November 2007 arXiv papers

Komei Fukuda, Christophe Weibel

The objective of this paper is to study a special family of Minkowski sums, that is of polytopes relatively in general position. We show that the maximum number of faces in the sum can be attained by this family. We present a new linear equation that is satisfied by f-vectors of the sum and the summands. We study some of the implications of this equation.

P. Facchi, U. Marzolino, G. Parisi, S. Pascazio

We study a random matrix model for the statistical properties of the purity of a bipartite quantum system at a finite (fictitious) temperature. This enables us to write the generating function for the cumulants, for both balanced and unbalanced bipartitions. It also unveils an unexpected feature of the system, namely the existence of two phase transitions, c

N. L. Harshman, P. Singh

When two non-relativistic particles scatter in one dimension, they can become entangled. This entanglement process is constrained by the symmetries of the scattering system and the boundary conditions on the incoming state. Applying these constraints, three different mechanisms of entanglement can be identified: the superposition of reflected and transmitted

Yonatan Kahn, Michael Schmitt, Tim Tait

A model has been proposed in which neutral scalar particles chi, of mass 1-10 MeV, annihilate through the exchange of a light vector boson U, of mass 10-100 MeV, to produce the 511 keV line observed emanating from the center of the galaxy. The chi interacts weakly with normal matter and is a viable dark matter candidate. If the U-boson couples to quarks as w

Raouf Dridi, Michel Petitot

The goal of the present paper is to propose an enhanced ordinary differential equations solver by exploitation of the powerful equivalence method of Élie Cartan. This solver returns a target equation equivalent to the equation to be solved and the transformation realizing the equivalence. The target ODE is a member of a dictionary of ODE, that are regarded a

Francisco Jesus Castro-Jimenez, Nobuki Takayama

We give algorithms of computing bases of logarithmic cohomology groups for square-free polynomials in two variables. (Fixed typos of v1)

R. D. Ferdman, I. H. Stairs, M. Kramer, R. N. Manchester

The double pulsar system PSR J0737-3039A/B is a highly relativistic double neutron star (DNS) binary, with a 2.4-hour orbital period. The low mass of the second-formed NS, as well the low system eccentricity and proper motion, point to a different evolutionary scenario compared to other known DNS systems. We describe analysis of the pulse profile shape over

T. Y. Lam, R. K. Sheth

Nonlinear evolution can sometimes be modelled by a deterministic mapping from initial to final of the local smoothed overdensity. Perturbation theory methods base on this deterministic and local mapping and ignore the 'cloud-in-cloud' effect, while the excursion set approach methods take this nonlocality into account. We compared these methods using

Kyle R. Stewart, James S. Bullock, Risa H. Wechsler, Ariyeh H. Maller

We study the merger histories of galaxy dark matter halos using a high resolution LCDM N-body simulation. Our merger trees follow ~17,000 halos with masses M_0 = (10^11--10^13) Msun at z=0 and track accretion events involving objects as small as m = 10^10 Msun. We find that mass assembly is remarkably self-similar in m/M_0, and dominated by mergers that are

Jiunn-Wei Chen, Juven Wang

In the hadronic phase, the dominant configuration of QCD with two flavors of massless quarks is a gas of massless pions. We calculate the bulk viscosity (zeta) using the Boltzmann equation with the kinetic theory generalized to incorporate the trace anomaly. We find that the dimensionless ratio zeta/s, s being the entropy density, is monotonic increasing bel

Y. Liu, B. Chakraborty

We investigate the conformations of a semiflexible polymer confined to a square box. Results of Monte Carlo simulations show the existence of a shape transition when the persistence length of the polymer becomes comparable to the dimensions of box. An order parameter is introduced to quantify this behavior. A simple mean-field model is constructed to study t

Dorothee Petit, Ana-Vanessa Jausovec, Dan Read, Russell P. Cowburn

The potential experienced by transverse domain walls (TDWs) in the vicinity of asymmetric constrictions or protrusions in thin Permalloy nanowires is probed using spatially resolved magneto-optical Kerr effect measurements. Both types of traps are found to act as pinning centers for DWs. The strength of pinning is found to depend on the trap type as well as

William B. Kilgore

I describe a method for determining the coefficients of scalar integrals for one-loop amplitudes in quantum field theory. The method is based upon generalized unitarity and the behavior of amplitudes when the free parameters of the cut momenta approach infinity. The method works for arbitrary masses of both external and internal legs of the amplitudes. It th

Kazunori Kohri, David H. Lyth, Alessandro Melchiorri

Black hole formation may occur if the spectrum of the curvature perturbation ζincreases strongly as the scale decreases. As no such increase is observed on cosmological scales, black hole formation requires strongly positive running n' of the spectral index n, though the running might only kick in below the `cosmological scales' probed by the CMB ani

Steven B. Giddings, Mark Srednicki

Aspects of super-planckian gravitational scattering and black hole formation are investigated, largely via a partial-wave representation. At large and decreasing impact parameters, amplitudes are expected to be governed by single graviton exchange, and then by eikonalized graviton exchange, for which partial-wave amplitudes are derived. In the near-Schwarzsc

G. Benfatto, P. Falco, V. Mastropietro

We prove the Coleman's conjecture on the equivalence between the massless Sine-Gordon model with finite volume interaction and the Thirring model with a finite volume mass term.

Ghaith Ayesh Hiary

The Riemann zeta function on the critical line can be computed using a straightforward application of the Riemann-Siegel formula, Schönhage's method, or Heath-Brown's method. The complexities of these methods have exponents 1/2, 3/8 (=0.375), and 1/3 respectively. In this paper, three new fast and potentially practical methods to compute zeta are pre

Valentino Magnani

We characterize locally Lipschitz mappings and existence of Lipschitz extensions through a first order nonlinear system of PDEs. We extend this study to graded group-valued Lipschitz mappings defined on compact Riemannian manifolds. Through a simple application, we emphasize the connection between these PDEs and the Rumin complex. We introduce a class of 2-s

Ghaith Ayesh Hiary

A poly-log time method to compute the truncated theta function, its derivatives, and integrals is presented. The method is elementary, rigorous, explicit, and suited for computer implementation. We repeatedly apply the Poisson summation formula to the truncated theta function while suitably normalizing the linear and quadratic arguments after each repetition

Igor Belegradek

We study spaces obtained from a complete finite volume complex hyperbolic n-manifold M by removing a compact totally geodesic complex (n-1)-submanifold. The main result is that the fundamental group of M-S is relatively hyperbolic, relative to fundamental groups of the ends of M-S, and M-S admits a complete finite volume A-regular Riemannian metric of negati

R. Czyzykiewicz, P. Moskal, H. -H. Adam, A. Budzanowski

We present the results of measurements of the analysing power for the p(pol)p --> pp eta reaction at the excess energies of Q=10 and 36 MeV, and interpret these results within the framework of the meson exchange models. The determined values of the analysing power at both excess energies are consistent with zero implying that the eta meson is produced predom

Angelo Loinger, Tiziana Marsico

We point out that an important portion of the high energy of the cosmic rays from extragalactic sources can be attributed to a Hilbertian repulsive effect, which is a consequence of Einstein equations without cosmological term.

Marco Taoso, Gianfranco Bertone, Antonio Masiero

An extraordinarily rich zoo of non-baryonic Dark Matter candidates has been proposed over the last three decades. Here we present a 10-point test that a new particle has to pass, in order to be considered a viable DM candidate: I.) Does it match the appropriate relic density? II.) Is it {\it cold}? III.) Is it neutral? IV.) Is it consistent with BBN? V.) Doe

P. Moskal, R. Czyzykiewicz, H. -H. Adam, A. Budzanowski

We summarise measurements of the COSY-11 collaboration concerning the excitation functions of the near threshold pseudoscalar meson production in the proton-proton interaction. The results are discussed in the context of the meson-nucleon and hyperon-nucleon interactions. We conclude that the $η$-proton interaction is significantly stronger than the eta'

G. Chaudhuri, S. Das Gupta, M. Mocko

The isoscaling parameter usually denoted by $α$ depends upon both the symmetry energy coefficient and the isotopic contents of the dissociating systems. We compute $α$ in theoretical models: first in a simple mean field model and then in thermodynamic models using both grand canonical and canonical ensembles. For finite systems the canonical ensemble is much

Yehuda Hoffman, Luis A. Martinez-Vaquero, Gustavo Yepes, Stefan Gottloeber

To study the local Hubble flow, we have run constrained dark matter (DM) simulations of the Local Group (LG) in the concordance LCDM and OCDM cosmologies, with identical cosmological parameters apart from the Lambda term. The simulations were performed within a computational box of 64 h^{-1}Mpc centred on the LG. The initial conditions were constrained by th

Jen-Feng Hsu, Yeo-Yie Charng, Hsiang-nan Li

We show that few-percent Okubo-Zweig-Iizuka-rule violating effects in the quark-flavor basis for the $η$-$η'$ mixing can enhance the chiral scale associated with the $η_q$ meson few times. This enhancement is sufficient for accommodating the dramatically different data of the $B\toη^{\prime} K$ and $B\toηK$ branching ratios. We comment on other proposals

Hyuk-Jae Jang, Jing Xu, Jing Li, Biqin Huang

We demonstrate the injection and transport of spin-polarized electrons through n-type doped silicon with in-plane spin-valve and perpendicular magnetic field spin precession and dephasing ("Hanle effect") measurements. A voltage applied across the transport layer is used to vary the confinement potential caused by conduction band-bending and control

Andrea Cappelli, Ivan D. Rodriguez

We derive semiclassical ground state solutions that correspond to the quantum Hall states earlier found in the Maxwell-Chern-Simons matrix theory. They realize the Jain composite-fermion construction and their density is piecewise constant as that of phenomenological wave functions. These results support the matrix theory as a possible effective theory of th

T. G. Arshakian, R. Stepanov, R. Beck, P. Frick

The future new-generation radio telescope SKA (Square Kilometre Array) and its precursors will provide a rapidly growing number of polarized radio sources. Hundred and thousands polarized background sources can be measured towards nearby galaxies thus allowing their detailed magnetic field mapping by means of Faraday rotation measures (RM). We aim to estimat

Peter Tingley

We give a formula for the universal R-matrix of the quantized universal enveloping algebra $U_q(\g).$ This is similar to a previous formula due to Kirillov-Reshetikhin and Levendorskii-Soibelman, except that where they use the action of the braid group element $T_{w_0}$ on each representation, we show that one can instead use a system of weight preserving en

Zhuo Li, Eli Waxman

Electromagnetic energy losses of charged pions and muons suppress the expected high energy, >1E18 eV, neutrino emission from sources of ultrahigh energy, >1E19 eV, cosmic-rays. We show here that >1E19 eV photons produced in such sources by neutral pion decay may escape the sources, thanks to the Klein-Nishina suppression of the pair production cross section,

JLQCD Collaboration, H. Fukaya, S. Aoki, S. Hashimoto

We calculate mesonic two-point functions in the epsilon-regime of two-flavor QCD on the lattice with exact chiral symmetry. We use gauge configurations of size 16^3 32 at the lattice spacing a \sim 0.11 fm generated with dynamical overlap fermions. The sea quark mass is fixed at \sim 3 MeV and the valence quark mass is varied in the range 1-4 MeV, both of wh

K. Dosen, Z. Petric

A survey is given of results about coherence for categories with finite products and coproducts. For these results, which were published previously by the authors in several places, some formulations and proofs are here corrected, and matters are updated. The categories investigated in this paper formalize equality of proofs in classical and intuitionistic c

S. E. S. Andresen, F. Wu, R. Danneau, D. Gunnarsson

We have investigated radio-frequency single-electron transistor (RF-SET) operation of single-walled carbon nanotube quantum dots in the strong tunneling regime. At 4.2 K and carrier frequency 754.2 MHz, we reach a charge sensitivity of 2.3e-6 e/Hz^(1/2) over a bandwidth of 85 MHz. Our results indicate a gain-bandwidth product of 3.7e13 Hz^(3/2)/e, which is b

Gagan B. Mohanty

We report recent measurements of branching fractions and charge asymmetries of charmless hadronic B decays using the data collected with the BABAR detector at the PEP-II asymmetric energy e+e- collider.

Artem V. Galaktionov, Mikhail S. Kalenkov, Andrei D. Zaikin

We develop a detailed microscopic theory describing dc Josephson effect and Andreev bound states in superconducting junctions with a half-metal. In such systems the supercurrent is caused by triplet pairing states emerging due to spin-flip scattering at the interfaces between superconducting electrodes and the half-metal. For sufficiently clean metals we pro

Gerhard Groessing

By assuming that a particle of energy hbar.omega is actually a dissipative system maintained in a nonequilibrium steady state by a constant throughput of energy (heat flow), the exact Schroedinger equation is derived, both for conservative and nonconservative systems. Thereby, only universal properties of oscillators and nonequilibrium thermostatting are use

Bruce Blackadar, Eberhard Kirchberg

It is shown that a separable C*-algebra is inner quasidiagonal if and only if it has a separating family of quasidiagonal irreducible representations. As a consequence, a separable C*-algebra is a strong NF algebra if and only if it is nuclear and has a separating family of quasidiagonal irreducible representations. We also obtain some permanence properties

Davide Loi, Stefano Mossa, Leticia F. Cugliandolo

We follow the dynamics of an ensemble of interacting self-propelled motorized particles in contact with an equilibrated thermal bath. We find that the fluctuation-dissipation relation allows for the definition of an effective temperature that is compatible with the results obtained using a tracer particle as a thermometer. The effective temperature takes a v

Luis A. Zapata, Aina Palau, Paul Ho, Peter Schilke

We present high angular resolution ($\sim$ 3$''$) and sensitive 1.3 mm continuum, cyanogen (CN) and vinyl cyanide (C$_2$H$_3$CN) line observations made with the Submillimeter Array (SMA) toward one of most highly obscured objects of the W51 IRS2 region, W51 North. We find that the CN line exhibits a pronounced inverse P-Cygni profile indicating that

Alan Horwitz

Let $m_{2}<m_{1}$ be two given nonnegative integers with $n=m_{1}+m_{2}+1$. For suitably differentiable $f$, we let $P,Q\in π_{n}$ be the Hermite polynomial interpolants to $f$ which satisfy $P^{(j)}(a)=f^{(j)}(a),j=0,1,...,m_{1}$ and $P^{(j)}(b)=f^{(j)}(b),j=0,1,...,m_{2},$ $Q^{(j)}(a)=f^{(j)}(a),j=0,1,...,m_{2}$ and $Q^{(j)}(b)=f^{(j)}(b),j=0,1,...,m_{1}$.

J. V. Holm, H. I. Jørgensen, K. Grove-Rasmussen, J. Paaske

We have studied electron transport in clean single-walled carbon nanotube quantum dots. Because of the large number of Coulomb blockade diamonds simultaneously showing both shell structure and Kondo effect, we are able to perform a detailed analysis of tunneling renormalization effects. Thus determining the environment induced level shifts of this artificial

Christian Bogner, Stefan Weinzierl

We consider multi-loop integrals in dimensional regularisation and the corresponding Laurent series. We study the integral in the Euclidean region and where all ratios of invariants and masses have rational values. We prove that in this case all coefficients of the Laurent series are periods.

Young-Hoon Kiem, Han-Bom Moon

We compare the Kontsevich moduli space of genus 0 stable maps to projective space with the quasi-map space when $d=3$. More precisely, we prove that when $d=3$, the obvious birational map from the quasi-map space to the moduli space of stable maps is the composition of three blow-ups followed by two blow-downs. Furthermore, we identify the blow-up/down cente

Paola Marigo, Leo Girardi, Alessandro Bressan, Martin A. T. Groenewegen

We present a large set of theoretical isochrones, whose distinctive features mostly reside on the greatly improved treatment of the thermally pulsing asymptotic giant branch (TP-AGB) phase. Essentially, we have coupled the TP-AGB tracks described in Paper I, at their stages of pre-flash quiescent H-shell burning, with the evolutionary tracks for the previous

A. Cieply, J. Smejkal

We present an exact solution to the $K^{-}$-proton bound state problem formulated in the momentum space. The 1s level characteristics of the kaonic hydrogen are computed simultaneously with the available low energy $K^{-}p$ data. In the strong interaction sector the meson-baryon interactions are described by means of an effective (chirally motivated) separab

S. Ali, F. M. Mahomed, Asghar Qadir

The linearization of complex ordinary differential equations is studied by extending Lie&#39;s criteria for linearizability to complex functions of complex variables. It is shown that the linearization of complex ordinary differential equations implies the linearizability of systems of partial differential equations corresponding to those complex ordinary di

Igor V. Lerner, Vladimir I. Yudson, Igor V. Yurkevich

We have studied low-temperature properties of interacting electrons in a one-dimensional quantum wire (Luttinger liquid) side-hybridized with a single-level impurity. The hybridization induces a back-scattering of electrons in the wire which strongly affects its low energy properties. Using a one-loop renormalization group approach valid for a weak electron-

S. Ali, F. M. Mahomed, Asghar Qadir

The Lie linearizability criteria are extended to complex functions for complex ordinary differential equations. The linearizability of complex ordinary differential equations is used to study the linearizability of corresponding systems of two real ordinary differential equations. The transformations that map a system of two nonlinear ordinary differential e

F. Palumbo

I recently proposed a method of bosonization valid for systems of an even number of fermions whose partition function is dominated at low energy by bosonic composites. This method respects all symmetries, in particular fermion number conservation. I extend it to treat odd systems and excitations involving unpaired fermions.

Prabhakar G. Vaidya, Sajini Anand P. S, Nithin Nagaraj

Singular Value Decomposition (SVD) is a powerful tool in linear algebra.We propose an extension of SVD for both the qualitative detection and quantitative determination of nonlinearity in a time series. The paper illustrates nonlinear SVD with the help of data generated from nonlinear maps and flows (differential equations).

Claudio Nassif

The paper aims to introduce a new symmetry principle in the space-time geometry through the elimination of the classical idea of rest and by including a universal minimum limit of speed in the subatomic world. Such a limit, unattainable by particles, represents a preferred reference frame associated with a universal background field that breaks Lorentz symme

Thomas Barthel, Ulrich Schollwöck

We discuss relaxation in bosonic and fermionic many-particle systems. For integrable systems, the time evolution can cause a dephasing effect, leading for finite subsystems to certain steady states. We give an explicit derivation of those steady subsystem states and devise sufficient prerequisites for the dephasing to take place. We also find simple scenario

The BABAR Collaboration, B. Aubert

We present a measurement of the branching fraction and photon energy spectrum for the decay B --> X_s gamma using data from the BaBar experiment. The data sample corresponds to an integrated luminosity of 210 fb^{-1}, from which approximately 680 000 BB events are tagged by a fully reconstructed hadronic decay of one of the B mesons. In the decay of the seco

Chang-Zheng Yuan

In this talk, we present the recent results on charmonium decays from the BES experiment at the BEPC collider. The analyses are based on a 14 million psi(2S) events data sample. We report results on leptonic decays, hadronic decays, and radiative decays of psi(2S), as well as hadronic decays of chi_cJ states and rare or forbidden decays of J/psi.

S. Paulin-Henriksson, A. Amara, L. Voigt, A. Refregier

The control of systematic effects when measuring galaxy shapes is one of the main challenges for cosmic shear analyses. In this context, we study the fundamental limitations on shear accuracy due to the measurement of the Point Spread Function (PSF) from the finite number of stars. In order to do that, we translate the accuracy required for cosmological para

Michal Kreps

We review recent results in heavy quark hadron spectroscopy at the Tevatron. With increasing data samples the Tevatron experiments start to uncover information on the b-hadrons. Most important are the first observations of the narrow Bs** as well as Sigma_b, Sigma_b* and Xi_b- baryons. In addition we present updated results on the narrow B** and Bc mesons.

John G. Hartnett, Koichi Hirano

A Fourier analysis on galaxy number counts from redshift data of both the Sloan Digital Sky Survey and the 2dF Galaxy Redshift Survey indicates that galaxies have preferred periodic redshift spacings of $Δz =$ 0.0102, 0.0246, and 0.0448 in the SDSS and strong agreement with the results from the 2dF GRS. The redshift spacings are confirmed by the mass density

Elena Caceres, Raphael Flauger, Matthias Ihl, Timm Wrase

We present new supergravity backgrounds generated by N_c D5-branes, wrapping the S^2 of the resolved conifold, in the presence of N_f = 2 N_c smeared flavor D5-branes. The smearing allows us to take their backreaction on the geometry into account. We discuss the consistency, stability, and supersymmetry of these types of setups. We find near horizon geometri

Atilla Yilmaz

We consider random walk $(X_n)_{n\geq0}$ on $\mathbb{Z}^d$ in a space--time product environment $ω\inΩ$. We take the point of view of the particle and focus on the environment Markov chain $(T_{n,X_n}ω)_{n\geq0}$ where $T$ denotes the shift on $Ω$. Conditioned on the particle having asymptotic mean velocity equal to any given $ξ$, we show that the empirical

Lu-Xin Liu

The dynamics of a vortex string, which describes the Nambu-Goldtone modes of the spontaneous breakdown of the target space D=4, N=1 supersymmetry and internal $U(1)_R$ symmetry to the world sheet ISO(1,1) symmetry, is constructed by using the approach of nonlinear realization. The resulting action describing the low energy oscillations of the string into the

Akaki Tikaradze

In this paper we consider an infinitesimal Hecke algebra of $sl_2$ in positive characteristic. We show that it is a finitely generated module over its center, and the smooth and the Azumaya loci of its center coincide.

Abdellatif Zaidi, Shivaprasad Kotagiri, J. Nicholas Laneman, Luc Vandendorpe

We consider a state-dependent full-duplex relay channel with the state of the channel non-causally available at only the relay. In the framework of cooperative wireless networks, some specific terminals can be equipped with cognition capabilities, i.e, the relay in our model. In the discrete memoryless (DM) case, we derive lower and upper bounds on channel c

David S. Spiegel, Kristen Menou, Caleb A. Scharf

According to the standard liquid-water definition, the Earth is only partially habitable. We reconsider planetary habitability in the framework of energy-balance models, the simplest seasonal models in physical climatology, to assess the spatial and temporal habitability of Earth-like planets. We quantify the degree of climatic habitability of our models wit

M. Baker

We use effective magnetic SU(N) pure gauge theory with cutoff M and fixed gauge coupling g_m to calculate non-perturbative magnetic properties of the deconfined phase of SU(N) Yang-Mills theory. We obtain the response to an external closed loop of electric current by reinterpreting and regulating the calculation of the one loop effective potential in Yang-Mi

Veronique Godin

Chas and Sullivan have defined an intersection-type product on the homology of the free loop space LM of an oriented manifold M. In this paper we show how to extend this construction to a topological conformal field theory of degree d. In particular, we get operations on the homology of LM which are parameterized by the homology of the moduli space of open-c

Shinsuke Iwao

A box-ball system with more than one kind of balls is obtained by the generalized periodic discrete Toda equation (pd Toda eq.). We study the pd Toda equation in view of algebraic geometry. The time evolution of pd Toda eq. is linearized on an algebraic variety, and theta function solutions are obtained.

D. Bozi, J. M. P. Carmelo, K. Penc, P. D. Sacramento

A dynamical theory which accounts for all microscopic one-electron processes is used to study the spectral function of the 1D Hubbard model for the whole $(k, ω)$-plane, beyond previous studies which focused on the weight distribution in the vicinity of the singular branch lines only. While our predictions agree with those of the latter studies concerning th

Oleg Eroshkin

By the classical result of E. Bedford, a real-analytic non-generic manifold is pluripolar. We extend this result for manifolds of the Gevrey class. This also gives a generalization of the recent result of D. Coman, N. Levenberg and E. Poletsky on pluripolarity of curves of the Gevrey class.

Michael A. Reid, Brenda C. Matthews

We report interferometric observations of the high-mass star-forming object IRAS 23033+5951. Our observations reveal two massive molecular cloud cores, designated IRAS 23033+5951-MMS1 and IRAS 23033+5951-MMS2. MMS1 has already formed a massive protostar and MMS2 appears to be on the verge of doing so. The latter core may be an example of a massive analogue t

Paulo C. C. Freire

We present here the results of Arecibo timing of PSR B1516+02B, a 7.95-ms pulsar in a binary system with a ~0.17 solar mass companion and an orbital period of 6.85 days located in the globular cluster M5. The eccentricity of the orbit (e = 0.14) has allowed a measurement of the rate of advance of periastron: (0.0136 +/- 0.0007) degrees per year. It is very l

C. J. Schrijver, M. L. DeRosa, T. Metcalf, G. Barnes

Solar flares and coronal mass ejections are associated with rapid changes in field connectivity and powered by the partial dissipation of electrical currents in the solar atmosphere. A critical unanswered question is whether the currents involved are induced by the motion of pre-existing atmospheric magnetic flux subject to surface plasma flows, or whether t

G. Brunner, K. Sheth, L. Armus, M. Wolfire

We have mapped the warm molecular gas traced by the H_2 S(0) - H_2 S(5) pure rotational mid-infrared emission lines over a radial strip across the nucleus and disk of M51 (NGC 5194) using the Infrared Spectrograph (IRS) on the Spitzer Space Telescope. The six H_2 lines have markedly different emission distributions. We obtained the H_2 temperature and surfac

Kenneth M. Hanson

Least-squares data analysis is based on the assumption that the normal (Gaussian) distribution appropriately characterizes the likelihood, that is, the conditional probability of each measurement d, given a measured quantity y, p(d | y). On the other hand, there is ample evidence in nuclear physics of significant disagreements among measurements, which are i

Brian A. Benson

We consider the structure of a variation of the Fibonacci sequence which is determined by a Bernoulli process. The associated structure of all Bernoulli variations of the Fibonacci sequence can be represented by a directed binary tree, which we denote X, with vertex labels representing the specific state of the recurrence variation. Since X is a binary tree,

F. I. Cooperstock, S. Tieu

We consider the gravitational collapse of a spherically symmetric ball of dust in the general relativistic weak gravity regime. The velocity of the matter as viewed by external observers is compared to the velocity gauged by local observers. While the comparison in the case of very strong gravity is seen to follow the pattern familiar from studies of test pa

Leonid Petrov

Neither astronomical technique, including VLBI, can measure nutation directly. Estimates of parameters of the nutation model are produced by solving the LSQ problem of adjusting millions parameters using estimates of group delay. The choice of the mathematical model for nutation used in the estimation process of analysis of group delays affects our ability t

Renato Higa

I present preliminary results of effective field theory applied to nuclear cluster systems, where Coulomb interactions play a significant role.

C. Pinte, F. Menard, J. P. Berger, M. Benisty

For young Herbig Ae/Be stars, near-infrared interferometric measurements have revealed a correlation between the luminosity of the central object and the position of the disk inner rim. This correlation breaks down for the cooler T Tauri stars, a fact often interpreted in terms of disks with larger inner radii. In most cases, the conversion between the obser

M. Göckeler, Philipp Hägler, R. Horsley, Y. Nakamura

Algorithmic progress in recent years made it possible to simulate QCD with Nf=2 flavours of O(a)-improved Wilson fermions at very light quark masses. We present the current results for baryon spectrum states, the nucleon axial coupling and the lowest moment of unpolarised nucleon structure functions. Special emphasis is given to a comparison of our calculati

Feryal Ozel, Tolga Guver, Ersin Gogus

Anomalous X-ray Pulsars (AXPs) belong to a class of neutron stars believed to harbor the strongest magnetic fields in the universe, as indicated by their energetic bursts and their rapid spindowns. We have developed a theoretical model that takes into account processes in the atmospheres and magnetospheres of ultramagnetic neutron stars, as well as the effec

Stephane Job, Francisco Melo, Adam Sokolow, Surajit Sen

The features of solitary waves observed in horizontal monodisperse chain of barely touching beads not only depend on geometrical and material properties of the beads but also on the initial perturbation provided at the edge of the chain. An impact of a large striker on a monodisperse chain, and similarly a sharp decrease of bead radius in a stepped chain, ge

Sungho Han, Pradeep Kumar, H. Eugene Stanley

We perform molecular dynamics simulations to investigate the diffusive motion of TIP5P water in the direction perpendicular to the two hydrophobic confining walls. To calculate the diffusion coefficient, we use the concept of the characteristic residence time which is calculated from the exponential decay of the residence time probability distribution functi

Evgenya Shkolnik, David A. Bohlender, Gordon A. H. Walker, Andrew Collier Cameron

Evidence suggesting an observable magnetic interaction between a star and its hot Jupiter appears as a cyclic variation of stellar activity synchronized to the planet&#39;s orbit. In this study, we monitored the chromospheric activity of 7 stars with hot Jupiters using new high-resolution echelle spectra collected with ESPaDOnS over a few nights in 2005 and

Bjorn Poonen

Let G be a commutative algebraic group over Q. Let Gamma be a subgroup of G(Q) contained in the union of the compact subgroups of G(Q_p). We formulate a guess for the dimension of the closure of Gamma in G(Q_p), and show that its correctness for certain tori is equivalent to Leopoldt&#39;s conjecture.

Nicolas Doiron-Leyraud, Louis Taillefer

In a recent Comment [arXiv:0711.4654], Y. Ando raises two valid issues in relation to our low-temperature heat transport study of YBa$_2$Cu$_3$O$_y$ across the insulator-to-superconductor boundary: 1) the possible role of twin boundaries in scattering phonons; 2) the best fitting procedure for extracting a fermionic (linear) term from the data. In this Reply

H. Polinder

We have constructed the leading order strangeness S=-1,-2 baryon-baryon potential in a chiral effective field theory approach. The chiral potential consists of one-pseudoscalar-meson exchanges and non-derivative four-baryon contact terms. The potential, derived using SU(3)_f symmetry constraints, contains six independent low-energy coefficients. We have solv

M. Dubinin, A. Sukachev

We consider the K^0 - \bar K^0 and B^0 - \bar B^0 mixings in the MSSM with the two-Higgs-doublet scalar sector featuring explicit CP violation, and the Yukawa sector of type II. In the case of strong mixing between CP-odd and CP-even states the existence of light charged Higgs is allowed in the model. The mass splitting Δm_{LS} and the amount of indirect CP

L. Amendola, M. Gasperini, C. Ungarelli

A model of non-local dilaton interactions, motivated by string duality symmetries, is applied to a scenario of &#34;coupled quintessence&#34; in which the dilaton dark energy is non-locally coupled to the dark-matter sources. It is shown that the non-local effects tend to generate a backreaction which -- for strong enough coupling -- can automatically compen

Vikas Anant, Ayman F. Abouraddy, Karl K. Berggren

Novel optical phenomena, including electromagnetically induced transparency, slow light, superluminal light propagation, have recently been demonstrated in diverse physical implementations. These phenomena are challenging to realize in practical systems because they require quantum coherence as well as careful preparation and control of prescribed quantum st

Ian J Leary

Computations in the cohomology of finite groups.

Stefan Sellner, Alexander Gerlach, Stefan Kowarik, Frank Schreiber

We present a comparative study of the growth of the technologically highly relevant gate dielectric and encapsulation material aluminum oxide in inorganic and also organic heterostructures. Atomic force microscopy studies indicate strong similarities in the surface morphology of aluminum oxide films grown on these chemically different substrates. In addition

Ian J Leary, Muge Saadetoglu

For each subcomplex of the standard CW-structure on any torus, we compute the homology of a certain infinite cyclic regular covering space. In all cases when the homology is finitely generated, we also compute the cohomology ring. For aspherical subcomplexes of the torus our computation gives the homology and cohomology of Bestvina-Brady groups. We compute t

Ian J Leary

Under mild conditions on the space X, we describe the additive structure of the integral cohomology of the space $X^p \times_{C_p}EC_p$ in terms of the cohomology of X. We give weaker results for other similar spaces, and deduce various corollaries concerning the cohomology of finite groups.

I. J. Leary, B. Schuster

We study the question of whether the Morava K-theory of the classifying space of an elementary abelian group V is a permutation module (in either of two distinct senses) for the automorphism group of V. We use Brauer characters and computer calculations. We construct and implement an algorithm for finding permutation submodules of maximal dimension inside mo

I. J. Leary, B. Schuster, N. Yagita

We show that certain subrings of the cohomology of a finite p-group P may be realised as the images of restriction from suitable virtually free groups. We deduce that the cohomology of P is a finite module for any such subring. Examples include the ring of `universally stable elements&#39; defined by Evens and Priddy, and rings of invariants such as the mod-

David J Green, Ian J Leary

The mod-p cohomology ring of the extraspecial p-group of exponent p is studied for odd p. We investigate the subquotient ch(G) generated by Chern classes modulo the nilradical. The subring of ch(G) generated by Chern classes of one-dimensional representations was studied by Tezuka and Yagita. The subring generated by the Chern classes of the faithful irreduc

Warren Dicks, Ian J Leary

A right-angled Coxeter group is a group with a given set of generators of order two, subject only to the relations that certain pairs of the generators commute. Various papers have shown how homological properties of the Coxeter group are related to homological properties of the simplicial complex whose simplices are the sets of commuting generators. Using t

H. H. Glover, I. J. Leary, C. B. Thomas

We give a definition of the Yagita invariant at a prime p of an arbitrary group G, and compute the invariant for each prime for the general linear groups over any integrally closed subring of the complex numbers. We also compute the invariants for special linear groups over the same rings, except in some cases when both the degree of the linear group and the