April 2001 arXiv papers — page 3
Showing 201–300 of 2,540 papers
Edwin Langmann
We give a self-contained presentation and comparison of two different algorithms to explicitly solve quantum many body models of indistinguishable particles moving on a circle and interacting with two-body potentials of $1/\sin^2$-type. The first algorithm is due to Sutherland and well-known; the second one is a limiting case of a novel algorithm to solve th
Alexander Brudnyi
In the paper we prove a factorization theorem for representations of fundamental groups of compact Kähler manifolds ({\em Kähler groups}) into solvable matrix groups. We apply this result to prove that the universal covering of a compact Kähler manifold with a residually solvable fundamental group is holomorphically convex.
Michael Kunzinger
We present the construction of an associative, commutative algebra $\hat {\mathcal G}$ of generalized functions on a manifold $X$ satisfying the following optimal set of permanence properties: (i)The space of distributions on $X$ is linearly embedded into $\hat {\mathcal G}$, $f(p)\equiv 1$ is the unity in the algebra. (ii) For every smooth vector field $ξ$
A. Brudnyi
Proceeding the study of local properties of analytic functions started in [Br] we prove new dimensionless inequalities for such functions in terms of their Chebyshev degree. As a consequence, we obtain the reverse Holder inequalities for analytic functions with absolute (i.e., independent of dimension) constants. For polynomials such inequalities were recent
Michael Grosser
This contribution presents a comprehensive analysis of Colombeau (-type) algebras in the range between the diffeomorphism invariant algebra introduced in Part I and Colombeau's original algebra. Along the way, it provides several classification results which are indispensable for obtaining an intrinsic description of a (full) Colombeau algebra on a manif
Masato Okado, Anne Schilling, Mark Shimozono
The relation of crystal bases with $q$-identities is discussed, and some new results on crystals and $q$-identities associated with the affine Lie algebra $C_n^{(1)}$ are presented.
Donald Yau
We introduce Clapp-Puppe type generalized Lusternik-Schnirelmann (co)category in a Quillen model category. We establish some of their basic properties and give various characterizations of them. As the first application of these characterizations, we show that our generalized (co)category is invariant under Quillen modelization equivalences. In particular, g
Robin Hartshorne
In this paper we review the notions of gonality and Clifford index of an abstract curve. For a curve embedded in a projective space, we investigate the connection between the \ci of the curve and the \gc al properties of its \emb. In particular if $C$ is a curve of degree $d$ in $¶^3$, and if $L$ is a multisecant of maximum order $k$, then the pencil of plan
Robin Hartshorne
We review the present state of the problem, for each degree $d$ and genus $g$, is the Hilbert scheme of locally Cohen--Macaulay curves in ${\mathbb P}^3$ connected?
Francois Ebobisse, Rodica Toader
In this paper we study the integral representation in the space SBD(O) of special functions with bounded deformation of some L^1-norm lower semicontinuous functionals invariant with respect to rigid motions.
Elise Benlolo, Yasmine B. Sanderson
We study the structure of hypersurface orbital varieties of sl(N,C) (those that are hypersurfaces in the nilradical of some parabolic subalgebra) and how information about this structure is encoded in the standard Young tableau associated to it by the Robinson-Schensted algorithm. We present a conjecture for the exact form of the unique non-linear defining e
Manfred Einsiedler, Douglas Lind, Richard Miles, Thomas Ward
A general framework for investigating topological actions of $Z^d$ on compact metric spaces was proposed by Boyle and Lind in terms of expansive behavior along lower-dimensional subspaces of $R^d$. Here we completely describe this expansive behavior for the class of algebraic $Z^d$-actions given by commuting automorphisms of compact abelian groups. The descr
A. Kishimoto, S. Sakai
We prove that the pure state space is homogeneous under the action of the group of asymptotically inner automorphisms for all the separable simple nuclear C*-algebras. If simplicity is not assumed for the C*-algebras, the set of pure states whose GNS representations are faithful is homogeneous for the above action.
H. Futamura, N. Kataoka, A. Kishimoto
We prove that the pure state space is homogeneous under the action of the automorphism group (or a certain smaller group of approximately inner automorphisms) for a fairly large class of simple separable nuclear C*-algebras, including the approximately homogeneous C*-algebras and the class of purely infinite C*-algebras which has been recently classified by
Daniel Huybrechts
This paper studies the infinitesimal variation of the Lefschetz decomposition associated with a compatible sl_2-representation on a graded algebra. This allows to prove that the Jordan-Lefschetz property holds infinitesimally for the Kaehler Lie algebra (introduced by Looijenga and Lunts) of any compact Kaehler manifold. As a second application we describe h
Nathan Berkovits
Recently, the superstring was covariantly quantized using the BRST-like operator $Q = \oint λ^αd_α$ where $λ^α$ is a pure spinor and $d_α$ are the fermionic Green-Schwarz constraints. By performing a field redefinition and a similarity transformation, this BRST-like operator is mapped to the sum of the Ramond-Neveu-Schwarz BRST operator and $η_0$ ghost. This
C. Gonera, P. Kosinski, P. Maslanka
A gauge theory equivalent to the hamiltonian reduction scheme for rational Calogero - Moser model is presented.
K. Murakami
We study the system of the Dp'-brane with Dp-brane (p<p') inside, in the case where B_{ij} field is a nonvanishing constant. In order to understand how the Dp-brane is viewed from the Dp'-brane worldvolume theory, we investigate the process in which the Dp-brane is probed with p'-p' open string. We calculate the scattering amplitudes among p-p' open strings
L. Laperashvili
This review is devoted to Anti-Grand Unification and to the Multiple Point Model solution of problems of the unification of gauge interactions. According to this model, near the Planck scale there exists a Multiple Critical Point (MCP), where vacua of all fields existing in nature are degenerate. The MCP rules over the evolution of all inverse finestructure
Realization of the Large Mixing Angle Solar Neutrino Solution in an SO(10) Supersymmetric Grand Unified Model
hep-phC. H. Albright, S. M. Barr
An SO(10) supersymmetric grand unified model proposed earlier leading to the solar solution involving ``just-so'' vacuum oscillations is reexamined to study its ability to obtain the other possible solar solutions. It is found that all four viable solar neutrino oscillation solutions can be achieved in the model simply by modification of the right-ha
D. F. Carvalho, M. E. Gomez, S. Khalil
We analyze the lepton-flavor violation in supersymmetric models with non-universal soft breaking terms derived from strings. We show that the non-universality of the scalar masses enhances the branching ratios more significantly than the non-universality of the A-terms
A. P. Bakulev, S. V. Mikhailov, N. G. Stefanis
Using QCD sum rules with nonlocal condensates the twist-2 pion distribution amplitude is determined by means of its moments and their confidence intervals, including also radiative corrections. An admissible set of pion distribution amplitudes is constructed in the a_2, a_4 plane of the Gegenbauer polynomial expansion coefficients. The determined a_2, a_4 re
Zurab Berezhiani, Ilia Gogoladze, Archil Kobakhidze
The gauge coupling constant unification at the low ($O$(TeV)) scale can be obtained just in four dimensions, without help of the power like renormalization group evolution in extra dimensions, due to the presence of some extra particle states at intermediate scales. We show explicit examples of such extra states in the range of 100 GeV -- 1 TeV which can be
B. Ananthanarayan, J. Pasupathy
Plausible interrelations between parameters of the standard model are studied. The empirical value of the top quark mass, when used in the renormalization group equations, suggests that the ratio of the colour SU(3) gauge coupling $g_3$, and the top coupling $g_t$ is independent of the renormalization scale. On the other hand, variety of top-condensate model
G. Boix
The current status of the experimental knowledge of $\Bs$ meson physics is reviewed. Results from LEP and CDF on the width difference $\dgs$ are presented, the corresponding average is found to be in good agreement with the present theoretical estimation. The $\Bs$ oscillations have not yet been resolved, despite the progress recently achieved by SLD and ALE
Jet energy scale setting with "photon+Jet" events at LHC energies. Minijets and cluster suppression and photon Pt - jet Pt disbalance
hep-exD. V. Bandourin, V. F. Konoplianikov, N. B. Skachkov
In this paper the study of "photon+Jet" events is continued and the event number determination useful for jet energy scale setting with the possible CMS detector hadron calorimeter calibration at LHC is fulfiled. The sources of photon Pt and jet Pt disbalance are exposed. It is shown that the cluster Pt limitation, which is found in an event outside
Jet energy scale setting with "Gamma+Jet" events at LHC energies. Detailed study of the background suppression
hep-exD. V. Bandourin, V. F. Konoplyanikov, N. B. Skachkov
The possibilities of the background events suppression, based on the QCD subprocesses of qg-, gg-, qq- scattering with big cross sections, to the signal \gpj events are studied. Basing on the introduced selection criteria, the background suppression factors and signal events selection efficiencies and the number of the events, that can be collected at LHC wi
D. V. Bandourin, V. F. Konoplyanikov, N. B. Skachkov
It is shown that "photon+Jet" events, being collected at LHC, would provide us with the data sufficient for an extraction of gluon distribution function in a proton using valence and s quark distributions measured in the same experiment with another physical proces A new region of 10^{-4}< x < 10^{-1} with 1.6x10^3< Q^2<10^5 ~(GeV/c)^2 can be covered
Jet energy scale setting with "photon+Jet" events at LHC energies. Selection of events with a clean "photon+Jet" topology and photon Pt - jet Pt disbalance
hep-exD. V. Bandourin, V. F. Konoplyanikov, N. B. Skachkov
It is shown in the paper that Pt activity limitation (modulus of the vector sum) of all particle beyond "photon+Jet" system Pt^out leads to the noticeable photon Pt - jet Pt disbalance decreasing. On a simultaneous restriction of the cluster Pt and Pt^out from above it is possible to reach an acceptable balance between photon Pt - jet Pt with a suffi
Kirill A. Bronnikov
We enumerate all possible types of spacetime causal structures that can appear in static, spherically symmetric configurations of a self-gravitating, real, nonlinear, minimally coupled scalar field ϕin general relativity, with an arbitrary potential V(ϕ), not necessarily positive-definite. It is shown that a variable scalar field adds nothing to the list of
Coaxing Confidences from an Old Friend: Probabilistic Classifications from Transformation Rule Lists
cs.CLRadu Florian, John C. Henderson, Grace Ngai
Transformation-based learning has been successfully employed to solve many natural language processing problems. It has many positive features, but one drawback is that it does not provide estimates of class membership probabilities. In this paper, we present a novel method for obtaining class membership probabilities from a transformation-based rule list cl
Radu Florian, David Yarowsky
This paper presents a novel method of generating and applying hierarchical, dynamic topic-based language models. It proposes and evaluates new cluster generation, hierarchical smoothing and adaptive topic-probability estimation techniques. These combined models help capture long-distance lexical dependencies. Experiments on the Broadcast News corpus show sig
J. S. Frasier
In this thesis are presented analytical results and numerical simulations concerning resonant processes in a frozen gas. This work was begun with the intent of modeling experiments involving energy transfer due to dipole-dipole interactions between ultracold Rydberg atoms, and the subsequent propagation of dipolar excitons. However, the results and the techn
Colin Denniston, Enzo Orlandini, J. M. Yeomans
We study the kinetics of the nematic-isotropic transition in a two-dimensional liquid crystal by using a lattice Boltzmann scheme that couples the tensor order parameter and the flow consistently. Unlike in previous studies, we find the time dependences of the correlation function, energy density, and the number of topological defects obey dynamic scaling la
A. Gorlitz, J. M. Vogels, A. E. Leanhardt, C. Raman
Bose-Einstein condensates of sodium atoms have been prepared in optical and magnetic traps in which the energy-level spacing in one or two dimensions exceeds the interaction energy between atoms, realizing condensates of lower dimensionality. The cross-over into two-dimensional and one-dimensional condensates was observed by a change in aspect ratio and satu
M. J. Mehl, D. A. Papaconstantopoulos, D. J. Singh
Density functional calculations are used to investigate the effects of partial substitutional alloying of the B site in MgB2 with C and Be alone and combined with alloying of the Mg site with Cu. The effect of such substitutions on the electronic structure, electron phonon coupling and superconductivity are discussed. We find that Be substitution for B is un
Asymmetric Primitive-Model Electrolytes: Debye-Huckel Theory, Criticality and Energy Bounds
cond-mat.stat-mechDaniel M. Zuckerman, Michael E. Fisher, Stefan Bekiranov
Debye-Huckel (DH) theory is extended to treat two-component size- and charge-asymmetric primitive models, focussing primarily on the 1:1 additive hard-sphere electrolyte with, say, negative ion diameters, a--, larger than the positive ion diameters, a++. The treatment highlights the crucial importance of the charge-unbalanced ``border zones'' around
M. S. Laad, E. Müller-Hartmann
Motivated by the unusual features observed in the transport properties of the ferromagnetic "bad metal" $SrRuO_{3}$, we construct a model incorporating essential features of the realistic structure of this nearly cubic material. In particular, we show how the $t_{2g}$orbital {\it orientation} in the perfectly cubic structure determines the peculiar s
Coulomb interaction and stability of CE-type structure in half-doped manganites, reply
cond-mat.str-elJeroen van den Brink, Giniyat Khaliullin, Daniel Khomskii
In his Comment (cond-mat/0104353), Shen points out that the on-site Coulomb interaction, that can cause charge order in half-doped manganites, also destabilizes the magnetic CE-phase observed in these systems. This is a valid observation, but it is not a priori clear whether in the relevant parameter regime the C-phase is indeed lower in energy then the CE-p
M. A. Hayward, M. K. Haas, A. P. Ramirez, T. He
The effects of partial substitution of Cu and Co for Ni in the intermetallic perovskite superconductor MgCNi3 are reported. Calculation of the expected electronic density of states suggests that electron (Cu) and hole (Co) doping should have different effects. For MgCNi3-xCux, solubility of Cu is limited to approximately 3% (x = 0.1), and Tc decreases system
Influence of quantum fluctuations on zero-temperature phase transitions between collinear and noncollinear states in frustrated spin systems
cond-mat.str-elSven E. Krüger, Johannes Richter
We study a square-lattice spin-half Heisenberg model where frustration is introduced by competing nearest-neighbor bonds of different signs. We discuss the influence of quantum fluctuations on the nature of the zero-temperature phase transitions from phases with collinear magnetic order at small frustration to phases with noncollinear spiral order at large f
L. A. Ponomarenko, A. de Visser, E. Brück, A. M. Tishin
We have calculated the low-field magnetic susceptibility $χ$ of a system consisting of non-interacting mono-dispersed nanoparticles using a classical statistical approach. The model makes use of the assumption that the axes of symmetry of all nanoparticles are aligned and oriented at a certain angle $ψ$ with respect to the external magnetic field. An analyti
Energy landscapes, lowest gaps, and susceptibility of elastic manifolds at zero temperature
cond-mat.stat-mechE. T. Seppälä, M. J. Alava
We study the effect of an external field on (1+1) and (2+1) dimensional elastic manifolds, at zero temperature and with random bond disorder. Due to the glassy energy landscape the configuration of a manifold changes often in abrupt, ``first order'' -type of large jumps when the field is applied. First the scaling behavior of the energy gap between t
Andrea Cavagna, Irene Giardina, Giorgio Parisi
Recent numerical developments in the study of glassy systems have shown that it is possible to give a purely geometric interpretation of the dynamic glass transition by considering the properties of unstable saddle points of the energy. Here we further develop this program in the context of a mean-field model, by analytically studying the properties of the c
Spin dynamical properties and orbital states of the layered perovskite La_2-2x_Sr_1+2x_Mn_2_O_7 (0.3 <= x < 0.5)
cond-mat.str-elK. Hirota, S. Ishihara, H. Fujioka, M. Kubota
Low-temperature spin dynamics of the double-layered perovskite La_2-2x_Sr_1+2x_Mn_2_O_7 (LSMO327) was systematically studied in a wide hole concentration range (0.3 <= x < 0.5). The spin-wave dispersion, which is almost perfectly 2D, has two branches due to a coupling between layers within a double-layer. Each branch exhibits a characteristic intensity oscil
Sheng Xu, Yutaka Moritomo, Kenichi Kato, Arao Nakamura
Effects of magnetic impurity on the superconductivity has been investigated in Mg1-xMnB2. With increase of Mn concentration x, the lattice constant c (perpendicular to the boron sheet) decreases at a rate of -1.4 % (= dlnc/dx), while a remains nearly unchanged. The transition temperature Tc steeply decreases with $x$ at a rate of dTc/dx = - 159 K. These resu
Density-Matrix Algorithm for Phonon Hilbert Space Reduction in the Numerical Diagonalization of Quantum Many-Body Systems
cond-mat.str-elAlexander Weiße, Gerhard Wellein, Holger Fehske
Combining density-matrix and Lanczos algorithms we propose a new optimized phonon approach for finite-cluster diagonalizations of interacting electron-phonon systems. To illustrate the efficiency and reliability of our method, we investigate the problem of bipolaron band formation in the extended Holstein Hubbard model.
Vortex dynamics in layered superconductors with correlated defects: influence of interlayer coupling
cond-mat.supr-conA. Engel, H. J. Trodahl, J. C. Abele, D. Smith
We report a detailed study of the vortex dynamics and vortex phase diagrams of two amorphous Ta_0.3Ge_0.7/Ge multilayered films with intrinsic coplanar defects, but different interlayer coupling. A pinned Bose-glass phase in the more weakly coupled sample exists only below a cross-over field H* in striking contrast to the strongly coupled film. Above H* the
E. N. M. Cirillo, F. Nardi, A. D. Polosa
It is discussed how the equilibrium properties of the Ising model are described by an Hamiltonian with an antiferromagnetic low temperature behavior if only an heat bath dynamics, with the characteristics of a Probabilistic Cellular Automaton, is assumed to determine the temporal evolution of the system.
Z. V. Popovic, V. A. Ivanov, O. P. Khoung, T. Nakamura
We have studied polarized Raman spectra of (TMTSF)2PF6 single crystals in the wide spectral and temperature range using different laser energies. We observed and assigned 23 Raman active modes. The carbon C=C in-phase and out-of-phase stretching modes at 1464 cm-1 and 1602 cm-1 show strong electron-molecular-vibration coupling. The mode at about 1565 cm-1 is
L. Hough, L. A. K. Donev, R. J. Zieve
We have measured a precessing superfluid vortex line, stretched from a wire to the wall of a cylindrical cell. By contrast to previous experiments with a similar geometry, the motion along the wall is smooth. The key difference is probably that our wire is substantially off center. We verify several numerical predictions about the motion, including an asymme
Bidhan Chandra Bag, Suman Kumar Banik, Deb Shankar Ray
Based on a Fokker-Planck description of external Ornstein-Uhlenbeck noise and cross-correlated noise processes driving a dynamical system we examine the interplay of the properties of noise processes and the dissipative characteristic of the dynamical system in the steady state entropy production and flux. Our analysis is illustrated with appropriate example
Tin-Lun Ho
We show that as the number of vortices in a three dimensional Bose-Einstein Condensate increases, the system reaches a "quantum Hall" regime where the density profile is a Gaussian in the xy-plane and an inverted parabolic profile along z. The angular momentum of the system increases as the vortex lattice shrinks. However, Coriolis force prevents the
A High Spatial Resolution Analysis of the MAXIMA-1 Cosmic Microwave Background Anisotropy Data
astro-phA. T. Lee, P. Ade, A. Balbi, J. Bock
We extend the analysis of the MAXIMA-1 cosmic microwave background (CMB) data to smaller angular scales. MAXIMA, a bolometric balloon experiment, mapped a 124 deg$^2$ region of the sky with 10\arcmin resolution at frequencies of 150, 240 and 410 GHz during its first flight. The original analysis, which covered the multipole range $36 \leq \ell \leq 785$, is
Caltech Faint Galaxy Redshift Survey XV: Classification of Galaxies with 0.2 < z < 1.1 in the Hubble Deep Field (North) and its Flanking Fields
astro-phSidney van den Bergh, Judith G. Cohen, Christopher Crabbe
To circumvent the spatial effects of resolution on galaxy classification, the images of 233 objects of known redshift in the Hubble Deep Field (HDF) and its Flanking Fields (FF) that have redshifts in the range 0.20 < z < 1.10 were degraded to the resolution that they would have had if they were all located at a redshift z= 1.00. As in paper XIV of the prese
Cold Gas Kinematics in an L* Spiral Galaxy at z=0.437: The Nature of Damped Lyman-alpha Absorbers
astro-phF. H. Briggs, A. G. de Bruyn, R. C. Vermeulen
Westerbork Radio Synthesis Telescope observations of the redshifted 21cm line absorber against the z_em = 0.871 double lobed quasar 3C196 show that the intervening absorber is an L approximately equal L* spiral galaxy (3C196-G1) and that the absorbing layer of cold gas extends to radii of at least 30 h_50^-1 kpc. The new data solve several long standing puzz
Y. -Z. Qian, G. J. Wasserburg
The recent discovery by Cayrel et al. of U in CS 31082-001 along with Os and Ir at greatly enhanced abundances but with [Fe/H]=-2.9 strongly reinforces the argument that there are at least two kinds of SNII sources for r-nuclei. One source is the high-frequency H events responsible for heavy r-nuclei (A>135) but not Fe. The H-yields calculated from data on o
The Farthest Known Supernova: Support for an Accelerating Universe and a Glimpse of the Epoch of Deceleration
astro-phAdam G. Riess, Peter E. Nugent, Brian P. Schmidt, John Tonry
We present photometric observations of an apparent Type Ia supernova (SN Ia) at a redshift of ~1.7, the farthest SN observed to date. SN 1997ff, was discovered in a repeat observation by the HST of the HDF-), and serendipitously monitored with NICMOS on HST throughout the GTO campaign. The SN type can be determined from the host galaxy type:an evolved, red e
Spyros Basilakos
We attempt to put constraints on different cosmological and biasing models by combining the recent clustering results of X-ray sources in the local ($z\le 0.1$) and distant universe ($z\sim 1$). To this end we compare the measured angular correlation function for bright (Akylas et al. 2000) and faint (Vikhlinin & Forman 1995) {\em ROSAT} X-ray sources respec
G. Chartas, X. Dai, S. C. Gallagher, G. P. Garmire
The mini Broad Absorption Line (BAL) quasar RX J0911.4+0551 was observed with the Advanced CCD Imaging Spectrometer (ACIS) of the Chandra X-ray Observatory for ~ 29 ks as part of a gravitational lens (GL) survey aimed at measuring time-delays. Timing analysis of the light-curve of the lensed image A2 shows a rapid flux variation with a duration of about 2000
D. Lynden-Bell, J. P. O'Dwyer
We produce the simple formula for the radius R of a cold body of mass M, (4 pi rho/3)^{1/3} R = I.M^{1/3} / [1+ (M/Mp)^{2/3}], where I is one for white dwarfs with non-relativistic electrons, but depends on the ratio of the total mass to Mch, the Chandrasekhar mass. Mp is the mass of the planet of maximum radius and rho is the density of the material at low
G. S. Bisnovatyi-Kogan, N. V. Ardeljan, S. G. Moiseenko
Jet formation is connected most probably with matter acceleration from the vicinity of rotating magnetized bodies. It is usually related to the mass outflows and ejection from accretion disks around black holes. Problem of jet collimation is discussed. Collapse of a rotating magnetized body during star formation or supernovae explosion may lead to a jet-like
A. Ray, R. Petre, E. M. Schlegel
We report on the X-ray observation of the radio selected supernova SN1979C carried out with ASCA in 1997 December and serendipitously available from a Chandra Guaranteed Time Observation in 1999 November. The supernova, of type SN II-Linear (SN IIL), was first observed in the optical and occurred in the weakly barred, almost face on spiral galaxy NGC 4321 (M
Daniele Fargion
Fireballs are huge isotropic explosions models widely believed to explain Gamma Ray Burst, GRBs (Piran,1999); ever-new versions consider wide beamed (10^o) Jet explosions hitting external shells. On the contrary, since 1994-1998, we argued (Fargion 1995-2000; see also Blackman et all.1996) that GRBs (as well as Soft Gamma Repeaters SGR) are spinning and prec
Henry B. Throop, John Bally, Larry W. Esposito, Mark J. McCaughrean
Hundreds of circumstellar disks in the Orion nebula are being rapidly destroyed by the intense ultraviolet radiation produced by nearby bright stars. These young, million-year-old disks may not survive long enough to form planetary systems. Nevertheless, the first stage of planet formation -- the growth of dust grains into larger particles -- may have begun
Victor Galitski, D. D. Sokoloff
We consider a dynamo wave in the solar convective shell for the kinematic $αω$-dynamo model. The spectrum and eigenfunctions of the corresponding equations are derived analytically with the aid of the WKB method. Our main aim here is to investigate the dynamo wave behavior in the vicinity of the solar poles. Explicit expressions for the incident and reflecte
O. Doré, L. Knox, A. Peel
We have developed a fast, accurate and generally applicable method for inferring the power spectrum and its uncertainties from maps of the cosmic microwave background (CMB) in the presence of inhomogeneous and correlated noise. For maps with 10 to 100 thousand pixels, we apply an exact power spectrum estimation algorithm to submaps of the data at various res
A. K. Mittal, Daksh Lohiya
Assuming a fractal distribution of matter in the universe, consequences that follow from the General Theory of Relativity and the Copernican Principle for fractal cosmology are examined. The change in perspective necessary to deal with a fractal universe is highlighted. An ansatz that provides a concrete application of the Conditional Cosmological Principle
Jorgen Rasmussen, Mark A. Walton
We present the first polytope volume formulas for the multiplicities of affine fusion, the fusion in Wess-Zumino-Witten conformal field theories, for example. Thus, we characterise fusion multiplicities as discretised volumes of certain convex polytopes, and write them explicitly as multiple sums measuring those volumes. We focus on su(2), but discuss higher
Lam Hui, Zoltan Haiman, Matias Zaldarriaga, Tal Alexander
We reassess constraints on the cosmological baryon density from observations of the mean decrement and power spectrum of the Lyman-alpha forest, taking into account uncertainties in all free parameters in the simplest gravitational instability model. The uncertainty is dominated by that of the photoionizing background, but incomplete knowledge of the thermal
Angular dependence of novel magnetic quantum oscillations in a quasi-two-dimensional multiband Fermi liquid with impurities
cond-mat.str-elA. M. Bratkovsky, A. S. Alexandrov
The semiclassical Lifshitz-Kosevich-type description is given for the angular dependence of quantum oscillations with combination frequencies in a multiband quasi-two-dimensional Fermi liquid with a constant number of electrons. The analytical expressions are found for the Dingle, thermal, spin, and amplitude (Yamaji) reduction factors of the novel combinati
Yael Naze, Jean-Marie Vreux, Gregor Rauw
Since the beginning of the past century, the nature of HD 108 has been a subject of intense debate. One after another, astronomers explored its variability and attributed it either to binarity, or to changes in the stellar wind of a single star. In this article, we analyse a 30 years long campaign of spectroscopic observations of this star with special empha
Daniel E. Holz
With the advent of large, deep surveys, the observation of a strongly gravitationally lensed supernova becomes increasingly likely. High-redshift surveys continue apace, with a handful of type Ia supernovae observed to date at redshifts of one or greater. In addition, a satellite (the Supernova/Acceleration Probe [SNAP]) has been proposed dedicated to observ
Yongzhong Xu, Max Tegmark, Angelica de Oliveira-Costa
We measure the cosmic microwave background (CMB) power spectrum on angular scales l~30-200 (1-6 degrees) from the QMASK map, which combines the data from the QMAP and Saskatoon experiments. Since the accuracy of recent measurements leftward of the first acoustic peak is limited by sample-variance, the large area of the QMASK map (648 square degrees) allows u
Kristian Helmerson, Li You
We propose a direct, coherent coupling scheme that can create massively entangled states of Bose-Einstein condensed atoms. Our idea is based on an effective interaction between two atoms from coherent Raman processes through a (two atom) molecular intermediate state. We compare our scheme with other recent proposals for generation of massive entanglement of
Eric S. Perlman, John T. Stocke, John Conway, Chris Reynolds
We present 3-band HST imaging of three z</=0.1 compact symmetric objects (CSOs): 4C 31.04, 1946+708 and 1146+596. These objects were chosen on the basis of proximity to Earth as well as HI 21 cm absorption. The inner H-band isophotes of these galaxies are well fit by "nuker" models, typical of nearby ellipticals. Each shows a significant flattening i
J. G. Russo, A. A. Tseytlin
Models of closed superstrings in certain curved NS-NS magnetic flux backgrounds are exactly solvable in terms of free fields. They interpolate between free superstring theories with periodic and antiperiodic boundary conditions for fermions around some compact direction, and, in particular, between type 0 and type II string theories. Using ``9-11 flip'&#
W. Herbst, C. A. L. Bailer-Jones, R. Mundt
We have determined new rotation periods for 404 stars in the Orion Nebula Cluster using the Wide Field Imager attached to the MPG/ESO 2.2 m telescope on La Silla, Chile. Mass estimates are available for 335 of these and most have M < 0.3 M_sun. We confirm the existence of a bimodal period distribution for the higher mass stars in our sample and show that the
Larry McLerran
The Color Glass Condensate is a state of high density gluonic matter which controls the high energy limit of hadronic matter. These lectures begin with a discussion of general problems of high energy strong interactions. The infinite momentum frame description of a single hadron at very small x is developed, and this picture is applied to the description of
C. Bobeth, T. Ewerth, F. Krüger, J. Urban
We report on a calculation of Higgs-boson contributions to the decays B_s -> l^+l^- and B -> K l^+l^- (l=e, mu) which are governed by the effective Hamiltonian describing b -> s l^+ l^-. Compact formulae for the Wilson coefficients are provided in the context of the type-II two-Higgs-doublet model (2HDM) and supersymmetry (SUSY) with minimal flavour violatio
Stuart A. Norton, Karl Gebhardt, Ann I. Zabludoff, Dennis Zaritsky
We use long-slit spectroscopic observations of the sample of E+A galaxies described by Zabludoff et al. to constrain the nature of the progenitors and remnants of the E+A phase of galaxy evolution. We measure spatially-resolved kinematic properties of the young (<~1 Gyr) and old (> few Gyr) stellar populations. The young stellar populations are more centrall
Vincenzo Barone, Alessandro Drago, Philip G. Ratcliffe
We review the present state of knowledge regarding the transverse polarisation (or transversity) distributions of quarks. After some generalities on transverse polarisation, we formally define the transversity distributions within the framework of a classification of all leading-twist distribution functions. We describe the QCD evolution of transversity at l
Michael C. Birse, Thomas D. Cohen, Judith A. McGovern
The propagation of low-momentum baryons through QCD matter at low isospin density is studied using chiral perturbation theory. When the isospin chemical potential exceeds a critical value, the dispersion relation for the lowest nucleon mode becomes anomalous near zero momentum---increasing momentum yields decreasing energy---so that the momentum for the lowe
Xavier Calmet, Andrey Neronov
We discuss nonminimal couplings of fermions to the electromagnetic field, which generically appear in models with extra dimensions. We consider models where the electromagnetic field is generated by the Kaluza-Klein mechanism. The nonminimal couplings contribute at tree-level to anomalous magnetic and electric dipole moments of fermions. We use recent measur
Quantum Mechanics, Quantum Gravity, and Approximate Lorentz Invariance from a Classical Phase-Boundary Universe
hep-thMichael Grady
A classical dynamical system in a four-dimensional Euclidean space with universal time is considered. The space is hypothesized to be originally occupied by a uniform substance, pictured as a liquid, which at some time became supercooled. Our universe began as a nucleation event initiating a liquid to solid transition. The universe we inhabit and are directl
G. Duplancic, H. Pasagic, M. Praszalowicz, J. Trampetic
This report is an attempt to explain both s- and p-wave nonleptonic hyperon decays by means of the QCD enhanced effective weak Hamiltonian supplemented by the SU(3) Skyrme model used to estimate nonperturbative matrix elements. The model has only one free parameter, namely, the Skyrme charge $e$, which is fixed through the experimental values of the octet-de
Matthias Neubert
The element |V_{ub}| of the quark mixing matrix can be extracted with small theoretical uncertainties by combining weighted integrals over the endpoint regions of the lepton spectrum in B -> X_u l nu decays and the photon spectrum in B -> X_s gamma decays. The perturbative corrections to this determination are computed at next-to-leading order including oper
T. Bartsch, J. Main, G. Wunner
Harmonic inversion techniques have been shown to be a powerful tool for the semiclassical quantization and analysis of quantum spectra of both classically integrable and chaotic dynamical systems. Various computational procedures have been proposed for this purpose. Our aim is to find out which method is numerically most efficient. To this end, we summarize
Reply to Comment on "Pipe network model for scaling of dynamic interfaces in porous media''
cond-mat.softChi-Hang Lam, Viktor K. Horváth
Here we give further evidences to support our scaling relation described in our previous paper [cond-mat/0006459, Phys. Rev. Lett. Vol.85, pp.1238 (2000)].
I. Maksimov, D. Baabe, H. -H. Klauss, F. J. Litterst
We present a detailed structural investigation via neutron diffraction of differently heat treated samples Fe2VAl and Fe2+xV1-xAl. Moreover, the magnetic behaviour of these materials is studied by means of mSR and Mossbauer-experiments. Our structural investigation indicates that quenched Fe2VAl, exhibiting the previously reported "Kondo insulating like&
P. P. Papadopoulos, R. J. Ivison
We examine the physical conditions of the molecular gas in the extremely red object (ERO), HR10 at z=1.44, as constrained by the recent detection of CO J+1 -> J, J=1, 4 lines. The line ratios of such widely spaced CO transitions are extremely sensitive probes of gas excitation; in the case of the HR10, they provide a rare opportunity to study the state of th
Joerg Huefner, Pengfei Zhuang
The recently published data for $<p^2_t>$ for $J/ψ$ production in Pb-Pb collisions at 158 A GeV are analyzed. For low values of transverse energy $E_t$, where normal suppression dominates, $<p^2_t> (E_t)$ scales with the path length of the gluons which fuse to make the $J/ψ$. In the $E_t$ domain of anomalous suppression $<p^2_t> (E_t)$ is found to rise linea
Andrei N. Soklakov, Ruediger Schack
We consider a typical setup of cavity QED consisting of a two-level atom interacting strongly with a single resonant electromagnetic field mode inside a cavity. The cavity is resonantly driven and the output undergoes continuous homodyne measurements. We derive an explicit expression for the state of the system conditional on a discrete photocount record. Th
B. Hall, M. Lisak, D. Anderson, R. Fedele
A novel statistical approach based on the Wigner transform is proposed for the description of partially incoherent optical wave dynamics in nonlinear media. An evolution equation for the Wigner transform is derived from a nonlinear Schrodinger equation with arbitrary nonlinearity. It is shown that random phase fluctuations of an incoherent plane wave lead to
G. E. Volovik
Painleve-Gullstrand metric of the black hole allows to discuss the fermion zero modes inside the hole. The statistical mechanics of the fermionic microstates can be responsible for the black hole thermodynamics. Fermion zero modes also lead to quantization of the horizon area.
J. P. Wittmer, A. Tanguy, J. -L. Barrat, L. Lewis
Structures involving solid particles of nanometric dimensions play an increasingly important role in material sciences. These structures are often characterized through the vibrational properties of their constituent particles, which can be probed by spectroscopic methods. Interpretation of such experimental data requires an extension of continuum elasticity
Fiorenzo Bastianelli, N. D. Hari Dass
We discuss a simplified method for computing trace anomalies in d=6 and d<6 dimensions. It is known that in the quantum mechanical approach trace anomalies in d dimensions are given by a (1+d/2)-loop computation in an auxiliary 1d sigma model with arbitrary geometry. We show how one can obtain the same information using a simpler d/2-loop calculation on an a
Non-adiabatically detecting the geometric phase of the macroscopic quantum state with symmetric SQUID
quant-phWang Xiangbin, Matsumoto Keiji
We give a simple way to detect the geometric phase shift and the conditional geometric phase shift with Josephson junction system. Comparing with the previous work(Falcl G, Fazio R, Palma G.M., Siewert J and Verdal V, {\it Nature} {\bf 407}, 355(2000)), our scheme has two advantages. We use the non-adiabatic operation, thus the detection is less affected by
Ishwaree P. Neupane
A treatment of linearized gravity with the Einstein-Gauss-Bonnet interaction terms in $D\geq$ 5 is given in the Randall-Sundrum brane background. This Letter has outlined some interesting features of the brane world gravity and Newtonian potential correction with the GB interaction term. We find that the GB coupling $α$ renormalizes the effective four-dimens
D. Bernard, N. Regnault, D. Serban
We introduce a large N version of the spin quantum Hall transition problem. It is formulated as a problem of Dirac fermions coupled to disorder, whose Hamiltonian belong to the symmetry class C. The fermions carry spin degrees of freedom valued in the algebra sp(2N), the spin quantum Hall effect corresponding to N=1. Arguments based on renormalization group