June 2007 arXiv papers — page 7
Showing 601–700 of 4,521 papers
Jasper van Wezel, Tjerk Oosterkamp, Jan Zaanen
According to the hypothesis of Penrose and Diosi, quantum state reduction is a manifestation of the incompatibilty of general relativity and the unitary time evolution of quantum physics. Dimensional analysis suggests that Schrodinger cat type states should collapse on measurable time scales when masses and lengths of the order of bacterial scales are involv
Bruno A. N. Travencolo, Luciano da F. Costa
In this work we propose the use of a hirarchical extension of the polygonality index as a means to characterize and model geographical networks: each node is associated with the spatial position of the nodes, while the edges of the network are defined by progressive connectivity adjacencies. Through the analysis of such networks, while relating its topologic
Pierre-Henri Chavanis, Clement Sire
We derive general kinetic and hydrodynamic models of chemotactic aggregation that describe certain features of the morphogenesis of biological colonies (like bacteria, amoebae, endothelial cells or social insects). Starting from a stochastic model defined in terms of N coupled Langevin equations, we derive a nonlinear mean field Fokker-Planck equation govern
Wolfgang Steimle
This work treats on the question whether a given map f: M -> B of smooth closed manifolds is homotopic to a smooth fiber bundle. We define a first obstruction in H^1(B;Wh(π_1(E))) and, provided that this obstruction vanishes and one additional condition is verified, a second obstruction in Wh(π_1(E)) >. Both elements vanish if the answer to the above questio
XMM-Newton observation of the persistent Be/neutron-star system X Persei at a high-luminosity level
astro-phN. La Palombara, S. Mereghetti
We report on the XMM-Newton observation of the HMXRB X Persei, the prototype of the persistent and low-luminosity Be/neutron star pulsars, which was performed on February 2003. The source was detected at a luminosity level of ~ 1.4x10^35 erg/s, which is the highest level of the latest three decades. The pulsation period has increased up to 839.3 s, thus conf
Georg Hein
We construct vector bundles $R^r_μ$ on a smooth projective curve $X$ having the property that for all sheaves $E$ of slope $μ$ and rank $r$ on $X$ we have an equivalence: $E$ is a semistable vector bundle $\iff$ $Hom(R^r_μ,E)=0$. As a byproduct of our construction we obtain effective bounds on $r$ such that the linear system $|R \cdot Θ|$ has base points on
Unambiguous symmetry assignment for the top valence band of ZnO by magneto-optical studies of the free A-exciton state
cond-mat.mtrl-sciLu Ding, Chunlei Yang, Hongtao He, Fengyi Jiang
We studied the circular polarization and angular dependences of the magneto-photoluminescence spectra of the free A-exciton 1S state in wurtzite ZnO at T = 5 K. The circular polarization properties of the spectra clearly indicate that the top valence band has Gamma_7 symmetry. The out-of-plane component of the magnetic field, which is parallel to the sample&
Ian Percival, Barry Garraway
According to Bell's theorem, local realism is incompatible with quantum theory. However, it depends on an implied assumption about quantum measurement. We suggest that the assumption might be removed by a detailed quantum analysis of the interaction between the measured system and measuring apparatus using Born's statistical interpretation. But it is
Li zhigang, Wei-Tou Ni, Antonio Pulido Paton
New unification theories predict Large Extra Dimensions (LEDs). If that is the case, gravity would be stronger at short ranges than what Newtonian gravity predicts. LEDs could also have effects at atomic level. In this paper we propose a new method to constrain the size of gravity-only LEDs by analyzing how these LEDs modify the energy of the atomic transiti
Ben Lillie, Jing Shu, Tim M. P. Tait
We study the properties of $g^{1}$, the first excited state of the gluon in representative variants of the Randall Sundrum model with the Standard Model fields in the bulk. We find that measurements of the coupling to light quarks (from the inclusive cross-section for $pp\to g^{1} \to t\bar t$), the coupling to bottom quarks (from the rate of $pp\to g^{1} b$
Wei-Gang Wang, Yu-Qing Lou
In broad astrophysical contexts of large-scale gravitational collapses and outflows and as a basis for various further astrophysical applications, we formulate and investigate a theoretical problem of self-similar MHD for a non-rotating polytropic gas of quasi-spherical symmetry permeated by a completely random magnetic field. We derive two coupled nonlinear
Lunar Outgassing, Transient Phenomena and The Return to The Moon, III: Observational and Experimental Techniques
astro-phArlin P. S. Crotts
In Papers II and III we show that Transient Lunar Phenomena (TLPs) are likely related to lunar outgassing, albeit in ways not fully understood. Here we propose a path forward, in which current and forthcoming technologies provide a more controlled, sensitive probe of lunar outgassing. Many of these techniques are being realized for the first time. Given the
Tawanda Gwena, Montserrat Teixidor i Bigas
Given a vector bundle $E$ of rank $r$ and degree $d$ on a curve $C$ of genus $g$, one can associate to $E$ in a natural way several other vector bundles. For example, one can take wedge powers of $E$. If $E$ is generated by global sections, the kernel of the evaluation map of sections is again a vector bundle. Also, new vector bundles can be produced by taki
Lunar Outgassing, Transient Phenomena and The Return to The Moon, II: Predictions for Interactions between Outgassing and Regolith
astro-phArlin P. S. Crotts, Cameron Hummels
We consider the implications from Paper I on how gas leaking through the lunar surface might interact with the regolith, and in what respects this might affect or cause the appearance of optical Transient Lunar Phenomena (TLPs). We consider briefly a range of phenomena, but concentrate at the extremes of high and low gas flow rate, which might represent the
Alexander Berenstein, Clifton Ealy, Ayhan Günaydin
We characterize thorn-independence in a variety of structures, focusing on the field of real numbers expanded by predicate defining a dense multiplicative subgroup, G, satisfying the Mann property and whose pth powers are of finite index in G. We also show such structures are super-rosy and eliminate imaginaries up to codes for small sets.
Arlin P. S. Crotts
Herein the transient lunar phenomena (TLP) report database is subjected to a discriminating statistical filter robust against sites of spurious reports, and produces a restricted sample that may be largely reliable. This subset is highly correlated geographically with the catalog of outgassing events seen by the Apollo 15, 16 and Lunar Prospector alpha-parti
Metal-insulator transition in the two-orbital Hubbard model at fractional band fillings: Self-energy functional approach
cond-mat.str-elKensuke Inaba, Akihisa Koga
We investigate the infinite-dimensional two-orbital Hubbard model at arbitrary band fillings. By means of the self-energy functional approach, we discuss the stability of the metallic state in the systems with same and different bandwidths. It is found that the Mott insulating phases are realized at commensurate band fillings. Furthermore, it is clarified th
Arlin P. S. Crotts
Transient lunar phenomena (TLPs) have been reported for centuries, but their nature is largely unsettled. A review of TLP reports shows regularities in the observations; a key question is whether this structure is imposed by human observer effects, terrestrial atmospheric effects or processes tied to the lunar surface. I interrogate an extensive TLP catalog
Jongchul Mun, Patrick Medley, Gretchen K. Campbell, Luis G. Marcassa
The stability of superfluid currents in a system of ultracold bosons was studied using a moving optical lattice. Superfluid currents in a very weak lattice become unstable when their momentum exceeds 0.5 recoil momentum. Superfluidity vanishes already for zero momentum as the lattice deep reaches the Mott insulator(MI) phase transition. We study the phase di
The globular cluster system in NGC5866: optical observations from HST Advanced Camera for Surveys
astro-phCantiello, Michele, Blakeslee, John P.
We perform a detailed study of the Globular Cluster (GC) system in the galaxy NGC5866 based on F435W, F555W, and F625W (~ B, V, and R) HST Advanced Camera for Surveys images. Adopting color, size and shape selection criteria, the final list of GC candidates comprises 109 objects, with small estimated contamination from background galaxies, and foreground sta
Michael J. Ramsey-Musolf
I discuss low energy searches for new physics beyond the Standard Model, identifying the role played by chiral symmetries in these searches and in various new physics scenarios. I focus in particular on electric dipole moment searches; precision studies of weak decays and electron scattering; and neutrino properties and interactions.
Intrinsic alignments of galaxies and their effects on weak lensing detections of mass concentrations
astro-phZ. H. Fan
In this paper we investigate the influence of the intrinsic alignment of background galaxies on weak lensing detections of mass concentrations. Specifically, we analyze the number counts of false peaks resulting from intrinsic ellipticities in lensing convergence maps. Including the alignment of source galaxies, the full noise variance from intrinsic ellipti
H. -J. Grimm, J. McDowell, A. Zezas, D. -W. Kim
In this paper we investigate the X-ray spectra and X-ray spectral variability of compact X-ray sources for 3 Chandra observations of the Local Group galaxy M33. The observations are centered on the nucleus and the star forming region NGC 604. In the observations 261 sources have been detected. For a total of 43 sources the number of net counts is above 100,
Jan Johannes, Suhasini Subba Rao
In this paper we consider nonparametric estimation for dependent data, where the observations do not necessarily come from a linear process. We study density estimation and also discuss associated problems in nonparametric regression using the 2-mixing dependence measure. We compare the results under 2-mixing with those derived under the assumption that the
Molecular dynamics simulations of the dipolar-induced formation of magnetic nanochains and nanorings
cond-mat.mtrl-sciA. Hucht, S. Buschmann, P. Entel
Iron, cobalt and nickel nanoparticles, grown in the gas phase, are known to arrange in chains and bracelet-like rings due to the long-range dipolar interaction between the ferromagnetic (or super-paramagnetic) particles. We investigate the dynamics and thermodynamics of such magnetic dipolar nanoparticles for low densities using molecular dynamics simulation
W. G. Dantas, M. J. de Oliveira, J. F. Stilck
By using the transfer matrix approach, we investigate the asymptotic behavior of the entropy of flexible chains with $M$ monomers each placed on stripes. In the limit of high density of monomers, we study the behavior of the entropy as a function of the density of monomers and the width of the stripe, inspired by recent analytical studies of this problem for
Current-voltage characteristic of parallel-plane ionization chamber with inhomogeneous ionization
physics.gen-phDimitar G. Stoyanov
The balances of particles and charges in the volume of parallel-plane ionization chamber are considered. Differential equations describing the distribution of current densities in the chamber volume are obtained. As a result of the differential equations solution an analytical form of the current-voltage characteristic of parallel-plane ionization chamber wi
Ivan Penkov, Alexander S. Tikhomirov
Twisted ind-Grassmannians are ind-varieties $\GG$ obtained as direct limits of Grassmannians $G(r_m,V^{r_m})$, for $m\in\ZZ_{>0}$, under embeddings $ϕ_m:G(r_m,V^{r_m})\to G(r_{m+1}, V^{r_{m+1}})$ of degree greater than one. It has been conjectured in \cite{PT} and \cite{DP} that any vector bundle of finite rank on a twisted ind-Grassmannian is trivial. We pr
Marta Volonteri, Marek Sikora, Jean-Pierre Lasota
We investigate the conjecture by Sikora, Stawarz & Lasota (2007) that the observed AGN--radio-loudness bimodality can be explained by the morphology-related bimodality of black-hole spin distribution in the centers of galaxies: central black holes in giant elliptical galaxies may have (on average) much larger spins than black holes in spiral/disc galaxies. W
Wavefunctions, Green's functions and expectation values in terms of spectral determinants
nlin.CDMartin Sieber
We derive semiclassical approximations for wavefunctions, Green's functions and expectation values for classically chaotic quantum systems. Our method consists of applying singular and regular perturbations to quantum Hamiltonians. The wavefunctions, Green's functions and expectation values of the unperturbed Hamiltonian are expressed in terms of the
N. Brodskiy, J. Dydak, B. Labuz, A. Mitra
James \cite{Jam} introduced uniform covering maps as an analog of covering maps in the topological category. Subsequently Berestovskii and Plaut \cite{BP3} introduced a theory of covers for uniform spaces generalizing their results for topological groups \cite{BP1}-\cite{BP2}. Their main concepts are discrete actions and pro-discrete actions, respectively. I
Davide Fioravanti, Marco Rossi
We consider the highest anomalous dimension operator in the SU(2) sector of planar ${\cal N}=4$ SYM at all-loop, though neglecting wrapping contributions. In any case, the latter enter the loop expansion only after a precise length-depending order. In the thermodynamic limit we write both a linear integral equation for the Bethe root density and a linear sys
Edward Anderson
Relational particle dynamics include the dynamics of pure shape and cases in which absolute scale or absolute rotation are additionally meaningful. These are interesting as regards the absolute versus relative motion debate as well as discussion of conceptual issues connected with the problem of time in quantum gravity. In spatial dimension 1 and 2 the relat
Dirac neutrino mass from the beta decay end-point modified by the dynamics of a Lorentz-violating equation of motion
hep-phAlex E. Bernardini
Using a generalized procedure for obtaining the equation of motion of a propagating fermionic particle, we examine previous claims for a lightlike preferred axis embedded in the framework of Lorentz-invariance violation with preserved algebra. In a high energy scale, the corresponding equation of motion is reduced to a conserving lepton number chiral (VSR) e
Alex E. Bernardini
We obtain the solutions for the tunneling zone of a one-dimensional electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave equation regime when the incoming wave packet exhibits the possibility of being almost totally transmitted through the potential barrier. The conditions for the occurrence of accelerated and, eventually, superluminal tu
The Exact Correspondence between Phase Times and Dwell Times in a Symmetrical Quantum Tunneling Configuration
quant-phAlex E. Bernardini
The general and explicit relation between the phase time and the dwell time for quantum tunneling or scattering is investigated. Considering a symmetrical collision of two identical wave packets with an one-dimensional barrier, here we demonstrate that these two distinct transit time definitions give connected results where, however, the phase time (group de
Theoretical correlation between possible evidences of neutrino chiral oscillations and polarization measurements
hep-phAlex E. Bernardini, Marcelo M. Guzzo
Reporting about the formalism with the Dirac equation we describe the dynamics of chiral oscillations for a fermionic particle non-minimally coupling with an external magnetic field. For massive particles, the chirality and helicity quantum numbers represent different physical quantities of representative importance in the study of chiral interactions, in pa
Influence of second-order corrections to the energy-dependence of neutrino flavor conversion formulae
hep-phAlex E. Bernardini, Marcelo M. Guzzo
We discuss the {\em intermediate} wave-packet formalism for analytically quantifying the energy dependence of the two-flavor conversion formula that is usually considered for analyzing neutrino oscillations and adjusting the focusing horn, target position and/or detector location of some flavor conversion experiments. Following a sequence of analytical appro
Neutron electric polarizability from unquenched lattice QCD using the background field approach
hep-latMichael Engelhardt
A calculational scheme for obtaining the electric polarizability of the neutron in lattice QCD with dynamical quarks is developed, using the background field approach. The scheme differs substantially from methods previously used in the quenched approximation, the physical reason being that the QCD ensemble is no longer independent of the external electromag
Brett Parker
The category of exploded torus fibrations is an extension of the category of smooth manifolds in which some adiabatic limits look smooth. (For example, the limits considered in tropical geometry appear smooth, also degenerations corresponding to an algebraic family with normal crossing singularities are smooth.) In this paper we prove a compactness theorem f
Rudro R. Biswas, Subir Sachdev, Dam T. Son
We consider the problem of screening of an electrically charged impurity in a clean graphene sheet. When electron-electron interactions are neglected, the screening charge has a sign opposite to that of the impurity, and is localized near the impurity. Interactions between electrons smear out the induced charge density to give a large-distance tail that foll
Clara Loeh, Roman Sauer
The simplicial volume introduced by Gromov provides a topologically accessible lower bound for the minimal volume. Lafont and Schmidt proved that the simplicial volume of closed, locally symmetric spaces of non-compact type is positive. In this paper, we present a generalization of this result to certain non-compact locally symmetric spaces of finite volume,
Evgeny I. Buchbinder, Justin Khoury, Burt A. Ovrut
New Ekpyrotic Cosmology is an alternative scenario of early universe cosmology in which the universe existed before the big bang. The simplest model relies on two scalar fields, whose entropy perturbation leads to a scale-invariant spectrum of density fluctuations. The ekpyrotic solution has a tachyonic instability along the entropy field direction which, a
Clayton Heller, Isaac Shlosman, Lia Athanassoula
We investigate the formation and evolution of galactic disks immersed in assembling live DM halos. Disk/halo components have been evolved from the cosmological initial conditions and represent the collapse of an isolated density perturbation. The baryons include gas (which participates in star formation [SF]) and stars. The feedback from the stellar energy r
Branching fraction and CP-violation charge asymmetry measurements for B-meson decays to eta K+-, etapi+-, eta'K, eta'pi+-, omega K, and omegapi+-
hep-exThe BABAR Collaboration, B. Aubert et al
We present measurements of the branching fractions for B0 meson decays to eta'K0 and omegaK0, and of the branching fractions and CP-violation charge asymmetries for B+ meson decays to etapi+, etaK+, eta'pi+, eta'K+, omegapi+, and omegaK+. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 383 million
Loison Hoi, James M. Cline
Well-known causality arguments show that events occurring during or at the end of inflation, associated with reheating or preheating, could contribute a blue component to the spectrum of primordial curvature perturbations, with the dependence k^3. We explore the possibility that they could be observably large in CMB, LSS, and Lyman-alpha data. We find that a
Iosif Bena, Chih-Wei Wang, Nicholas P. Warner
We construct the first smooth, horizonless ``microstate geometries'' that have the same charges, dipole charges and angular momenta as a BPS black ring whose horizon is macroscopic. These solutions have exactly the same geometry as black rings, except that the usual infinite throat is smoothly capped off at a very large depth. If the solutions preser
Bruno Henriques, Serena Bertone, Peter Thomas
We present results for a galaxy formation model that includes a simple treatment for the disruption of dwarf galaxies by gravitational forces and galaxy encounters within galaxy clusters. This is implemented a posteriori in a semi-analytic model by considering the stability of cluster dark matter sub-haloes at z=0. We assume that a galaxy whose dark matter s
T. D. Andersen, C. C. Lim
Negative specific heat is a dramatic phenomenon where processes decrease in temperature when adding energy. It has been observed in gravo-thermal collapse of globular clusters. We now report finding this phenomenon in bundles of nearly parallel, periodic, single-sign generalized vortex filaments in the electron magnetohydrodynamic (EMH) model for the unbound
V. Kreiman
We give a positive equivariant Littlewood-Richardson rule also discovered independently by Molev. Our proof generalizes a proof by Stembridge of the ordinary Littlewood-Richardson rule. We describe a weight-preserving bijection between our indexing tableaux and the Knutson-Tao puzzles.
M. Hossain Ali
We study the Hawking thermal spectrum in dragging coordinate system and the tunneling radiation characteristics of hot NUT-Kerr-Newman-Kasuya spacetime. The tunneling rates at the event and cosmological horizon are found to be related to the change of Bekenstein-Hawking entropy. The radiation spectrum is not pure thermal and thus there is a correction to the
Angelo Loinger, Tiziana Marsico
We reconsider some subtle points concerning the relativistic treatment of the gravitational fields generated by spherically symmetric structures.
William H. Kinney
I discuss the current status of inflationary cosmology in light of the recent WMAP 3-year data release. The basic predictions of inflation are all supported by the data. Inflation also makes predictions which have not been well tested by current data but can be by future experiments, most notably a deviation from a scale-invariant power spectrum and the prod
Matthias R. Schreiber, Jean-Pierre Lasota
Since the Fine Guiding Sensor (FGS) on the Hubble Space Telescope (HST) was used to measure the distance to SS Cyg to be $166\pm12$ pc, it became apparent that at this distance the disc instability model fails to explain the absolute magnitude during outburst. It remained, however, an open question whether the model or the distance have to be revised. Recent
Xufen Wu, HongSheng Zhao, Benoit Famaey, G. Gentile
The self-binding energy and stability of a galaxy in MOND-based gravity are curiously decreasing functions of its center of mass acceleration towards neighbouring mass concentrations. A tentative indication of this breaking of the Strong Equivalence Principle in field galaxies is the RAVE-observed escape speed in the Milky Way. Another consequence is that sa
The BABAR Collaboration, B. Aubert
We analyze the decay B0 --> K+ K- K0 using 383 million B-Bbar events collected by the BaBar detector at SLAC to extract CP violation parameter values over the Dalitz plot. Combining all K+ K- K0 events, we find A_CP = -0.015 +/- 0.077 +/- 0.053 and beta_eff = 0.352 +/- 0.076 +/- 0.026 rad, corresponding to a CP violation significance of 4.8 sigma. A second s
James P. Bagrow
We present a new benchmarking procedure that is unambiguous and specific to local community-finding methods, allowing one to compare the accuracy of various methods. We apply this to new and existing algorithms. A simple class of synthetic benchmark networks is also developed, capable of testing properties specific to these local methods.
Pablo Fernández, Albrecht Ott
Cell mechanical properties are fundamental to the organism but remain poorly understood. We report a comprehensive phenomenological framework for the nonlinear rheology of single fibroblast cells: a superposition of elastic stiffening and viscoplastic kinematic hardening. Our results show, that in spite of cell complexity its mechanical properties can be cas
Surface and Bulk Properties of Deposits Grown with a Bidisperse Ballistic Deposition Model
cond-mat.stat-mechF. A. Silveira, F. D. A. Aarão Reis
We study roughness scaling of the outer surface and the internal porous structure of deposits generated with the three-dimensional bidisperse ballistic deposition (BBD), in which particles of two sizes are randomly deposited. Systematic extrapolation of roughness and dynamical exponents and the comparison of roughness distributions indicate that the top surf
S. Heinz, N. S. Schulz, W. N. Brandt, D. K. Galloway
We analyzed the zero-order image of a 50 ks Chandra gratings observation of Circinus X-1, taken in 2005 during the source's low-flux state. Circinus X-1 is an accreting neutron star that exhibits ultra-relativistic arcsecond-scale radio jets and diffuse arcminute-scale radio jets and lobes. The image shows a clear excess along the general direction of th
Alexey V. Gorshkov, Liang Jiang, Markus Greiner, Peter Zoller
We suggest a new method for quantum optical control with nanoscale resolution. Our method allows for coherent far-field manipulation of individual quantum systems with spatial selectivity that is not limited by the wavelength of radiation and can, in principle, approach a few nanometers. The selectivity is enabled by the nonlinear atomic response, under the
Dengming Ming, Marian Anghel, Michael E. Wall
Inherent structure theory is used to discover strong connections between simple characteristics of protein structure and the energy landscape of a Go model. The potential energies and vibrational free energies of inherent structures are highly correlated, and both reflect simple measures of networks of native contacts. These connections have important conseq
A. Delgado, G. F. Giudice, P. Slavich
We address the mu problem of gauge mediation by considering a singlet chiral superfield coupled to the Higgs and messenger fields. We compute the soft terms generated below the messenger scale and study the phenomenological consequences of the model. The experimental bound on the Higgs mass provides a severe constraint that identifies three special regions o
G. Abrams, P. N. Ánh, A. Louly, E. Pardo
We prove an algebraic version of the Gauge-Invariant Uniqueness Theorem, a result which gives information about the injectivity of certain homomorphisms between ${\mathbb Z}$-graded algebras. As our main application of this theorem, we obtain isomorphisms between the Leavitt path algebras of specified graphs. From these isomorphisms we are able to achieve tw
Ulrich Raitzsch, Vera Bendkowsky, Rolf Heidemann, Björn Butscher
When ground state atoms are excited to a Rydberg state, van der Waals interactions among them can lead to a strong suppression of the excitation. Despite the strong interactions the evolution can still be reversed by a simple phase shift in the excitation laser field. We experimentally prove the coherence of the excitation in the strong blockade regime by ap
CDF Collaboration, T. Aaltonen
We report an observation of new bottom baryons produced in proton-antiproton collisions at the Tevatron. Using 1.1 fb^{-1} of data collected by the CDF II detector, we observe four Λ_b^0π^{\pm} resonances in the fully reconstructed decay mode Λ_b^0 \to Λ_c^+ π^-, where Λ_c^+ \to p K^- π^+. We interpret these states as the Σ_b^{(*)\pm} baryons and measure the
Shunsuke Takagi, Ryo Takahashi
Smith and Van den Bergh introduced the notion of finite F-representation type as a characteristic $p$ analogue of the notion of finite representation type. In this paper, we prove two finiteness properties of rings with finite F-representation type. The first property states that if $R=\bigoplus_{n \ge 0}R_n$ is a Noetherian graded ring with finite (graded)
Dan Solomon
It is generally assumed that quantum field theory (QFT) is gauge invariant. However it is well known that non-gauge invariant terms appear in various calculations. This problem was recently examined in [9] for a "simple" field theory and it was shown that for this case QFT in the Schroedinger picture is not, in fact, gauge invariant. In order to shed
Sachie Kimura, Aldo Bonasera
We estimate the ratios of bare astrophysical S-factors at zero incident energy for proton and deuteron induced reactions in a model which assumes a compound nucleus formation probability plus a statistical decay. The obtained ratios agree well with available experimental values, as far as the reactions which have dominant s-wave entrance channel components a
Valentin Ferenczi, Eloi Medina Galego
A group G is representable in a Banach space X if G is isomorphic to the group of isometries on X in some equivalent norm. We prove that a countable group G is representable in a separable real Banach space X in several general cases, including when $G=\{-1,1\} \times H$, H finite and $\dim X \geq |H|$, or when G contains a normal subgroup with two elements
German Olivares, Fernando Atrio-Barandela, Diego Pavon
Interacting quintessence models have been proposed to explain or, at least, alleviate the coincidence problem of late cosmic acceleration. In this paper we are concerned with two aspects of these kind of models: (i) the dynamical evolution of the model of Chimento et al. [L.P. Chimento, A.S. Jakubi, D. Pavon, and W. Zimdahl, Phys. Rev. D 67, 083513 (2003).],
A. Just, H. Jahreiss
We present an evolutionary disc model for the thin disc in the solar cylinder based on a continuous star formation history and a continuous dynamical heating of the stellar subpopulations. The vertical distribution of the stellar subpopulations are calculated self-consistently in dynamical equilibrium. The SFR and AVR of the stellar subpopulations are determ
D. Ebert, R. N. Faustov, V. O. Galkin, W. Lucha
Masses of tetraquarks with two heavy quarks and open charm and bottom are calculated in the framework of the diquark-antidiquark picture in the relativistic quark model. All model parameters were regarded as fixed by previous considerations of various properties of mesons and baryons. The light quarks and diquarks are treated completely relativistically. The
Jean Cardinal, Vlady Ravelomanana, Mario Valencia-Pabon
In the minimum sum edge coloring problem, we aim to assign natural numbers to edges of a graph, so that adjacent edges receive different numbers, and the sum of the numbers assigned to the edges is minimum. The {\em chromatic edge strength} of a graph is the minimum number of colors required in a minimum sum edge coloring of this graph. We study the case of
Wolfgang Altmannshofer, Andrzej J. Buras, Diego Guadagnoli, Michael Wick
Under the assumption of Minimal Flavour Violation (MFV), the Unitarity Triangle (UT) can be determined by using only angle measurements and tree-level observables. In this respect, the most accurate quantities today available are sin 2 beta_{psi Ks}, |Vcb| and |Vub|. Among the latter, |Vub| is at present the quantity suffering from largest systematic uncerta
Quantum Brachistochrone Problem and the Geometry of the State Space in Pseudo-Hermitian Quantum Mechanics
quant-phAli Mostafazadeh
A non-Hermitian operator with a real spectrum and a complete set of eigenvectors may serve as the Hamiltonian operator for a unitary quantum system provided that one makes an appropriate choice for the defining inner product of the physical Hilbert state. We study the consequences of such a choice for the representation of states in terms of projection opera
A. Barbara, J. Le Perchec, P. Quemerais, T. Lopez-Rios
Light localization on commensurate arrangements of metallic sub-wavelength grooves is studied. We theoretically show that as the degree of commensuration tends to an irrational number new light localization states are produced. These have properties close to that reported for hot spots on disordered surfaces and are not permitted for simple period gratings.
Why metallic surfaces with grooves a few nanometers deep and wide may strongly absorb visible light
cond-mat.otherJ. Le Perchec, P. Quemerais, A. Barbara, T. Lopez-Rios
It is theoretically shown that nanometric silver lamellar gratings present very strong visible light absorption inside the grooves, leading to electric field intensities by several orders of magnitude larger than that of the impinging light. This effect, due to the excitation of long wave vector surface plasmon polaritons with particular small penetration de
P. San-Jose, E. Prada, D. S. Golubev
We analyze the full transport statistics of graphene with smooth disorder at low dopings. First we consider the case of 1D disorder for which the transmission probability distribution is given analytically in terms of the graphene-specific mean free path. All current cumulants are shown to scale with system parameters (doping, size, disorder strength and cor
Sébastien Jansou, Nicolas Ressayre
We study deformations of orbit closures for the action of a connected semisimple group $G$ on its Lie algebra $\mathfrak{g}$, especially when $G$ is the special linear group. The tools we use are on the one hand the invariant Hilbert scheme and on the other hand the sheets of $\mathfrak{g}$. We show that when $G$ is the special linear group, the connected co
Yuri V. Lvov, Kurt L. Polzin, Naoto Yokoyama
We report evaluations of a resonant kinetic equation that suggest the slow time evolution of the Garrett and Munk spectrum is {\em not}, in fact, slow. Instead nonlinear transfers lead to evolution time scales that are smaller than one wave period at high vertical wavenumber. Such values of the transfer rates are inconsistent with conventional wisdom that re
R. Vilela Mendes
Based on criteria of mathematical simplicity and consistency with empirical market data, a model with volatility driven by fractional noise has been constructed which provides a fairly accurate mathematical parametrization of the data. Here, some features of the model are discussed and, using agent-based models, one tries to find which agent strategies and (
Free and smooth boundaries in 2-D finite-difference schemes for transient elastic waves
physics.class-phBruno Lombard, Joël Piraux, Céline Gélis, Jean Virieux
A method is proposed for accurately describing arbitrary-shaped free boundaries in single-grid finite-difference schemes for elastodynamics, in a time-domain velocity-stress framework. The basic idea is as follows: fictitious values of the solution are built in vacuum, and injected into the numerical integration scheme near boundaries. The most original feat
CP asymmetries with Longitudinal and Transverse Beam Polarizations in Neutralino Production and Decay into the Z^0 Boson at the ILC
hep-phA. Bartl, K. Hohenwarter-Sodek, T. Kernreiter, O. Kittel
We study neutralino production at the linear collider with the subsequent two-body decays ~chi^0_i -> ~chi^0_n Z^0 and Z^0 -> l^+ l^-, with l=e, mu, tau, or Z^0 -> q q- with q=c,b. We show that transverse electron and positron beam polarizations allow the definition of unique CP observables. These are azimuthal asymmetries in the distributions of the final l
Karlheinz Gröchenig, Richard F. Bass
We consider the problem of random sampling for band-limited functions. When can a band-limited function $f$ be recovered from randomly chosen samples $f(x_j), j\in \mathbb{N}$? We estimate the probability that a sampling inequality of the form A\|f\|_2^2 \leq \sum_{j\in \mathbb{N}} |f(x_j)|^2 \leq B \|f\|_2^2 hold uniformly all functions $f\in L^2(\mathbb{R}
Nikos Irges, Francesco Knechtli, Magdalena Luz
We compute the Coleman-Weinberg potential with a finite cut-off for pure SU(2) and SU(3) five-dimensional gauge theories compactified on an interval. We show that besides the expected Coulomb phase located at and in the vicinity of the free infrared stable or "trivial" fixed point, the theory possesses also a Higgs phase. We compare the results from
Andrzej Kucharski, Szymon Plewik
A compact space X is I-favorable if, and only if X can be representing as a limit of $σ$-complete inverse system of compact metrizable spaces with skeletal bonding maps.
Isabel Sainz, Gunnar Björk
We study entanglement dynamics between four qubits interacting through two isolated Jaynes-Cummings hamiltonians, via the entanglement measure based on the wedge product. We compare the results with similar results obtained using bipartite concurrence resulting in what is referred to as "entanglement sudden death". We find a natural entanglement inva
Pierre Parrend, Stéphane Frénot
The OSGi Platform finds a growing interest in two different applications domains: embedded systems, and applications servers. However, the security properties of this platform are hardly studied, which is likely to hinder its use in production systems. This is all the more important that the dynamic aspect of OSGi-based applications, that can be extended at
Veselin G. Filev
We consider a D7-brane probe of $AdS_{5}\times S^5$ in the presence of pure gauge $B$-field. The dual gauge theory is flavored Yang-Mills theory in external magnetic field. We explore the dependence of the fermionic condensate on the bare quark mass $m_{q}$ and study the discrete self-similar behavior of the theory near the origin of the parametric space. We
ZEUS Collaboration, S. Chekanov
The cross section for high-E_T dijet production in photoproduction has been measured with the ZEUS detector at HERA using an integrated luminosity of 81.8 pb-1. The events were required to have a virtuality of the incoming photon, Q^2, of less than 1 GeV^2 and a photon-proton centre-of-mass energy in the range 142 < W < 293 GeV. Events were selected if at le
Birefringence (rotation of polarization plane and spin dichroism) of deuterons in carbon target
nucl-thV. Baryshevsky, A. Rouba
Birefringence phenomenon for deuteron with energy up 20 MeV in carbon target is considered. The estimation for spin dichroism and for angle of rotation of polarization plane of deuterons is presented. It is shown that magnitude of the phenomenon strongly depends on behavior of the deuteron wave functions on small distance between nucleon in deuteron.
Tobias Ganzow, Sasha Rubin
We compare the expressiveness of two extensions of monadic second-order logic (MSO) over the class of finite structures. The first, counting monadic second-order logic (CMSO), extends MSO with first-order modulo-counting quantifiers, allowing the expression of queries like ``the number of elements in the structure is even''. The second extension allo
Inverted Mass Hierarchy from Scaling in the Neutrino Mass Matrix: Low and High Energy Phenomenology
hep-phA. Blum, R. N. Mohapatra, W. Rodejohann
Best-fit values of recent global analyzes of neutrino data imply large solar neutrino mixing, vanishing U_{e3} and a non-maximal atmospheric neutrino mixing angle theta_{23}. We show that these values emerge naturally by the hypothesis of "scaling" in the Majorana neutrino mass matrix, which states that the ratios of its elements are equal. It also p
A. Manashov, A. Schafer
We calculate the volume corrections to the two-pion matrix element of twist two operators.
Muhammad Akashi, Noam Soker
We propose that the large, radius of ~1000 AU, circumbinary rotating disks observed around some post-asymptotic giant branch (post-AGB) binary stars are formed from slow AGB wind material that is pushed back to the center of the nebula by wide jets. We perform 2D-axisymmetrical numerical simulations of fast and wide jets that interact with the previously eje
L. Campanelli, P. Cea, L. Tedesco
Recent Wilkinson Microwave Anisotropy Probe (WMAP) data confirm the Cosmic Microwave Background (CMB) quadrupole anomaly. We further elaborate our previous proposal that the quadrupole power can be naturally suppressed in axis-symmetric universes. In particular, we discuss in greater detail the CMB quadrupole anisotropy and considerably improve our analysis.
On an explicit construction of Parisi landscapes in finite dimensional Euclidean spaces
cond-mat.dis-nnYan V. Fyodorov, Jean-Philippe Bouchaud
We construct a N-dimensional Gaussian landscape with multiscale, translation invariant, logarithmic correlations and investigate the statistical mechanics of a single particle in this environment. In the limit of high dimension N>>1 the free energy of the system in the thermodynamic limit coincides with the most general version of Derrida's Generalized R
H. Jung, A. V. Kotikov, A. V. Lipatov, N. P. Zotov
We use the unintegrated Parton Density Functions of the gluon obtained from a fit to measurements of the structure functions F2 and F2c at HERA to describe the experimental data for F2b, FL and FL at fixed W.
Measurement of the p anti-p to t anti-t Production Cross Section and the Top Quark Mass at sqrt{s}=1.96 TeV in the All-Hadronic Decay Mode
hep-exCDF Collaboration, T. Aaltonen
We report the measurements of the t anti-t production cross section and of the top quark mass using 1.02 fb^-1 of p anti-p data collected with the CDFII detector at the Fermilab Tevatron. We select events with six or more jets on which a number of kinematical requirements are imposed by means of a neural network algorithm. At least one of these jets must be