May 2007 arXiv papers — page 3
Showing 201–300 of 4,683 papers
Remco van der Hofstad, Wouter Kager
We study occurrences of patterns on clusters of size n in random fields on Z^d. We prove that for a given pattern, there is a constant a>0 such that the probability that this pattern occurs at most an times on a cluster of size n is exponentially small. Moreover, for random fields obeying a certain Markov property, we show that the ratio between the numbers
Quantum field propagator for extended-objects in the microcanonical ensemble and the S-matrix formulation
hep-thDiego. J. Cirilo-Lombardo
Starting with the well-known Nambu-Goto action for an N-extended body system the propagator in the microcanonical ensemble is explicitly computed. This propagator is independent of the temperature and, in contrast with the previous references, takes account on all the non-local effects produced by the extended objects (e.g., strings) in interaction. The rela
Riccarda Rossi, Antonio Segatti, Ulisse Stefanelli
This paper addresses the long-time behavior of gradient flows of non convex functionals in Hilbert spaces. Exploiting the notion of generalized semiflows by J. M. Ball, we provide some sufficient conditions for the existence of a global attractor. The abstract results are applied to various classes of non convex evolution problems. In particular, we discuss
Hans-Bert Rademacher
We give a lower bound for the length of a non-trivial geodesic loop on a simply-connected and compact manifold of even dimension with a non-reversible Finsler metric of positive flag curvature. Harris and Paternain use this estimate in their recent paper [HP] to give a geometric characterization of dynamically convex Finsler metrics on the 2-sphere.
Dan Coman, Vincent Guedj, Ahmed Zeriahi
Let $(X,ω)$ be a compact Kähler manifold. We introduce and study the largest set $DMA(X,ω)$ of $ω$-plurisubharmonic (psh) functions on which the complex Monge-Ampère operator is well defined. It is much larger than the corresponding local domain of definition, though still a proper subset of the set $PSH(X,\om)$ of all $\om$-psh functions. We prove that cert
B. Bastin, S. Grévy, D. Sohler, O. Sorlin
The energies of the excited states in very neutron-rich $^{42}$Si and $^{41,43}$P have been measured using in-beam $γ$-ray spectroscopy from the fragmentation of secondary beams of $^{42,44}$S at 39 A.MeV. The low 2$^+$ energy of $^{42}$Si, 770(19) keV, together with the level schemes of $^{41,43}$P provide evidence for the disappearance of the Z=14 and N=28
Gary R. Goldstein, Kameshwar C. Wali
Recent experimental findings of several mesons and baryons with "beauty" and "charm" as flavors remind us of the days when strangeness was discovered, and how its inclusion led to SU(3)-flavor symmetry with enormous success in the classification of the "proliferated" states into SU(3) multiplets. One of the key elements was the succes
Isaiah Lankham
This dissertation collects together results on Patience Sorting and its generalizations. It incorporates the results of math.CO/0506358, math.CO/0507031, and math.CO/0512122, as well as previously unpublished results.
Hiroto Kobayashi
Effective Liouville operators of the first- and the second-order symplectic integrators are obtained for the one-dimensional harmonic-oscillator system. The operators are defined only when the time step is less than two. Absolute values of the coordinate and the momentum monotonically increase for large time steps.
Peter P. Rohde, William J. Munro, Timothy C. Ralph, Peter van Loock
We discuss experimental effects in the implementation of a recent scheme for performing bus mediated entangling operations between qubits. Here a bus mode, a strong coherent state, successively undergoes weak Kerr-type non-linear interactions with qubits. A quadrature measurement on the bus then projects the qubits into an entangled state. This approach has
I. Kostyukov, E. Nerush, A. Pukhov
We investigate the dynamics of a relativistic electron in a strongly nonlinear plasma wave in terms of classical mechanics by taking into account the action of the radiative reaction force. The two limiting cases are considered. In the first case where the energy of the accelerated electrons is low, the electron makes many betatron oscillations during the ac
Kazuyuki Yoshimura, Peter Davis, Atsushi Uchida
We have found that a novel type of entrainment occurs in two nonidentical limit cycle oscillators subjected to a common external white Gaussian noise. This entrainment is anomalous in the sense that the two oscillators have different mean frequencies, where the difference is constant as the noise intensity increases, but their phases come to be locked for al
B. M. Levin
The quantitative description of the orthopositronium anomalies ("isotope anomaly" in a gaseous neon for the "resonance conditions" and "lambda{T}-anomaly" in non-resonance conditions) is possible on the basis of a hypothesis about restoration of spontaneously broken complete relativity (A.F.Andreev, 1982) of the limited space-time 
On the perturbation of the electromagnetic energy due to the presence of inhomogeneities with small diameters
math-phChristian Daveau, Abdessatar Khelifi
We consider solutions to the time-harmonic Maxwell problem in $\R^3$. For such solution we provide a rigorous derivation of the asymptotic expansions in the practically interesting situation, where a finite number of inhomogeneities of small diameter are imbedded in the entire space. Then, we describe the behavior of the electromagnetic energy caused by the
Mathias Drton
The Behrens-Fisher problem concerns testing the equality of the means of two normal populations with possibly different variances. The null hypothesis in this problem induces a statistical model for which the likelihood function may have more than one local maximum. We show that such multimodality contradicts the null hypothesis in the sense that if this hyp
Usha N. Bhosle, Indranil Biswas
Let X be a geometrically connected smooth projective curve of genus one, defined over the field of real numbers, such that X does not have any real points. We classify the isomorphism classes of all stable real algebraic vector bundles over X.
Uffe V. Poulsen, Klaus Molmer
We present an analysis of the quantum state resulting from the dissociation of diatomic molecules prepared in a condensate vortex state. The many-body state preserves the rotational symmetry of the system in quantum correlated states by having two equally populated components with angular momentum adding to unity. A simple two-mode analysis and a full quantu
The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
astro-phM. Arnould, S. Goriely, K. Takahashi
The r-process, or the rapid neutron-capture process, of stellar nucleosynthesis is called for to explain the production of the stable (and some long-lived radioactive) neutron-rich nuclides heavier than iron that are observed in stars of various metallicities, as well as in the solar system. A very large amount of nuclear information is necessary in order to
The Age, Metallicity and Alpha-Element Abundance of Galactic Globular Clusters from Single Stellar Population Models
astro-phJon T. Mendel, Robert N. Proctor, Duncan A. Forbes
Establishing the reliability with which stellar population parameters can be measured is vital to extragalactic astronomy. Galactic GCs provide an excellent medium in which to test the consistency of Single Stellar Population (SSP) models as they should be our best analogue to a homogeneous (single) stellar population. Here we present age, metallicity and $α
Hanhee Paik, B. K. Cooper, S. K. Dutta, R. M. Lewis
We report measurements of spectroscopic linewidth and Rabi oscillations in three thin-film dc SQUID phase qubits. One device had a single-turn Al loop, the second had a 6-turn Nb loop, and the third was a first order gradiometer formed from 6-turn wound and counter-wound Nb coils to provide isolation from spatially uniform flux noise. In the 6 - 7.2 GHz rang
The unification of Pythagorean theorem for electronic orbitals with Kepler's law for planetary orbits
physics.gen-phKunming Xu
In the context of two-dimensional spacetime within a helium atom, both 1s electrons are characterized by wave functions that observe duality equation. They are symmetric, orthogonal and interwoven, forming a dynamic rope structure at any moment. Instead of elliptical orbit of planets around the sun, electronic orbitals take the form of matter state transform
Joao Magueijo, John W. Moffat
In a recent note Ellis criticizes varying speed of light theories on the grounds of a number of foundational issues. His reflections provide us with an opportunity to clarify some fundamental matters pertaining to these theories.
Paul Loya, Sergiu Moroianu, Jinsung Park
We study the adiabatic limit of the eta invariant of the Dirac operator over cofinite quotient of PSL(2,R), which is a noncompact manifold with a nonexact fibred-cusp metric near the ends.
The local supermassive black hole mass density: corrections for dependencies on the Hubble constant
astro-phAlister W. Graham, Simon P. Driver
We have investigated past measurements of the local supermassive black hole mass density, correcting for hitherto unknown dependencies on the Hubble constant, which, in some cases, had led to an underestimation of the mass density by factors of ~2. Correcting for this, we note that the majority of past studies yield a local supermassive black hole mas densit
Juan G. Restrepo, Edward Ott, Brian R. Hunt
The largest eigenvalue of the adjacency matrix of a network plays an important role in several network processes (e.g., synchronization of oscillators, percolation on directed networks, linear stability of equilibria of network coupled systems, etc.). In this paper we develop approximations to the largest eigenvalue of adjacency matrices and discuss the rela
Experimental indication of anomalous sensitivity in many-body systems: Deterministic randomness in complex quantum collisions?
quant-phQi Wang, Jian-Long Han, Yu-Chuan Dong, Song-Lin Li
We have experimentally tested a recently suggested possibility for anomalous sensitivity of the cross sections of dissipative heavy ion collisions. Cross sections for the $^{19}$F+$^{27}$Al dissipative collisions were measured at the fixed energy 118.75 MeV of the $^{19}$F for the 12 different beam spots on the same target foil. The data demonstrate dramatic
M. Ablikim
$R$ measurement data taken with the BESII detector at center-of-mass energies between 3.7 and 5.0 GeV is fitted to determine resonance parameters (mass, total width, electron width) of the high mass charmonium states, $ψ(3770)$, $ψ(4040)$, $ψ(4160)$ and $ψ(4415)$. Various effects, including the relative phases between the resonances, interferences, the energ
Kenneth R. Davidson, Dilian Yang
Kumjian and Pask introduced an aperiodicity condition for higher rank graphs. We present a detailed analysis of when this occurs in certain rank 2 graphs. When the algebra is aperiodic, we give another proof of the simplicity of $\ca(\Fth)$. The periodic C*-algebras are characterized, and it is shown that $\ca(\Fth) \simeq \rC(\bT) \otimes \fA$ where $\fA$ i
Kenneth R. Davidson, Stephen C. Power, Dilian Yang
An analysis is given of $*$-representations of rank 2 single vertex graphs. We develop dilation theory for the non-selfadjoint algebras $\A_θ$ and $\A_u$ which are associated with the commutation relation permutation $θ$ of a 2 graph and, more generally, with commutation relations determined by a unitary matrix $u$ in $M_m(\bC) \otimes M_n(\bC)$. We show tha
G. S. Stinson, J. J. Dalcanton, T. Quinn, T. Kaufmann
We simulate the collapse of isolated dwarf galaxies using SPH + N-Body simulations including a physically motivated description of the effects of supernova feedback. As the gas collapses and stars form, the supernova feedback disrupts enough gas to temporarily quench star formation. The gas flows outward into a hot halo, where it cools until star formation c
Jonathan E. Grindlay, the EXIST Team
The synergy of GLAST and the proposed EXIST mission as the Black Hole Finder Probe in the Beyond Einstein Program is remarkable. With its full-sky per orbit hard X-ray imaging (3-600 keV) and "nuFnu" sensitivity comparable to GLAST, EXIST could measure variability and spectra of Blazars in the hard X-ray synchrotron component simultaneous with GLAST
I. Kravchenko
The RICE experiment seeks to measure ultra-high energy neutrinos (E(nu)>10 PeV) by detection of the radio wavelength Cherenkov radiation produced by neutrino-ice collisions within Antarctic ice. An array of 16 dipole antennas, buried at depths of 100-400 m, and sensitive over the 100-500 MHz frequency range, has been continuously taking data for the last sev
Hemachander Subramanian, J. E. Han
We computationally study the frustrated magnetic configurations of a thin soft magnetic layer with the boundary condition fixed by underlying hard magnets. Driven by geometrical constraints and external magnetic field, transitions between frustrated energy minima result in magnetic hysteretic behavior. The presence of soft-magnet introduces strong undulation
D. Clarke, G. -W. Chern, O. A. Tretiakov, O. Tchernyshyov
In this report we demonstrate a simple model for the motion of a vortex domain wall in a ferromagnetic strip of submicron width under the influence of an external magnetic field. The model exhibits three distinct dynamical regimes. In a viscous regime at low fields the wall moves rigidly with a velocity proportional to the field. Above a critical field the m
Lutz Duembgen, Christoph Leuenberger
Benford's law states that for many random variables X > 0 its leading digit D = D(X) satisfies approximately the equation P(D = d) = log_{10}(1 + 1/d) for d = 1,2,...,9. This phenomenon follows from another, maybe more intuitive fact, applied to Y := log_{10}(X): For many real random variables Y, the remainder U := Y - floor(Y) is approximately uniformly
Stefano Giusto, Ashish Saxena
We consider stationary axisymmetric solutions of general relativity that asymptote to five dimensional Minkowski space. It is known that this system has a hidden SL(3,R) symmetry. We identify an SO(2,1) subgroup of this symmetry group that preserves the asymptotic boundary conditions. We show that the action of this subgroup on a static solution generates a
Bjarke Hammersholt Roune
The paper that was here is a preprint that was never turned into a proper paper. In particular it does not have enough citations to the literature. The paper "The Slice Algorithm For Irreducible Decomposition of Monomial Ideals" contains a much better description of the Label algorithm than this preprint did. If you still wish to read the original pr
Davis C. Doherty
Linearly projecting smooth projective varieties provides a method of obtaining hypersurfaces birational to the original varieties. We show that in low dimension, the resulting hypersurfaces only have Du Bois singularities. Moreover, we conclude that these Du Bois singularities are in fact semi log canonical. However, we demonstrate the existence of counterex
Cassini UVIS Observations of the Io Plasma Torus. IV. Modeling Temporal and Azimuthal Variability
astro-phA. J. Steffl, P. A. Delamere, F. Bagenal
In this fourth paper in a series, we present a model of the remarkable temporal and azimuthal variability of the Io plasma torus observed during the Cassini encounter with Jupiter. Over a period of three months, the Cassini Ultraviolet Imaging Spectrograph (UVIS) observed a dramatic variation in the average torus composition. Superimposed on this long-term v
Yehuda Hoffman, Ofer Lahav, Gustavo Yepes, Yaniv Dover
We study the distinct effects of Dark Matter and Dark Energy on the future evolution of nearby large scale structures using constrained N-body simulations. We contrast a model of Cold Dark Matter and a Cosmological Constant (LCDM) with an Open CDM (OCDM) model with the same matter density Omega_m =0.3 and the same Hubble constant h=0.7. Already by the time t
Aiyou Chen, Jin Cao
Network tomography has been regarded as one of the most promising methodologies for performance evaluation and diagnosis of the massive and decentralized Internet. This paper proposes a new estimation approach for solving a class of inverse problems in network tomography, based on marginal distributions of a sequence of one-dimensional linear projections of
A. Baule, R. Friedrich
We calculate the two-point correlation function <x(t2)x(t1)> for a subdiffusive continuous time random walk in a parabolic potential, generalizing well-known results for the single-time statistics to two times. A closed analytical expression is found for initial equilibrium, revealing a clear deviation from a Mittag-Leffler decay.
Sergio Iguri, Carmen Nunez
We review the Coulomb gas computation of three-point functions in the SL(2,R) WZNW model and obtain explicit expressions for generic states. These amplitudes have been computed in the past by this and other methods but the analytic continuation in the number of screening charges required by the Coulomb gas formalism had only been performed in particular case
P. Bechtle
This article gives an overview of the recent searches and measurements of $b\to d$ penguin transitions with the BaBar experiment. The branching fraction of these decays in the Standard Model (SM) is expected to be a factor of 10 or more lower than the corresponding $b\to s$ penguin transitions, but a deviation from the SM prediction would be an equally strik
Mario Rabinowitz
Quantum mechanics (QM) clearly violates Newton's First Law of Motion (NFLM) in the quantum domain for one of the simplest problems, yielding an effect in a force-free region much like the Aharonov-Bohm effect. In addition, there is an incompatibility between the predictions of QM in the classical limit, and that of classical mechanics (CM) with respect t
Hsien-Hang Shieh, Greg van Anders, Mark Van Raamsdonk
The Lin-Maldacena geometries are nonsingular gravity duals to degenerate vacuum states of a family of field theories with SU(2|4) supersymmetry. In this note, we show that at large N, where the number of vacuum states is large, there is a natural `macroscopic' description of typical states, giving rise to a set of coarse-grained geometries. For a given c
Alessandro Giuliani, Tony Rothman
We find an exact solution for the stability limit of relativistic charged spheres for the case of constant gravitational mass density and constant charge density. We argue that this provides an absolute stability limit for any relativistic charged sphere in which the gravitational mass density decreases with radius and the charge density increases with radiu
Yu. A. Kravtsov, B. Bieg, K. Yu. Bliokh
Equation for evolution of the four-component Stokes vector in weakly anisotropic and smoothly inhomogeneous media is derived on the basis of quasi-isotropic approximation of the geometrical optics method, which provides consequent asymptotic solution of Maxwell equations. Our equation generalizes previous results, obtained for the normal propagation of elect
Jakub Mielczarek, Marek Szydlowski
In this paper we investigate tensor modes of perturbations in the universe governed by Loop Quantum Cosmology. We derive the equation for tensor modes and investigate numerically effects of quantum corrections. This investigation reveals that the region of super-adiabatic amplification of tensor modes is smaller in comparison with the classical case. Neglect
Johannes Nordström
We prove that for a 7-dimensional manifold M with cylindrical ends the moduli space of exponentially asymptotically cylindrical torsion-free G_2 structures is a smooth manifold (if non-empty), and study some of its local properties. We also show that the holonomy of the induced metric of an exponentially asymptotically cylindrical G_2 manifold M is exactly G
Dan Olteanu, Christoph Koch, Lyublena Antova
Uncertain information is commonplace in real-world data management scenarios. The ability to represent large sets of possible instances (worlds) while supporting efficient storage and processing is an important challenge in this context. The recent formalism of world-set decompositions (WSDs) provides a space-efficient representation for uncertain data that
Vijay Balasubramanian, Bartlomiej Czech, Donald Marolf, Klaus Larjo
Most quantum states have wavefunctions that are widely spread over the accessible Hilbert space and hence do not have a good description in terms of a single classical geometry. In order to understand when geometric descriptions are possible, we exploit the AdS/CFT correspondence in the half-BPS sector of asymptotically AdS_5 x S^5 universes. In this sector
Klaus Larjo
We define a metric operator in the 1/2-BPS sector of the D1-D5 CFT, the eigenstates of which have a good semi-classical supergravity dual; the non-eigenstates cannot be mapped to semi-classical gravity duals. We also analyse how the data defining a CFT state manifests itself in the gravity side, and show that it is arranged into a set of multipoles. Interest
Stefan Kukulies
We show that a given rational Shimura curve Y with strictly maximal Higgs field in the moduli space of g-dimensional abelian varieties does not generically intersect the Schottky locus for large g. We achieve this by using a result of Viehweg and Zuo which says that if Y parameterizes a family of curves of genus g, then the corresponding family of Jacobians
Christos G. Tsagas, Anthony Challinor, Roy Maartens
General relativity marked the beginning of modern cosmology and it has since been at the centre of many of the key developments in this field. In the present review, we discuss the general-relativistic dynamics and perturbations of the standard cosmological model, the Friedmann-Lemaitre universe, and how these can explain and predict the properties of the ob
Stefano Marino
A novel approach to protein multiple sequence alignment is discussed: substantially this method counterparts with substitution matrix based methods (like Blosum or PAM based methods), and implies a more deterministic approach to chemical/physical sub-grouping of amino acids . Amino acids (aa) are divided into sub-groups with successive derivations, that resu
Ph. Hägler, W. Schroers, J. Bratt, R. G. Edwards
We present a comprehensive study of the lowest moments of nucleon generalized parton distributions in N_f=2+1 lattice QCD using domain wall valence quarks and improved staggered sea quarks. Our investigation includes helicity dependent and independent generalized parton distributions for pion masses as low as 350 MeV and volumes as large as (3.5 fm)^3, for a
John D. Barrow, N. J. Nunes
A computation of the inflationary observables n_{s} and r is made for `logamediate' inflation where the cosmological scale factor expands as $a=\exp (A(\ln t)^λ)$, and is compared to their predicted values in the intermediate inflationary theory, where $a=\exp (Bt^{f})$. Both versions prove to be consistent with observational measurements of the cosmic b
Robin Blume-Kohout, Hui Khoon Ng, David Poulin, Lorenza Viola
We introduce a general operational characterization of information-preserving structures (IPS) -- encompassing noiseless subsystems, decoherence-free subspaces, pointer bases, and error-correcting codes -- by demonstrating that they are isometric to fixed points of unital quantum processes. Using this, we show that every IPS is a matrix algebra. We further e
Sinéad Keegan
Certain integrable models are described by pairs (X,Y) of ADET Dynkin diagrams. At high energy these models are expected to have a conformally invariant limit. The S-matrix of the model determines algebraic equations, whose solutions are mapped to the central charge and scaling dimensions of the corresponding conformal field theory. We study the equations of
Masakazu A. R. Kobayashi, Tomonori Totani, Masahiro Nagashima
We present a new theoretical model for the luminosity functions (LFs) of Lyman alpha (Lya) emitting galaxies in the framework of hierarchical galaxy formation. We extend a semi-analytic model of galaxy formation that reproduces a number of observations for local and high-z galaxies, without changing the original model parameters but introducing a physically-
Generating Minimally Coupled Einstein-Scalar Field Solutions from Vacuum Solutions with Arbitrary Cosmological Constant
gr-qcKjell Tangen
This paper generalizes two previously known techniques for generating minimally coupled Einstein-scalar field solutions in 4 dimensions; the Buchdahl and Fonarev transformations. By applying this solution generation technique, minimally coupled Einstein-scalar field solutions can be generated from vacuum solutions with arbitrary cosmological constant in arbi
K. S. Babu, Abdel G. Bachri, Zurab Tavartkiladze
We present a new realization of inverted neutrino mass hierarchy based on $S_3 \times {\cal U}(1)$ flavor symmetry. In this scenario, the deviation of the solar oscillation angle from $π/4$ is correlated with the value of $θ_{13}$, as they are both induced by a common mixing angle in the charged lepton sector. We find several interesting predictions: $\te_{1
Hongbao Zhang, Wuhan Zhong, Zong-Hong Zhu, Song He
Taking into account that Sandage-Loeb test is unique in its coverage of the redshift desert and available in the near future, we explore the cosmic time evolution behavior of the source redshift for holographic dark energy model, an important competing cosmological model. As a result, we find that Sandage-Loeb test can provide a extremely strong bound on $Ω^
A. Bassetto, G. De Pol
The light-cone gauge allows to single out a set of ``transverse'' fields (TF), whose Green functions are free from UV divergences in SYM N=4. Green functions with external lines involving the remaining fields do instead exhibit divergences: indeed those fields can be expressed, by solving their equations of motion, as composite operators in terms of
A Plane-Symmetric Inhomogeneous Cosmological Model of Perfect Fluid Distribution with Electromagnetic Field I
gr-qcAnirudh Pradhan, P. K. Singh, A. K. Yadav
A plane-symmetric inhomogeneous cosmological model of perfect fluid distribution with electro-magnetic field is obtained. The source of the magnetic field is due to an electric current produced along the z-axis. $F_{12}$ is the non-vanishing component of electromagnetic field tensor. To get a deterministic solution, we assume the free gravitational field is
Christian S. Fischer, Dominik Nickel, Jochen Wambach
We investigate hadronic unquenching effects in light quarks and mesons. Within the non-perturbative continuum framework of Schwinger-Dyson and Bethe-Salpeter equations we quantify the strength of the back reaction of the pion onto the quark-gluon interaction. To this end we add a Yang-Mills part of the interaction such that unquenched lattice results for var
F. Ambrosino, A. Antonelli, M. Antonelli, F. Archilli
Preliminary result on the charged kaon lifetime, obtained by the KLOE experiment operating at DA$Φ$NE, the Frascati $ϕ$-factory, is presented
Alastair Kay
In this paper, we place bounds on when it is impossible to purify a noisy two-qubit state if all the gates used in the purification protocol are subject to adversarial local, independent, noise. It is found that the gate operations must be subject to less than 5.3% error. An existing proof that purification is equivalent to error correction is used to show t
Hamiltonian and Brownian systems with long-range interactions: III. The BBGKY hierarchy for spatially inhomogeneous systems
cond-mat.stat-mechPierre-Henri Chavanis
We study the growth of correlations in systems with weak long-range interactions. Starting from the BBGKY hierarchy, we determine the evolution of the two-body correlation function by using an expansion of the solutions of the hierarchy in powers of 1/N in a proper thermodynamic limit $N\to +\infty$. These correlations are responsible for the ``collisional&#
On the Sensitivity of Massive Star Nucleosynthesis and Evolution to Solar Abundances and to Uncertainties in Helium Burning Reaction Rates
astro-phClarisse Tur, Alexander Heger, Sam M. Austin
We explore the dependence of pre-supernova evolution and supernova nucleosynthesis yields on the uncertainties in helium burning reaction rates. Using the revised solar abundances of Lodders (2003) for the initial stellar composition, instead of those of Anders & Grevesse (1989), changes the supernova yields and limits the constraints that those yields place
J. Grain, A. Barrau
The phenomenology of quantum systems in curved space-times is among the most fascinating fields of physics, allowing --often at the gedankenexperiment level-- constraints on tentative theories of quantum gravity. Determining the dynamics of fields in curved backgrounds remains however a complicated task because of the highly intricate partial differential eq
Temperature dependence of the impurity-induced resonant state in Zn-doped Bi_2Sr_2CaCu_2O$_{8+δ}$ by Scanning Tunneling Spectroscopy
cond-mat.supr-conH. Kambara, Y. Niimi, M. Ishikado, S. Uchida
We report on the temperature dependence of the impurity-induced resonant state in Zn-doped Bi_2Sr_2CaCu_2O$_{8+δ}$ by scanning tunneling spectroscopy at 30 mK < T < 52 K. It is known that a Zn impurity induces a sharp resonant peak in tunnel spectrum at an energy close to the Fermi level. We observed that the resonant peak survives up to 52 K. The peak broad
B. A. Kniehl, G. Kramer, I. Schienbein, H. Spiesberger
We calculate the transverse-momentum (p_T) distribution for the inclusive hadroproduction of B mesons at intermediate values of p_T at next-to-leading order (NLO) in a dedicated finite-mass scheme using realistic non-perturbative fragmentation functions that are obtained through a global fit to e^+e^- data from CERN LEP1 and SLAC SLC exploiting their univers
N. Sadooghi, A. Sodeiri Jalili
The static Coulomb potential of Quantum Electrodynamics (QED) is calculated in the presence of a strong magnetic field in the lowest Landau level (LLL) approximation using two different methods. First, the vacuum expectation value of the corresponding Wilson loop is calculated perturbatively in two different regimes of dynamical mass $m_{dyn.}$, {\it i.e.},
Margherita Barile
We describe classes of toric varieties of codimension 2 which are either minimally defined by 3 binomial equations over any algebraically closed field, or are set-theoretic complete intersections in exactly one positive characteristic.
E. A. Kuraev, V. N. Pervushin, M. K. Volkov
It is shown in the work of one of the authors in 1979 (MKV) that the contribution to the amplitude of this decay from diagrams with one baryon loop is equal to zero and contributions from diagrams with meson loops appear very small. However, pole diagrams with intermediate vector mesons were not considered there. Here it is shown that contributions of these
Mu-in Park
The holographic description of the three-dimensional Kerr-de Sitter space with a gravitational Chern-Simons term is studied, in the context of dS/CFT correspondence. The space has only one (cosmological) event horizon and its mass and angular momentum are identified from the holographic energy-momentum tensor at the asymptotic infinity. The thermodynamic ent
T. R. S. Prasanna
A first principles analysis of order-disorder transition in alloys shows that ordering energy is a function of temperature due to thermal vibrations. The inter-nuclear potential energy term converges if zero point vibrations are incorporated and this method can replace the Ewald sum method. Core energy contributions to the ordering energy are stored exclusiv
Structural distortions and model Hamiltonian parameters: from LSDA to a tight-binding description of LaMnO_3
cond-mat.str-elClaude Ederer, Chungwei Lin, Andrew J. Millis
The physics of manganites is often described within an effective two-band tight-binding (TB) model for the Mn e_g electrons, which apart from the kinetic energy includes also a local "Hund's rule" coupling to the t_{2g} core spin and a local coupling to the Jahn-Teller (JT) distortion of the oxygen octahedra. We test the validity of this model by
W. Yi, G. -D. Lin, L. -M. Duan
We discuss the experimental signal for the Bose condensation of cold atoms in an optical lattice at finite temperature. Instead of using the visibility of the interference pattern via the time-of-flight imaging, we show that the momentum space density profile in the first Brillouin zone, in particular its bimodal distribution, provides an unambiguous signal
Critical mass of bacterial populations in a generalized Keller-Segel model. Analogy with the Chandrasekhar limiting mass of white dwarf stars
cond-mat.stat-mechPierre-Henri Chavanis, Clement Sire
We point out a remarkable analogy between the limiting mass of white dwarf stars (Chandrasekhar's limit) and the critical mass of bacterial populations in a generalized Keller-Segel model of chemotaxis [Chavanis & Sire, PRE, 69, 016116 (2004)]. This model is based on generalized stochastic processes leading to the Tsallis statistics. The equilibrium stat
New Lax pair for restricted multiple three wave interaction system, quasiperiodic solutions and bi-hamiltonian structure
nlin.SIN. A. Kostov, A. V. Tsiganov
We study restricted multiple three wave interaction system by the inverse scattering method. We develop the algebraic approach in terms of classical $r$-matrix and give an interpretation of the Poisson brackets as linear $r$-matrix algebra. The solutions are expressed in terms of polynomials of theta functions. In particular case for $n=1$ in terms of Weiers
Gauge invariances vis-{á}-vis Diffeomorphisms in second order metric gravity: A new Hamiltonian approach
hep-thPradip Mukherjee, Anirban Saha
A new analysis of the gauge invariances and their unity with diffeomorphism invariances in second order metric gravity is presented which strictly follows Dirac's constrained Hamiltonian approach.
Heavy Meson Distribution Amplitudes of Definite Geometric Twist with Contribution of 3-Particle Distribution Amplitudes
hep-phB. Geyer, O. Witzel
Under the constraints of HQET the equations of motion of heavy meson distribution amplitudes of definite geometric twist, using the knowledge of their off-cone structure, are reformulated as a set of algebraic equations. Together with equations due to various Dirac structures various relations between the (sets of) independent two- and three particle distrib
Resonant spin polarization in a two-dimensional hole gas: Effect of the Luttinger term, structural inversion asymmetry and Zeeman splitting
cond-mat.mes-hallTianxing Ma
The electric-field-induced resonant spin polarization of a two-dimensional hole gas described by Luttinger Hamiltonian with structural inversion asymmetry and Zeeman splitting in a perpendicular magnetic field was studied. The spin polarization arising from splitting between the light and the heavy hole bands shows a resonant peak at a certain magnetic field
K. Fialkowski, R. Wit
We analyze recent data on the electroproduction of hadrons on nuclei using the Lund model for electroproduction on nucleons and a simple geometrical model for the absorption effects. We show that the model seems to overestimate the A-dependence of the absorption effects, although it described the earlier data of the same HERMES experiment reasonably well. We
Makoto Ozawa
We introduce a new numerical knot invariant, termed the \textit{segment number}, which is derived from partitioned knot diagrams subject to specific over/under-crossing constraints. We prove that a knot is non-trivial if and only if its segment number is at least 3. Furthermore, we investigate the structural properties of the directed graph associated with a
B. Pasquini, S. Boffi
The first moment of longitudinal and transverse spin densities of quarks in the nucleon are calculated in a light-front constituent quark model for the different cases of quark and nucleon polarization. Significant distortions are found for the transverse spin densities. In particular the Sivers function is predicted with opposite sign for up and down quarks
Lin He, Chinping Chen, Ning Wang, Wei Zhou
Finite size effect on the antiferromagnetic transition temperature, TN, of Co3O4 nanoparticles of 75, 35, and 16 nm in diameter, has been investigated. The AFM transition point, TN, reduces with the decreasing diameter, d. Along with the results from the previous experiments on the Co3O4 nanoparticles of 8 and 4.3 nm, the variation of TN with d appears to fo
Norihito Toyota
In this article we discuss network growth based on Prisoner's Dilemma(PD) where palyers on nodes in a network palay with its linked players. The players estimate total profits in the PD. When a new node is attached, the node make linkes to nodes in the network with the probabilities in proportion to the profits made by the game. Iterating this process, a
Terry A. Loring
The C*-algebra qC is the smallest of the C*-algebras qA introduced by Cuntz in the context of KK-theory. An important property of qC is the natural isomorphism of K0 of D with classes of homomorphism from qC to matrix algebras over D. Our main result concerns the exponential (boundary) map from K0 of a quotient B to K1 of an ideal I. We show if a K0 element
T. Yamanishi
We propose a new model for describing baryon semi-leptonic decays for estimating $F$ and $D$ values with explicit breaking effects of both SU(3) and SU(2) flavor symmetry, where all possible SU(3) and SU(2) breaking effects are induced from an effective interaction. An overall fit including the weak magnetism form factor yields $F=0.477\pm 0.001$ and $D=0.83
Ji-Rong Ren, Ran Li
As a simple but important example of dynamical black hole, we analysis the dynamical black hole in $n$-dimensional Vaidya spacetime in detail. We investigated the thermodynamics of field equation in $n$-dimensional Vaidya spacetime. The unified first law was derived in terms of the methods proposed by Sean A Hayward. The first law of dynamical black hole was
Ji-Rong Ren, Ran Li, Fei-Hu Liu
Recently, it has been suggested that Hawking radiation can be derived from quantum tunnelling methods. In this letter, we calculated Hawking temperature of dilatonic black holes from tunnelling formalism. The two semi-classical methods adopted here are: the null-geodesic method proposed by Parikh and Wilczek and the Hamilton-Jacobi method propsed by Angheben
Vladimir Chernousov, Lucy Lifschitz, Dave Witte Morris
If Gamma is a nonuniform, irreducible lattice in a semisimple Lie group whose real rank is greater than 1, we show Gamma contains a subgroup that is isomorphic to a nonuniform, irreducible lattice in either SL(3,R), SL(3,C), or a direct product SL(2,R)^m x SL(2,C)^n$, with m + n > 1. (In geometric terms, this can be interpreted as a statement about the exist
Frederick A. Matsen, Elchanan Mossel, Mike Steel
In this paper we apply new geometric and combinatorial methods to the study of phylogenetic mixtures. The focus of the geometric approach is to describe the geometry of phylogenetic mixture distributions for the two state random cluster model, which is a generalization of the two state symmetric (CFN) model. In particular, we show that the set of mixture dis
Huagui Duan, Yiming Long
We prove that for every $\Q$-homological Finsler 3-sphere $(M,F)$ with a bumpy and irreversible metric $F$, either there exist two non-hyperbolic prime closed geodesics, or there exist at least three prime closed geodesics.
Bram Boroson, Saeqa Dil Vrtilek, John C. Raymond, Martin Still
We observed an entire 1.7 day orbit of the X-ray binary Hercules X-1 with the Far Ultraviolet Spectroscopic Explorer (FUSE). Changes in the O VI 1032,1037 line profiles through eclipse ingress and egress indicate a Keplerian accretion disk spinning prograde with the orbit. These observations may show the first double-peaked accretion disk line profile to be
M. Urano, J. Tonishi, H. Inoue, T. Saito
The vortex state in a single crystal of the layered organic superconductor κ-(BEDT-TTF2Cu(NCS)2, where BEDT-TTF (or ET) is bis(ethylenedithio)tetrathiafulvalene, was studied by 1H-NMR. Under a low field region around 0.75 T, the vortex glass-liquid transition was demonstrated by a diverging of the longitudinal nuclear spin relaxation rate and peak-broadening