December 2006 arXiv papers — page 25

Yi-Zhong Fan

We discuss the current interpretations of the {\it Swift} GRB X-ray afterglows, mainly focusing on the sharp decline at the prompt tail emission, and the shallow decay afterward, which is then followed by the conventional pre-\emph{Swift} decay behavior, and the possible X-ray flares during the latter two stages. We emphasize the role of the central engine i

Jacco Th. van Loon

I review existing methods for determining mass-loss rates of red giants and red supergiants based on infrared data. The simplest method is based on models for the absorption and emission by dust which forms in the dense outflows from these cool stars. I discuss the parameters and assumptions upon which the method relies, review relationships between the mass

C. C. Cheung

Highlights of recent observations of extended jets in AGN are presented. Specifically, we discuss new spectral constraints enabled by Spitzer, studies of the highest-redshift (z~4) radio/X-ray quasar jets, and a new VLBA detection of superluminal motion in the M87 jet associated with a recent dramatic X-ray outburst. Expanding on the title, inverse Compton e

Richard Dodson, Dion Lewis, Peter McCulloch

Pulsar timing at the Mt Pleasant observatory has focused on Vela, which can be tracked for 18 hours of the day. These nearly continuous timing records extend over 24 years allowing a greater insight into details of timing noise, micro glitches and other more exotic effects. In particular we report the glitch parameters of the 2004 event, along with the recon

E. Saar

The lecture introduces a trous wavelet transforms, explains how to estimate the spatial density for galaxy distributions, and, finally, how to describe the morphology of cosmological density fields. An example application of these methods to the 2dFGRS gives unexpected results.

Takamitsu Miyaji, Giovanni Zamorani, Nico Cappelluti, Roberto Gilli

We present the first results of the measurements of angular auto-correlation functions (ACFs) of X-ray point sources detected in the XMM-Newton observations of the 2 deg2 COSMOS field (XMM-COSMOS). A significant positive signals have been detected in the 0.5-2 (SFT) band, in the angle range of 0.5-24 arcminutes, while the positive signals were at the 2 and 3

Jun Ma, Yanbin Yang, David Burstein, Zhou Fan

We have constrained the age of the globular cluster S312 in the Andromeda galaxy (M31) by comparing its multicolor photometry with theoretical stellar population synthesis models. This is both a check on the age of this globular cluster, as well a check on our methodology. Main-sequence photometry has been the most direct method for determining the age of a

K. Aoki, H. Furusawa, K. Ohta, T. Yamada

We present the results of deep imaging of the field of GRB 050904 with Suprime-Cam on the Subaru 8.2m telescope. We have obtained a narrow-band (130 A) image centered at 9200 A (NB921) and an i'-band image with total integration times of 56700 and 24060 s, respectively. The host galaxy was not detected within 1'' of the afterglow position. An obj

K. Aoki, I. Iwata, K. Ohta, N. Tamura

We discovered non-stellar Balmer absorption lines in two many-narrow-trough FeLoBALs (mntBALs) by the near-infrared spectroscopy with Subaru/CISCO. Presence of the non-stellar Balmer absorption lines is known to date only in the Seyfert galaxy NGC 4151, thus our discovery is the first cases for quasars. Since all known active galactic nuclei with Balmer abso

Jingwen Wu, Michael M. Dunham, Neal J. Evans, Tyler L. Bourke

We present the results of a submillimeter survey of 53 low-mass dense cores with the Submillimeter High Angular Resolution Camera II (SHARC-II). The survey is a follow-up project to the Spitzer Legacy Program ``From Molecular Cores to Planet-Forming Disks'', with the purpose being to create a complete data set of nearby low-mass dense cores from the

K. V. Parchevsky, A. G. Kosovichev

Results of numerical 3D simulations of propagation of acoustic waves inside the Sun are presented. A linear 3D code which utilizes realistic OPAL equation of state was developed by authors. Modified convectively stable standard solar model with smoothly joined chromosphere was used as a background model. High order dispersion relation preserving numerical sc

Carlos Hernandez-Monteagudo, Zoltan Haiman, Raul Jimenez, Licia Verde

We consider the pumping of the $63.2 μ$m fine structure line of neutral OI in the high--redshift intergalactic medium (IGM), in analogy with the Wouthuysen--Field effect for the 21cm line of cosmic HI. We show that the soft UV background at $\sim 1300$Åcan affect the population levels, and if a significant fraction of the IGM volume is filled with ``fossil H

V. Mainieri, G. Hasinger, N. Cappelluti, M. Brusa

We present a detailed spectral analysis of point-like X-ray sources in the XMM-COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10 keV energy band and have been identified through optical spectroscopy. The majority of the sources are well described by a simple power-law model with either no absorption

A. Finoguenov, L. Guzzo, G. Hasinger, N. Z. Scoville

We present the results of a search for galaxy clusters in the first 36 XMM-Newton pointings on the COSMOS field. We reach a depth for a total cluster flux in the 0.5-2 keV band of 3x10-15 ergs cm-2 s-1, having one of the widest XMM-Newton contiguous raster surveys, covering an area of 2.1 square degrees. Cluster candidates are identified through a wavelet de

M. Brusa, G. Zamorani, A. Comastri, G. Hasinger

[ABRIGED] We present the optical identification of a sample of 695 X-ray sources detected in the first 1.3 deg^2 of the XMM-COSMOS survey, down to a 0.5-2 keV (2-10 keV) limiting flux of ~10^-15 erg cm-2 s-1 (~5x10^-15 erg cm^-2 s-1). We were able to associate a candidate optical counterpart to ~90% (626) of the X-ray sources, while for the remaining ~10% of

J. M. Castro Cerón, M. J. Michałowski, J. Hjorth, D. Watson

We analyse 4.5, 8 and 24 um band Spitzer images of six gamma ray burst host galaxies at redshifts close to 1. We constrain their star formation rates (SFR) based on the entire available spectral energy distribution rather than the 24 um band only. Further, we estimate their stellar masses (M*) based on rest frame K band luminosities. Our sample spans a wide

Kirill A. Kazakov

The power spectrum of finite-temperature quantum electromagnetic fluctuations produced by elementary charge carriers under the influence of external electric field is investigated. It is found that under the combined action of the photon heat bath and the external field, the low-frequency asymptotic of the power spectrum is modified both qualitatively and qu

Dragan Slavkov Hajdukovic

The gravitational properties of antimatter are still a secret of nature. One outstanding possibility is that there is a gravitational repulsion between matter and antimatter (in short we call it antigravity). We argue that in the case of antigravity the collapse of a black hole doesn't end with singularity and that deep inside the horizon, the gravitatio

U. Aglietti, A. Belyaev, S. Berge, A. Blum

The search for Higgs bosons in both the standard model and its extensions is well under way at the Tevatron. As the integrated luminosity collected increases into the multiple inverse femptobarn range, these searches are becoming very interesting indeed. Meanwhile, the construction of the Large Hadron Collider (LHC) and its associated experiments at CERN are

Andrzej J. Maciejewski, Maria Przybylska, Tomasz Stachowiak, Marek Szydlowski

We investigate the Liouvillian integrability of Hamiltonian systems describing a universe filled with a scalar field (possibly complex). The tool used is the differential Galois group approach, as introduced by Morales-Ruiz and Ramis. The main result is that the generic systems are non-integrable, although there still exist some values of parameters for whic

J. Hernandez-Sanchez, C. G. Honorato, G. Tavares-Velasco, J. J. Toscano

This paper has been withdrawn and merged with hep-ph/0611379 for publication in Physical Review D

Martin J. Savage

I discuss the latest progress in calculating baryon-baryon interactions with lattice QCD. The latest results from the NPLQCD collaboration for nucleon-nucleon scattering along with preliminary calculations of hyperon-nucleon scattering are presented.

Yunhi Cho, Hyuk Kim

We define and study an extended hyperbolic space which contains the hyperbolic space and de Sitter space as subspaces and which is obtained as an analytic continuation of the hyperbolic space. The construction of the extended space gives rise to a complex valued geometry consistent with both the hyperbolic and de Sitter space. Such a construction shed a ligh

I. M. Dremin

The coherent hadron production analogous to Cherenkov radiation of photons gives rise to the ring-like events. Being projected on the ring diameter they produce the two-bump structure recently observed for the away-side jets at RHIC. The position of the peaks and their height determine such properties of the hadronic medium as its nuclear index of refraction

Spyros D. Avramis, Konstadinos Sfetsos, Konstadinos Siampos

Computing heavy quark-antiquark potentials within the AdS/CFT correspondence often leads to behaviors that differ from what one expects on general physical grounds and field-theory considerations. To isolate the configurations of physical interest, it is of utmost importance to examine the stability of the string solutions dual to the flux tubes between the

Nikolas Akerblom, Ralph Blumenhagen, Dieter Lust, Erik Plauschinn

The Affleck-Dine-Seiberg instanton generated superpotential for SQCD with Nf=Nc-1 flavours is explicitly derived from a local model of engineered intersecting D6-branes with a single E2-instanton. This computation extends also to symplectic gauge groups with Nf=Nc flavours.

S. M. Soskin, R. Mannella, O. M. Yevtushenko

We have developed the {\it general method} for the description of {\it separatrix chaos}, basing on the analysis of the separatrix map dynamics. Matching it with the resonant Hamiltonian analysis, we show that, for a given amplitude of perturbation, the maximum width of the chaotic layer in energy may be much larger than it was assumed before. We apply the a

John McGreevy, Eva Silverstein, David Starr

We show, using a theorem of Milnor and Margulis, that string theory on compact negatively curved spaces grows new effective dimensions as the space shrinks, generalizing and contextualizing the results in hep-th/0510044. Milnor's theorem relates negative sectional curvature on a compact Riemannian manifold to exponential growth of its fundamental group,

Keith S. M. Lee, Zoltan Ligeti, Iain W. Stewart, Frank J. Tackmann

We point out that in inclusive B -> Xs l+ l- decay an angular decomposition provides a third (q^2 dependent) observable sensitive to a different combination of Wilson coefficients than the rate and the forward-backward asymmetry. Since a precise measurement of q^2 dependence requires large data sets, it is important to consider the data integrated over regio

Alexander Lenz, Ulrich Nierste

We update the theory predictions for the mass difference $\dm_s$, the width difference $\dg_s$ and the CP asymmetry in flavour-specific decays, $a_{\rm fs}^{s}$, for the \bbs system. In particular we present a new expression for the element $Γ_{12}^s$ of the decay matrix, which enters the predictions of $\dg_s$ and $a_{\rm fs}^{s}$. To this end we introduce

Hong Liu, Krishna Rajagopal, Urs Achim Wiedemann

Expectation values of Wilson loops define the nonperturbative properties of the hot medium produced in heavy ion collisions that arise in the analysis of both radiative parton energy loss and quarkonium suppression. We use the AdS/CFT correspondence to calculate the expectation values of such Wilson loops in the strongly coupled plasma of N=4 super Yang-Mill

H. Zhu, K. Lai, D. C. Tsui, S. P. Bayrakci

Cyclotron resonance at microwave frequencies is used to measure the band mass (m_b) of the two-dimensional holes (2DH's) in carbon-doped (100) GaAs/AlxGa1-xAs heterostructures. The measured m_b shows strong dependences on both the 2DH density(p) and the GaAs quantum well width (W). For a fixed W, in the density range (0.4x10^11 to 1.1x10^11 cm^-2) studie

Iakovos Androulidakis, Georges Skandalis

We construct the holonomy groupoid of any singular foliation. In the regular case this groupoid coincides with the usual holonomy groupoid of Winkelnkemper (1983); the same holds in the singular cases of Bigonnet and Pradines (1985) and Debord (2001), which from our point of view can be thought of as being "almost regular". In the general case, the h

Andrey O. Matveev

A tope committee K* for a simple oriented matroid M is a subset of its maximal covectors such that every positive halfspace of M contains more than half of the covectors from K*. The structures of the family of all committees for M, and of the family of its committees that contain no pairs of opposites, are described. A Farey subsequence associated with the

Simeon Hellerman, Ian Swanson

We present an exact solution of superstring theory that interpolates in time between an initial type 0 phase and a final phase whose physics is exactly that of the bosonic string. The initial theory is deformed by closed-string tachyon condensation along a lightlike direction. In the limit of large tachyon vev, the worldsheet conformal field theory precisely

Marcus K. Benna, Anatoly Dymarsky, Igor R. Klebanov

We provide new evidence for the gauge/string duality between the baryonic branch of the cascading SU(k(M+1)) \times SU(kM) gauge theory and a family of type IIB flux backgrounds based on warped products of the deformed conifold and R^{3,1}. We show that a Euclidean D5-brane wrapping all six deformed conifold directions can be used to measure the baryon expec

Rodrigo S. Nemmen, Richard G. Bower, Arif Babul, Thaisa Storchi-Bergmann

The power of jets from black holes are expected to depend on both the spin of the black hole and the structure of the accretion disk in the region of the last stable orbit. We investigate these dependencies using two different physical models for the jet power: the classical Blandford-Znajek (BZ) model and a hybrid model developed by Meier. In the BZ case, t

E. Lunghi, J. Matias

Transverse asymmetries in the decay B->K*(K pi)l+l- are an extremely sensitive probe of right-handed flavour-changing neutral currents. We show how to include the contribution from the chiral partner of the electromagnetic operator on the transverse asymmetries at NLO in QCD factorization. We then consider supersymmetric models with non-minimal flavour viola

Lenhard Ng

We discuss the relation between arc index, maximal Thurston--Bennequin number, and Khovanov homology for knots. As a consequence, we calculate the arc index and maximal Thurston--Bennequin number for all knots with at most 11 crossings. For some of these knots, the calculation requires a consideration of cables which also allows us to compute the maximal sel

Francesco Benini, Felipe Canoura, Stefano Cremonesi, Carlos Nunez

Using AdS/CFT, we study the addition of an arbitrary number of backreacting flavors to the Klebanov-Witten theory, making many checks of consistency between our new Type IIB plus branes solution and expectations from field theory. We study generalizations of our method for adding flavors to all N=1 SCFTs that can be realized on D3-branes at the tip of a Cala

Dave Bacon

It has recently been shown that quantum computers can efficiently solve the Heisenberg hidden subgroup problem, a problem whose classical query complexity is exponential. This quantum algorithm was discovered within the framework of using pretty-good measurements for obtaining optimal measurements in the hidden subgroup problem. Here we show how to solve the

V. K. Mitrjushkin

The work is dedicated to the derivation of the 'functional' integral representation of the disorder parameter. This derivation resolves the problem of the choice of the so called modifed action as well as the problem of the choice of the boundary conditions along the 'time' direction. The question of the gauge fixing in the functional integra

G. Ruggiero

Silicon detectors for the Roman Pots of the large hadron collider TOTEM experiment aim for full sensitivity at the edge where a terminating structure is required for electrical stability. This work provides an innovative approach reducing the conventional width of the terminating structure to less than 100 microns, still using standard planar fabrication tec

Eli Hawkins

Many interesting C*-algebras can be viewed as quantizations of Poisson manifolds. I propose that a Poisson manifold may be quantized by a twisted polarized convolution C*-algebra of a symplectic groupoid. Toward this end, I define polarizations for Lie groupoids and sketch the construction of this algebra. A large number of examples show that this idea unifi

Roger Bielawski, Victor Pidstrygach

We observe that the analogue of the Gelfand-Zeitlin action on gl(n,C), which exists on any symplectic manifold M with an Hamiltonian action of GL(n,C), has a natural interpretation as a residual action, after we identify M with a symplectic quotient of the product of M with T*GL(n-1,C)x...xT*GL(1,C). We also show that the Gelfand-Zeitlin actions on T*GL(n,C)

Gonzalo Travieso, Luciano da Fontoura Costa

The problem of real-time processing is one of the most challenging current issues in computer sciences. Because of the large amount of data to be treated in a limited period of time, parallel and distributed systems are required, whose performance depends on a series of factors including the interconnectivity of the processing elements, the application model

F. Deppisch, H. Päs

A measurement of neutrinoless double beta decay in one isotope does not allow to determine the underlying physics mechanism. We discuss the discrimination of mechanisms for neutrinoless double beta decay by comparing ratios of half life measurements for different isotopes. Six prominent examples for specific new physics contributions to neutrinoless double b

A. Månsson, P. G. L. Porta Mana, G. Björk

This paper offers examples of concrete numerical applications of Bayesian quantum-state-assignment methods to a three-level quantum system. The statistical operator assigned on the evidence of various measurement data and kinds of prior knowledge is computed partly analytically, partly through numerical integration (in eight dimensions) on a computer. The me

Jae-Hyun Yang

In this paper, we study the right regular representation of a finite group $G$ on the vector space consisting of vector valued functions on $Γ\backslash G$ with a subgroup $Γ$ of $G$ and give a trace formula using the work of M.-F. Vigneras.

Cristina Butucea

We consider the convolution model where i.i.d. random variables $X_i$ having unknown density $f$ are observed with additive i.i.d. noise, independent of the $X$'s. We assume that the density $f$ belongs to either a Sobolev class or a class of supersmooth functions. The noise distribution is known and its characteristic function decays either polynomially

V. I. Danilov, A. V. Karzanov, G. A. Koshevoy

A regular $A_n$-crystal is an edge-colored directed graph, with $n$ colors, related to an irreducible highest weight integrable module over $U_q(sl_{n+1})$. Based on Stembridge's local axioms for regular simply-laced crystals and a structural characterization of regular $A_2$-crystals in \cite{DKK-07}, we present a new combinatorial construction, the so-

Wei-Liang Qian, Rone Andrade, Otavio Socolowski, Frederique Grassi

The transverse momentum distributions for hadrons in 200GeV Au-Au collision at RHIC is calculated using a smoothed particle hydrodynamics code SPheRIO, and are compared with the data from STAR and PHOBOS Collaborations. By employing the equation of state which explicitly incorporate the strangeness conservation and introducing strangeness chemical potential

Jean B. Lasserre

We provide explicit conditions for a real polynomial $f$ of degree 2d to be a sum of squares (s.o.s.), stated only in terms of the coefficients of $f$, i.e. with no lifting. All conditions are simple and provide an explicit description of a convex polyhedral subcone of the cone of s.o.s. polynomials of degree at most 2d. We also provide a simple condition to

Silvia Vaula

We study the reduction of the Free Differential Algebra (FDA) of D=11 supergravity to an ordinary algebra. We show that in flat background and with vanishing three-form field strength, the corresponding minimal FDA can be reduced to an Inonu-Wigner contraction of Sezgin's M-Algebra. We also prove that in flat background but with a non trivial three-form fiel

A. C. Robin, R. M. Rich, H. Aussel, P. Capak

We report on the stellar content of the COSMOS two degree field, as derived from a rigorous star/galaxy separation approach developed for using stellar sources to define the point spread function variation map used in a study of weak galaxy lensing. The catalog obtained in one filter from the ACS (Advanced Camera for Survey on the Hubble Space Telescope) is

Andrei Khrennikov, Marcus Nilsson

We discuss the similarity of the degeneration structure of the genetic code with a pure number theoretic -- ``divisors code.'' The most interesting thing about our observation is not that there is a connection between number theory and the genetic code, but the simplicity of the rule. We hope that the observation and the naive model presented in this

Kaiki Taro Inoue, Joseph Silk

We explore the large angular scale temperature anisotropies in the cosmic microwave background (CMB) due to homogeneous local dust-filled voids in a flat Friedmann-Robertson-Walker universe with a cosmological constant. In comparison with the equivalent dust-filled void model in the Einstein-de Sitter background, we find that the anisotropy for compensated a

L. Nogach

Measurements by the STAR collaboration of neutral pion production at large Feynman x (x_F) in the first polarized proton collisions at $\sqrt{s}=200$ GeV were reported previously. Cross sections measured at $\eta=3.3$, 3.8 and 4.0 are found to be consistent with next-to-leading order perturbative QCD calculations. The analyzing power is consistent with zero

A. S. Khvorostukhin, V. D. Toneev, D. N. Voskresensky

The proposed earlier relativistic mean-field model with hadron masses and coupling constants depending on the $σ$-meson field is generalized to finite temperatures. Within this approach we simulate the in-medium behavior of the hadron masses motivated by the Brown-Rho scaling. The high-lying baryon resonances and boson excitations as well as excitations of t

C. L. Carilli, T. Murayam, R. Wang, E. Schinnerer

We present observations at 1.4 and 250 GHz of the $z\sim 5.7$ Ly$α$ emitters (LAE) in the COSMOS field found by Murayama et al.. At 1.4 GHz there are 99 LAEs in the lower noise regions of the radio field. We do not detect any individual source down to 3$σ$ limits of $\sim 30μ$Jy beam$^{-1}$ at 1.4 GHz, nor do we detect a source in a stacking analysis, to a 2

James M. Cline

A pedagogical introduction to aspects of string cosmology, including the landscape (BPBT) solution to the cosmological constant problem, brane-antibrane inflation, warped compactification, the KKLMMT model, the eta problem of SUGRA models, DBI inflation, Kahler modulus and racetrack inflation, the D3-D7 model, cosmic superstrings, and the problem of reheatin

Manuela Campanelli, Carlos O. Lousto, Yosef Zlochower, Badri Krishnan

We use the `moving puncture' approach to perform fully non-linear evolutions of spinning quasi-circular black-hole binaries with individual spins not aligned with the orbital angular momentum. We evolve configurations with the individual spins (parallel and equal in magnitude) pointing in the orbital plane and 45-degrees above the orbital plane. We intro

L. A. Glinka

We propose the new quantization of homogenous cosmological models. Four fundamental methods are applied to the cosmological model and efficiently jointed. The Dirac method for constrained systems is used, then the Fock space is built and the second quantization is carried out. Finally, the diagonalization ansatz, which is a combination of the Bogoliubov tran

M. Krumpe, G. Lamer, A. D. Schwope, S. Wagner

We report on a medium deep XMM-Newton survey of the Marano Field and optical follow-up observations. The mosaicked XMM-Newton pointings in this optical quasar survey field cover 0.6 square degree with a total of 120 ksec good observation time. We detected 328 X-ray sources in total. The turnover flux of our sample is f~5x10^(-15) erg/cm^2/s in the 0.2-10 keV

Hernan D. Rozenfeld, Shlomo Havlin, Daniel ben-Avraham

We explore the concepts of self-similarity, dimensionality, and (multi)scaling in a new family of recursive scale-free nets that yield themselves to exact analysis through renormalization techniques. All nets in this family are self-similar and some are fractals - possessing a finite fractal dimension - while others are small world (their diameter grows loga

Karen L. van der Molen, R. Willem Tjerkstra, Allard P. Mosk, Ad Lagendijk

We have experimentally studied the distribution of the spatial extent of modes, and the crossover from essentially single-mode to distinctly multi-mode behavior inside a porous gallium phosphide random laser. This system serves as a paragon for random lasers due to its exemplary high index contrast. In the multi-mode regime we observed mode competition. We h

A. A. Fraerman, O. G. Udalov

The volt-ampere characteristics of a medium with helical magnetic structure are theoretically studied. Phenomenological and microscopic theories of a diode effect in such a medium are proposed. Diode effect appears only in the medium with noncoplanar magnetic structure. Two mechanisms for the diode effect are considered. They are electron energy spectrum asy

L. Bergamin, D. Izzo, A. Pinchook

We critically review our recent claims that it is possible to obtain a propellantless propulsion device similar to electrodynamic tethers by means of a closed wire partially shielded by a superconductor from the outer magnetic field. We find that such a device is not possible as it violates basic physical laws. Furthermore, we show what is the correct local

Marcus Ansorg

We present a multi-domain spectral method to compute initial data of binary systems in General Relativity. By utilizing adapted conformal coordinates, the vacuum region exterior to the gravitational sources is divided up into two subdomains within which the spectral expansion of the field quantities is carried out. If a component of the binary is a neutron s

Saharon Shelah

We prove that g (the groupwise density number) is smaller or equal to b^+ (the successor of the minimal cardinality of a non-dominated subset of omega^omega).

A. Schilling, M. Reibelt

We describe how we can precisely measure variations in the entropy S of small solid samples below room temperature, as a function the temperature T or the external magnetic field H, respectively. A simple differential-thermal analysis (DTA) technique allows, in principle, for the measurement of variations in S without any instrumental broadening of the data.

Raj Gandhi, Walter Winter

We discuss the neutrino oscillation physics of a very long neutrino factory baseline over a broad range of lengths (between 6000 km and 9000 km), centered on the ``magic baseline'' ($\sim$ 7500 km) where correlations with the leptonic CP phase are suppressed by matter effects. Since the magic baseline depends only on the density, we study the impact

Olaf Duemmer, Werner Krauth

We perform a high-precision calculation of the critical exponents for the long-range elastic string driven through quenched disorder at the depinning transition, at zero temperature. Large-scale simulations are used to avoid finite-size effects and to enable high precision. The roughness, growth, and velocity exponents are calculated independently, and the d

Steven Moal, Maximilien Portier, Nassim Zahzam, Michèle Leduc

We describe two-photon photoassociation (PA) experiments operated in an ultracold gas of metastable $^4$He$^*$ atoms in the $2^3S_1$ state. Atom-molecule dark resonances as well as Raman signals provide information on the exotic molecule in the least bound vibrational J=2, $v=14$ state of the $^5Σ_g^+$ interaction potential of two spin-polarized metastable a

M. Chaichian, A. Tureanu, R. B. Zhang, X. Zhang

A Riemannian geometry of noncommutative n-dimensional surfaces is developed as a first step towards the construction of a consistent noncommutative gravitational theory. Historically, as well, Riemannian geometry was recognized to be the underlying structure of Einstein's theory of general relativity and led to further developments of the latter. The not

Milan Batista

The article treats the classical problem of stability of steady rotation of a rigid homogeneous ellipsoid on a rigid smooth plane which rotates about its vertical axis. The condition for the steady rotation is derived from the Euler-Poisson equations.

Oliver Cooley, Nikolaos Fountoulakis, Daniela Kühn, Deryk Osthus

Chvatal, Roedl, Szemeredi and Trotter proved that the Ramsey numbers of graphs of bounded maximum degree are linear in their order. In previous work, we proved the same result for 3-uniform hypergraphs. Here we extend this result to k-uniform hypergraphs, for any integer k > 3. As in the 3-uniform case, the main new tool which we prove and use is an embeddin

Helena Granstrom

A Gleason-type theorem is proved for two restricted classes of informationally complete POVMs in the qubit case. A particular (incomplete) Kochen-Specker colouring, suggested by Appleby in dimension three, is generalized to arbitrary dimension. We investigate its effectivity as a function of dimension, using two different measures of this. In particular, we

M. A. Braun, G. P. Vacca

The Reggeon field theory with zero transverse dimensions is studied in the Hamiltonian formulation for both sub-and supercritical pomeron. Mathematical aspects of the model, in particular the scalar products in the space of quantum states, are discussed. Relation to reaction-diffusion processes is derived in absence of pomeron merging. Numerical calculations

H. M. Bui, J. P. Keating

Hybrid Euler-Hadamard products have previously been studied for the Riemann zeta function on its critical line and for Dirichlet L-functions in the context of the calculation of moments and connections with Random Matrix Theory. According to the Katz-Sarnak classification, these are believed to represent families of L-function with unitary symmetry. We here

Ellen Baake, Inke Herms

Populations evolving under the joint influence of recombination and resampling (traditionally known as genetic drift) are investigated. First, we summarise and adapt a deterministic approach, as valid for infinite populations, which assumes continuous time and single crossover events. The corresponding nonlinear system of differential equations permits a clo

Zhi-Yong Wang, Cai-Dong Xiong

Though both theoretical and experimental investigations have revealed the superluminal behavior of evanescent electromagnetic waves, there are many disputes about the physical meaning and validity of such superluminal phenomenon, which is due to the fact that the traditional investigations are based on the theory of tunneling time, and concerned with the pro

G. Endimioni

An automorphism of a group is said to be normal if it preserves each normal subgroup. In this paper, we determine the normal automorphisms of a free metabelian nilpotent group.

Marcos Marino

We propose a formalism inspired by matrix models to compute open and closed topological string amplitudes in the B-model on toric Calabi-Yau manifolds. We find closed expressions for various open string amplitudes beyond the disk, and in particular we write down the annulus amplitude in terms of theta functions on a Riemann surface. We test these ideas on lo

Jarmo Makela, Ari Peltola

We perform an analysis where Einstein's field equation is derived by means of very simple thermodynamical arguments. Our derivation is based on a consideration of the properties of a very small, spacelike two-plane in a uniformly accelerating motion.

The KLOE Collaboration, F. Ambrosino

We have measured the ratio $R_ϕ=BR(ϕ\to η^{\prime} γ)/BR(ϕ\to ηγ)$ by looking for the radiative decays $ϕ\to η^{\prime} γ$ and $ϕ\to ηγ$ in the final states $π^+π^-$ 7 $γ$'s and 7 $γ$'s respectively, in a sample of $\sim 1.3\cdot 10^{9}$ $ϕ$ mesons produced at the Frascati $ϕ$-factory. We obtain $R_ϕ=(4.77\pm0.09_{stat}\pm0.19_{sys})\cdot 10^{-3}$ fr

Sergi Lozano, Alex Arenas, Angel Sanchez

We study the evolutionary Prisoner's Dilemma on two social networks obtained from actual relational data. We find very different cooperation levels on each of them that can not be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community stru

Manuel Bodirsky

A relational structure is a core, if all its endomorphisms are embeddings. This notion is important for computational complexity classification of constraint satisfaction problems. It is a fundamental fact that every finite structure has a core, i.e., has an endomorphism such that the structure induced by its image is a core; moreover, the core is unique up

Kaushik Majumdar

Defining and measuring phase synchronization in a pair of nonlinear time series are highly nontrivial. This can be done with the help of Fourier transform, when it exists, for a pair of stored (hence stationary) signals. In a time series instantaneous phase is often defined with the help of Hilbert transform. In this paper phase of a time series has been def

N. S. Mankoc Borstnik, H. B. Nielsen

The genuine Kaluza-Klein-like theories--with no fields in addition to gravity--have difficulties with the existence of massless spinors after the compactification of some space dimensions \cite{witten}. We proposed (Phys. Lett. B 633 (2006)771) such a boundary condition for spinors in 1+5 compactified on a flat disk that ensures masslessness of spinors in d=

John Jeffers

The fidelity of postselecting devices based on direct photon number detection can be significantly improved by insertion of a phase-insensitive optical amplifier in front of the detector. The scheme is simple, and the cost to the probability of obtaining the appropriate detector outcome is low.

Matjaz Perc, Attila Szolnoki, Gyorgy Szabo

We study a six-species Lotka-Volterra type system on different two-dimensional lattices when each species has two superior and two inferior partners. The invasion rates from predator sites to a randomly chosen neighboring prey's site depend on the predator-prey pair, whereby cyclic symmetries within the two three-species defensive alliances are conserved

Meirav Amram, David Garber, Mina Teicher

We compute the fundamental groups of the complements of the family of real conic-line arrangements with up to two conics which are tangent to each other at two points, with an arbitrary number of tangent lines to both conics. All the resulting groups turn out to be big.

Andreas Recknagel, Rafal R. Suszek

We study the non-commutative matrix model which arises as the low-energy effective action of open strings in WZW models. We re-derive this fuzzy effective gauge dynamics in two different ways, without recourse to conformal field theory. The first method starts from a linearised version of the WZW sigma model, which is classically equivalent to an action of S

Jae-Hyun Yang

In this article, we prove that a lattice representation of the Heisenberg group $H_{\mathbb R}^{(g,h)}$ associated to a lattice $L$ and a positive definite symmetric half-integral matrix M of degree $h$ is unitarily equivalent to the direct sum of $(det 2M)^g$ copies of the Schroedinger representation of $H_{\mathbb R}^{(g,h)}$.

Jae-Hyun Yang

In this article, we prove a decomposition theorem on differential polynomials of theta functions of high level.

Carlos Gutierrez, Benito Pires

We provide an affirmative answer to the Cr Closing Lemma, r>1, for a large class of flows defined on every closed surface.

R. Komendarczyk

Let $M$ be a compact orientable Seifered fibered 3-manifold without a boundary, and $α$ an $S^1$-invariant contact form on $M$. In a suitable adapted Riemannian metric to $α$, we provide a bound for the volume $\text{Vol}(M)$ and the curvature, which implies the universal tightness of the contact structure $ξ=\kerα$.

Shiro Goto, Naoyuki Matsuoka, Ryo Takahashi

This paper explores the structure of quasi-socle ideals I=Q:m^2 in a Gorenstein local ring A, where Q is a parameter ideal and m is the maximal ideal in A. The purpose is to answer the problem of when Q is a reduction of I and when the associated graded ring G(I) = \bigoplus_{n \geq 0}I^n/I^{n+1} is Cohen-Macaulay. Wild examples are explored.

Michael Courtney, Amy Courtney

As education systems move toward business models of operation, there is a strong tendency to misidentify the student as the customer. Misidentifying the student as the customer leads to interpretation of the course credit or degree as the product. The true product is the additional knowledge, skill, and ability that course credit and degree should represent.