July 2002 arXiv papers — page 15

K. G. Selivanov, T. N. Tomaras

The enhancement in the decay rate of the Kaluza-Klein vacuum due to the presence of a brane is studied, both in the test brane approximation and beyond it. Spontaneous brane materialization in the Kaluza-Klein vacuum is also described.

J. G. Esteve

The origin of the anomalies is analyzed. It is shown that they are due to the fact that the generators of the symmetry do not leave invariant the domain of definition of the Hamiltonian and then a term, normally forgotten in the Heisenberg equation, gives an extra contribution responsible for the non conservation of the charges. This explanation is equivalen

H. Weigel

In this talk I review studies of hadron structure functions in bosonized chiral quark models. Such models require regularization and I show that the two--fold Pauli--Villars regularization scheme not only fully regularizes the effective action but also leads the scaling laws for structure functions. This scheme is consistent with other computations of the pi

Qaisar Shafi, Zurab Tavartkiladze

We discuss how an anomalous U(1) symmetry when appended to MSSM and SUSY GUTs [e.g. SU(5)] can help overcome a variety of puzzles related to charged fermion masses and mixings, flavor changing processes, proton decay and neutrino oscillations. Proton lifetime for SU(5) GUT, in particular, is predicted in a range accessible to the ongoing or planned searches.

M. Beneke

In this talk I report recent results on hadronic B decays obtained with the QCD factorization approach. In the first part I update the fit of the Wolfenstein parameters (\barρ,\barη) to CP-averaged B -> pi pi, pi K branching fractions, and give the correlation between the time-dependent and direct CP asymmetry in B_d -> pi^+pi^- decay. In the second part I p

V. E. Lyubovitskij, P. Wang, Th. Gutsche, Amand Faessler

We apply the perturbative chiral quark model at one loop to calculate the strange form factors of the nucleon. A detailed numerical analysis of the strange magnetic moments and radii of the nucleon, and also the momentum dependence of the form factors is presented.

Stanislav Dubnicka, Anna-Zuzana Dubnickova, Peter Weisenpacher

General solution of asymptotic conditions, derived previously for n vector-meson parametrization of electromagnetic form factor of any strongly interacting particle with asymptotics 1/t^m (m<n) and combined with a form factor normalization condition, is presented. The special case of m=n and the solution of asymptotic conditions without any form factor norma

V. G. Krivokhijine, A. V. Kotikov

We reanalyze deep inelastic scattering data of BCDMS Collaboration by including proper cuts of ranges with large systematic errors. We perform also the fits of high statistic deep inelastic scattering data of BCDMS, SLAC, NM and BFP Collaborations taking the data separately and in combined way and find good agreement between these analyses. We extract the va

M. R. Pennington

Why should we study mesons in 2002? Two approaches to relating quark and gluon dynamics to hadron physics, namely QCD sum rules and effective field theories, are briefly discussed. These are linked by progress in the study of strong QCD, both by lattice Monte Carlo methods and in the continuum. These provide the translation from quark dynamics to hadron phys

S. Scopetta, V. Vento

An approach is described to calculate Generalized Parton Distributions (GPDs) in Constituent Quark Models (CQM). The GPDs are obtained from wave functions to be evaluated in a given CQM. The general relations linking the twist-two GPDs to the form factors and to the leading twist quark densities are recovered. Results for the leading twist, unpolarized GPD i

A. Giovannini, R. Ugoccioni

Continuing previous work, forward-backward multiplicity correlations are studied in asymmetric collisions in the framework of the weighted superposition mechanism of different classes of events. New parameters for the asymmetric clan distribution and for the particle leakage from clans in one hemisphere to the opposite one are introduced to effectively class

A. Szczurek

We model large angle intermediate energy pion-pion scattering by the pQCD two-gluon (2g) exchange contribution and discuss the onset of the dominance of the Glauber-Gribov-Landshoff (GGL) component. The pQCD 2g exchange contribution becomes substantial already at $|t|\sim$ 1 GeV^{2}, but the pQCD exchange dominance is deferred to $|t|\sim$ 3 GeV^{2} because

M. L. Nekrasov

The modified perturbation theory (MPT), based on direct expansion of probabilities instead of amplitudes, allows one to avoid divergences in the phase-space integrals resulting from production and decay of unstable particles. In the present paper the range of applicability of MPT is determined numerically in the case of the process $e^+e^- \to (γ,Z) \to t\ba

Y. Kurihara

A new method to construct event-generators based on next-to-leading order QCD matrix-elements and leading-logarithmic parton showers is proposed. Matrix elements of loop diagrams as well as those of a tree level can be generated using an automatic system. A soft/collinear singularity is treated using a leading-log subtraction method. Higher order re-summatio

Charanjit S. Aulakh

We propose Susy GUTs have a UV attractor at E ~ Lambda_{cU} ~ 10^{17} GeV where gauge symmetries ``confine&#39;&#39; forming singlet condensates at scales E ~ Lambda_{cU}. The length l_U ~ Lambda_{cU}^{-1} characterizies the size of gauge non- singlet particles yielding a picture dual to the Dual Standard model of Vachaspati. This Asymptotic Slavery (AS) fix

Zheng-Tao Wei, Mao-Zhi Yang

Again, this preprint has been combined with hep-ph/0207106, which is co-authored by both of us. Therefore, this preprint has been withdrawn. Readers are welcome to refer to hep-ph/0207106.

J. Shigemitsu, S. Collins, C. T. H. Davies, J. Hein

Semileptonic, B --> pi, l nubar, decays are studied on quenched anisotropic lattices using tree-level tadpole improved Symanzik glue, NRQCD heavy quark and D234 light quark actions. Constrained fitting methods are applied to extract groundstate contributions to two-point and three-point correlators. We agree with previous lattice determinations of the form f

Enrico Calzavarini, Laura Sartori, Fabio Schifano, Raffaele Tripiccione

We discuss some computational problems associated to matched filtering of experimental signals from gravitational wave interferometric detectors in a parallel-processing environment. We then specialize our discussion to the use of the APEmille and apeNEXT processors for this task. Finally, we accurately estimate the performance of an APEmille system on a com

Peter B. Groves, Paul R. Anderson, Eric D. Carlson

A method for computing the stress-energy tensor for the quantized, massless, spin 1/2 field in a general static spherically symmetric spacetime is presented. The field can be in a zero temperature state or a non-zero temperature thermal state. An expression for the full renormalized stress-energy tensor is derived. It consists of a sum of two tensors both of

Jochen L. Leidner

Information needs are naturally represented as questions. Automatic Natural-Language Question Answering (NLQA) has only recently become a practical task on a larger scale and without domain constraints. This paper gives a brief introduction to the field, its history and the impact of systematic evaluation competitions. It is then demonstrated that an NLQA sy

E. Cuansing, H. Nakanishi

The eigenvalue spectra of the transition probability matrix for random walks traversing critically disordered clusters in three different types of percolation problems show that the random walker sees a developing Euclidean signature for short time scales as the local, full-coordination constraint is iteratively applied.

W. Montfrooij, M. C. Aronson, B. D. Rainford, J. A. Mydosh

We present the results of inelastic neutron scattering measurements, performed near the antiferromagnetic quantum critical point in Ce(Ru_{0.24} Fe_{0.76})_2 Ge_2. Both local and long range fluctuations of the local moments are observed, but due to the Kondo effect only the latter are critical. We propose a phenomenological expression which fits the energy $

Petter Holme

We investigate growing networks based on Barabasi and Albert&#39;s algorithm for generating scale-free networks, but with edges sensitive to overload breakdown. the load is defined through edge betweenness centrality. We focus on the situation where the average number of connections per vertex is, as the number of vertices, linearly increasing in time. After

S. Sivasubramanian, A. Widom, Y. N. Srivastava

The rise in temperature from the adiabatic compression of a bubble is computed in thermodynamic mean field (van der Waals) theory. It is shown that the temperature rise is higher for the noble gas atoms than for more complex gas molecules. The adiabatic temperature rise is shown to be sufficient for producing sonoluminescence via the excited electronic state

K. Ishida, D. E. MacLaughlin, O. O. Bernal, R. H. Heffner

Muon spin relaxation (muSR) experiments have been carried out at low temperatures in the non-Fermi-liquid heavy-fermion compound YbRh_2Si_2. The longitudinal-field muSR relaxation function is exponential, indicative that the dynamic spin fluctuations are homogeneous. The relaxation rate 1/T_1 varies with applied field as H^{-y}, y = 1.0 \pm 0.1, which implie

Qiuping A. Wang

Although Gödel&#39;s incompleteness theorem made mathematician recognize that no axiomatic system could completely prove its correctness and that there is an eternal hole between our knowledge and the world, physicists so far continue to work on the approaches based on the hypothesis to completely or approximately know the systems of interest. In this paper,

D. E. MacLaughlin, M. S. Rose, B. -L. Young, O. O. Bernal

Zero-field muSR experiments in the heavy-fermion alloys Ce_{1-x}La_xAl_3, x = 0 and 0.2, examine a recent proposal that the system exhibits a strong anisotropic Kondo effect. We resolve a damped oscillatory component for both La concentrations, indicative of disordered antiferromagnetism. For x = 0.2 the oscillation frequency decreases smoothly with increasi

D. E. MacLaughlin, M. S. Rose, Ben-Li Young, O. O. Bernal

Magnetic resonance (muSR and NMR) studies of f-electron non-Fermi-liquid (NFL) materials give clear evidence that structural disorder is a major factor in NFL behavior. Longitudinal-field muSR relaxation measurements at low fields reveal a wide distribution of muon relaxation rates and divergences in the frequency dependence of spin correlation functions in

L. Correale, E. Marinari, V. Martin-Mayor

We present a general and powerful numerical method useful to study the density matrix of spin models. We apply the method to finite dimensional spin glasses, and we analyze in detail the four dimensional Edwards-Anderson model with Gaussian quenched random couplings. Our results clearly support the existence of replica symmetry breaking in the thermodynamica

Z. Burda, J. Erdmann, B. Petersson, M. Wattenberg

We discuss the scaling properties of free branched polymers. The scaling behaviour of the model is classified by the Hausdorff dimensions for the internal geometry: d_L and d_H, and for the external one: D_L and D_H. The dimensions d_H and D_H characterize the behaviour for long distances while d_L and D_L for short distances. We show that the internal Hausd

Alexey Kovalev, Arne Brataas, Gerrit E. W. Bauer

The spin-transfer in biased disordered ferromagnet (F) - normal metal (N) systems is calculated by the diffusion equation. For F1-N2-F2 and N1-F1-N2-F2-N3 spin valves, the effect of spin-flip processes in the normal metal and ferromagnet parts are obtained analytically. Spin-flip in the center metal N2 reduces the spin-transfer, whereas spin-flip in the oute

Xuedong Hu, S. Das Sarma

We review our work on the interplay between non-resonant gates and solid state environment in various solid state quantum computer architectures and the resulting gate errors. Particular, we show that adiabatic condition can be satisfied in small quantum dots, while higher energy excited states can play important role in the evolution of a Cooper-pair-box ba

K. Takaki, A. Koizumi, T. Hanaguri, M. Nohara

The microwave complex surface impedance Z_s of Y(Ni_{1-x}Pt_x)_2B_2C was measured at 0.5 K under magnetic fields H up to 7T. In nominally pure YNi_2B_2C, which is a strongly anisotropic s-wave superconductor, the flux flow resistivity ρ_f calculated from Z_s was twice as large as that expected from the conventional normal-state vortex core model. In Pt-doped

J. van Mourik, D. Saad

The problem of vertex coloring in random graphs is studied using methods of statistical physics and probability. Our analytical results are compared to those obtained by exact enumeration and Monte-Carlo simulations. We critically discuss the merits and shortcomings of the various methods, and interpret the results obtained. We present an exact analytical ex

T. Castan, A. Planes, A. Saxena

For multi-stage, displacive structural transitions we present a general framework that accounts for various intermediate modulated phases, elastic constant, phonon and related thermodynamic anomalies. Based on the presence or absence of modulated phases we classify these transformations in four categories and apply this approach to four different representat

I. I. Smolyaninov, A. V. Zayats, A. Stanishevsky, C. C. Davis

We report first observation of photon tunneling gated by light at a different wavelength in an artificially created array of nanometer scale cylindrical channels in a thick gold film. Polarization properties of gated light provide strong proof of the enhanced nonlinear optical mixing in nanometric channels involved in the process. This suggests the possibili

A. Bharathi, S. Jemima Balaselvi, M. Premila, T. N. Sairam

Following the recent theoretical prediction of superconductivity in hole doped LiBC by Rosner et al [1], we have attempted to synthesise Li deficient LixBC (x = 1, 0.8, 0.6 and 0.4) and look for superconductivity in this system. Our synthesis procedure, following the recipe for MgB2, involves reaction of elemental components in a Ta crucible at 900o C under

E. V. Sampathkumaran

We report the results of ac susceptibility chi measurements for various compositions of the series, Ce_2Pd_{1-x}Co_xSi_3, in the polycrystalline form, which has been previously reported to undergo a transformation from magnetic ordering to non-magnetic Kondo lattice behavior as x is varied from 0 to 1. A finding of emphasis here is that the features in ac ch

J. Androulakis, N. Katsarakis, Z. Viskadourakis, J. Giapintzakis

We present a comparative study of both the magnetic and magnetotransport properties for two members of the perovskite solid solution LaNixCo1-xO3 (x=0.2, 0.6) located on opposite sides of the chemically induced metal-to-insulator transition. LaNi0.6Co0.4O3 exhibits metallic behavior and small but negative magnetoresistance, whereas LaNi0.2Co0.8O3 exhibits se

A. Garcia-Lekue, J. M. Pitarke, E. V. Chulkov, A. Liebsch

The combined effect of single-particle and collective surface excitations in the decay of image-potential states on Ag surfaces is investigated, and the origin of the long-standing discrepancy between experimental measurements and previous theoretical predictions for the lifetime of these states is elucidated. Although surface-plasmon excitation had been exp

S. B. Roy, S. Chaudhary, M. K. Chattopadhyay, P. Chaddah

We present results of magnetization measurements showing that the magnetic response of the antiferromagnetic state of SmMn_2Ge_2 depends on the path used in the field(H)-temperature(T) phase space to reach this state. Distinct signature of metastablity is observed in this antiferromagnetic state when obtained via field-cooling/field-warming paths. The isothe

Yuval Gefen

Recent experiments involving semiconducting quantum dots embedded in Aharonov-Bohm interferometry setups suggest that information concerning the phase of electron wavefunctions can be obtained from transport measurements. Here we review the basics of the theory of electron interferometry, some of the relevant experimental results, and recent theoretical deve

M. N. Kiselev, K. Kikoin, L. W. Molenkamp

It is shown that the resonance Kondo tunneling through a double quantum dot (DQD) with even occupation and singlet ground state may arise at a strong bias, which compensates the energy of singlet/triplet excitation. Using the renormalization group technique we derive scaling equations and calculate the differential conductance as a function of an auxiliary d

L. -G. Strolger, R. C. Smith, N. B. Suntzeff, M. M. Phillips

SN 1999aw was discovered during the first campaign of the Nearby Galaxies Supernova Search (NGSS) project. This luminous, slow-declining (Delta m_{15} (B) = 0.81 \pm 0.03) Type Ia supernova was noteworthy in at least two respects. First, it occurred in an extremely low luminosity host galaxy that was not visible in the template images, nor in initial subsequ

J. S. Lazendic, M. Wardle, A. J. Green, J. B. Whiteoak

We have undertaken a study of radio and infrared molecular-line emission towards several SNRs in order to investigate molecular signatures of SNR shocks, and to test models for OH maser production in SNRs. Here we present results on G349.7+0.2.

L. J. Tacconi, R. Genzel, D. Lutz, D. Rigopoulou

We present new near-infrared Keck and VLT spectroscopic data on the stellar dynamics in late stage, ultra-luminous infrared galaxy (ULIRG) mergers . We now have information on the structural and kinematic properties of 18 ULIRGs, 8 of which contain QSO-like active galactic nuclei. The host properties (velocity dispersion, effective radius, effective surface

Masao Sako, Ali Kinkhabwala, Steven M. Kahn, Ehud Behar

High resolution spectroscopic observations of Seyfert galaxies with Chandra and XMM-Newton allows us to study the detailed ionization and thermal structures of the X-ray absorbing/emitting material in the circumnuclear environment. The vast improvement in the spectral resolving power by more than an order of magnitude enables us, for the first time, to unamb

J. Christensen-Dalsgaard

Oscillations detected on the solar surface provide a unique possibility for investigations of the interior properties of a star. Through major observational efforts, including extensive observations from space, as well as development of sophisticated tools for the analysis and interpretation of the data, we have been able to infer the large-scale structure a

A. Eff-Darwich, S. G. Korzennik, S. J. Jimenez-Reyes, F. Perez Hernandez

We have analyzed changes in the acoustic oscillation eigenfrequencies measured over the past 7 years by the GONG, MDI and LOWL instruments. The observations span the period from 1994 to 2001 that corresponds to half a solar cycle, from minimum to maximum solar activity. These data were inverted to look for a signature of the activity cycle on the solar strat

Adam Burrows

In this brief contribution, I touch on a subset of recent efforts in spectral and opacity modeling aimed at improving our understanding of brown dwarfs, L dwarfs, and T dwarfs. I discuss theoretical calculations of the alkali line profiles, newly generated CrH opacities, new evidence for refractory rainout in T dwarfs from optical spectral measurements, and

Michael S. Brotherton, Scott M. Croom, Carlos De Breuck, Robert H. Becker

We report the correct classification of an overlooked Fanaroff-Riley class II radio-loud quasar with broad absorption lines, only the second such object so identified. The rare properties of this quasar, LBQS 1138-0126, are twice overlooked. First LBQS 1138-0126 was found in the Large Bright Quasar Survey but only noted as a possible broad absorption line qu

Eric F. Bell

Rest-frame far-ultraviolet (FUV) luminosities form the `backbone&#39; of our understanding of star formation at all cosmic epochs. FUV luminosities are typically corrected for dust by assuming that extinction indicators which have been calibrated for local starbursting galaxies apply to all star-forming galaxies. I present evidence that `normal&#39; star-for

Axel Brandenburg

The connection between helically isotropic MHD turbulence and mean-field dynamo theory is reviewed. The nonlinearity in the mean-field theory is not yet well established, but detailed comparison with simulations begin to help select viable forms of the nonlinearity. The crucial discriminant is the magnetic helicity, which is known to evolve only on a slow re

Axel Brandenburg, Wolfgang Dobler

Recent progress in the theory of solar and stellar dynamos is reviewed. Particular emphasis is placed on the mean-field theory which tries to describe the collective behavior of the magnetic field. In order to understand solar and stellar activity, a quantitatively reliable theory is necessary. Much of the new developments center around magnetic helicity con

Steven H. Saar, Axel Brandenburg

We explore the dependence of the amplitude of stellar dynamo cycle variability (as seen in the Mount Wilson Ca II HK timeseries data) on other stellar parameters. We find that the fractional cycle amplitude A_cyc (i.e. the ratio of the peak-to-peak variation to the average) decreases somewhat with mean activity, increases with decreasing effective temperatur

K. M. Pontoppidan, F. L. Schoeier, E. F. van Dishoeck, E. Dartois

We present a 4.5-4.85 micron R=5000 spectrum of the low mass class I young stellar object GSS 30 IRS1 (L=25L_sun) in the rho Ophiuchus core, observed with the infrared spectrometer (ISAAC) on the Very Large Telescope (VLT-UT1). Strong line emission from the ro-vibrational transitions of 12CO and 13CO is detected. In total more than 40 distinct lines are seen

G. Fiorentini, B. Ricci

We review the observational information on the constancy of the fine structure constant alpha. We find that small improvements on the measurement of ^{187}Re lifetime can provide significant progress in exploring the range of variability suggested by QSO data. We also discuss the effects of a time varying alpha on stellar structure and evolution. We find tha

Jeremy Kepner, Stan Ahalt

The true costs of high performance computing are currently dominated by software. Addressing these costs requires shifting to high productivity languages such as Matlab. MatlabMPI is a Matlab implementation of the Message Passing Interface (MPI) standard and allows any Matlab program to exploit multiple processors. MatlabMPI currently implements the basic si

B. Smalley, F. Kupka

Balmer lines are an important diagnostic of stellar atmospheric structure, since they are formed at a wide range of depths within the atmosphere. The different Balmer lines are formed at slightly different depths making them useful atmospheric diagnostics. The low sensitivity to surface gravity for stars cooler than ~8000 K makes them excellent diagnostics i

R. Zamanov, P. Marziani, J. W. Sulentic, M. Calvani

We investigate the radial velocity difference between the [OIII]5007,4959 and H-beta lines for a sample of 200 low redshift AGN. We identify seven objects showing an [OIII]5007 blueshift relative to H-beta with amplitude larger than 250 km/s (blue &#34;outliers&#34;). These line shifts are found in sources where the broad high ionization lines (e.g. CIV1549)

R. M. Bandyopadhyay, C. Brocksopp, R. P. Fender

We have accumulated multiwavelength lightcurves for eight black hole X-ray binaries which have been observed to enter a supposed ``soft X-ray transient&#39;&#39; outburst, but which in fact remained in the low/hard state throughout the outburst. Comparison of the lightcurve morphologies, spectral behaviour, properties of the QPOs and the radio jet provides t

Ross S. Collins, Christian R. Kaiser, Simon J. Cox

We have studied time variability in the flux from the flat spectrum synchrotron radiation of the Blandford & Konigl (1979) model for relativistic, conical jets. The resulting model has been applied to the flux variation of the flat spectrum of GRS 1915+105 observed by Fender & Pooley (2000). This comparison has highlighted a fundamental problem of the Blandf

L. van Zyl, T. Naylor, P. A. Charles, Z. Ioannou

The bright X-ray binary X2127+119 in the core of the globular cluster M15 has long been thought to be in an unusual evolutionary state, in which the binary is embedded in a common envelope. Support for this idea comes from X2127+119&#39;s absorption lines, which are blue shifted at all orbital phases, indicating the existence of outflows from the system. A c

V. S. Dhillon, S. P. Littlefair, T. R. Marsh, M. J. Sarna

We present K-band echelle spectra of the cataclysmic variable SS Cyg and the pre-cataclysmic variable V471 Tau in order to measure the strengths of the 12CO and 13CO bands at 2.3525 and 2.3448 microns, respectively, and so perform the observational test of the common-envelope model of close binary star evolution proposed by Sarna et al. (1995). Although we f

E. Sturm, D. Lutz, A. Verma, H. Netzer

We present medium resolution (R approx. 1500) ISO-SWS 2.4--45 micron spectra of a sample of 29 galaxies with active nuclei. This data set is rich in fine structure emission lines tracing the narrow line regions and (circum-)nuclear star formation regions, and it provides a coherent spectroscopic reference for future extragalactic studies in the mid-infrared.

J. M Diego, J. Mohr, J. Silk, G. Bryan

We develop a new method for estimating the redshift of galaxy clusters through resolved images of the Sunyaev-Zel&#39;dovich effect (SZE). Our method is based on morphological observables which can be measured by actual and future SZE experiments. The method is tested using a set of high resolution hydrodynamical simulations of galaxy clusters at different r

Th. Boller, L. C. Gallo, D. Lutz, E. Sturm

In this paper we report on an XMM-Newton observation of the ultraluminous infrared QSO Mrk 1014. The X-ray observation reveals a power-law dominated (photon index of about 2.2) spectrum with a slight excess in the soft energy range. AGN and starburst emission models fit the soft excess emission equally well, however, the most plausible explanation is an AGN

Jie Ding

We used ultraviolet spectra from HST/STIS (R=30,000), together with optical spectra from Keck/HIRES (R=45,000), to study the three MgII-selected absorption systems at z=0.9254, 0.9276, and 0.9342 toward the quasar PG 1206+459. A multi-phase gaseous structure, with low-ionization components produced in small condensations and high-ionization ones in diffuse c

Steven Weinberg

This paper presents a completely analytic treatment of cosmological fluctuations whose wavelength is small enough to come within the horizon well before the energy densities of matter and radiation become equal. This analysis yields a simple formula for the conventional transfer function T(k) at large wave number k, which agrees very well with computer calcu

Sebastian Wolf

A revised and greatly improved version of the 3D continuum radiative transfer code MC3D is presented. It is based on the Monte-Carlo method and solves the radiative transfer problem self-consistently. It is designed for the simulation of dust temperatures in arbitrary geometric configurations and the resulting observables: spectral energy distributions, wave

J. P. Cassinelli, J. C. Brown, M. Maheswaran, N. A. Miller

Despite extensive study, the mechanisms by which Be star disks acquire high densities and angular momentum while displaying variability on many time scales are still far from clear. In this paper, we discuss how magnetic torquing may help explain disk formation with the observed quasi-Keplerian (as opposed to expanding) velocity structure and their variabili

Olivier Doré, Lloyd Knox, Alan Peel

We present an analytic method for rapidly forecasting the accuracy of gravitational potential reconstruction possible from measurement of radial peculiar velocities of every galaxy cluster with M > M_th in solid angle θ^2 and over redshift range z_min < z < z_max. These radial velocities can be determined from measurement of the kinetic and thermal Sunyaev-Z

Ilija Dukovski, Jon Machta

The random field Ising model in three dimensions with Gaussian random fields is studied at zero temperature for system sizes up to 60^3. For each realization of the normalized random fields, the strength of the random field, Delta and a uniform external, H is adjusted to find the finite-size critical point. The finite-size critical point is identified as the

S. G. Korzennik, M. C. Rabello-Soares, J. Schou

The characteristic of the solar acoustic spectrum is such that mode lifetimes get shorter and spatial leaks get closer in frequency as the degree of a mode increases for a given order. A direct consequence of this property is that individual p-modes are only resolved at low and intermediate degrees, and that at high degrees, individual modes blend into ridge

L. N. Bulaevskii, Ch. Helm

The Josephson plasma resonance in layered superconductors with alternating critical current densities is investigated in a low perpendicular magnetic field. In the vortex solid phase the current densities and the squared bare plasma frequencies decrease linearly with the magnetic field. Taking into account the coupling due to charge fluctuations on the layer

Ludmila Kiseleva-Eggleton, Eric Bois, Nicolas Rambaux, Rudolf Dvorak

In order to distinguish between regular and chaotic planetary orbits we apply a new technique called MEGNO in a wide neighbourhood of orbital parameters determined using standard two-body Keplerian fits for HD 12661, HD 38529, HD 37124 and HD 160691 planetary systems. We show that the currently announced orbital parameters place these systems in very differe

Joseph Emerson, Yaakov S. Weinstein, Seth Lloyd, D. G. Cory

Recent work has connected the type of fidelity decay in perturbed quantum models to the presence of chaos in the associated classical models. We demonstrate that a system&#39;s rate of fidelity decay under repeated perturbations may be measured efficiently on a quantum information processor, and analyze the conditions under which this indicator is a reliable

James M. Cline, Hassan Firouzjahi, Patrick Martineau

We argue that it may be possible to reheat the universe after inflation driven by D-brane annihilation, due to the coupling of massless fields to the time-dependent tachyon condensate which describes the annihilation process. This mechanism can work if the original branes annihilate to a stable brane containing the standard model. Given reasonable assumption

Charles F. Doran, Michael Faux

We explicitly derive a complementary pair of four-dimensional M-theory brane-world models, linked by a five-dimensional bulk, each of which has a unique anomaly-free chiral spectrum. This is done via resolution of local consistency requirements, in the context of the simplest global quotient T7/G with ten-dimensional fixed-planes, for which a chiral four-dim

Nicolas Hadjiconstantinou, Alejandro L. Garcia, Martin Z. Bazant, Gang He

We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. Specifically, we establish how these errors depend on Mach number, Knudsen number, number of particles, etc. Expressions for the common hydrodynamic variables of interest such as flow velocity, temperature, densi

Anne M Green

WIMP direct detection experiments are just reaching the sensitivity required to detect galactic dark matter in the form of neutralinos. Data from these experiments are usually analysed under the simplifying assumption that the Milky Way halo is an isothermal sphere with maxwellian velocity distribution. Observations and numerical simulations indicate that ga

N. N. Nikolaev, W. Schäfer, B. G. Zakharov, V. R. Zoller

We derive the two-plateau momentum distribution of final state (FS) quarks produced in deep inelastic scattering (DIS) off nuclei in the saturation regime. The diffractive plateau which dominates for small transverse momentum p measures precisely the momentum distribution of quarks in the beam photon, the role of the nucleus is simply to provide an opacity.

The MACRO Collaboration, M. Ambrosio

The MACRO detector was located in the Hall B of the Gran Sasso underground Laboratories under an average rock overburden of 3700 hg/cm^2. A transition radiation detector composed of three identical modules, covering a total horizontal area of 36 m^2, was installed inside the empty upper part of the detector in order to measure the residual energy of muons. T

B. Aubert

We present results on time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 88 million Y(4S) --> B Bbar decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We study events in which one neutral B meson is fully reconstruct

T. Eckl, W. Hanke, E. Arrigoni

Recent reflectivity measurements provide evidence for a &#34;violation&#34; of the in-plane optical integral in the underdoped high-T_c compound Bi_2Sr_2CaCu_2O_{8+δ} up to frequencies much higher than expected by standard BCS theory. The sum rule violation may be related to a loss of in-plane kinetic energy at the superconducting transition. Here, we show t

Matteo Luca Ruggiero, Angelo Tartaglia

This paper contains a review of the theory and practice of gravitomagnetism, with particular attention to the different and numerous proposals which have been put forward to experimentally or observationally verify its effects. The basics of the gravitoelectromagnetic form of the Einstein equations is expounded. Then the Lense-Thirring and clock effects are

Arjun Berera, Thomas W. Kephart

Thermal inflation usually requires an inflationary potential with nonrenormalizable operators (NROs). We demonstrate how O&#39;Raifeartaigh models with or without NROs can provide thermal inflation and a solution to the moduli problem, as well as provide SUSY breaking. We then discuss a scenario where generalized O&#39;Raifeartaigh potentials (with NROs) are

T. Frederico, Hans-Christian Pauli, Shan-Gui Zhou

We show that the splitting between the light pseudo-scalar and vector meson states is due to the strong short-range attraction in the ^1S_0 sector which makes the pion and the kaon light particles. We use a light-cone QCD-inspired model of the mass squared operator with harmonic confinement and a Dirac-delta interaction. We apply a renormalization method to

I. M. Sokolov

We show that a formal solution of a rather general non-Markovian Fokker-Planck equation can be represented in a form of an integral decomposition and thus can be expressed through the solution of the Markovian equation with the same Fokker-Planck operator. This allows us to classify memory kernels into safe ones, for which the solution is always a probabilit

S. Biermann, F. Aryasetiawan, A. Georges

We propose a dynamical mean field approach for calculating the electronic structure of strongly correlated materials from first principles. The scheme combines the GW method with dynamical mean field theory, which enables one to treat strong interaction effects. It avoids the conceptual problems inherent to conventional ``LDA+DMFT&#39;&#39;, such as Hubbard

A. V. Burlakov, L. A. Krivitskiy, S. P. Kulik, G. A. Maslennikov

We proposed the procedure of measuring the unknown state of the three-level system - the qutrit, which was realized as the arbitrary polarization state of the single-mode biphoton field. This procedure is accomplished for the set of the pure states of qutrits; this set is defined by the properties of SU(2) transformations, that are done by the polarization t

D. A. Garanin, R. Schilling

We study the Landau-Zener-Stueckelberg (LZS) effect for a two-level system with a time-dependent nonlinear bias field (the sweep function) W(t). Our main concern is to investigate the influence of the nonlinearity of W(t) on the probability P to remain in the initial state. The dimensionless quantity epsilon = pi Delta ^2/(2 hbar v) depends on the coupling D

T. Stauber, A. Mielke

The spin-boson model is studied by means of flow equations for Hamiltonians. Our truncation scheme includes all coupling terms which are linear in the bosonic operators. Starting with the canonical generator $η_c=[H_0,H]$ with $H_0$ resembling the non-interacting bosonic bath, the flow equations exhibit a universal attractor for the Hamiltonian flow. This al

Yutaka Sakamura

We derive the low-energy effective theory on the BPS domain wall in 4D N=1 global SUSY theories in terms of the 3D superfields. Our derivation makes the preserved SUSY by the wall manifest and the procedure for integrating out the massive modes easier. Our procedure clarifies how the 3D superfields are embedded into the 4D chiral and vector superfields. We a

J. M. Diego, J. Mohr, J. Silk, G. Bryan

We develop a new method to estimate the redshift of galaxy clusters through resolved images of the Sunyaev-Zel&#39;dovich effect (SZE). Our method is based on morphological observables which can be measured by actual and future SZE experiments. We test the method with a set of high resolution hydrodynamical simulations of galaxy clusters at different redshif

G. M. von Hippel, R. R. Horgan

We present a self-consistent determination of the screening mass for chromomagnetic fields in QCD within the framework of dimensional reduction. The three-dimensional Chern-Simons density is used as a mass term for a self-consistent perturbative calculation that yields a value of m ~ 1.604 g^2 N/2pi for the magnetic screening mass.

Abhishek Chaudhuri, P. A. Sreeram, Surajit Sengupta

We study the steady state structure and dynamics of an interface in a pure Ising system on a square lattice placed in an inhomogeneous external field. The field has a profile with a fixed shape designed to stabilize a flat interface, and is translated with velocity v_e. For small v_e, the interface is stuck to the profile, is macroscopically smooth, and is r

D. Daghero, R. S. Gonnelli, G. A. Ummarino, V. A. Stepanov

We analyze the results of point-contact measurements in La_{2-x}Sr_{x}CuO_{4} (LSCO) previously reported as a clear evidence of the separation between gap and pseudogap in this copper oxide. Here we show that, in addition to this, the conductance curves of our point-contact junctions -- showing clear Andreev reflection features -- can be interpreted as suppo

J. M. Carmona, J. L. Cortes, J. Gamboa, F. Mendez

The connection between Lorentz invariance violation and noncommutativity of fields in a quantum field theory is investigated. A new dispersion relation for a free field theory with just one additional noncommutative parameter is obtained. While values for the noncommutative scale much larger than 10^{-20} eV^{-1} are ruled out by the present experimental sta

Himanshu Agrawal

We study networks constructed from gene expression data obtained from many types of cancers. The networks are constructed by connecting vertices that belong to each others&#39; list of K-nearest-neighbors, with K being an a priori selected non-negative integer. We introduce an order parameter for characterizing the homogeneity of the networks. On minimizing