July 2009 arXiv papers — page 14

D0 Collaboration, V. Abazov

The D0 collaboration reports direct evidence for electroweak production of single top quarks through the t-channel exchange of a virtual W boson. This is the first analysis to isolate an individual single top quark production channel. We select events containing an isolated electron or muon, missing transverse energy, and two, three or four jets from 2.3 fb^

Ulrich W Heinz

Ideal hydrodynamic simulations are performed to compute the evolution with collision energy of hadron spectra and elliptic flow between AGS and LHC energies. We argue that viscous effects should decrease with increasing energy, improving the applicability of ideal fluid dynamics at higher energies. We show that the increasing radial flow at higher energies p

Niek J. Bouman, Serge Fehr

We propose a framework for analyzing classical sampling strategies for estimating the Hamming weight of a large string, when applied to a multi-qubit quantum system instead. The framework shows how to interpret such a strategy and how to define its accuracy when applied to a quantum system. Furthermore, we show how the accuracy of any strategy relates to its

Mason A. Porter

In this chapter, we discuss experiments that realize the discrete nonlinear Schrödinger (DNLS) equations. The relevance of such descriptions arises from the competition of three common features: nonlinearity, dispersion, and a medium to large level of (periodic, quasiperiodic, or random) discreteness in space. DNLS equations have been especially prevalent in

Charles Bordenave, Marc Lelarge, Justin Salez

We investigate the rank of the adjacency matrix of large diluted random graphs: for a sequence of graphs $(G_n)_{n\geq0}$ converging locally to a Galton--Watson tree $T$ (GWT), we provide an explicit formula for the asymptotic multiplicity of the eigenvalue 0 in terms of the degree generating function $ϕ_*$ of $T$. In the first part, we show that the adjacen

Lawrence Horwitz, Avi Gershon, Marcelo Schiffer

It has been shown that the orbits of motion for a wide class of nonrelativistic Hamiltonian systems can be described as geodesic flows on a manifold and an associated dual. This method can be applied to a four dimensional manifold of orbits in spacetime associated with a relativistic system. We show that a relativistic Hamiltonian which generates Einstein ge

Kohtaroh Miura, Takashi Z. Nakano, Akira Ohnishi, Noboru Kawamoto

We investigate the chiral phase transition in the strong coupling lattice QCD at finite temperature and density with finite coupling effects. We adopt one species of staggered fermion, and develop an analytic formulation based on strong coupling and cluster expansions. We derive the effective potential as a function of two order parameters, the chiral conden

Suman Sinha, Soumen Kumar Roy

Monte Carlo simulation has been performed in a two-dimensional modified XY-model first proposed by Domany et. al [E. Domany, M. Schick and R. H. Swendsen, Phys. Rev. Lett. 52, 1535 (1984)]. The cluster algorithm of Wolff has been used and multiple histogram reweighting is performed. The first order scaling behavior of the quantities like specific heat, order

Antongiulio Fornasiero

A structure M is pregeometric if the algebraic closure is a pregeometry in all M' elementarily equivalent to M. We define a generalisation: structures with an existential matroid. The main examples are superstable groups of U-rank a power of omega and d-minimal expansion of fields. Ultraproducts of pregeometric structures expanding a field, while not pre

Pedro A. Garcia-Sanchez, Ignacio Ojeda

A finitely generated commutative monoid is uniquely presented if it has only a minimal presentation. We give necessary and sufficient conditions for finitely generated, combinatorially finite, cancellative, commutative monoids to be uniquely presented. We use the concept of gluing to construct commutative monoids with this property. Finally for some relevant

Fabrice Ardhuin, Erick Rogers, Alexander Babanin, Jean-François Filipot

New parameterizations for the spectra dissipation of wind-generated waves are proposed. The rates of dissipation have no predetermined spectral shapes and are functions of the wave spectrum and wind speed and direction, in a way consistent with observation of wave breaking and swell dissipation properties. Namely, the swell dissipation is nonlinear and propo

Sung-Gi Kim, Nobuhiro Maekawa, Keiko I. Nagao, Mihoko M. Nojiri

We study the LHC signature of the minimal supersymmetric standard model with non-universal sfermion masses. In the model, soft masses of gauginos and the 3rd generation of 10 of SU(5) are around the weak scale, while other sfermion soft mass is universal and around a few TeV. Such sfermion mass spectrum is motivated not only from flavor, CP and naturalness c

Adi Zitrin, Tom Broadhurst, Yoel Rephaeli, Sharon Sadeh

We identify 13 sets of multiply-lensed galaxies around MACS J0717.5+3745 ($z=0.546$), outlining a very large tangential critical curve of major axis $\sim2.8\arcmin$, filling the field of HST/ACS. The equivalent circular Einstein radius is $θ_{e}= 55 \pm 3\arcsec$ (at an estimated source redshift of $z_{s}\sim2.5$), corresponding to $r_e\simeq 350\pm 20 kpc$

J. Barré

We introduce models of generic rigidity percolation in two dimensions on hierarchical networks, and solve them exactly by means of a renormalization transformation. We then study how the possibility for the network to self organize in order to avoid stressed bonds may change the phase diagram. In contrast to what happens on random graphs and in some recent n

Franziska Synatschke, Holger Gies, Andreas Wipf

We study the phases and fixed-point structure of two-dimensional supersymmetric Wess-Zumino models with one supercharge. Our work is based on the functional renormalization group formulated in terms of a manifestly off-shell supersymmetric flow equation for the effective action. Within the derivative expansion, we solve the flow of the superpotential also in

Maria Bras-Amorós, Klara Stokes

A (v,b,r,k) combinatorial configuration is a (r,k)-biregular bipartite graph with v vertices on the left and b vertices on the right and with no cycle of length 4. Combinatorial configurations have become very important for some cryptographic applications to sensor networks and to peer-to-peer communities. Configurable tuples are those tuples (v,b,r,k) for w

Yakov Eliashberg, Soren Galatius, Nikolai Mishachev

We give an alternative proof of Madsen-Weiss' generalized Mumford conjecture. Our proof is based on ideas similar to Madsen-Weiss' original proof, but it is more geometrical and less homotopy theoretical in nature. At the heart of the argument is a geometric version of Harer stability, which we formulate as a theorem about folded maps.

Yuhan Lim

We prove that the instanton knot homology KHI(K) as defined by Kronheimer and Mrowka (Knots, sutures and excision, preprint), recovers the Alexander polynomial for knots K in the 3-sphere.

Andreas Bierwage, Liu Chen, Fulvio Zonca

The kinetic excitation of ideal magnetohydrodynamic (MHD) discrete Alfven eigenmodes in the second MHD ballooning stable domain is studied in the presence of a thermal ion temperature gradient (ITG), using linear gyrokinetic particle-in-cell simulations of a local flux tube in shifted-circle tokamak geometry. The instabilities are identified as alpha-induced

Andreas Bierwage, Liu Chen, Fulvio Zonca

In the second magnetohydrodynamic (MHD) ballooning stable domain of a high-beta tokamak plasma, the Schroedinger equation for ideal MHD shear Alfven waves has discrete solutions corresponding to standing waves trapped between pressure-gradient-induced potential wells. Our goal is to understand how these so-called alpha-induced toroidal Alfven eigenmodes alph

Tong Li, Xiao-Gang He

We study LHC signatures of Type III seesaw in which SU(2)_L triplet leptons are introduced to supply the heavy seesaw masses. To detect the signals of these heavy triplet leptons, one needs to understand their decays to standard model particles which depend on how light and heavy leptons mix with each other. We concentrate on the usual solutions with small l

Brando Bellazzini, Mihail Mintchev, Paul Sorba

We explore the possibility to break time reversal invariance at the junction of quantum wires. The universal features in the bulk of the wires are described by the anyon Luttinger liquid. A simple necessary and sufficient condition for the breaking of time reversal invariance is formulated in terms of the scattering matrix at the junction. The phase diagram

Hikaru Kawamura

Detailed account is given of the chirality scenario of experimental spin-glass transitions. In this scenario, the spin glass order of weakly anisotropic Heisenberg-like spin-glass magnets including canonical spin glasses are essentially chirality driven. Recent numerical and experimental results are discussed in conjunction with this scenario.

Misha Verbitsky

Let M be a compact, holomorphically symplectic Kahler manifold, and $η$ a (1,1)-current which is nef (a limit of Kahler forms). Assume that the cohomology class of $η$ is parabolic, that is, its top power vanishes. We prove that all Lelong sets of $η$ are coisotropic. When M is generic, this is used to show that all Lelong numbers of $η$ vanish. We prove tha

Kai Cai, Megan K. Pickett, Richard H. Durisen, Anne M. Milne

There has been disagreement currently about whether cooling in protoplanetary disks can be sufficiently fast to induce the formation of gas giant protoplanets via gravitational instabilities. Simulations by our own group and others indicate that this method of planet formation does not work for disks around young, low- mass stars inside several tens of AU, w

Liling Sun, Xi Dai, Chao Zhang, Wei Yi

We discover a pressure induced quantum phase transition from the superconducting state to the non-superconducting Kondo screened phase associated with a 2% volume collapse in CeFeAsO0.7F0.3 through measurements of high-pressure resistance, synchrotron x-ray diffraction, and x-ray absorption spectroscopy (XAS) in a diamond anvil cell. Our XAS data of Ce-L3 in

K. Kanaya, T. Umeda, S. Aoki, S. Ejiri

We propose a fixed scale approach to calculate the equation of state (EOS) in lattice QCD. In this approach, the temperature T is varied by Nt at fixed lattice spacings. This enables us to reduce T=0 simulations which are required to provide basic data in finite temperature studies but are quite expensive in the conventional fixed-Nt approach. Since the conv

H. Liu, Y. M. Liu, T. Li, S. M. Wang

Magnetic metamaterials consist of magnetic resonators smaller in size than their excitation wavelengths. Their unique electromagnetic properties were characterized by the effective media theory at the early stage. However, the effective media model does not take into account the interactions between magnetic elements; thus, the effective properties of bulk m

Y. Maezawa, S. Aoki, S. Ejiri, T. Hatsuda

The free energy between a static quark and an antiquark is studied by using the color-singlet Polyakov-line correlation at finite temperature in lattice QCD with 2+1 flavors of improved Wilson quarks. From the simulations on $32^3 \times 12$, 10, 8, 6, 4 lattices in the high temperature phase, based on the fixed scale approach, we find that, the heavy-quark

Mitsuo I. Tsumagari

We present both analytically and numerically the consistent analysis from the Affleck-Dine (AD) dynamics to the subsequent semiclassical evolution in both gravity-mediated and gauge-mediated models. We obtain analytically the elliptic motions in the AD dynamics as the analogy of the well-known Kepler-problem, and by solving the equations of motion in a latti

E. Bauer, G. Garbarino

The contribution of ground state correlations (GSC) to the non--mesonic weak decay of $^{12}_Λ$C and other medium to heavy hypernuclei is studied within a nuclear matter formalism implemented in a local density approximation. We adopt a weak transition potential including the exchange of the complete octets of pseudoscalar and vector mesons as well as a resi

Christopher A. Onken

This paper has been withdrawn by the author. The velocity structure of the broad-line region is reflective of the radiation pressure over much longer timescales than are probed by year-to-year changes in reverberation mapping results. Hence, the paper's test of the Marconi et al. model is not valid.

Craig A. Tracy, Harold Widom

We give an exact expression for the distribution of the position X(t) of a single second class particle in the asymmetric simple exclusion process (ASEP) where initially the second class particle is located at the origin and the first class particles occupy the sites {1,2,...}.

W. V. Pogosov, H. J. Zhao, V. R. Misko, F. M. Peeters

The influence of random pinning on the vortex dynamics in a periodic square potential under an external drive is investigated. Using theoretical approach and numerical experiments, we found several dynamical phases of vortex motion that are different from the ones for a regular pinning potential. Vortex transfer is controlled by kinks and antikinks, which ei

Rodger I. Thompson, Jill Bechtold, John H. Black, Daniel Eisenstein

In an effort to resolve the discrepancy between two measurements of the fundamental constant mu, the proton to electron mass ratio, at early times in the universe we reanalyze the same data used in the earlier studies. Our analysis of the molecular hydrogen absorption lines in archival VLT/UVES spectra of the damped Lyman alpha systems in the QSOs Q0347-383

Rainer J. Fries

We discuss how the chemical composition of QCD jets is altered by final state interactions in surrounding nuclear matter. We describe this process through conversions of leading jet particles. We find that conversions lead to an enhancement of kaons at high transverse momentum in Au+Au collisions at RHIC, while their azimuthal asymmetry v_2 is suppressed.

P. P. Avelino, J. C. R. E. Oliveira, R. Menezes, J. Menezes

The role of domain wall junctions in Carter's pentahedral model is investigated both analytically and numerically. We perform, for the first time, field theory simulations of such model with various initial conditions. We confirm that there are very specific realizations of Carter's model corresponding to square lattice configurations with X-type jun

David A. Kessler, Leonard M. Sander

Dispersal of species to find a more favorable habitat is important in population dynamics. Dispersal rates evolve in response to the relative success of different dispersal strategies. In a simplified deterministic treatment (J. Dockery, V. Hutson, K. Mischaikow, et al., J. Math. Bio. 37, 61 (1998)) of two species which differ only in their dispersal rates t

Yoram Bachrach, Edith Elkind, Reshef Meir, Dmitrii Pasechnik

A key question in cooperative game theory is that of coalitional stability, usually captured by the notion of the \emph{core}--the set of outcomes such that no subgroup of players has an incentive to deviate. However, some coalitional games have empty cores, and any outcome in such a game is unstable. In this paper, we investigate the possibility of stabiliz

James D. Lowenthal, David C. Koo, Luc Simard, Eelco van Kampen

We present deep two-dimensional spectra of 22 candidate and confirmed Lyman break galaxies (LBGs) at redshifts 2<z<4 in the Hubble Deep Field (HDF) obtained at the Keck II telescope. The targets were preferentially selected with spatial extent and/or multiple knot morphologies, and we used slitmasks and individual slits tilted to optimize measurement of any

P. D. Klaassen, C. D. Wilson, E. R. Keto, Q. Zhang

We present molecular line and 1.4 mm continuum observations towards five massive star forming regions at arcsecond resolution using the Submillimeter Array (SMA). We find that the warm molecular gas surrounding each HII region (as traced by SO_2 and OCS) appears to be undergoing bulk rotation. From the molecular line emission and thermal component of the con

R. I. Hynes, C. K. Bradley, M. Rupen, E. Gallo

We present a multiwavelength study of the black hole X-ray binary V404 Cyg in quiescence, focusing upon the spectral energy distribution (SED). Radio, optical, UV, and X-ray coverage is simultaneous. We supplement the SED with additional non-simultaneous data in the optical through infrared where necessary. The compiled SED is the most complete available for

H. W. W. Spoon, J. Holt

We report the discovery of blue shifted (delta(V) > 200 km/s) mid-infrared [NeIII] and/or [NeV] emission in 25 out of 82 ULIRGs (30% of our sample). The incidence of blue shifted [NeV] emission is even higher (59%) among the sources with a [NeV] detection -- the tell-tale signature of an active galactic nucleus (AGN). Sixteen ULIRGs in our sample, eleven of

B. D. Lehmer, D. M. Alexander, S. C. Chapman, Ian Smail

We present X-ray point-source catalogs for a deep 400 ks Chandra ACIS-I exposure of the SSA22 field. The observations are centred on a z = 3.09 protocluster, which is populated by Lyman break galaxies (LBGs), Lyalpha emitters (LAEs), and extended Lyalpha-emitting blobs (LABs). The survey reaches ultimate (3 count) sensitivity limits of 5.7 X 10^-17 and 3.0 X

A. Valavanis, Z. Ikonić, R. W. Kelsall

Intervalley mixing between conduction-band states in low-dimensional Si/SiGe heterostructures induces splitting between nominally degenerate energy levels. The symmetric double-valley effective mass approximation and the empirical pseudopotential method are used to find the electronic states in different types of quantum wells. A reasonably good agreement be

C. H. Yeung, K. Y. Michael Wong

We apply statistical physics to study the task of resource allocation in random networks with limited bandwidths along the transportation links. The mean-field approach is applicable when the connectivity is sufficiently high. It allows us to derive the resource shortage of a node as a well-defined function of its capacity. For networks with uniformly high c

T. Hubsch, V. Pankovic

Generalizing a recent analysis, we model the quantum Zeno and anti-Zeno effects with a quickly switched, ideal LC/LR circuit, in the limiting case of it alternating very many times between its short LC and even shorter LR regime. If the initial current is arranged to be negligible, the capacitor turns out never to discharge. If the initial current is made do

C. M. S. da Conceicao, E. C. Marino

Quantum topological excitations (skyrmions) are analyzed from the point of view of their duality to spin excitations in the different phases of a disordered two-dimensional, short-range interacting, SO(3) quantum magnetic system of Heisenberg type. The phase diagram displays all the phases, which are allowed by the duality relation. We study the large distan

Jonathan F. Donges, Yong Zou, Norbert Marwan, Jürgen Kurths

Complex network theory provides a powerful framework to statistically investigate the topology of local and non-local statistical interrelationships, i.e. teleconnections, in the climate system. Climate networks constructed from the same global climatological data set using the linear Pearson correlation coefficient or the nonlinear mutual information as a m

Jorge Vitorio Pereira, Carlo Perrone

We study the subvariety of integrable 1-forms in a finite dimensional vector space $W \subset Ω^1(\mathbb C^n,0)$. We prove that the irreducible components with dimension comparable with the rank of $W$ are of minimal degree.

Yossi Azar, Benjamin Birnbaum, L. Elisa Celis, Nikhil R. Devanur

Bargaining games on exchange networks have been studied by both economists and sociologists. A Balanced Outcome for such a game is an equilibrium concept that combines notions of stability and fairness. In a recent paper, Kleinberg and Tardos introduced balanced outcomes to the computer science community and provided a polynomial-time algorithm to compute th

Nira Dyn, Maria Skopina

We study multivariate trigonometric polynomials, satisfying a set of constraints close to the known Strung-Fix conditions. Based on the polyphase representation of these polynomials relative to a general dilation matrix, we develop a simple constructive method for a special type of decomposition of such polynomials. These decompositions are of interest to th

Damian Eads, Edward Rosten, David Helmbold

We present BEAMER: a new spatially exploitative approach to learning object detectors which shows excellent results when applied to the task of detecting objects in greyscale aerial imagery in the presence of ambiguous and noisy data. There are four main contributions used to produce these results. First, we introduce a grammar-guided feature extraction syst

Andrew S. H. Shevchuk, Derek B. Fox, Robert E. Rutledge

We report the results of a 30 ks Chandra ACIS-S observation of the isolated compact object 1RXS J141256.0+792204 (Calvera). The X-ray spectrum is adequately described by an absorbed neutron star hydrogen atmosphere model with an effective temperature at infinity of 88.3 +/- 0.8 eV and radiation radius at infinity of 4.1 +/- 0.1 km/kpc. The best-fit blackbody

Ira Herbst, Erik Skibsted

We study spatial analyticity properties of solutions of the Navier-Stokes equations and obtain new growth rate estimates for the analyticity radius. We also study stability properties of strong global solutions of the Navier-Stokes equations with data in H^r, r greater or equal 1/2, and prove a stability result for the analyticity radius.

Hasan Sahin, S. Cahangirov, M. Topsakal, E. Bekaroglu

Using first-principles plane wave calculations, we investigate two dimensional honeycomb structure of Group IV elements and their binary compounds, as well as the compounds of Group III-V elements. Based on structure optimization and phonon mode calculations, we determine that 22 different honeycomb materials are stable and correspond to local minima on the

Naser Zamani

Let $R$ be a commutative ring with non-zero identity and $M$ be a unitary $R$-module. Let $\mathcal{S}(M)$ be the set of all submodules of $M$, and $ϕ:\mathcal{S}(M)\to \mathcal{S}(M)\cup \{\emptyset\}$ be a function. We say that a proper submodule $P$ of $M$ is a prime submodule relative to $ϕ$ or $ϕ$-prime submodule if $a\in R$, $x\in M$ with $ax\in P\setm

Jillian Bornak, Bernard J McNamara, Thomas E Harrison, Michael P Rupen

The low mass X-ray binary and Z source GX 17+2 undergoes infrared K-band brightening episodes of at least 3.5 magnitudes. The source of these episodes is not known. Prior published K-band magnitudes and new K-band measurements acquired between 2006 and 2008 suggest that the episodes last at least 4 hours and have a period of 3.01254 $\pm$ 0.00002 days. Futur

Richard Moloney, Gary McGuire

This paper presents two kinds of division polynomials for twisted Edwards curves. Their chief property is that they characterise the $n$-torsion points of a given twisted Edwards curve. We also present results concerning the coefficients of these polynomials, which may aid computation.

Brian Karrer, M. E. J. Newman

We study random graph models for directed acyclic graphs, an important class of networks that includes citation networks, food webs, and feed-forward neural networks among others. We propose two specific models, roughly analogous to the fixed edge number and fixed edge probability variants of traditional undirected random graphs. We calculate a number of pro

Florian Loder, Arno P. Kampf, Thilo Kopp

In the BCS theory of superconductivity, one assumes that all Cooper pairs have the same center of mass momentum. This is indeed enforced by self consistency, if the pairing interaction is momentum independent. Here, we show that for an attractive nearest neighbor interaction, this is different. In this case, stable solutions with pairs with momenta q and -q

Steffen Krusch, Mark Roberts

In this talk, we describe recent developments in the Skyrme model. Our main focus is on discussing various effects which need to be taken into account, when calculating the properties of light atomic nuclei in the Skyrme model. We argue that an important step is to understand &#34;spinning Skyrmions&#34; and discuss the theory of relative equilibria in this

Thomas Gibaud, Peter Schurtenberger

Concentrated aqueous solutions of the protein lysozyme undergo a liquid solid transition upon a temperature quench into the unstable spinodal region below a characteristic arrest temperature of Tf=15C. We use video microscopy and ultra-small angle light scattering in order to investigate the arrested structures as a function of initial concentration, quench

Jan Perina, Marco Centini, Concita Sibilia, Mario Bertolotti

Random nonlinear layered structures have been found to be a useful source of photon pairs with perfectly indistinguishable un-entangled photons emitted into a very narrow spectral range. Localization of the interacting optical fields typical for random structures gives relatively high photon-pair fluxes. Superposing photon-pair emission quantum paths at diff

Rupali Kundu

We have investigated the effects of inplane and interplane nearest neighbour overlap integrals ($s_0$ and $s_1$) and site energy difference between atoms in two different sublattices in the same graphene layer ($Δ$) on the electronic dispersion of bilayer graphene within tight binding model. Also, modifications in bilayer graphene bands due to inplane next n

L. Piau, S. Turck-Chieze, V. Duez, R. F. Stein

Context : On its asteroseismic side, the initial run of CoRoT was partly devoted to the solar like star HD49933.The eigenmodes of this F dwarf have been observed with unprecedented accuracy. Aims : We investigate quantitatively the impact of changes in the modeling parameters like mass and composition. More importantly we investigate how a sophisticated phys

C. W. James, R. D. Ekers, C. J. Philips, R. J. Protheroe

The lunar Cherenkov technique is a method to use radio-telescopes to detect ultra-high energy cosmic rays (CR) and neutrinos ($ν$). By observing the short-duration ($\sim$few nanosecond) pulses of coherent Cherenkov radiation emitted from particle cascades via the Askaryan Effect in the Moon&#39;s outer layers (nominally the regolith), the primary particles

Jared C. Bronski, Mathew A. Johnson, Todd Kapitula

We consider periodic solutions to equations of Korteweg-Devries type. While the stability theory for periodic waves has received much some attention the theory is much less developed than the analogous theory for solitary wave stability, and appears to be mathematically richer. We prove an index theorem giving an exact count of the number of unstable eigenva

C. W. James, R. D. Ekers, C. J. Philips, R. J. Protheroe

This contribution describes the experimental set-up implemented by the LUNASKA project at the Australia Telescope Compact Array (ATCA) to enable the radio-telescope to be used to search for pulses of coherent Cherenkov radiation from UHE particle interactions in the Moon with an unprecedented bandwidth, and hence sensitivity. Our specialised hardware include

A. Criado

In a recent article J. Aldaz proved that the weak L1 bounds for the centered maximal operator associated to finite radial measures cannot be taken independently with respect to the dimension. We show that at least for small p near to 1 the same result holds for the Lp bounds of such measures with decreasing densities. We also give some concrete examples, tha

Benjamin Bahr, Bianca Dittrich

In Regge calculus space time is usually approximated by a triangulation with flat simplices. We present a formulation using simplices with constant sectional curvature adjusted to the presence of a cosmological constant. As we will show such a formulation allows to replace the length variables by 3d or 4d dihedral angles as basic variables. Moreover we will

Filippo Bracci, Manuel D. Contreras, Santiago Diaz-Madrigal

We show that an evolution family of the unit disc is commuting if and only if the associated Herglotz vector field has separated variables. This is the case if and only if the evolution family comes from a semigroup of holomorphic self-maps of the disc.

Benjamin Bahr, Bianca Dittrich

We consider the notion of improved and perfect actions within Regge calculus. These actions are constructed in such a way that they - although being defined on a triangulation - reproduce the continuum dynamics exactly, and therefore capture the gauge symmetries of General Relativity. We construct the perfect action in three dimensions with cosmological cons

Wojciech Kaminski, Jerzy Lewandowski, Tomasz Pawlowski

A general quantum constraint of the form $C= - \partial_T^2 \otimes B - I\otimes H$ (realized in particular in Loop Quantum Cosmology models) is studied. Group Averaging is applied to define the Hilbert space of solutions and the relational Dirac observables. Two cases are considered. In the first case, the spectrum of the operator $(1/2)π^2 B - H$ is assume

Krzysztof R. Apt, Frank S. de Boer, Ernst-Rüdiger Olderog

We argue that verification of recursive programs by means of the assertional method of C.A.R. Hoare can be conceptually simplified using a modular reasoning. In this approach some properties of the program are established first and subsequently used to establish other program properties. We illustrate this approach by providing a modular correctness proof of

Jose Reslen, Sougato Bose

We study the effect of long range particle exchange in bosonic arrangements. We show that by combining the solution of the Heisenberg equations of motion with matrix product state representation it is possible to investigate the dynamics as well as the ground state while including particle exchange beyond next-neighbours sites. These ideas are then applied t

P. Buonsante, R. Franzosi, V. Penna

We study the dynamical stability of the macroscopic quantum oscillations characterizing a system of three coupled Bose-Einstein condensates arranged into an open-chain geometry. The boson interaction, the hopping amplitude and the central-well relative depth are regarded as adjustable parameters. After deriving the stability diagrams of the system, we identi

Anja C. Schroeder, Renee C. Kraan-Korteweg, Patricia A. Henning

As part of our programme to map the large-scale distribution of galaxies behind the southern Milky Way, we observed 314 optically-selected, partially-obscured galaxies in the Zone of Avoidance (ZOA) in the Crux and Great Attractor (GA) regions. The observations were conducted with the Parkes 64m radio telescope, in a single-pixel pointed mode, reaching an rm

Leah Epstein, Elena Kleiman, Julian Mestre

The subset sum algorithm is a natural heuristic for the classical Bin Packing problem: In each iteration, the algorithm finds among the unpacked items, a maximum size set of items that fits into a new bin. More than 35 years after its first mention in the literature, establishing the worst-case performance of this heuristic remains, surprisingly, an open pro

Xuefeng Wang, Ming Zhao, David D Nolte, Timothy L Ratliff

Mass-sensing biosensor arrays for protein detection require no fluorophores or enzyme labels. However, few mass biosensor protein arrays have demonstrated successful application in high background samples, such as serum. In this paper, we test the BioCD as a mass biosensor based on optical interferometry of antibodies covalently attached through Schiff-base

Paolo De Gregorio, Lamberto Rondoni, Michele Bonaldi, Livia Conti

We consider a system in direct contact with a thermal reservoir and which, if left unperturbed, is well described by a memory-less equilibrium Langevin equation of the second order in the time coordinate. In such conditions, the strength of the noise fluctuations is set by the damping factor, in accordance with the Fluctuation and Dissipation theorem. We stu

G. Cescutti, F. Matteucci, A. McWilliam, C. Chiappini

The evolution of C and O abundances in the Milky Way can impose strong constraints on stellar nucleosynthesis and help understanding the formation and evolution of our Galaxy. The aim is to review the measured C and O abundances in the disk and bulge of the Galaxy and compare them with model predictions. We adopt two successful chemical evolution models for

Balázs Pozsgay

In this thesis we investigate finite size effects in 1+1 dimensional integrable QFT. In particular we consider matrix elements of local operators (finite volume form factors) and vacuum expectation values and correlation functions at finite temperature. In the first part of the thesis we give a complete description of the finite volume form factors in terms

A. Recati, N. Pavloff, I. Carusotto

We apply the microscopic Bogoliubov theory of dilute Bose-Einstein condensates to analyze quantum and thermal fluctuations in a flowing atomic condensate in the presence of a sonic horizon. For the simplest case of a step-like horizon, closed-form analytical expressions are found for the spectral distribution of the analog Hawking radiation and for the densi

Zhen-Qing Chen, Tusheng Zhang

In this paper, we prove that there exists a unique, bounded continuous weak solution to the Dirichlet boundary value problem for a general class of second-order elliptic operators with singular coefficients, which does not necessarily have the maximum principle. Our method is probabilistic. The time reversal of symmetric Markov processes and the theory of Di

Peter Filip

Initial eccentricity of the interacting volume of QCD matter created in collisions of prolate and oblate nuclei is studied using optical Glauber simulation. Collisions of prolate 165-Ho + 165-Ho nuclei and Au+Au nuclei are investigated (assuming oblate ground-state deformation for 197-Au nucleus). Qualitative predictions are obtained for RHIC energies.

Holger Reeker

This paper works towards a K(1)-local multiplicative splitting of SU-bordism.

Kazumasa A. Takeuchi, Masafumi Kuroda, Hugues Chaté, Masaki Sano

This is a comprehensive report on the phase transition between two turbulent states of electroconvection in nematic liquid crystals, which was recently found by the authors to be in the directed percolation (DP) universality class [K. A. Takeuchi et al., Phys. Rev. Lett. 99, 234503 (2007)]. We further investigate both static and dynamic critical behavior of

Pierre Bérard, Ricardo Sa Earp

In this paper we study the maximal stable domains on minimal catenoids in Euclidean and hyperbolic spaces and in $H^2 \times R$. We in particular investigate whether half-vertical catenoids are maximal stable domains (\emph{Lindelöf&#39;s property}). We also consider stable domains on catenoid-cousins in hyperbolic space. Our motivations come from Lindelöf&#

P. Dufour, E. M. Green, G. Fontaine, P. Brassard

We present follow-up time-series photometric observations that confirm and extend the results of the significant discovery made by Barlow et al.(2008) that the Hot DQ white dwarfs SDSS J220029.08-074121.5 and SDSS J234843.30-094245.3 are luminosity variable. These are the second and third known members of a new class of pulsating white dwarfs, after the prot

Didier Sornette

We develop the concept of ``dragon-kings&#39;&#39; corresponding to meaningful outliers, which are found to coexist with power laws in the distributions of event sizes under a broad range of conditions in a large variety of systems. These dragon-kings reveal the existence of mechanisms of self-organization that are not apparent otherwise from the distributio

Thorsten Erdmann, Martin Howard, Pieter Rein ten Wolde

During embryonic development, differentiating cells respond via gene expression to positional cues from morphogen gradients. While gene expression is often highly erratic, embryonic development is precise. We show by theory and simulations that diffusion of the expressed protein can enhance the precision of its expression domain. While diffusion lessens the

A. A. Lutovinov, S. S. Tsygankov

We review the results of a timing analysis of the observations for ten bright X-ray pulsars (with fluxes >100 mCrab in the 20-100 keV energy band) that fell within the INTEGRAL field of view from 2003 to 2007. The dependence of the pulse profile on the energy and intrinsic source luminosity has been investigated; particular attention has been paid to searchi

Claudia G. Rocha, Luis E. F. Foa Torres, Gianaurelio Cuniberti

We report on a theoretical study of the effects of time-dependent fields on electronic transport through graphene nanoribbon devices. The Fabry-Pérot interference pattern is modified by an ac gating in a way that depends strongly on the shape of the graphene edges. While for armchair edges the patterns are found to be regular and can be controlled very effic

Julia K. Becker, Athina Meli, Peter L. Biermann

The high-peaked BL Lac object Pks2155-304 shows high variability at multiwavelengths, i.e. from optical up to TeV energies. A giant flare of around 1 hour at X-ray and TeV energies was observed in 2006. In this context, it is essential to understand the physical processes in terms of the primary spectrum and the radiation emitted, since high-energy emission

Anuj Dawar, Stephan Kreutzer

We investigate the parameterized complexity of generalisations and variations of the dominating set problem on classes of graphs that are nowhere dense. In particular, we show that the distance-d dominating-set problem, also known as the (k,d)-centres problem, is fixed-parameter tractable on any class that is nowhere dense and closed under induced subgraphs.

The Pierre Auger Collaboration, J. Abraham, P. Abreu, M. Aglietta

The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the

Sven Zschocke, Sergei A. Klioner

A rigorous analytical solution of light propagation in Schwarzschild metric in post-post Newtonian approximation has been presented in \cite{report1}. In \cite{report2} it has been asserted that the sum of all those terms which are of order ${{\cal O} (\frac{m^2}{d^2})}$ and ${{\cal O}(\frac{m^2}{d_σ^2})}$ is not greater than $15/4 π\frac{m^2}{d^2}}$ and $15

M. B. Altaie

The Friedmann paradigm for a dynamical universe emanating from a spacetime singularity is critically reviwed. Quantum effects, playing the essential role at the very early stages, suggests that the universe may follow different course to that presented by the standard Friedmann solutions. The investigation of the back-reaction effect of the vacuum energy of

Hans Boehringer, Norbert Werner

Galaxy clusters, the largest clearly defined objects in our Universe, are ideal laboratories to study in detail the cosmic evolution of the intergalactic intracluster medium (ICM) and the cluster galaxy population. For the ICM, which is heated to X-ray radiating temperatures, X-ray spectroscopy is the most important tool to obtain insight into the structure