July 2007 arXiv papers — page 7

Sean M. Moran, Richard S. Ellis, Tommaso Treu, Graham P. Smith

We present new results from our comprehensive comparative survey of two massive, intermediate redshift galaxy clusters, Cl0024+17 (z=0.39) and MS0451-03 (z=0.54). We identify and study several key classes of `transition objects' whose stellar populations or dynamical states indicate a recent or ongoing change in morphology and star formation rate. For th

Don N. Page

Hartle and Srednicki have argued that there is no observational evidence favoring our typicality. Here it is shown that such evidence does arise from including the `normalization principle' requirement that the sum of the likelihoods for all possible observations is normalized to unity in each theory.

B. W. Holwerda, M. Meyer, M. Regan, D. Calzetti

Dust in galaxies can be mapped by either the FIR/sub-mm emission, the optical or infrared reddening of starlight, or the extinction of a known background source. We compare two dust extinction measurements for a set of fifteen sections in thirteen nearby galaxies, to determine the scale of the dusty ISM responsible for disk opacity: one using stellar reddeni

Todd L. Veldhuizen

Software is a communication system. The usual topic of communication is program behavior, as encoded by programs. Domain-specific libraries are codebooks, domain-specific languages are coding schemes, and so forth. To turn metaphor into method, we adapt toolsfrom information theory--the study of efficient communication--to probe the efficiency with which lan

B. W. Holwerda, B. Draine, K. D. Gordon, R. A. Gonzalez

The quantity of dust in a spiral disk can be estimated using the dust's typical emission or the extinction of a known source. In this paper, we compare two techniques, one based on emission and one on absorption, applied on sections of fourteen disk galaxies. The two measurements reflect, respectively the average and apparent optical depth of a disk sect

Frederick W. Strauch

We derive an exact propagation scheme for nonlinear Schroedinger equations. This scheme is entirely analogous to the propagation of linear Schroedinger equations. We accomplish this by defining a special operator whose algebraic properties ensure the correct propagation. As applications, we provide a simple proof of a recent conjecture regarding higher-order

Erasmo Ferreira, Flavio Pereira

Solutions for the amplitudes that give accurate description of pp and p-pbar scattering at high energies are investigated, with particular attention given to the properties of their zeros and slopes, whose determination is required for the study of the Coulomb interference region. Proper extrapolations of these quantities to the LHC energies are important fo

Alessandro D'Andrea

I show that simple finite vertex algebras are commutative, and that the Lie conformal algebra structure underlying a reduced (i.e., without nilpotent elements) finite vertex algebra is nilpotent.

V. F. Mitrović, G. Koutroulakis, M. -A. Vachon, M. Horvatić

We report ^{115}In nuclear magnetic resonance (NMR) measurements in the heavy-fermion superconductor CeCoIn_5 as a function of temperature in different magnetic fields applied parallel to the $(\hat a, \hat b)$ plane. The measurements probe a part of the phase diagram in the vicinity of the superconducting critical field H_{c2} where a possible inhomogeneous

B. V. Fine, J. P. R. Bakker, J. I. Dijkhuis

We describe a mechanism, which links the long-range potential fluctuations induced by charged defects to the low frequency resistance noise widely known as 1/f noise. This mechanism is amenable to the first principles microscopic calculation of the noise spectrum, which includes the absolute noise intensity. We have performed such a calculation for the thin

Gloria Sala, Jochen Greiner, Marco Ajello, Eugenio Bottacini

The galactic black hole candidate XTE J1817-330 was discovered in outburst by RXTE in January 2006. We present here the results of an XMM-Newton Target of opportunity observation (TOO), performed on 13 March 2006 (44 days after the maximum), and an INTEGRAL observation performed on 15-18 February 2006 (18 days after the maximum). The EPIC-pn camera on-board

Constanze Metzger, Ivan Favero, Alexander Ortlieb, Khaled Karrai

We investigated the opto-mechanical properties of a Fabry-Perot cavity with a mirror mounted on a spring. Such a structure allows the cavity length to change elastically under the effect of light induced forces. This opto-mechanical coupling is exploited to control the amplitude of mechanical fluctuation of the mirror. We present a model developed in the cla

Alexander Lanyov, Sergei Shmatov

The potential of the Compact Muon Solenoid (CMS) experiment to measure Drell-Yan muon pairs is discussed. Muon pairs can be measured in CMS with high precision up to very high invariant masses. The systematic errors are considered. The potential to carry out precise measurements of the forward-backward asymmetry is discussed.

A. Vazdekis, R. F. Peletier

Stellar populations, building blocks of galaxies, are direct tracers of the star formation history, the chemical enrichment and the assembly of galaxies in the Universe. They therfore allow us to understand how galaxies formed and evolved. This last decade has witnessed a revolution in our observations of galaxies; with larger telescopes and new instruments

Xiuxiong Chen, Yudong Tang

For smooth test configurations, there always exist C^{1,1} geodesic rays in Kahler metric space parallel to the algebraic ray. The $\yen$ invariant agrees with Futaki invariant, at least under nice assumptions. Explicit examples in Toric cases are calculated. On simple test configurations, Donaldson's correspondence between HCMA solution and holomorphic

Marian Anghel, Ingo Steinwart

We consider the problem of designing almost optimal predictors for dynamical systems from a finite sequence of noisy observations and incomplete knowledge of the dynamics and the noise. We first discuss the properties of the optimal (Bayes) predictor and present the limitations of memory-free forecasting methods, and of any finite memory methods in general.

J. M. Borrero, L. R. Bellot Rubio, D. A. N. Mueller

We employ a 3-dimensional magnetohydrostatic model of a horizontal flux tube, embedded in a magnetic surrounding atmosphere, to successfully reproduce the azimuthal and center-to-limb variations of the Net Circular Polarization observed in sunspot penumbrae. This success is partly due to the realistic modeling of the interaction between the flux tube and the

Adrian Tanasa, Fabien Vignes-Tourneret

We contruct here the Hopf algebra structure underlying the process of renormalization of non-commutative quantum field theory.

M. Czakon, A. Mitov, S. Moch

We present the two-loop virtual QCD corrections to the production of heavy quarks in gluon fusion. The results are exact in the limit when all kinematical invariants are large compared to the mass of the heavy quark up to terms suppressed by powers of the heavy-quark mass. Our derivation uses a simple relation between massless and massive QCD scattering ampl

KLOE collaboration, F. Ambrosino, A. Antonelli, M. Antonelli

We report a preliminary measurement of the slope parameter $α$ for the $η\to 3\piz$ decay carried out with KLOE at DA$Φ$NE; where $α$ is the parameter describing the energy dependence of the square of the matrix element for this decay. By fitting the event density in the Dalitz plot with a collected statistic of 420 pb$^{-1}$ we determine $α= -0.027 \pm 0.00

Ambar N. Sengupta

We present a description of two dimensional Yang-Mills gauge theory on the plane and on compact surfaces, examining the topological, geometric and probabilistic aspects.

Hans U. Boden, Cynthia L. Curtis

We establish a formula for the SL(2,C) Casson invariant of spliced sums of homology spheres along knots. Along the way, we show that the SL(2,C) Casson invariant vanishes for spliced sums along knots in the 3-sphere.

Robert L. Intemann

Stewart has provided a position-space derivation of an identity for the volume integral of the square of a vector field that was quoted by Gubarev, Stodolsky and Zakharov. In this comment, I provide a momentum-space derivation of this result, generalized to the scalar product of two complex vector fields. This approach demonstrates the effective use of the F

Maria Bergemann, Thomas Gehren

We present a detailed NLTE analysis of 39 MnI lines in the solar spectrum. The influence of NLTE effects on the line formation and element abundance is investigated. Our goal is the derivation of solar log gfe values for manganese lines, which will later be used in differential abundance analysis of metal-poor stars. The method of spectrum synthesis is emplo

Ozren Perse

Let $L(-{1/2}(l+1),0)$ be the simple vertex operator algebra associated to an affine Lie algebra of type $A_{l}^{(1)}$ with the lowest admissible half-integer level $-{1/2}(l+1)$, for even l. We study the category of weak modules for that vertex operator algebra which are in category $\cal{O}$ as modules for the associated affine Lie algebra. We classify irr

B. A. Ivanov, C. E. Zaspel

A spin-polarized current with the polarization perpendicular to the plane of a vortex-state disk results in renormalization of the effective damping for a given magnetization mode, and the effective damping becomes zero if the current exceeds a threshold value. The lowest threshold current corresponds to the lowest frequency vortex gyroscopic mode. For large

S. Verley, F. Combes, L. Verdes-Montenegro, G. Bergond

Star formation depends strongly both on the local environment of galaxies, and on the internal dynamics of the interstellar medium. To disentangle the two effects, we obtained, in the framework of the AMIGA project, Ha and Gunn r photometric data for more than 200 spiral galaxies lying in very low-density regions of the local Universe. We characterise the Ha

A. Sellerholm, J. Conrad, L. Bergstrom, J. Edsjo

Measurement of the extragalactic background (EGBR) of diffuse gamma-rays is perhaps one of the most challenging tasks for future gamma-ray observatories, such as GLAST. This is because any determination will depend on accurate subtraction of the galactic diffuse and celestial foregrounds, as well as point sources. However, the EGBR is likely to contain very

Y. F. Huang, T. Lu, K. S. Cheng

The discovery of multiband afterglows definitely shows that most $γ$-ray bursts are of cosmological origin. $γ$-ray bursts are found to be one of the most violent explosive phenomena in the Universe, in which astonishing ultra-relativistic motions are involved. In this article, the multiband observational characteristics of $γ$-ray bursts and their afterglow

Moez Draief, Jean Mairesse

We analyze the service times of customers in a stable M/M/1 queue in equilibrium depending on their position in a busy period. We give the law of the service of a customer at the beginning, at the end, or in the middle of the busy period. It enables as a by-product to prove that the process of instants of beginning of services is not Poisson. We then proceed

Wolfgang Lucha, Dmitri Melikhov, Silvano Simula

We study systematic errors of the ground-state parameters obtained by Shifman-Vainshtein-Zakharov (SVZ) sum rules, making use of the harmonic-oscillator potential model as an example. In this case, one knows the exact solution for the polarization operator, which allows one to obtain both the OPE to any order and the parameters (masses and decay constants) o

David Berge

The ATLAS detector at CERN's Large Hadron Collider (LHC) will be exposed to proton-proton collisions from beams crossing at 40 MHz. At the design luminosity of 10^34 cm^-2 s^-1 there are on average 23 collisions per bunch crossing. A three-level trigger system will select potentially interesting events in order to reduce the read-out rate to about 200 Hz

George P. Yanev, M. Ahsanullah, M. I. Beg

Bairamov et al. (Aust N Z J Stat 47:543-547, 2005) characterize the exponential distribution in terms of the regression of a function of a record value with its adjacent record values as covariates. We extend these results to the case of non-adjacent covariates. We also consider a more general setting involving monotone transformations. As special cases, we

Florence Durret, Gastao B. Lima Neto

We have analyzed XMM-Newton archive data for five clusters of galaxies (redshifts 0.223 to 0.313) covering a wide range of dynamical states, from relaxed objects to clusters undergoing several mergers. We present here temperature maps of the X-ray gas together with a preliminary interpretation of the formation history of these clusters.

Po Hu

In this note, we define the notion of a cactus set, and show that its geometric realization is naturally an algebra over Voronov's cactus operad, which is equivalent to the framed 2-dimensional little disks operad $\mathcal{D}_2$. Using this, we show that the Hochschild cohomology of a Poincaré algebra A is an algebra over (the chain complexes of) $\math

P. Calabrese, J. -S. Caux

The physics of the attractive one-dimensional Bose gas (Lieb-Liniger model) is investigated with techniques based on the integrability of the system. Combining a knowledge of particle quasi-momenta to exponential precision in the system size with determinant representations of matrix elements of local operators coming from the Algebraic Bethe Ansatz, we obta

Eduardo Sanz, Chantal Valeriani, Daan Frenkel, Marjolein Dijkstra

We report a numerical study of the rate of crystal nucleation in a binary suspension of oppositely charged colloids. Two different crystal structures compete in the thermodynamic conditions under study. We find that the crystal phase that nucleates is metastable and, more surprisingly, its nucleation free energy barrier is not the lowest one. This implies th

P. Buonsante, Francesco Massel, Vittorio Penna, Alessandro Vezzani

In the present paper we describe the properties induced by disorder on an ultracold gas of Bosonic atoms loaded into a two-dimensional optical lattice with global confinement ensured by a parabolic potential. Our analysis is centered on the spatial distribution of the various phases, focusing particularly on the superfluid properties of the system as a funct

S. Datta, O. Waldmann, A. D. Kent, V. A. Milway

High-frequency electron paramagnetic resonance (EPR) studies of the antiferromagnetic Mn-$[3\times 3]$ molecular grid clearly reveal a breaking of the $ΔS = 0$ selection rule, providing direct evidence for the mixing of spin wavefunctions ($S$-mixing) induced by the comparable exchange and magneto-anisotropy energy scales within the grid. This finding highli

A. Pipino, A. D'Ercole, F. Matteucci

Elliptical galaxies probably host the most metal rich stellar populations in the Universe. The processes leading to both the formation and the evolution of such stars are discussed by means of a new gas dynamical model which implements detailed chemical evolution prescriptions. Moreover, the radial variations in the metallicity distribution of these stars ar

A. Rebassa-Mansergas, B. T. Gaensicke, P. Rodriguez-Gil, M. R. Schreiber

We present a detailed analysis of 101 white dwarf-main sequence binaries (WDMS) from the Sloan Digital Sky Survey (SDSS) for which multiple SDSS spectra are available. We detect significant radial velocity variations in 18 WDMS, identifying them as post common envelope binaries (PCEBs) or strong PCEB candidates. Strict upper limits to the orbital periods are

Andreas Vogt

We briefly discuss recent research on the spin-averaged parton densities of the proton, focusing on some aspects relevant to hard processes at the LHC. Specifically, after recalling the basic framework and the need for higher-order calculations, we address the evolution equations governing the scale dependence of the parton distributions and their solution,

T. Herpay, A. Patkos

Charged pions produced in very high energy hadronic interactions might be the dominant source of cosmic neutrinos in the GeV--TeV range. Spectral energy power of π^+ radiation by high energy protons moving in strong magnetic fields typical for magnetars is determined with a semiclassical treatment of the effective pion-nucleon model. The main characteristics

Moez Draief, Jean Mairesse, Neil O'Connell

Consider the single server queue with an infinite buffer and a FIFO discipline, either of type M/M/1 or Geom/Geom/1. Denote by A the arrival process and by s the services. Assume the stability condition to be satisfied. Denote by D the departure process in equilibrium and by r the time spent by the customers at the very back of the queue. We prove that (D,r)

L. Piro, J. W. den Herder, T. Ohashi

How structures on various scales formed and evolved from the early Universe up to present time is a fundamental question of astrophysical cosmology. EDGE will trace the cosmic history of the baryons from the early generations of massive star by Gamma-Ray Burst (GRB) explosions, through the period of cluster formation, down to very low redshifts, when between

M. Rossi, R. Rota, E. Vitali, D. E. Galli

We have investigated the ground state properties of solid $^4$He with the Shadow Path Integral Ground State method. This exact T=0 K projector method allows to describes quantum solids without introducing any a priori equilibrium position. We have found that the efficiency in computing off-diagonal properties in the solid phase sensibly improves when the dir

Constantinos G. Vayenas, Stamatia Giannareli, Stamatios Souentie

The magnitude of gravity at subatomic distances was investigated in the nuclear size range by examining the vibrational kinetic energy of baryons and quarks, treated as waveparticles and strings, in the 4He and 2H nuclei. Due to the relativistic increase in mass and concomitant wave particle confinement at high vibrational energies, it is found that gravitat

Sylvain Ravy, Jean-Paul Itie, Alain Polian, Michael Hanfland

We present a high-pressure x-ray diffuse scattering study of the ABO$_3$ ferroelectric perovskites BaTiO_3 and KNbO_3. The well-known diffuse lines are observed in all the phases studied. In KNbO_3, we show that the lines are present up to 21.8 GPa, with constant width and a slightly decreasing intensity. At variance, the intensity of the diffuse lines obser

D. E. Galli, L. Reatto, W. M. Saslow

For solid 4He and solid p-H2, using the flow-energy-minimizing one-body phase function and exact T=0 K Monte Carlo calculations of the local density, we have calculated the phase function, the velocity profile and upper bounds for the superfluid fraction f_s. At the melting pressure for solid 4He we find that f_s < 0.20-0.21, about ten times what is observed

David Garcia-Aldea, J. E. Alvarellos

There is a number of explicit kinetic energy density functionals for non-interacting electron systems that are obtained in terms of the electron density and its derivatives. These semilocal functionals have been widely used in the literature. In this work we present a comparative study of the kinetic energy density of these semilocal functionals, stressing t

Tomohiro Yamada

We show asymptotic upper and lower bounds for the greatest common divisor of N and $σ(N)$. We also show that there are infinitely many integers N with fairly large g.c.d. of N and $σ(N)$.

Matteo Petrera, Yuri B. Suris

The first part of the present paper is devoted to a systematic construction of continuous-time finite-dimensional integrable systems arising from the rational su(2) Gaudin model through certain contraction procedures. In the second part, we derive an explicit integrable Poisson map discretizing a particular Hamiltonian flow of the rational su(2) Gaudin model

H. S. Nataraj, B. K. Sahoo, B. P. Das, R. K. Chaudhuri

The enhancement factors of the electric dipole moment (EDM) of the ground states of two paramagnetic atoms; rubidium (Rb) and caesium (Cs) which are sensitive to the electron EDM are computed using the relativistic coupled-cluster theory and our results are compared with the available calculations and measurements. The possibility of improving the limit for

Carlos E. Valencia, Marcos I. Barrita

Given two graphs G and H its 1-{\it join} is the graph obtained by taking the disjoint union of G and H and adding all the edges between a nonempty subset of vertices of G and a nonempty subset of vertices of H. In general, composition operations of graphs has played a fundamental role in some structural results of graph theory and in particular the 1-join c

Sergey Bezzateev, Natalia Shekhunova

It is shown that subclasses of separable binary Goppa codes, $Γ(L,G)$ - codes, with $L=\{α\in GF(2^{2l}):G(α)\neq 0 \}$ and special Goppa polynomials G(x) can be presented as a chain of embedded codes. The true minimal distance has been obtained for all codes of the chain.

Olivier Pierre-Louis, Anna Chame, Yukio Saito

We report on the dewetting of a monolayer on a solid substrate, where mass transport occurs via surface diffusion. For a wide range of parameters, a labyrinthine pattern of bilayer islands is formed. An irreversible regime and a thermodynamic regime are identified. In both regimes, the velocity of a dewetting front, the wavelength of the bilayer island patte

Ricardo Lopez-Ruiz, Jaime Sanudo, Xavier Calbet

We show that the Boltzmann factor has a geometrical origin. Its derivation follows from the microcanonical picture. The Maxwell-Boltzmann distribution or the wealth distribution in human society are some direct applications of this new interpretation.

Prakash Mathews, V. Ravindran

For the dilepton production at hadron collider in TeV scale gravity models, inclusion of QCD corrections to NLO stabilises the cross section with respect to scale variations. The K-factors for the various distributions for the ADD and RS model at both LHC and Tevatron are presented.

S. Sabatini, J. I. Davies, S. Roberts, R. Scaramella

The nature of the dwarf galaxy population as a function of location in the cluster and within different environments is investigated. We have previously described the results of a search for low surface brightness objects in data drawn from an East-West strip of the Virgo cluster (Sabatini et al., 2003) and have compared this to a large area strip outside of

The KLOE Collaboration

The KLOE Experiment at the $ϕ$ factory DA$Φ$NE, has measured the cross section $σ(e^+e^-\toπ^+π^-γ)$ using two different selection schemes: requiring the photon emission at small polar angle and detecting the photon at large polar angle in the calorimeter. Using a theoretical radiator function we extract the pion form factor and obtain the $ππ$ contribution

A. Andronic, P. Braun-Munzinger, J. Stachel

We present predictions of the thermal model for hadron ratios in central Pb+Pb collisions at LHC.

A Andronic, P Braun-Munzinger, K Redlich, J Stachel

We present predictions of the statistical hadronization model for charmed hadrons production in Pb+Pb collisions at LHC.

Yoshiaki Hyodo, Masahiro Tsujimoto, Kenji Hamaguchi, Katsuji Koyama

We present the results of a Suzaku spectroscopic study of the soft extended X-ray emission in the HII region M17. The spectrum of the extended emission was obtained with a high signal-to-noise ratio in a spatially-resolved manner using the X-ray Imaging Spectrometer (XIS). We established that the contamination by unresolved point sources, the Galactic Ridge

Patrick Erik Bradley

A conceptual framework for cluster analysis from the viewpoint of p-adic geometry is introduced by describing the space of all dendrograms for n datapoints and relating it to the moduli space of p-adic Riemannian spheres with punctures using a method recently applied by Murtagh (2004b). This method embeds a dendrogram as a subtree into the Bruhat-Tits tree a

A. Fierro, E. Del Gado, A. de Candia, A. Coniglio

We study the formation of a colloidal gel by means of Molecular Dynamics simulations of a model for colloidal suspensions. A slowing down with gel-like features is observed at low temperatures and low volume fractions, due to the formation of persistent structures. We show that at low volume fraction the dynamic susceptibility, which describes dynamic hetero

Eleonora Nagali, Tiziano De Angelis, Fabio Sciarrino, Francesco De Martini

We investigate the multiphoton states generated by high-gain optical parametric amplification of a single injected photon, polarization encoded as a &#39;&#39;qubit&#39;&#39;. The experiment configuration exploits the optimal phase-covariant cloning in the high gain regime. The interference fringe pattern showing the non local transfer of coherence between t

Fiorella Burgio

The Equation of State (EoS) of dense matter represents a central issue in the study of compact astrophysical objects and heavy ion reactions at intermediate and relativistic energies. We have derived a nuclear EoS with nucleons and hyperons within the Brueckner-Hartree-Fock approach, and joined it with quark matter EoS. For that, we have employed the MIT bag

V. D. Blondel, J. -L. Guillaume, J. M. Hendrickx, C. de Kerchove

We consider local leaders in random uncorrelated networks, i.e. nodes whose degree is higher or equal than the degree of all of their neighbors. An analytical expression is found for the probability of a node of degree $k$ to be a local leader. This quantity is shown to exhibit a transition from a situation where high degree nodes are local leaders to a situ

Akiyuki Ishikawa, Atushi Tanaka, Akira Shudo

The interplay between chaotic tunneling and dynamical localization in mixed phase space is investigated. Semiclassical analysis using complex classical orbits reveals that tunneling through torus regions and transport in chaotic regions are not independent processes, rather they are strongly correlated and described by complex orbits with both properties. Th

Christoph Weiss, Niklas Teichmann

A previous publication [Europhysics Letters 78, 10009 (2007)] suggested to coherently generate mesoscopic superpositions of a two-component Bose-Einstein condensate in a double well under perfectly symmetric conditions. However, already tiny asymmetries can destroy the entanglement properties of the ground state. Nevertheless, even under more realistic condi

C. Martin-Zaidi, P-. O. Lagage, E. Pantin, E. Habart

We present high resolution spectroscopic mid-infrared observations of the circumstellar disk around the Herbig Ae star HD97048 with the VLT Imager and Spectrometer for the mid-InfraRed (VISIR). We detect the S(1) pure rotational line of molecular hydrogen (H2) at 17.035 microns arising from the disk around the star. This detection reinforces the claim that H

Thomas Kluge

Several determinations of the strong coupling from the H1 Collaboration are reviewed.

Thomas Kluge

Inclusive jet production is studied in neutral current deep-inelastic positron-proton scattering at large four momentum transfer squared Q^2>150 GeV^2 with the H1 detector at HERA. The measurements are found to be well described by calculations at next-to-leading order in perturbative QCD. The running of the strong coupling is demonstrated and the value of a

Friedrich Wagemann

Fialowski and Schlichenmaier constructed examples of global deformations of Lie algebras of vector fields from deforming the underlying variety. We formulate their approach in a conceptual way. Namely, we construct a stack of deformations and a morphism form the moduli stack of stable marked curves. The morphism associates to a family of marked curves the fa

Alexander Wood

Measurements of the microlensing optical depth, tau, towards the Galactic bulge appear to depend on the method used to obtain them. Those values based on the lensing of red clump giants (RCGs) appear to be significantly lower than those based on the lensing of all stars along the line of sight. This discrepancy is still not understood. Through Monte Carlo si

M. S. Santhanam, Siddharth Arora

We show that two coupled map lattices that are mutually coupled to one another with a delay can display zero delay synchronization if they are driven by a third coupled map lattice. We analytically estimate the parametric regimes that lead to synchronization and show that the presence of mutual delays enhances synchronization to some extent. The zero delay o

Marius Dadarlat, Andrew S. Toms

We prove that the infinite tensor power of a unital separable C*-algebra absorbs the Jiang-Su algebra Z tensorially if and only if it contains, unitally, a subhomogeneous algebra without characters. This yields a succinct universal property for Z in a category so large that there are no unital separable C*-algebras without characters known to lie outside it.

Toshiyuki Izumi, Yoshiki Imai, Tetsuro Saso

Magnetization and energy gap of Kondo insulator YbB_{12} are calculated theoretically based on the previously proposed tight-binding model composed of Yb 5d$ε$ and 4f $Γ_8$ orbitals. It is found that magnetization curves are almost isotropic, naturally expected from the cubic symmetry, but that the gap-closing field has an anisotropy: the gap closes faster f

Katsuya Eda, Umed H. Karimov, Dušan Repovš

Using the topologist sine curve we present a new functorial construction of cone-like spaces, starting in the category of all path-connected topological spaces with a base point and continuous maps, and ending in the subcategory of all simply connected spaces. If one starts by a noncontractible n-dimensional Peano continuum for any n>0, then our construction

Emiko Hiyama, Hideo Suganuma, Masayasu Kamimura

We study the five-quark system $uudd{\bar s}$ in the standard non-relativistic quark model by solving the scattering problem. Using the Gaussian Expansion Method (GEM), we perform the almost precise multi-quark calculations by treating a very large five-body modelspace including the NK scattering channel explicitly. Although a lot of pseudostates (discretize

D. Schmeltzer, Hsuan-Yeh Chang

We report the solution of the persistent current in two coupled rings in the presence of external magnetic fluxes. We showed that the magnetic fluxes modify the global phase of the electronic wave function for multiple connected geometry formed by the coupled rings. We obtained an exact solution for the persistent current and investigated the exact solution

Shi-Hua Ouyang, Chi-Hang Lam, J. Q. You

Coherent single electron spin oscillation in a double quantum dot system driven by a magnetic electron spin resonance field is studied theoretically using a Bloch-type rate equation approach. The oscillation frequency and relaxation time obtained using typical model parameters are consistent with experiment findings. The dominant decoherence mechanism is ide

Tsuyoshi Houri, Takeshi Oota, Yukinori Yasui

Assuming the existence of a single rank-2 closed conformal Killing-Yano tensor with a certain symmetry we show that there exist mutually commuting rank-2 Killing tensors and Killing vectors. We also discuss the condition of separation of variables for the geodesic Hamilton-Jacobi equations.

Philip V. Fellman, Adam Groothuis, Sharon Mertz, Roxana Wright

The modeling of technology succession and new technology adoption includes a wide array of techniques from complexity theory. In our previous work, we applied the results of the Windrum-Birchenhall model to technology policy and technology development strategies. However, as we began to explore the Windrum-Birchenhall simulation we discovered significant lim

Mario Argeri, Pierpaolo Mastrolia

We review in a pedagogical way the method of differential equations for the evaluation of D-dimensionally regulated Feynman integrals. After dealing with the general features of the technique, we discuss its application in the context of one- and two-loop corrections to the photon propagator in QED, by computing the Vacuum Polarization tensor exactly in D. F

Omran Ahmadi, Igor E. Shparlinski, Jose Felipe Voloch

We obtain a lower bound on the multiplicative order of Gauss periods which generate normal bases over finite fields. This bound improves the previous bound of J. von zur Gathen and I. E. Shparlinski.

Shiguo Lian, Jinsheng Sun, Zhiquan Wang

A hash function is constructed based on a three-layer neural network. The three neuron-layers are used to realize data confusion, diffusion and compression respectively, and the multi-block hash mode is presented to support the plaintext with variable length. Theoretical analysis and experimental results show that this hash function is one-way, with high key

Victor Galitski, Yong Baek Kim

Recent experiments on the organic compound κ-(ET)_2Cu_2(CN)_3 have provided a promising example of a two dimensional spin liquid state. This phase is described by a two-dimensional spinon Fermi sea coupled to a U(1) gauge field. We study Kohn-Luttinger-like pairing instabilities of the spinon Fermi surface due to singular interaction processes with twice-the

S. M. Sergeev

A relation between q-oscillator R-matrix of the tetrahedron equation and decompositions of Poinkare-Birkhoff-Witt type bases for nilpotent subalgebras of U_q(sl_n) is observed.

Philip V. Fellman, Mark Strathern

Although much political capital has been made regarding the war on terrorism, and while appropriations have gotten underway, there has been a dearth of deep work on counter-terrorism, and despite massive efforts by the federal government, most cities and states do not have a robust response system. In fact, most do not yet have a robust audit system with whi

H. Ito, M. Kino, N. Kawakatu, N. Isobe

We investigate the total kinetic powers (L_{j}) and ages (t_{age}) of powerful jets of four FR II radio sources (Cygnus A, 3C 223, 3C 284, and 3C 219) by the detail comparison of the dynamical model of expanding cocoons with observed ones. It is found that these sources have quite large kinetic powers with the ratio of L_{j} to the Eddington luminosity (L_{E

Vladimir V. Kisil

We discuss parabolic versions of Euler&#39;s identity e^{it}=cos t + i sin t. A purely algebraic approach based on dual numbers is known to produce a very trivial relation e^{pt} = 1+pt. Therefore we use a geometric setup of parabolic rotations to recover the corresponding non-trivial algebraic framework. Our main tool is Moebius transformations which turn o

Jonathan J. Heckman, Cumrun Vafa

Utilizing the large N dual description of a metastable system of branes and anti-branes wrapping rigid homologous S^2&#39;s in a non-compact Calabi-Yau threefold, we study phase transitions induced by changing the positions of the S^2&#39;s. At leading order in 1/N the effective potential for this system is computed by the planar limit of an auxiliary matrix

G. E. Brown, C. -H. Lee, E. Moreno Mendez

Knowing the Kerr parameters we can make quantitative calculations of the rotational energy of black holes. We show that Nova Sco (GRO J1655 - 40), Il Lupi (4U 1543 - 47), XTE J1550 - 564 and GS 2023 + 338 are relics of gamma-ray burst (GRB) and Hypernova explosions. They had more than enough rotational energy to power themselves. In fact, they had so much en

Ted Jacobson

Microscopic state counting for a black hole in Loop Quantum Gravity yields a result proportional to horizon area, and inversely proportional to Newton&#39;s constant and the Immirzi parameter. It is argued here that before this result can be compared to the Bekenstein-Hawking entropy of a macroscopic black hole, the scale dependence of both Newton&#39;s cons

A. Danehkar

We present a brief review of the cohomological solutions of self-coupling interactions of the fields in the free Yang-Mills theory. All consistent interactions among the fields have been obtained using the antifield formalism through several order BRST deformations of the master equation. It is found that the coupling deformations halt exclusively at the sec

Alastair Hamilton, Andrey Lazarev

In this paper we establish the existence of certain structures on the ordinary and equivariant homology of the free loop space on a manifold or, more generally, a formal Poincar\'e duality space. These structures; namely the loop product, the loop bracket and the string bracket, were introduced and studied by Chas and Sullivan under the general heading `stri

D. Ostapchuk, G. Passante, R. Kobes, G. Kunstatter

In the standard geometric approach to a measure of entanglement of a pure state, $\sin^2θ$ is used, where $θ$ is the angle between the state to the closest separable state of products of normalized qubit states. We consider here a generalization of this notion to separable states consisting of products of unnormalized states of different dimension. In so doi

Oded Kenneth, Israel Klich

We explore the scattering approach to Casimir forces. Our main tool is the description of Casimir energy in terms of transition operators, as presented in Kenneth and Klich, Phys. Rev. Lett. 97, 160401 (2006). We study the convergence properties of the formula and how to utilize it, together with scattering data to compute the force. We illustrate the approa

Jeff McIntire, Ying Hu, Brian D. Serot

The loop expansion is applied to a chiral effective hadronic lagrangian; with the techniques of Infrared Regularization, it is possible to separate out the short-range contributions and to write them as local products of fields that are already present in our lagrangian. (The appropriate field variables must be re-defined at each order in loops.) The corresp