov

We study the following paradox associated with networks growing according to superlinear preferential attachment: superlinear preference cannot produce scale-free networks in the thermodynamic limit, but there are superlinearly growing network models that perfectly match the structure of some real scale-free networks, such as the Internet. We obtain an analy

B. D. Simmons, C. M. Urry

In order to assess the accuracy with which we can determine the morphologies of AGN host galaxies, we have simulated more than 50,000 ACS images of galaxies with z < 1.25, using image and noise properties appropriate for the GOODS survey. We test the effect of central point-source brightness on host galaxy parameter recovery with a set of simulated AGN host

Mario R. Perez, Bruce McCollum, Mario E. van den Ancker, Michael D. Joner

We assess the evolutionary status of the intriguing object Walker 90/V590 Mon, which is located about 20 arcminutes northwest of the Cone Nebula near the center of the open cluster NGC 2264. This object, according to its most recent optical spectral type determination (B7), which we confirmed, is at least 3 magnitudes too faint in V for the cluster distance,

Wing-Ho Ko, Patrick A. Lee, Xiao-Gang Wen

A Chern--Simons theory for the doped spin-1/2 kagomé system is constructed, from which it is shown that the system is an exotic superconductor that breaks time-reversal symmetry. It is also shown that the system carries minimal vortices of flux $hc/4e$ (as opposed to the usual $hc/2e$ in conventional superconductors) and contains fractional quasiparticles (i

Prateek Sharma, Eliot Quataert, James M. Stone

We study the effects of anisotropic thermal conduction on magnetized spherical accretion flows using global axisymmetric MHD simulations. In low collisionality plasmas, the Bondi spherical accretion solution is unstable to the magnetothermal instability (MTI). The MTI grows rapidly at large radii where the inflow is subsonic. For a weak initial field, the MT

M. S. Bothwell, M. P. Torres, M. R. Garcia, P. A. Charles

Context. In quiescence, the proposed optical counterpart to the neutron star low mass X-ray binary 4U 2129+47 (V1727 Cyg) shows a spectrum consistent with a late F-type subgiant and no radial velocity variations on the 5.24 hour binary period. This could imply that V1727 Cyg is a chance line of sight interloper. Radial velocity measurements, however, showed

Eugen Radu, Mikhail S. Volkov

We review the current status of the problem of constructing classical field theory solutions describing stationary vortex rings in Minkowski space in 3+1 dimensions. We describe the known up to date solutions of this type, such as the static knot solitons stabilized by the topological Hopf charge, the attempts to gauge them, the anomalous solitons stabilized

Bo-Wen Xiao

In this letter, the exact accelerating string solution of a heavy quark-antiquark pair is found in $AdS_5$ space. On the accelerating string, there is a particular scale which separates the radiation and the heavy quark. This scale is explicitly shown to be an event horizon in the proper frame of the heavy quark. Furthermore, we find a new correspondence, wh

G. Baskaran

Superconducting LaOFeAs family of even electron metallic systems have striking resemblance to odd electron cuprates. We suggest that this resemblance is caused by presence of two coupled 2D resonating valence bond systems in LaOFeAs . Bond charge repulsion and Hund coupling fuse the 2 species of valence bonds into closed strings with a Haldane gap, resulting

Casey M. Schneider-Mizell, Leonard M. Sander

We study a generalization of the voter model on complex networks, focusing on the scaling of mean exit time. Previous work has defined the voter model in terms of an initially chosen node and a randomly chosen neighbor, which makes it difficult to disentangle the effects of the stochastic process itself relative to the network structure. We introduce a proce

Julien Cassaigne, Christian Mauduit, Francois Nicolas

A D0L-system is a triple (A, f, w) where A is a finite alphabet, f is an endomorphism of the free monoid over A, and w is a word over A. The D0L-sequence generated by (A, f, w) is the sequence of words (w, f(w), f(f(w)), f(f(f(w))), ...). The corresponding sequence of lengths, that is the function mapping each non-negative integer n to |f^n(w)|, is called th

Korkut Bardakci

The present work continues the program of summing planar Feynman graphs on the world sheet. Although it is based on the same classical action introduced in the earlier work, there are important new features: Instead of the path integral used in the earlier work, the model is quantized using the canonical algebra and the Hamiltonian picture. The new approach

Deog Ki Hong, Ki-Myeong Lee, Cheonsoo Park, Ho-Ung Yee

We study how monopole catalysis of baryon decay is realized in holographic QCD. Physics of monopole catalysis becomes much simpler in holographic description as it occurs due to the violation of the Bianchi identity for the 5D gauge symmetry when magnetic monopole is present. In holographic QCD we find a unified picture of the baryon number violation under m

Z. W. Zhu, Z. A. Xu, X. Lin, G. H. Cao

We report the first Nernst effect measurement on the new iron-based superconductor LaO$_{1-x}$F$_{x}$FeAs $(x=0.1)$. In the normal state, the Nernst signal is negative and very small. Below $T_{c}$ a large positive peak caused by vortex motion is observed. The flux flowing regime is quite large compared to conventional type-II superconductors. However, a cle

A. I. Machavariani, Amand Faessler

The pion-nucleon bremsstrahlung $π+N\Longrightarrowγ&#39;+π&#39;+N&#39;$ is studied in a new form of current conservation. According to this condition, the internal and external particle radiation parts of the $πN$ radiation amplitude have opposite signs, i.e., they contain terms which must cancel each other. Therefore, one has a screening of the internal an

Shaon Sahoo, Raghunathan Rajamani, S. Ramasesha, Diptiman Sen

Generally, the first step in modeling molecular magnets involves obtaining the low-lying eigenstates of a Heisenberg exchange Hamiltonian which conserves total spin and belongs usually to a non-Abelian point group. In quantum chemistry, it has been a long standing problem to target a state which has definite total spin and also belongs to a definite irreduci

Mowei Cheng

In order to quantitatively study the accuracy of the unconditionally stable coarsening algorithms, we calculate the Fourier space multi step error on the order parameter field by explicitly distinguishing the analytic time $τ$ and the algorithmic time $t$. The calculation determines the error in the order parameter and the scaled correlations. This error con

H. T. Quan, S. Yang, C. P. Sun

For a two-level quantum mechanical system, we derive microscopically the exact expression for the fluctuation of microscopic work in a multi-step non-equilibrium process, and we rigorously prove that in an isothermal process, the fluctuation is vanishingly small, and the most probabilistic work just equals to the difference of the free energy. Our study demo

A. N. Ivanov, E. L. Kryshen, M. Pitschmann, P. Kienle

We investigate the influence of the strong Coulomb field of a heavy nucleus on massive neutrinos, produced in the K-shell electron capture (EC) decays of the H-like 140Pr58+ and 142Pm60+ ions. The corrections to the neutrino masses due to virtually produced charged lepton W-boson pairs in the strong Coulomb field of a nucleus with charge Ze are calculated an

William Arveson

Let $V$ be a norm-closed subset of the unit sphere of a Hilbert space $H$ that is stable under multiplication by scalars of absolute value 1. A {\em maximal vector} (for $V$) is a unit vector $ξ\in H$ whose distance to $V$ is maximum $d(ξ,V)=\sup_{\|η\|=1}d(η,V)$, $d(ξ,V)$ denoting the distance from $ξ$ to the set $V$. Maximal vectors generalize the {\em max

Marc Lackenby

We prove that every finitely generated Kleinian group that contains a finite, non-cyclic subgroup either is finite or virtually free or contains a surface subgroup. Hence, every arithmetic Kleinian group contains a surface subgroup.

Pascal Anastasopoulos, Francesco Fucito, Andrea Lionetto, Gianfranco Pradisi

We study an extension of the MSSM by an anomalous abelian vector multiplet and a Stückelberg multiplet. The anomalies are cancelled by the Green-Schwarz mechanism and the addition of Chern-Simons terms. The advantage of this choice over the standard one is that it allows for arbitrary values of the quantum numbers of the extra U(1). As a first step towards t

S. I. Denisov, Werner Horsthemke, Peter Hänggi

We derive the generalized Fokker-Planck equation associated with a Langevin equation driven by arbitrary additive white noise. We apply our result to study the distribution of symmetric and asymmetric Lévy flights in an infinitely deep potential well. The fractional Fokker-Planck equation for Lévy flights is derived and solved analytically in the steady stat

M. Passera, W. J. Marciano, A. Sirlin

After a brief review of the muon g-2 status, we analyze the possibility that the present discrepancy between experiment and the Standard Model (SM) prediction may be due to hypothetical errors in the determination of the hadronic leading-order contribution to the latter. In particular, we show how an increase of the hadro-production cross section in low-ener

K. Rasem Qandalji

We propose a single-step non-generational conjecture of all first class constraints,(involving only variables compatible with canonical Poisson brackets), for a realistic gauge singular field theory. We verify our proposal for the free electromagnetic field, Yang-Mills fields in interaction with spinor and scalar fields, and we also verify our proposal in th

Sascha Kurz, Reinhard Laue

Geometrical objects with integral sides have attracted mathematicians for ages. For example, the problem to prove or to disprove the existence of a perfect box, that is, a rectangular parallelepiped with all edges, face diagonals and space diagonals of integer lengths, remains open. More generally an integral point set $\mathcal{P}$ is a set of $n$ points in

Martin Reuter, Holger Weyer

We explore the nonperturbative renormalization group flow of Quantum Einstein Gravity (QEG) on an infinite dimensional theory space. We consider &#34;conformally reduced&#34; gravity where only fluctuations of the conformal factor are quantized and employ the Local Potential Approximation for its effective average action. The requirement of &#34;background i

Gunnar Moller, Steven H. Simon, Edward H. Rezayi

We provide numerical evidence for composite fermion pairing in quantum Hall bilayer systems at filling $ν=1/2 + 1/2$ for intermediate spacing between the layers. We identify the phase as $p_x + i p_y$ pairing, and construct high accuracy trial wavefunctions to describe the groundstate on the sphere. For large distances between the layers, and for finite syst

J. S. Bagla, Jayanti Prasad, Nishikanta Khandai

N-Body simulations are an important tool in the study of formation of large scale structures. Much of the progress in understanding the physics of galaxy clustering and comparison with observations would not have been possible without N-Body simulations. Given the importance of this tool, it is essential to understand its limitations as ignoring these can ea

Jean-Luc Lehners, Paul J. Steinhardt

It has been pointed out by several groups that ekpyrotic and cyclic models generate significant non-gaussianity. In this paper, we present a physically intuitive, semi-analytic estimate of the bispectrum. We show that, in all such models, there is an intrinsic contribution to the non-gaussianity parameter f_{NL} that is determined by the geometric mean of th

P. Petit, B. Dintrans, S. K. Solanki, J. -F. Donati

From a set of stellar spectropolarimetric observations, we report the detection of surface magnetic fields in a sample of four solar-type stars, namely HD 73350, HD 76151, HD 146233 (18 Sco) and HD 190771. Assuming that the observed variability of polarimetric signal is controlled by stellar rotation, we establish the rotation periods of our targets, with va

Cong-Feng Qiao, Jian Wang, Jian Xiong Wang, Yangheng Zheng

The EtabFDC is a matrix-element event generator package for $η_b$ hadroproduction at LHC. It generates $pp\toη_b X$ events for all possible parton-level $2\to2$ leading-order processes with three commonly used $η_b$ decay channels being implemented. The \pythia interface is used for parton-shower and hadronization to obtain the hadronic events. The FORTRAN c

Michael Kiermaier, Sascha Kurz

Motivated by integral point sets in the Euclidean plane, we consider integral point sets in affine planes over finite fields. An integral point set is a set of points in the affine plane $\mathbb{F}_q^2$ over a finite field $\mathbb{F}_q$, where the formally defined squared Euclidean distance of every pair of points is a square in $\mathbb{F}_q$. It turns ou

Gianni Tedesco, Uwe Aickelin

Network intrusion detection sensors are usually built around low level models of network traffic. This means that their output is of a similarly low level and as a consequence, is difficult to analyze. Intrusion alert correlation is the task of automating some of this analysis by grouping related alerts together. Attack graphs provide an intuitive model for

Sergei M. Kuzenko, Gabriele Tartaglino-Mazzucchelli

Using the superspace formulation for the 5D N = 1 Weyl supermultiplet developed in arXiv:0802.3953, we elaborate the concept of conformally flat superspace in five dimensions. For a large family of supersymmetric theories (including sigma-models and Yang-Mills theories) in the conformally flat superspace, we describe an explicit procedure to formulate their

E. I. Guendelman, A. B. Kaganovich

Solutions with degenerate metric ($det(g_{μν})=0$ or $g_{μν}=0$) in the first order formalism (FOF) are physically acceptable: they may describe topology changes (Horowitz) and reduction of &#34;metrical dimension&#34; (Tseytlin) of space-time. The latter implies disappearance of the volume element $\sqrt{-g}d^4x$ of 4-D space-time. We pay attention that bes

Luca Salasnich

We discuss the zero-temperature hydrodynamics equations of bosonic and fermionic superfluids and their connection with generalized Gross-Pitaevskii and Ginzburg-Landau equations through a single superfluid nonlinear Schrodinger equation.

Rustam Sadykov

Recently Galatius, Madsen, Tillmann and Weiss identified the homotopy type of the classifying space of the cobordism category of embedded d-dimensional manifolds [7] for each positive integer d. Their result lead to a new proof of the generalized standard Mumford conjecture. We extend the main theorem of [7] to the case of cobordism categories of embedded d-

Wei Chao, Zong-Guo Si, Zhi-zhong Xing, Shun Zhou

We explore an intriguing possibility to test the type-II seesaw mechanism of neutrino mass generation at the Large Hadron Collider (LHC). We show that the lepton-number-violating signatures of heavy Majorana neutrinos N_i (for i=1, 2, 3) and doubly-charged Higgs bosons H^++(H^--) can be closely correlated with each other in a class of TeV-scale type-II seesa

J. S. Jenkins, H. R. A. Jones, Y. Pavlenko, D. J. Pinfield

We present the results from high-resolution spectroscopic measurements to determine metallicities and activities of bright stars in the southern hemisphere. We have measured the iron abundances ([Fe/H]) and chromospheric emission indices (logR&#39;HK) of 353 solar-type stars with V=7.5-9.5. [Fe/H] abundances are determined using a custom chi^2 fitting proced

Linyuan Lü, Matus Medo, Yi-Cheng Zhang, Damien Challet

We introduce a fully probabilistic framework of consumer product choice based on quality assessment. It allows us to capture many aspects of marketing such as partial information asymmetry, quality differentiation, and product placement in a supermarket.

Hai-Zhou Lu, Shun-Qing Shen

A double-quantum-dot coupled to electrodes with spin-dependent splitting of chemical potentials (spin bias) is investigated theoretically by means of the Green&#39;s functions formalism. By applying a large spin bias, the quantum spin in a quantum dot (the dot 1) can be manipulated in a fully electrical manner. To noninvasively monitor the manipulation of th

M. Beccaria, G. Macorini, L. Panizzi, F. M. Renard

We have computed the one-loop electroweak expression of diagonal and non diagonal stop-antistop and sbottom-antisbottom production from initial state gluons at LHC. We have investigated the possibility that the one-loop effects exhibit a dependence on &#34;extra&#34; supersymmetric parameters different from the final squark masses. Our results, given for a c

Karol Zyczkowski

We propose an extended quantum theory, in which the number K of parameters necessary to characterize a quantum state behaves as fourth power of the number N of distinguishable states. As the simplex of classical N-point probability distributions can be embedded inside a higher dimensional convex body of mixed quantum states, one can further increase the dime

W. Wernsdorfer

Ramsey et al. [Nature Phys. 4, 277-281 (2008)] report the observation of quantum interference associated with tunnelling trajectories between states of different total spin length in a dimeric molecular nanomagnet. They argue that the interference is a consequence of the unique characteristics of a molecular Mn12 wheel, which behaves as a molecular dimer wit

Steven Hurder

We give a survey of the approaches to classifying foliations, starting with the Haefliger classifying spaces and the various results and examples about the secondary classes of foliations. Various dynamical properties of foliations are introduced and discussed, including expansion rate, local entropy, and orbit growth rates. This leads to a decomposition of

Maciej Dunajski

We introduce a dispersionless integrable system which interpolates between the dispersionless Kadomtsev-Petviashvili equation and the hyper-CR equation. The interpolating system arises as a symmetry reduction of the anti--self--dual Einstein equations in (2, 2) signature by a conformal Killing vector whose self--dual derivative is null. It also arises as a s