May 2009 arXiv papers — page 3

Pablo Rodriguez-Lopez

We obtain the Pairwise Summation Approximation (PSA) of the Casimir energy from first principles in the soft dielectric and soft diamagnetic limit, so we find that the PSA is an asymptotic approximation of the Casimir energy valid for large distances between the objects. We also obtain the PSA for the electromagnetic coupling part of the Casimir energy, so w

M. G. Zhao, for Bes Collaboration

There are about 33, 6.5 and 1.0 pb$^{-1}$ of $e^+e^-$ annihilation data have been taken around the center-of-mass energies of $\sqrt s=$ 3.773 GeV, at $\sqrt s=$ 3.650 GeV and at $\sqrt s=$ 3.6648 GeV, respectively, with the BES-II detector at the BEPC collider. By analyzing these data sets, we have measured the branching fraction for $ψ(3770)\to$ non-$D\bar

Abdulla Rakhimov, E. Ya. Sherman, Chul Koo Kim

We study properties of magnetic field-induced Bose-Einstein condensate of triplons as a function of temperature and the field within the Hartree-Fock-Bogoliubov approach including the anomalous density. We show that the magnetization is continuous across the transition, in agreement with the experiment. In sufficiently strong fields the condensate becomes un

Neil Ghani, Peter Hancock, Dirk Pattinson

We define representations of continuous functions on infinite streams of discrete values, both in the case of discrete-valued functions, and in the case of stream-valued functions. We define also an operation on the representations of two continuous functions between streams that yields a representation of their composite. In the case of discrete-valued func

M. van den Berg, M. Iversen

We study the variational problem $$\inf \{λ_k(Ω): Ω \textup{open in}\ \R^m,\ |Ω| < \infty, \ \h(\partial Ω) \le 1 \},$$ where $λ_k(Ω)$ is the $k$&#39;th eigenvalue of the Dirichlet Laplacian acting in $L^2(Ω)$, $\h(\partial Ω)$ is the $(m-1)$- dimensional Hausdorff measure of the boundary of $Ω$, and $|Ω|$ is the Lebesgue measure of $Ω$. If $m=2$, and $k=2,3

Sanjeev Kumar, Jeroen van den Brink, Arno P. Kampf

The experimental observation of multiferroic behavior in perovskite manganites with a spiral spin structure demands to clarify the origin of these magnetic states and their relation to ferroelectricity. We show that spin-spiral phases with diagonal wavevector and also the E-type phase exist for intermediate values of the Hund&#39;s rule and the Jahn-Teller c

David P. DiVincenzo

In this short review, I draw attention to new developments in the theory of fault tolerance in quantum computation that may give concrete direction to future work in the development of superconducting qubit systems. The basics of quantum error correction codes, which I will briefly review, have not significantly changed since their introduction fifteen years

Craig J. Hogan

Arguments based on general principles of quantum mechanics suggest that a minimum length or time associated with Planck-scale unification may entail a new kind of observable uncertainty in the transverse position of macroscopically separated bodies. Transverse positions vary randomly about classical geodesics in space and time by about the geometric mean of

Ian Kiming, Matthias Schuett, Helena Verrill

We show that noncongruence subgroups of SL_2(Z) projectively equivalent to congruence subgroups are ubiquitous. More precisely, they always exist if the congruence subgroup in question is a principal congruence subgroup Gamma(N) of level N>2, and they exist in many cases also for Gamma_0(N). The motivation for asking this question is related to modular forms

Edward Witten

Geometric Langlands duality relates a representation of a simple Lie group $G^\vee$ to the cohomology of a certain moduli space associated with the dual group $G$. In this correspondence, a principal $SL_2$ subgroup of $G^\vee$ makes an unexpected appearance. Why this happens can be explained using gauge theory, as we will see in this article, with the help

Christian H. Sanabria, R. Huerta-Quintanilla, M. Rodriguez-Achach

We study two kinds of economic exchange, additive and multiplicative, in a system of N agents. The work is divided in two parts, in the first one, the agents are free to interact with each other. The system evolves to a Boltzmann-Gibbs distribution with additive exchange and condenses with a multiplicative one. If bankruptcy is introduced, both types of exch

Andrei Khrennikov

One of the crucial differences between mathematical models of classical and quantum mechanics is the use of the tensor product of the state spaces of subsystems as the state space of the corresponding composite system. (To describe an ensemble of classical composite systems one uses random variables taking values in the Cartesian product of the state spaces

Lavinia Corina Ciungu, Anatolij Dvurečenskij

In this paper, we extend the notions of states and measures presented in \cite{DvPu} to the case of pseudo-BCK algebras and study similar properties. We prove that, under some conditions, the notion of a state in the sense of \cite{DvPu} coincides with the Bosbach state, and we extend to the case of pseudo-BCK algebras some results proved by J. Kühr only for

D. Baillie, P. B. Blakie

We present theory for the critical temperature of a Bose gas in a combined harmonic lattice potential based on a mean-field description of the system. We develop practical expressions for the ideal-gas critical temperature, and corrections due to interactions, the finite-size effect, and the occupation of excited bands. We compare our expressions to numerica

I. A. Ivanov, A. S. Kheifets

Increase of the cut-off value in the high order harmonics generation process is demonstrated for a special case of the driving field composed of several harmonics of a given frequency. It is shown that a moderate, of the order of 20%, increase in the cut-off value can be achieved. This result possibly constitutes an upper limit for the increase in the cut-of

J-M. Beaujour, D. Ravelosona, I. Tudosa, E. Fullerton

Transition metal ferromagnetic films with perpendicular magnetic anisotropy (PMA) have ferromagnetic resonance (FMR) linewidths that are one order of magnitude larger than soft magnetic materials, such as pure iron (Fe) and permalloy (NiFe) thin films. A broadband FMR setup has been used to investigate the origin of the enhanced linewidth in Ni$|$Co multilay

W. G. Dwyer, J. P. C. Greenlees, S. B. Iyengar

Gross and Hopkins have proved that in chromatic stable homotopy, Spanier-Whitehead duality nearly coincides with Brown-Comenetz duality. Our goal is to give a conceptual interpretation for this phenomenon in terms of the Gorenstein condition for maps of ring spectra in the sense of [Duality in algebra and topology, Adv. Math. 200 (2006), 357--402. arXiv: mat

Vadim Ohanyan

The sawtooth chain with pairs of $S=1/2$ spins interacting with $XXZ$-interactions placed on each second tooth is considered. All other interaction bonds are taken to be of Ising type. Exact statistical mechanical solution of the model within the direct transfer-matrix technique is obtained. The solution allows one to obtain exact analytic expressions for al

Hiroshi Goda, Takuya Sakasai

A homology cylinder over a surface consists of a homology cobordism between two copies of the surface and markings of its boundary. The set of isomorphism classes of homology cylinders over a fixed surface has a natural monoid structure and it is known that this monoid can be seen as an enlargement of the mapping class group of the surface. We now focus on a

Lixin Xu, Jianbo Lu, Wenbo Li

In this paper, motivated from the fact that a de Sitter cosmological boundary corresponds to a positive cosmological constant, we consider time variable cosmological constants, dubbed {\it horizon cosmological constants}. The horizon cosmological constants correspond to Hubble horizon, future event horizon and particle horizon are discussed respectively. Whe

Young-Hoon Kiem, Jun Li

We prove a wall crossing formula of Donaldson-Thomas type invariants without Chern-Simons functionals.

Fotini Markopoulou, Simone Severini

We point out that the total number of trails and the total number of paths of given length, between two vertices of a simple undirected graph, are obtained as expectation values of specifically engineered quantum mechanical observables. Such observables are contextual with some background independent theories of gravity and emergent geometry. Thus, we point

Edgar Carrera

Final state signatures of a single photon and missing transverse energy offer unique and powerful advantages in the search for new physics. This document presents the first observation of the Zgamma to nunu_bargamma process at the Tevatron Collider at 5.1 standard deviations significance, as well as some of the strongest limits on anomalous trilinear ZZgamma

Nadia Fawaz, Keyvan Zarifi, Merouane Debbah, David Gesbert

A multi-hop relaying system is analyzed where data sent by a multi-antenna source is relayed by successive multi-antenna relays until it reaches a multi-antenna destination. Assuming correlated fading at each hop, each relay receives a faded version of the signal from the previous level, performs linear precoding and retransmits it to the next level. Using f

M. A. Hossain, B. Bohnenbuck, Y. -D. Chuang, A. G. Cruz Gonzalez

We present a temperature-dependent resonant elastic soft x-ray scattering (REXS) study of the metal-insulator transition in Sr3(Ru1-xMnx)2O7, performed at both Ru and Mn L-edges. Resonant magnetic superstructure reflections, which indicate an incipient instability of the parent compound, are detected below the transition. Based on modelling of the REXS inten

A. M. Souza, D. O. Soares-Pinto, R. S. Sarthour, I. S. Oliveira

In the present work we show that a special family of materials, the metal carboxylates, may have entangled states up to very high temperatures. From magnetic susceptibility measurements, we have estimated the critical temperature below which entanglement exists in the cooper carboxylate \{Cu$_2$(O$_2$CH)$_4$\}\{Cu(O$_2$CH)$_2$(2-methylpyridine)$_2$\}, and we

Jiying Li, Thomas B. S. Jensen, Niels. H. Andersen, Jerel L. Zarestky

Elastic and inelastic neutron scattering studies of Li(Ni$_{1-x}$Fe$_{x}$)PO$_4$ single crystals reveal anomalous spin-wave dispersions along the crystallographic direction parallel to the characteristic wave vector of the magnetic incommensurate phase. The anomalous spin-wave dispersion ({\it magnetic soft mode}) indicates the instability of the Ising-like

Kwok Sau Fa

Usually, the Kohlrausch (stretched exponential) function is employed to fit the luminescence decays. In this work we propose to use the Tsallis distribution as an alternative to describe them. We show that the curves of the luminescence decay obtained from the Tsallis distribution are close to those ones obtained from the stretched exponential. Further, we s

Alejandro Jenkins

We summarize the results of previous research on the constraints imposed on quark masses by the anthropically-motivated requirement that there exist stable nuclei with the right charge to form complex molecules. We also mention an upper bound on the mass of the lightest lepton, derived from the requirement that such nuclei be stable against electron capture.

U. Baur

Standard Model Higgs pair production at e^+e^- colliders has the capability to determine the Higgs boson self-coupling λ. I present a detailed analysis of the e^+e^- -> ZHH and e^+e^- -> ν\barνHH signal channels, and the relevant background processes, for future e^+e^- linear colliders with center of mass energies of \sqrt{s}=0.5 TeV, 1 TeV, and 3 TeV. Speci

M. L. N. Ashby, D. Stern, M. Brodwin, R. Griffith

The Spitzer Deep, Wide-Field Survey (SDWFS) is a four-epoch infrared survey of ten square degrees in the Bootes field of the NOAO Deep Wide-Field Survey using the IRAC instrument on the Spitzer Space Telescope. SDWFS, a Cycle four Spitzer Legacy project, occupies a unique position in the area-depth survey space defined by other Spitzer surveys. The four epoc

Matthew A. Kohlmyer, Marcos D. Caballero, Richard Catrambone, Ruth W. Chabay

The performance of over 2000 students in introductory calculus-based electromagnetism (E&M) courses at four large research universities was measured using the Brief Electricity and Magnetism Assessment (BEMA). Two different curricula were used at these universities: a traditional E&M curriculum and the Matter & Interactions (M&I) curriculum. At each universi

M. Gliozzi, S. Satyapal, M. Eracleous, L. Titarchuk

We report the detection of a weak X-ray point source coincident with the nucleus of the bulgeless disk galaxy NGC 3621, recently discovered by Spitzer to display high ionization mid-infrared lines typically associated with AGN. These Chandra observations provide confirmation for the presence of an AGN in this galaxy, adding to the growing evidence that black

A. Weijmans, M. Cappellari, R. Bacon, P. T. de Zeeuw

We use the integral-field spectrograph SAURON to measure the stellar line-of-sight velocity distribution and absorption line strengths out to four effective radii (Re) in the early-type galaxies NGC 3379 and NGC 821. With our newly developed observing technique we can now probe these faint regions in galaxies that were previously not accessible with traditio

Han-Dong Chen, B. Wang, S. Das Sarma

We address the following important question: how to distinguish Kitaev models experimentally realized on small lattices from other non-topological interacting spin models. Based on symmetry arguments and exact diagonalization, we show that a particularly characteristic pattern of spin-spin correlations survives despite finite size, open boundary and thermal

David Blanc, Mark W. Johnson, James M. Turner

We explain how higher homotopy operations, defined topologically, may be identified under mild assumptions with (the last of) the Dwyer-Kan-Smith cohomological obstructions to rectifying homotopy-commutative diagrams.

P. Di Matteo, C. J. Jog, M. D. Lehnert, F. Combes

Through the analysis of a set of numerical simulations of major mergers between initially non-rotating, pressure supported progenitor galaxies with a range of central mass concentrations, we have shown that: (1) it is possible to generate elliptical-like galaxies, with v/sigma > 1 outside one effective radius, as a result of the conversion of orbital- into i

David W. Catlin, John P. D&#39;Angelo

We discuss some aspects of the theory of subelliptic estimates.

John P. D&#39;Angelo

We summarize some work on CR mappings invariant under a subgroup of U(n) and prove a result on the failure of rigidity.

Eleni Katifori, Gergely J. Szöllősi, Marcelo O. Magnasco

Leaf venation is a pervasive example of a complex biological network, endowing leaves with a transport system and mechanical resilience. Transport networks optimized for efficiency have been shown to be trees, i.e. loopless. However, dicotyledon leaf venation has a large number of closed loops, which are functional and able to transport fluid in the event of

Marco Martins Afonso, Andrea Mazzino

The dispersion of inertial particles continuously emitted from a point source is analytically investigated in the limit of small inertia. Our focus is on the evolution equation of the particle joint probability density function p(x,v,t), x and v being the particle position and velocity, respectively. For finite inertia, position and velocity variables are co

Francis Corson

The structure of networks that provide optimal transport properties has been investigated in a variety of contexts. While many different formulations of this problem have been considered, it is recurrently found that optimal networks are trees. It is shown here that this result is contingent on the assumption of a stationary flow through the network. When ti

Alexei Bespalov, Norbert Heuer

This paper presents an a priori error analysis of the hp-version of the boundary element method for the electric field integral equation on a piecewise plane (open or closed) Lipschitz surface. We use H(div)-conforming discretisations with Raviart-Thomas elements on a sequence of quasi-uniform meshes of triangles and/or parallelograms. Assuming the regularit

S. N. Filippov, V. I. Man&#39;ko

Spin-tomographic symbols of qudit states and spin observables are studied. Spin observables are associated with the functions on a manifold whose points are labelled by spin projections and 2-sphere coordinates. The star-product kernel for such functions is obtained in explicit form and connected with Fourier transform of characters of SU(2) irreducible repr

Jorge Mondejar

We address the issue of light-light scattering in the presence of a background field at low energies using effective lagrangians. We derive the Euler-Heisenberg lagrangian at one loop and modify it to incorporate the case of the interaction with a background field.

Manfred Hartl, Bruno Loiseau

Semi-abelian and finitely cocomplete homological categories are characterized in terms of four resp. three simple axioms, in terms of the basic categorical notions introduced in the first few chapters of MacLane&#39;s classical book. As an immediate application we show that categories of diagrams in semi-abelian and similar categories are of the same type; i

Cesar Manchein, Jane Rosa, Marcus W. Beims

A system plus environment conservative model is used to characterize the nonlinear dynamics when the time averaged energy for the system particle starts to decay. The system particle dynamics is regular for low values of the $N$ environment oscillators and becomes chaotic in the interval $13\le N\le15$, where the system time averaged energy starts to decay.

G. L. Gattobigio, A. Couvert, M. Jeppesen, R. Mathevet

We have experimentally demonstrated a high level of control of the mode populations of guided atom lasers (GALs) by showing that the entropy per particle of an optically GAL, and the one of the trapped Bose Einstein condensate (BEC) from which it has been produced are the same. The BEC is prepared in a crossed beam optical dipole trap. We have achieved isent

Daniel Naie

A formula for the irregularity of abelian coverings of the projective plane is established and some applications are presented.

António J. G. Bento, César Silva

Assuming the existence of a general nonuniform dichotomy for the evolution operator of a non-autonomous ordinary linear differential equation in a Banach space, we establish the existence of invariant stable manifolds for the semiflow generated by sufficiently small nonlinear perturbations of the linear equation. The family of dichotomies considered satisfie

V. K. Oikonomou

We study the influence of the shape of compact dimensions to the Casimir energy and Casimir force of a scalar field. We examine both the massive and the massless scalar field. The total spacetime topology is $M^D\times T^2_θ$, where $M^D$ is the $D$ dimensional Minkowski spacetime and $T^2_θ$ the twisted torus described by $R_1$, $R_2$ and $θ$. For the case

Devendraa Siingh, V Pant, A K Kamra

Simultaneous measurements of the small-, intermediate- and large- positive ions and air earth current density made at a coastal station, Maitri at Antarctica during January to February 2005, are reported. Although, small and large positive ion concentrations do not show any systematic diurnal variations, variations in them are almost similar to each other. O

Vladimir Mordachev, Sergey Loyka

A statistical model of interference in wireless networks is considered, which is based on the traditional propagation channel model and a Poisson model of random spatial distribution of nodes in 1-D, 2-D and 3-D spaces with both uniform and non-uniform densities. The power of nearest interferer is used as a major performance indicator, instead of a tradition

Hael Collins, R. Holman

This article examines how breaking a Lorentz-invariant description of nature at tiny space-time intervals would affect the non-Gaussian character of the pattern of primordial perturbations left by inflation. We specifically study a set of irrelevant operators that preserve the spatial symmetries of the usual inflationary background. The non-Gaussian componen

D. O. Gough

Astronomical observation of stellar rotation suggests that at least the surface layers of the Sun have lost a substantial amount of the angular momentum that they possessed at the beginning of the main-sequence phase of evolution; and solar-wind observations indicate that magnetic coupling is still draining angular momentum from the Sun today. In addition, h

Hari P. Dahal, Zi-Xiang Hu, N. A. Sinitsyn, Kun Yang

We study the edge states in graphene in the presence of a magnetic field perpendicular to the plane of the lattice. Most of the works done so far discuss the edge states in either zigzag or armchair edge graphene considering an isotropic electron hopping. In practice, graphene can have mixture of armchair and zigzag edges and the electron hopping can be anis

Michael E. Zieve

Recently Bassa, Garcia and Stichtenoth constructed a tower of function fields over GF(q^3) having many rational places relative to their genera. We show that, by removing the bottom field from this tower, we obtain the same tower we would obtain by removing certain fields from a tower constructed previously by Bezerra, Garcia and Stichtenoth.

Josep M. Pujol, Vijay Erramilli, Pablo Rodriguez

Online Social Networks (OSNs) have exploded in terms of scale and scope over the last few years. The unprecedented growth of these networks present challenges in terms of system design and maintenance. One way to cope with this is by partitioning such large networks and assigning these partitions to different machines. However, social networks possess unique

G. Fuchs, S. -L. Drechsler, N. Kozlova, J. Freudenberger

We report resistivity and upper critical field B_c2(T) data for As deficient LaO_(0.9)F_(0.1)FeAs_(1-delta) in a wide temperature and high field range up to 60 T. These disordered samples exhibit a slightly enhanced superconducting transition at T_c = 29 K and a significantly enlarged slope dB_(c2))/dT = -5.4 T/K near T_c which contrasts with a flattening of

Kirill Krasnov, Carlo Rovelli

Quantum black holes have been studied extensively in quantum gravity and string theory, using various semiclassical or background dependent approaches. We explore the possibility of studying black holes in the full non-perturbative quantum theory, without recurring to semiclassical considerations, and in the context of loop quantum gravity. We propose a defi

S. M. Gerasyuta, V. I. Kochkin

The relativistic four-quark equations are found in the framework of coupled-channel formalism. The dynamical mixing of the meson-meson states with the four-quark states is considered. The four-quark amplitudes of the tetraquarks, including $u$, $d$, $s$ and bottom quarks, are constructed. The poles of these amplitudes determine the masses and widths of $S$-w

Akil C. Narayan, Jan S. Hesthaven

We formulate and derive a generalization of an orthogonal rational-function basis for spectral expansions over the infinite or semi-infinite interval. The original functions, first presented by Wiener are a mapping and weighting of the Fourier basis to the infinite interval. By identifying the Fourier series as a biorthogonal composition of Jacobi polynomial

Laura Maruster, Stefan Maruster

The convergence of the projection algorithm for solving the convex feasibility problem for a family of closed convex sets, is in connection with the regularity properties of the family. In the paper [18] are pointed out four cases of such a family depending of the two characteristics: the emptiness and boudedness of the intersection of the family. The case f

Carlos Gershenson

Una de las presuposiciones de la ciencia desde los tiempos de Galileo, Newton y Laplace ha sido la previsibilidad del mundo. Esta idea ha influido en los modelos cientificos y tecnologicos. Sin embargo, en las ultimas decadas, el caos y la complejidad han mostrado que no todos los fenomenos son previsibles, aun siendo estos deterministas. Si el espacio de un

Ryan Martin

The Sudbury Neutrino Observatory (SNO) was a heavy water Cerenkov detector designed to solve the long-standing ``solar neutrino problem&#39;&#39;; a discrepancy between the measured and predicted flux of electron-flavour solar neutrinos. SNO measured the rate of charged-current and neutral-current reactions of neutrinos in heavy water and was able to demonst

Lucian Luca, Lucian L. Luca

The paper starts from the observation on the complexity of the manipulation of fuzzy processes that increases very rapidly with the extents of the processes representation. Therefore, a productive approach is to divide the problem into smaller parts, treated separately and then the results combined. Some algebraic results obtained by the authors are presente

Lucian Luca, Lucian L. Luca

This paper introduces the notion of fuzzy process as a formalism for the idea of fuzzy contact between a device and its environment. The notions of absolute correctness and relative correctness are defined. In order to work with concurrency it has been built an approach to manipulate the interactive processes as a single process and the resulted behavior has

Ch. Kant, J. Deisenhofer, V. Tsurkan, A. Loidl

We analyzed the magnetic susceptibilities of several Cr spinels using two recent models for the geometrically frustrated pyrochlore lattice, the Quantum Tetrahedral Mean Field model and a Generalized Constant Coupling model. Both models can describe the experimental data for ACr2 O4 (with A = Zn, Mg, and Cd) satisfactorily, with the former yielding a somewha

Dan L. Lacrama, Ioan Snep

This paper presents an original solution for flexible hand-written text division into rows. Unlike the standard procedure, the proposed method avoids the isolated characters extensions amputation and reduces the recognition error rate in the final stage.

Wolfram Weise

Recent developments and selected topics in low-energy QCD are summarized, from chiral effective field theory to systems with strange and charm quarks, from lattice QCD to precision experiments.

Stephan Rachel, Dirk Schuricht, Burkhard Scharfenberger, Ronny Thomale

We report on a spontaneous breakdown of parity in the ground state of a spin Hamiltonian involving nearest-neighbor interactions. This occurs for a one-dimensional model where spins transform under the gauge field representation of QCD, the eight-dimensional adjoint representation of SU(3). The ground state spontaneously violates parity and is two-fold degen

N. Ni, A. Thaler, A. Kracher, J. Q. Yan

Single crystalline Ba(Fe(1-x)TMx)2As2 (TM = Rh, Pd) series have been grown and characterized by structural, thermodynamic and transport measurements. These measurements show that the structural/magnetic phase transitions, found in pure BaFe2As2 at 134 K, are suppressed monotonically by the doping and that superconductivity can be stablized over a dome-like r

S. Kluth

Event shape data from e+e- annihilation into hadrons collected by the JADE experiment between sqrt(s)=14 and 44 GeV are used to determine the strong coupling alpha_S. QCD predictionscomplete to next-to-next-to-leading order (NLLO), alternatively combined with next-to-leading-log-approximation (NLLA) are used. The stability of the NNLO and NNLO+NLLA results w

John A. Wilson

New electronic Raman and I.R. spectroscopy results from optimally and overdoped high temperature superconducting (HTSC) cuprate systems are interpreted in terms of the negative-U, boson-fermion crossover model. Distinction is made between those features which follow the condensate gap, 2Delta(p), and those that are set by the local-pair binding energy, cursi

D. R. Reese, M. J. Thompson, K. B. MacGregor, S. Jackson

Context: Recent calculations of pulsation modes in rapidly rotating polytropic models and models based on the Self-Consistent Field method (MacGregor et al. 2007) have shown that the frequency spectrum of low degree pulsation modes can be described by an empirical formula similar to Tassoul&#39;s asymptotic formula (Tassoul 1980), provided that the underlyin

Benjamin Steinberg

We associate a 2-complex to the following data: a presentation of a semigroup $S$ and a transitive action of $S$ on a set $V$ by partial transformations. The automorphism group of the action acts properly discontinuously on this 2-complex. A sufficient condition is given for the 2-complex to be simply connected. As a consequence we obtain simple topological

Vin de Silva, Mikael Vejdemo-Johansson

Nonlinear dimensionality reduction (NLDR) algorithms such as Isomap, LLE and Laplacian Eigenmaps address the problem of representing high-dimensional nonlinear data in terms of low-dimensional coordinates which represent the intrinsic structure of the data. This paradigm incorporates the assumption that real-valued coordinates provide a rich enough class of

M. Schneider, V. Moshnyaga, P. Gegenwart

The ferromagnetic quantum phase transition in the perovskite ruthenate Sr$_{1-x}$Ca$_x$RuO$_3$ is studied by low-temperature magnetization and electrical resistivity measurements on thin films. The films were grown epitaxially on SrTiO$_3$ substrates using metalorganic aerosol deposition and characterized by X-ray diffraction and room temperature scanning tu

M. Moskalets, M. Buttiker

We analyze the frequency-dependent noise and the heat production rate for a dynamical quantum capacitor in the regime in which it emits single particles, electrons and holes. At low temperature and slow driving the relaxation resistance quantum, R_{q} = h/(2e^2), defines the heat production rate in both the linear and non-linear response regimes. If a double

Panagis Karazeris, Apostolos Matzaris, Jiri Velebil

We give conditions on a finitary endofunctor of a finitely accessible category to admit a final coalgebra. Our conditions always apply to the case of a finitary endofunctor of a locally finitely presentable (l.f.p.) category and they bring an explicit construction of the final coalgebra in this case. On the other hand, there are interesting examples of final

S. Trotzky, L. Pollet, F. Gerbier, U. Schnorrberger

Ultracold atomic gases in optical lattices have proven to be a controllable, tunable and clean implementation of strongly interacting quantum many-body systems. An essential prospect for such quantum simulators is their ability to map out the phase diagram of fundamental many-body model Hamiltonians. However, the results need to be validated first for repres

J Sanjuan, J Ramos-Castro, A Lobo

High-resolution temperature measurements are required in the LTP, i.e., 10 uK/sqrt(Hz) from 1 mHz to 30 mHz. This has been already accomplished with thermistors and a suitable low noise electronics. However, the frequency range of interest for LISA goes down to 0.1 mHz. Investigations on the performance of temperature sensors and the associated electronics a

Kristina Van Duijvendijk, Robert L. Jack, Frédéric Van Wijland

We consider the dynamics of a disordered p-spin model with p=2, analyzing the dynamics within Ruelle&#39;s thermodynamic formalism, We use an indicator of the dynamical activity to construct the relevant dynamical Gibbs ensemble. We prove that the dynamics in the low-temperature (spin glass) phase of the model take place at a second-order phase transition be

Nanae Taniguchi, for Belle Collaboration

We present recent results for radiative and electroweak penguin decays of $B$ me son at Belle. Measurements of differential branching fraction, isospin asymmetr y, $K^*$ polarization, and forward-backward asymmetry as functions of $q^2$ for $B \to K^{(*)}ll$ decays are reported. For the results of the radiative process, we report measurements of branching fr

Xavier Durang, Malte Henkel

Ageing in systems without detailed balance is studied in bosonic contact and pair-contact processes with Levy diffusion. In the ageing regime, the dynamical scaling of the two-time correlation function and two-time response function is found and analysed. Exact results for non-equilibrium exponents and scaling functions are derived. The behaviour of the fluc

Dominique Lecomte

Let $ξ\geq 1$ be a countable ordinal. We study the Borel subsets of the plane that can be made ${\bfΠ}^0_ξ$ by refining the Polish topology on the real line. These sets are called potentially ${\bfΠ}^0_ξ$. We give a Hurewicz-like test to recognize potentially ${\bfΠ}^0_ξ$ sets.

F. A. B. Coutinho, M. Amaku

A prescription invented a long time ago by Case and Danilov is used to get the wave function of point interactions in two and three dimensions.

K. A. Al-Hassanieh, C. D. Batista, G. Ortiz, L. N. Bulaevskii

We report on a new electromagnetic phenomenon that emerges in Mott insulators, i.e., materials that do not conduct electricity because of strong electronic Coulomb repulsion. The phenomenon manifests as antiferromagnetic ordering due to orbital electric currents which are spontaneously generated from the coupling between spin currents and an external homogen

Ying Ying Li

LHCb is the dedicated B physics experiment at the LHC and is due to start data taking later this year. Its goal is to search for new physics in very rare processes and make precision measurements of CP violation in B decays. The CKM angle gamma plays an important role in flavour physics in the Standard Model. LHCb will exploit the large variety of B hadrons

M. Zdrahal, K. Kampf, M. Knecht, J. Novotny

The branching ratio of the η->3πdecay is an important source of information on the value of the quark mass ratio 1/R=(m_d-m_u)/(m_s-\hat m). Furthermore, isospin breaking effects in the decays K->3πprovide information on the pion scattering lengths. The cusp effect in the K->3πdecays is presently being analyzed by the NA48 and KTeV experiments. From the theo

M. Lapert, R. Tehini, G. Turinici, D. Sugny

We consider the optimal control of quantum systems interacting non-linearly with an electromagnetic field. We propose new monotonically convergent algorithms to solve the optimal equations. The monotonic behavior of the algorithm is ensured by a non-standard choice of the cost which is not quadratic in the field. These algorithms can be constructed for pure

A. Giunta, E. Bozzo, F. Bernardini, G. Israel

IGR J18483-0311 was discovered with INTEGRAL in 2003 and later classified as a supergiant fast X-ray transient. It was observed in outburst many times, but its quiescent state is still poorly known. Here we present the results of XMM-Newton, Swift, and Chandra observations of IGRJ18483-0311. These data improved the X-ray position of the source, and provided

Tiberiu Marius Karnyanszky, Ovidiu Crista, Catalin Tuican

The goal of this paper is to offer a full support for universities and quality assessment committees in retrieving the feedback from their students regarding to their teaching staff. The computer based application presented before ([Cri07]) collects data from the students. Another part of the application, presented in this paper, processes this data and pres

K. S. Jasmine, R. Vasantha

Reuse-based software development provides an opportunity for better quality and increased productivity in the software products. One of the most critical aspects of the quality of a software system is its performance. The systematic application of software performance engineering techniques throughout the development process can help to identify design alter

Christopher Thomas

The most sensitive method to measure the CKM angle gamma is to exploit interference in B(+/-)->DK(+/-) decays, with the D-meson decaying to a hadronic final state. The analysis of quantum-correlated decays of the psi(3770) at CLEO-c provides invaluable information on the strong-phase difference between the D0 and D0bar across the Dalitz plane. Results from a

Xin Li

We associate reduced and full C*-algebras to arbitrary rings and study the inner structure of these ring C*-algebras. As a result, we obtain conditions for them to be purely infinite and simple. We also discuss several examples. Originially, our motivation comes from algebraic number theory.

Alin Isac, Claudia Isac

The aim of this paper is to present some computer aspects regarding the implementation and the employing of a dashboard in relation to the production activity. The paper begins with the theoretical presentation of the managerial perspective regarding the necessity of using the dashboard. The main functions of the dashboard in the production activity and the

M. E. Shaposhnikov, F. V. Tkachov

We address the question of whether the quantum scale-invariant theories introduced in [1] are renormalizable or play the role of effective field theories that are valid below the Planck scale $M_P$. We show that starting from two-loop level the renormalization procedure requires introduction of counter-terms with structures different from those in the initia

Marco Nardecchia

Naturalness arguments do not forbid the possibility that the first two families of squarks and sleptons are heavier than the rest of the supersymmetric spectrum. In this framework, we study the phenomenology related to the flavor physics and we give bounds on the flavor violating parameters that we compare with the case of nearly degenerate squarks. The pecu

Fyodor Nazarov, Vladimir Peller

We prove that if $f$ is a Lipschitz function on $\R$, $A$ and $B$ are self-adjoint operators such that ${\rm rank} (A-B)=1$, then $f(A)-f(B)$ belongs to the weak space $\boldsymbol{S}_{1,\be}$, i.e., $s_j(A-B)\le{\rm const} (1+j)^{-1}$. We deduce from this result that if $A-B$ belongs to the trace class $\boldsymbol{S}_1$ and $f$ is Lipschitz, then $f(A)-f(B