November 1999 arXiv papers — page 19
Showing 1,801–1,900 of 2,616 papers
Yoichi Ando
Using 61-T pulsed magnetic fields, the normal-state ρ_{ab} and ρ_{c} are measured in Bi-2201 system down to 0.66 K, and the coexistence of the "metallic" ρ_{ab} and the "semiconducting" ρ_{c}, usually called the charge confinement behavior, was confirmed to extend far below T_c. Recent measurement of the c-axis magnetoresistance under 16 T dc
J. Timmer, U. Schwarz, H. U. Voss, I. Wardinski
We analyze the variability in the X-ray lightcurves of the black hole candidate Cygnus X-1 by linear and nonlinear time series analysis methods. While a linear model describes the over-all second order properties of the observed data well, surrogate data analysis reveals a significant deviation from linearity. We discuss the relation between shot noise model
Numerical Models of Binary Neutron Star System Mergers. I.: Numerical Methods and Equilibrium Data for Newtonian Models
astro-phF. Douglas Swesty, Edward Y. M. Wang, Alan C. Calder
The numerical modeling of binary neutron star mergers has become a subject of much interest in recent years. While a full and accurate model of this phenomenon would require the evolution of the equations of relativistic hydrodynamics along with the Einstein field equations, a qualitative study of the early stages on inspiral can be accomplished by either Ne
Exploring Halo Substructure with Giant Stars: II. Mapping the Extended Structure of the Carina Dwarf Spheroidal Galaxy
astro-phS. R. Majewski, J. C. Ostheimer, R. J. Patterson, W. E. Kunkel
As part of our survey for substructure in the Milky Way halo as traced by giant stars, and to look for tidal stellar debris in the halo viable for measurement of the Galactic mass potential with SIM, we explore the distribution of stars beyond the nominal tidal radius of, but still associated with, the Carina dwarf spheroidal galaxy. We make use of a photome
B. M. Gaensler
I consider the state of play regarding associations of supernova remnants (SNRs) with anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs). The three AXP/SNR associations are convincing, and are consistent with AXPs being young, low-velocity neutron stars. The three SGR/SNR associations are far more likely to be chance superpositions, and rely
Li-Zhi Fang, Wolung Lee, Jesús Pando
We show that scale-scale correlations are a generic feature of slow-roll inflation theories. These correlations result from the long-time tails characteristic of the time dependent correlations because the long wavelength density perturbation modes are diffusion-like. A relationship between the scale-scale correlations and time-correlations is established pr
J. A. Johnson, M. Bolte, P. B. Stetson, J. E. Hesser
We present V, V-I color-magnitude diagrams (CMDs) for three old star clusters in the Large Magellanic Cloud (LMC): NGC 1466, NGC 2257 and Hodge 11. Our data extend about 3 magnitudes below the main-sequence turnoff, allowing us to determine accurate relative ages and the blue straggler frequencies. Based on a differential comparison of the CMDs, any age diff
The Molecular Gas-Star Formation Connection in an Optically-Selected Sample of Interacting Galaxies
astro-phHoward A. Bushouse, Steven D. Lord, Susan A. Lamb, Michael W. Werner
We have obtained CO(1-0) observations for a sample of 37 interacting galaxy systems, chosen from a parent sample of optically-selected interacting galaxies. The sample observed here spans a large range of interaction strengths and star formation rates (SFR). Using the standard CO-to-H2 conversion factor we find that the interacting galaxies are, on average,
F. Camilo, A. G. Lyne, R. N. Manchester, J. F. Bell
The Parkes multibeam pulsar survey uses a 13-element receiver operating at a wavelength of 20 cm to survey the inner Galactic plane with remarkable sensitivity. To date we have collected and analyzed data from 45% of the survey region (|b| < 5 deg.; 260 deg. < l < 50 deg.), and have discovered 440 pulsars, in addition to re-detecting 190 previously known one
P. A. Milne, J. D. Kurfess, R. L. Kinzer, M. D. Leising
By combining OSSE, SMM and TGRS observations of the galactic center region, Purcell et al. (1997) and Cheng et al. (1997) produced the first maps of galactic positron annihilation. That data-set has been augmented with additional data, both recent and archival, and re-analyzed to improve the spectral fitting. The improved spectral fitting has enabled the fir
M. Lopez-Corredoira, P. L. Hammersley, F. Garzon, E. Simonneau
A method based on Lucy (1974, AJ 79, 745) iterative algorithm is developed to invert the equation of stellar statistics for the Galactic bulge and is then applied to the K-band star counts from the Two-Micron Galactic Survey in a number of off-plane regions (10 deg.>|b|>2 deg., |l|<15 deg.). The top end of the K-band luminosity function is derived and the mo
D. C. Backer
In October 1997 daily monitoring observations of the Crab pulsar at 327 MHz and 610 MHz with an 85ft telescope in Green Bank, WV showed a jump in the dispersion by 0.12 cm^{-3} pc. Pulses were seen simultaneously at both old and new dispersions for a period of days. In the months before this event faint ghost emission, a replica of the pulse, was detected wi
P. J. Benson, A. Dullighan, A. Bonanos, K. K. McLeod
We describe optical photometric and spectroscopic observations of the bright variable BG Geminorum. Optical photometry shows a pronounced ellipsoidal variation of the K0 I secondary, with amplitudes of ~0.5 mag at VRI and a period of 91.645 days. A deep primary eclipse is visible for wavelengths < 4400A; a shallower secondary eclipse is present at longer wav
R. P. Fender
An empirical relation between `canonical' X-ray states in black hole X-ray binaries and radio emission is presented. In the Low/Hard state a quasi-continuous radio-emitting jet is produced. In the the High/Soft state the jet is not observed. In the Very High state and at major state transitions, which may correspond physically to rapid and/or significant
A wide field survey at the Northern Ecliptic Pole I: Number counts and angular correlation functions in K
astro-phM. W. Kuemmel, S. J. Wagner
We present the results from a multi colour survey performed at the Northern Ecliptic Pole (NEP). The survey is designed to identify the counterparts of faint sources from the ROSAT All Sky Survey and the IRAS survey and to study their optical/near-infrared properties. We observed the central square degree around the NEP in the optical bands B_J and R and in
C. Cerf, A. Jorissen
Amino acids occurring in proteins are, with rare exceptions, exclusively of the L-configuration. Among the many scenarios put forward to explain the origin of this chiral homogeneity (i.e., homochirality), one involves the asymmetric photolysis of amino acids present in space, triggered by circularly polarized UV radiation. The recent observation of circular
Bruce G. Elmegreen
Observations suggest that star formation occurs in only one or two crossing times for a range of scales spanning a factor of 1000. These observations include (1) measurements of embedded cluster ages in comparison with the cloud core dynamical times, (2) measurements of the age difference versus separation for clusters in the Large Magellanic Clouds in compa
Timothy C. Beers
I discuss the ongoing search for stars of the Milky Way which have been referred to as members of Population III. Following a discussion of possible definitions for these stars, I consider the reasons why astronomers have undertaken this search, and list some of the numerous astrophysical uses of the extremely metal-poor stars found along the way. I then rev
E. H. Richardson, A. Moore, T. Tilleman, David Crampton
A number of design options for image slicers for NGST and Gemini are being investigated. These image slicers are all of the focussing type and both refractive and reflective solutions are being explored. One such device, an image slicer that focuses 10 slices on a spectrograph slit is now in operation at the McMath Solar telescope. It consists of three lensl
D. Clowe, G. Luppino, N. Kaiser, I. Gioia
We present results of a weak gravitational lensing survey of six X-ray selected high-redshift clusters of galaxies. We find that the masses of the clusters derived from weak lensing are comparable to those derived from the X-ray observations. We show that many of the clusters have significant substructure not observed in the X-ray observations and that for t
S. Pellegrini, M. Cappi, L. Bassani, G. Malaguti
The LINER nucleus of the nearby spiral galaxy M81 was pointed by BeppoSAX, which caught it at the highest (2-10) keV flux level observed so far. The LECS, MECS and PDS data, extending over (0.1-100) keV, are used to investigate the physical similarities and differences between LINERs and AGNs. The continuum is well fitted by a power law of photon index \sim
Leo Stodolsky
If neutrinos have a small but non-zero mass, time-of-flight effects for neutrino bursts from distant sources can yield information on the large-scale geometry of the universe, the effects being proportional to the integral over time of the cosmological expansion parameter. In principle absolute physical determinations of the Hubble constant and the accelerat
Kohji Tomisaka
If the angular momentum of the molecular cloud core were conserved during the star formation process, a new-born star would rotate much faster than its fission speed. This constitutes the angular momentum problem of new-born stars. In this paper, the angular momentum transfer in the contraction of a rotating magnetized cloud is studied with axisymmetric MHD
K. -H. Raedler, U. Geppert
The paper deals with a simple spherical mean-field dynamo model of $α^2$-type in the case of high electrical conductivity. A spherically symmetric distribution of turbulent motions is assumed inside a spherical fluid body surrounded by free space, and some complete form of the corresponding mean electromotive force is taken into account. For a turbulence lac
B. Guiderdoni, J. E. G. Devriendt
The current and forthcoming observations of large samples of high-redshift galaxies selected according to various photometric and spectroscopic criteria can be interpreted in the context of galaxy formation, by means of models of evolving spectral energy distributions (SEDs). We hereafter present STARDUST which gives synthetic SEDs from the far UV to the sub
The Effect of the Outer Lindblad Resonance of the Galactic Bar on the Local Stellar Velocity Distribution
astro-phWalter Dehnen
Hydro-dynamical modeling of the inner Galaxy suggest that the radius of the outer Lindblad resonance (OLR) of the Galactic bar lies in the vicinity of the Sun. How does this resonance affect the distribution function in the outer parts of a barred disk, and can we identify any effect of the resonance in the velocity distribution f(v) actually observed in the
M. Livio, E. Waxman
We consider models for gamma-ray bursts in which a collimated jet expands either into a homogeneous medium or into a stellar wind environment, and calculate the expected afterglow temporal behavior. We show that (i) following a break and a faster decay, afterglows should exhibit a flattening, which may be detectable in both the radio and optical bands; (ii)
RX J0420.0-5022: An isolated neutron star candidate with evidence for 22.7 s X-ray pulsations
astro-phF. Haberl, W. Pietsch, C. Motch
We report the discovery of a new isolated neutron star candidate, RX J0420.0-5022, showing evidence (4 sigma) for 22.7 s X-ray pulsations in ROSAT data. NTT observations of the field around the soft X-ray source do not reveal any likely optical counterpart brighter than B = 25.25 implying an X-ray to optical flux ratio of >10^3.3 and ruling out other possibl
F. A. Aharonian, A. M. Atoyan
We discuss the link between the nonthermal X-radiation and TeV gamma-ray emission from SN 1006, and study the capabilities of both electronic and nucleonic models for explanation of the TeV flux observed from the northeast rim of SN 1006.
Bruce G. Elmegreen
Variations in the number of globular clusters per unit galaxy luminosity, which is the specific frequency, and the mass of globular clusters per unit total available mass, are reviewed. Correlations with galaxy luminosity and morphology, and with the properties of the associated galactic clusters are discussed, as are the color distributions of globular clus
Formation and loss of hierarchical structure in two-dimensional MHD simulations of wave-driven turbulence in interstellar clouds
astro-phBruce G. Elmegreen
Two dimensional compressible magneto-hydrodynamical (MHD) simulations run for 20 crossing times on a 800x640 grid with two stable thermal states show persistent hierarchical density structures and Kolmogorov turbulent motions in the interaction zone between incoming non-linear Alfven waves. These structures and motions are similar to what are commonly observ
K. Xilouris, A. Fruchter, D. R. Lorimer, J. Eder
The unique sensitivity of the Arecibo telescope at 430 MHz motivated a drift scan search of the visible sky divided up into eight declination strips. Based on an analysis of the data collected in the region assigned to us, eight new long-period pulsars have so far been discovered.
Jaume Garriga, Takahiro Tanaka
We discuss the weak gravitational field created by isolated matter sources in the Randall-Sundrum brane-world. In the case of two branes of opposite tension, linearized Brans-Dicke (BD) gravity is recovered on either wall, with different BD parameters. On the wall with positive tension the BD parameter is larger than 3000 provided that the separation between
Lucien Hardy, Adrian Kent
We define cheat sensitive cryptographic protocols between mistrustful parties as protocols which guarantee that, if either cheats, the other has some nonzero probability of detecting the cheating. We give an example of an unconditionally secure cheat sensitive non-relativistic bit commitment protocol which uses quantum information to implement a task which i
Akikazu Hashimoto, N. Itzhaki
Non-commutative supersymmetric Yang-Mills with rational Theta is dual to an ordinary supersymmetric Yang-Mills with a 't Hooft flux. It is believed that the simplest description is via the ordinary supersymmetric Yang-Mills. We claim, however, that the two descriptions form a hierarchy. The SYM description is the proper description in the ultra violet wh
Takahiko Matsubara, Alexander S. Szalay, Stephen D. Landy
We present the first results of the Karhunen-Loève (KL) eigenmodes applied to real data of the Las Campanas Redshift Survey (LCRS) to simultaneously measure the values of the redshift-distortion parameter, $β= Ω_0^{0.6}/b$, the linearly extrapolated normalization, $σ_8^{\rm L}$, and the CDM shape parameter, $Γ= Ω_0 h$. The results of our numerical likelihood
Fabrizio Gabbiani, Paulo F. Bedaque, Harald W. Griesshammer
The phase shifts for the higher partial waves (l\ge 1) in the spin quartet and doublet channel of nd scattering at centre-of-mass energies up to 15 MeV are presented at next-to-leading and next-to-next-to-leading order in an effective field theory in which pions are integrated out. As available, the results agree with both phase shift analyses and potential
Hae-Young Kee, Yong Baek Kim, Kazumi Maki
There are five distinct collective modes in the recently discovered p-wave superconductor Sr$_2$RuO$_4$; phase and amplitude modes of the order parameter, clapping mode (real and imaginary), and spin wave. The first two modes also exist in the ordinary s-wave superconductors, while the clapping mode with the energy $\sqrt{2} Δ(T)$ is unique to Sr$_2$RuO$_4$
Determination of the QCD color factor ratio CA/CF from the scale dependence of multiplicity in three jet events
hep-exJ. William Gary
I examine the determination of the QCD color factor ratio CA/CF from the scale evolution of particle multiplicity in e+e- three jet events. I fit an analytic expression for the multiplicity in three jet events to event samples generated with QCD multihadronic event generators. I demonstrate that a one parameter fit of CA/CF yields the expected result CA/CF=2
Effective Field Theory of the Zero-Temperature Triangular-Lattice Antiferromagnet: A Monte Carlo Study
cond-mat.stat-mechHui Yin, Bulbul Chakraborty, Nicholas Gross
Using a Monte Carlo coarse-graining technique introduced by Binder et al., we have explicitly constructed the continuum field theory for the zero-temperature triangular Ising antiferromagnet. We verify the conjecture that this is a gaussian theory of the height variable in the interface representation of the spin model. We also measure the height-height corr
L. Babukhadia, Ya. A. Berdnikov, A. N. Ivanov, M. D. Scadron
We demonstrate how a chiral soft pion theorem (SPT) shields the scalar meson ground state isoscalar $σ(600-700)$ and isospinor $κ(800-900)$ from detection in $a_{1}\toπ(ππ)_{\mathrm{swave}}$, $γγ\to2π^{\circ}$, $π^{-}p\toπ^{-}π^{+}n$ and $K^{-}p\to K^{-}π^{+}n$ processes. While pseudoscalar meson PVV transitions are known to be determined by (only) quark loo
Hans De Raedt, Anthony Hams, Kristel Michielsen, Koen De Raedt
We describe a quantum computer emulator for a generic, general purpose quantum computer. This emulator consists of a simulator of the physical realization of the quantum computer and a graphical user interface to program and control the simulator. We illustrate the use of the quantum computer emulator through various implementations of the Deutsch-Jozsa and
Hans Havlicek, Guenther Krenn, Johann Summhammer, Karl Svozil
We review and extend recent findings of Godsil and Zaks, who published a constructive coloring of the rational unit sphere with the property that for any orthogonal tripod formed by rays extending from the origin of the points of the sphere, exactly one ray is red, white and black. They also showed that any consistent coloring of the real sphere requires an
UKQCD Collaboration, K. C. Bowler, L. Del Debbio, J. M. Flynn
We present the results of a lattice computation of the form factors for B^0 ->pi^- l^+nu_l decays near zero-recoil. These results will allow a determination of the CKM matrix element |Vub| when measurements of the differential decay rate become available. We also provide models for extrapolation of the form factors and rate to the full recoil range. Our comp
R. S. Bhalerao, N. G. Kelkar, B. Ram
We present a physical model for polarized and unpolarized structure functions and parton density functions (PDFs) of the proton and the neutron. It reproduces the data on F_2^p(x,Q^2) for 0.00001<x<1 and 2.5<Q^2<5000 GeV^2, F_2^p(x)-F_2^n(x), F_2^n(x)/F_2^p(x), xg(x), dbar(x)-ubar(x), d(x)/u(x), the Gottfried sum, the fractional momentum of charged partons a
R. Pastor-Satorras, J. M. Rubi
We discuss the appareance of ordered structures in assemblies of magnetic particles. The phenomenon occurs when dipolar interactions and the thermal motion of the particles compete, and is mediated by screening and excluded volume effects. It is observed irrespective of the dimensionality of the system and the resulting structures, which may be regular or fr
Lars Andersson
We survey some known facts and open questions concerning the global properties of 3+1 dimensional spacetimes containing a compact Cauchy surface. We consider spacetimes with an $\ell$-dimensional Lie algebra of space-like Killing fields. For each $\ell \leq 3$, we give some basic results and conjectures on global existence and cosmic censorship.
Orbitally Driven Spin Pairing in the 3D Non-Magnetic Mott Insulator BaVS3: Evidence from Single Crystal Studies
cond-mat.str-elG. Mihaly, I. Kezsmarki, F. Zamborszky, M. Miljak
Static electrical and magnetic properties of single crystal BaVS_3 were measured over the structural (T_S=240K), metal-insulator (T_MI=69K), and suspected orbital ordering (T_X=30K) transitions. The resistivity is almost isotropic both in the metallic and insulating states. An anomaly in the magnetic anisotropy at T_X signals a phase transition to an ordered
C. S. Kim, Jake Lee, W. Namgung
New physics effects through the direct CP violation and the decay rate change are investigated in the semileptonic $D_{l4}$ decays, $D^\pm\to Kπl^\pm ν$, by including a scalar-exchange interaction with a complex coupling. In the decay process, we included various excited states as intermediate states decaying to the final hadrons, $K+π$, and found that among
Thermodynamics and Gravitation: From Glasses to Black Holes and Globular Star Clusters
cond-mat.stat-mechTheo M. Nieuwenhuizen
The topic of this conference is ``The Chaotic Universe''. One of the main achievements of last century has been to relate chaos in fluids to their thermodynamics. It is our purpose to make connection between chaos in gravitation and standard thermodynamics. Though there have been many previous steps and attempts, so far no convincing conclusion has been reac
Qingshan Yuan, Yumei Zhang, Hong Chen
The two-dimensional Jordan-Wigner transformation is used to investigate the zero temperature spin-Peierls transition for an anisotropic two-dimensional XY model in adiabatic limit. The phase diagram between the dimerized (D) state and uniform (U) state is shown in the parameter space of dimensionless interchain coupling $h$ $(=J_{\perp}/J)$ and spin-lattice
Y. Nambu, A. Tomita, Y. Chiba-Kohno, K. Nakamura
Quantum mechanical complementarity ensures the security of the key-distribution scheme reported by Brassard and Bennet in 1984 (BB84), but does not prohibit use of multi-photons as a signal carrier. We describe a novel BB84 scheme in which two nearly orthogonal coherent states carry the key, and the superposition of these states (cat states) protects the com
Local density of states around a magnetic impurity in high-Tc superconductors based on the t-J model
cond-mat.supr-conHiroki Tsuchiura, Yukio Tanaka, Masao Ogata, Satoshi Kashiwaya
The local density of states (LDOS) around a magnetic impurity in high-Tc superconductors is studied using the two-dimensional t-J model with a realistic band structure. The order parameters are determined in a self-consistent way within the Gutzwiller approximation and the Bogoliubov-de Gennes theory. In sharp contrast with the nonmagnetic impurity case, the
Frederic A. Rasio, Eric D. Pfahl, Saul Rappaport
We present a new dynamical scenario for the formation of short-period binary millisecond pulsars in globular clusters. Our work is motivated by the recent observations of 20 radio pulsars in 47 Tuc. In a dense cluster such as 47 Tuc, most neutron stars acquire binary companions through exchange interactions with primordial binaries. The resulting systems hav
Kirill Melnikov, Timo van Ritbergen
The last unknown contribution to hydrogen energy levels at order m alpha ^7, due to the slope of the Dirac form factor at three loops, is evaluated in a closed analytical form. The resulting shift of the hydrogen nS energy level is found to be 3.016/n^3 kHz. Using the QED calculations of the 1S Lamb shift, we extract a precise value of the proton charge radi
Christiane Koch, Bernd Esser
An analysis of the eigenstates of a symmetry-broken spin-boson Hamiltonian is performed by computing Bloch and Husimi projections. The eigenstate analysis is combined with the calculation of absorption bands of asymmetric dimer configurations constituted by monomers with nonidentical excitation energies and optical transition matrix elements. Absorption band
Marek Zukowski, Dagomir Kaszlikowski
In a gedankenexperiment N particles in a generalized GHZ-type beam entangled state (each particle can be in one of M beams) are fed into N symmetric 2M-port beam splitters (spatially separated). Correlation functions for such a process (using the Bell numbers value assignment approach) reveal a remarkable symmetry. For N=M+1 greater or equal to 4 a series of
H. De Raedt, A. H. Hams, K. Michielsen, S. Miyashita
We describe a quantum algorithm to compute the density of states and thermal equilibrium properties of quantum many-body systems. We present results obtained by running this algorithm on a software implementation of a 21-qubit quantum computer for the case of an antiferromagnetic Heisenberg model on triangular lattices of different size.
MGA Paris, M Plenio, D Jonathan, S Bose
We describe a nonlinear interferometric setup to perform a complete optical Bell measurement, i.e. to unambigously discriminate the four polarization entangled EPR-Bell photon pairs. The scheme is robust against detector inefficiency.
Anil K. Patnaik, G. S. Agarwal
An isotropic medium, having magnetic sublevels, when subjected to a magnetic field or an electromagnetic field can induce anisotropy in the medium; and as a result the plane of polarization of the probe field can rotate. Therefore the rotation due to the magnetic field alone, can be {\em controlled efficiently} with use of a coherent field. We show, using a
Y. Alhassid, G. F. Bertsch, S. Liu, H. Nakada
A simple formula for the ratio of the number of odd- and even-parity states as a function of temperature is derived. This formula is used to calculate the ratio of level densities of opposite parities as a function of excitation energy. We test the formula with quantum Monte Carlo shell model calculations in the $(pf+g_{9/2})$-shell. The formula describes we
Harald W. Griesshammer
A cartoon of the Effective Field Theory of many nucleon systems is drawn, concentrating on Compton scattering in the two nucleon system, and on $nd$ scattering in the three body system.
Sensitivity of tensor analyzing power in the process $d+p\to d+X$ to the longitudinal isoscalar form factor of the Roper resonance electroexcitation
nucl-thE. Tomasi-Gustafsson, M. P. Rekalo, R. Bijker, A. Leviatan
The tensor analyzing power of the process $d + p \to d + X$, for forward deuteron scattering in the momentum interval 3.7 to 9 GeV/c, is studied in the framework of $ω$ exchange in an algebraic collective model for the electroexcitation of nucleon resonances. We point out a special sensitivity of the tensor analyzing power to the isoscalar longitudinal form
Tomonori Tanigawa, Masayuki Matsuzaki
We propose a simple method to reproduce the ^1S_0 pairing properties of nuclear matter, which are obtained using a sophisticated model, by introducing a density-independent cutoff into the relativistic mean field model. This can be applied successfully to the physically relevant density range.
D. H. Barkhuff, S. P. Wells, T. Averett, D. H. Beck
We report the development and implementation of an energy feedback system for the MIT/Bates Linear Accelerator Center. General requirements of the system are described, as are the specific requirements, features, and components of the system unique to its implementation at the Bates Laboratory. We demonstrate that with the system in operation, energy fluctua
S. Altieri, O. Barnaba, A. Braghieri, M. Cambiaghi
MIDAS (MIcrostrip Detector Array System) is a compact silicon tracking telescope for charged particles emitted at small angles in intermediate energy photonuclear reactions. It was realized to increase the angular acceptance of the DAPHNE detector and used in an experimental program to check the Gerasimov-Drell-Hearn sum rule at the Mainz electron microtron,
Semi-classical asymptotics for the counting functions and Riesz means of Pauli and Dirac operators with large magnetic fields
math-phA. A. Balinsky, W. D. Evans, Roger T. Lewis
We study the asymptotic behavior, as Planck's constant $\hbar\to 0$, of the number of discrete eigenvalues and the Riesz means of Pauli and Dirac operators with a magnetic field $μ\mathbf{B}(x)$ and an electric field. The magnetic field strength $μ$ is allowed to tend to infinity as $\hbar\to 0$. Two main types of results are established: in the first $μ
Aernout C. D. van Enter
We point out that the high-q Potts model on a regular lattice at its transition temperature provides an example of a non-robust - in the sense recently proposed by Pemantle and Steif- phase transition.
Kazumitsu Sakai, Zengo Tsuboi
The thermodynamic Bethe ansatz is applied to a quantum integrable spin chain associated with the Lie superalgebra osp(1|2). Using the string hypothesis, we derive a set of infinite number of non-linear integral equations (thermodynamic Bethe ansatz equation), which characterize the free energy. The low temperature limit of the free energy is also discussed.
Jim Bryan, Sheldon Katz, Naichung Conan Leung
We study the contribution of multiple covers of an irreducible rational curve C in a Calabi-Yau threefold Y to the genus 0 Gromov-Witten invariants in the following cases. (1) If the curve C has one node and satisfies a certain genericity condition, we prove that the contribution of multiple covers of degree d is given by the sum of all 1/n^3 where n divides
The homotopy classification and the index of boundary value problems for general elliptic operators
math.APA. Yu. Savin, B. Yu. Sternin, B. -W. Schulze
We give the homotopy classification and compute the index of boundary value problems for elliptic equations. The classical case of operators that satisfy the Atiyah-Bott condition is studied first. We also consider the general case of boundary value problems for operators that do not necessarily satisfy the Atiyah-Bott condition.
Vladimir S. Matveev, Petar J. Topalov
This paper is a review on recently found connection between geodesically equivalent metrics and integrable geodesic flows. Suppose two different metrics on one manifold have the same geodesics. We show that then the geodesic flows of these metrics admit sufficiently many integrals (of a special form) in involution and vice versa. The quantum version of this
Noncommutative Residues, Dixmier's Trace, and Heat Trace Expansions on Manifolds with Boundary
math.APElmar Schrohe
For manifolds with boundary, we define an extension of Wodzicki's noncommutative residue to boundary value problems in Boutet de Monvel's calculus. We show that this residue can be recovered with the help of heat kernel expansions and explore its relation to Dixmier's trace.
Paul Larson
We give a proof that OCA holds in the Pmax extension of L(R). The proof is general enough to be adapted to most Pmax variations.
Scott Baldridge
The main results of this paper describes a formula for the Seiberg-Witten invariant of a 4-manifold which admits a nontrivial free S^1-action. We use this theorem to produce a nonsymplectic 4-manifold with a free circle action whose orbit space fibers over S^1. We also describe a 3-manifold which is not the orbit space of any symplectic 4-manifold with a fre
I. Mirković, K. Vilonen
This is an expanded version of the text ``Perverse Sheaves on Loop Grassmannians and Langlands Duality'', AG/9703010. The main new result is a topological realization of algebraic representations of reductive groups over arbitrary rings. We outline a proof of a geometric version of the Satake isomorphism. Given a connected, complex algebraic reductiv
A. N. Panov
We introduce the notion of pure Q-solvable algebra. The quantum matrices, quantum Weyl algebra, U_q(n) are the examples. It is proved that the skew field of fractions of pure Q-solvable algebra is isomorphic to the skew field of twisted rational functions. This is the quantum version of Gelfand-Kirillov conjecture for solvable algebraic Lie algebras.
Marco Mackaay
In this paper we define a class of state-sum invariants of compact closed oriented piece-wise linear 4-manifolds using finite groups. The definition of these state-sums follows from the general abstract construction of 4-manifold invariants using spherical 2-categories, as we defined in a previous paper, although it requires a slight generalization of that c
A. DeBenedictis, K. S. Viswanathan
We calculate, in the context of higher dimensional gravity, the stress-energy tensor and Weyl anomaly associated with anti-de Sitter and anti-de Sitter black hole solutions. The boundary counter-term method is used to regularize the action and the resulting stress-energy tensor yields both the correct black hole energies as well as a vacuum energy contributi
A. Bohm, H. Kaldass, S. Wickramasekara, P. Kielanowski
Gamow vectors are generalized eigenvectors (kets) of self-adjoint Hamiltonians with complex eigenvalues $(E_{R}\mp iΓ/2)$ describing quasistable states. In the relativistic domain this leads to Poincaré semigroup representations which are characterized by spin $j$ and by complex invariant mass square ${\mathsf{s}}={\mathsf{s}}_{R}=(M_{R}-\frac{i}{2}Γ_{R})^{2
Pasquier Models at c=1: Cylinder Partition Functions and the role of the Affine Coxeter Element
hep-thRobert P. T. Talbot
We calculate the partition functions of the affine Pasquier models on the cylinder in the continuum limit. We show that the partition function of any affine model may be expressed in terms of the orbit structure of the affine Coxeter element of the Weyl group associated with the defining graph of the model. Some of the consequences of this geometric relation
Tom Weidig
This is one of the `New Talents' seminars at `Erice International School of Subnuclear Physics 1999' and looks at numerical studies of (2+1)D topological Skyrme-like solitons; the baby skyrmions. We explain the concept of integrable and topological solitons. Then we introduce the non-linear sigma model in 2D in order to discuss the 3D nuclear Skyrme
Petre Dita
We show that the motion on the n-dimensional ellipsoid is complete integrable by exhibiting n integrals in involution. The system is separable at classical and quantum level, the separation of classical variables being realized by the inverse of the momentum map. This system is a generic one in a new class of n-dimensional complete integrable Hamiltonians de
H. Ikemori, S. Kitakado, H. Otsu, T. Sato
Quantization of a system constrained to move on a sphere is considered by taking a square root of the ``on sphere condition''. We arrive at the fibre bundle structure of the Hopf map in the cases of $S^{2} $and $S^{4}$. This leads to more geometrical understanding of monopole and instanton gauge structures that emerge in the course of quantization.
O. J. P. Eboli, T. L. Lungov
We study the single production of first generation leptoquarks in association with a e+/- at the Fermilab Tevatron. We focus our attention on final states exhibiting a e+e- pair and jets, and perform a detailed analyses of signal and backgrounds. The single leptoquark production cross section depends on the leptoquark Yukawa coupling to lepton-quark pairs an
A. B. Kaidalov, Yu. A. Simonov
Using a nonperturbative method based on asymptotic behaviour of Wilson loops we calculate masses of glueballs and corresponding Regge-trajectories. The only input is string tension fixed by meson Regge slope, while perturbative contributions to spin splittings are defined by standard alpha_s values. The masses of lowest glueball states are in a perfect agree
KNO Scaling in the Neutral Pion Multiplicity Distributions for pi^{-}-proton interactions at 40 and 250 GeV/c
hep-phL. Diósi, S. Krasznovszky, I. Wagner
We analysed the binomial multiplicity moments of the neutral pions, using an extension of the generating functional technique for detection losses. We applied this model-independent method to the individual gamma-weights of 10000 events of pi^{-}-proton interactions at 40 GeV/c. We compared the obtained results to those of 250 GeV/c. We used the FRITIOF and
A. H. Mueller
Partons are defined as the quanta in a Fock space description of a hadron. Gluon saturation is described in the Weizsäcker-Williams approximation for a large nucleus. The elements of DGLAP and BFKL evolution are given with the BFKL equation derived in a large-$N_c$ dipole formalism. A more general discussion of saturation is given in terms of a dipole scatte
Robert M. Harris, Christopher T. Hill, Stephen J. Parke
We present a calculation of the cross section for the process p pbar -> Zt' -> t tbar, the production of a Topcolor Z' with subsequent decay to top quark pairs in proton anti-proton collisions at 1.8 TeV. Variations of the cross section with varying assumptions about the model, the resonance width, the parton distributions and the renormalization sca
E. Marco, W. Weise
The gap Delta = 4 pi f_pi ~ 1.2 GeV of spontaneous chiral symmetry breaking is introduced as a scale delineating resonance and continuum regions in the QCD spectral sum rules for vector mesons. Basic current algebra results are easily recovered, and accurate sum rules for the lower moments of the spectral distributions are derived. The in-medium scaling of v
Sebastien Descotes
After recalling some connections between the Spontaneous Breakdown of Chiral Symmetry (SBChS) and the spectrum of the Dirac operator for Euclidean QCD on a torus, we use this tool to reconsider two related issues : the Zweig rule violation in the scalar channel and the dependence of SBChS order parameters on the number N_f of massless flavours. The latter wo
Quark-antiquark potential with retardation and radiative contributions and the heavy quarkonium mass spectra
hep-phD. Ebert, R. N. Faustov, V. O. Galkin
The charmonium and bottomonium mass spectra are calculated with the systematic account of all relativistic corrections of order v^2/c^2 and the one-loop radiative corrections. Special attention is paid to the contribution of the retardation effects to the spin-independent part of the quark-antiquark potential, and a general approach to accounting for retarda
A. Metz
Two complementary approaches to DIS at low $x$ and low $Q^2$ are presented. In the first case we apply a model containig two Pomeron trajectories. In the second case we determine the gluon density in the semiclassical treatment at next-to-leading order. Both approaches rely on the concept of soft color fields.
S. Plaszczynski, M. H Schune
We discuss the problem of theoretical uncertainties in the combination of observables related to the CKM matrix elements and propose a statistically sensible method for combining them. The overall fit is performed on present data, and constraints on the matrix elements are presented as well as on fB*sqrt(Bb). We then explore the implications of recent measur
N. N. Achasov, A. A. Kozhevnikov
Based on the Weinberg lagrangian or, in a new language, the lagrangian of hidden local symmetry added with the term induced by the anomalous lagrangian of Wess and Zumino, the dynamics of the decays rho to 4 pi and omega to 5 pi is considered. The excitation curves of rho resonance in its decay to 4 pi are obtained for the first time. The comparison with rec
F. Hautmann, Z. Kunszt, D. E. Soper
We discuss recent theoretical results on diffractive deeply inelastic scattering, focusing on the partonic picture of diffraction in configuration space and the predictions for the beta behavior and the scaling violation.
Ira Z. Rothstein
In this talk I review some recent applications of NRQCD. I first discuss the unquenched NRQCD lattice extractions of the strong coupling constant, paying particular attention to the recent advances in reducing systematic errors. I then discuss the progress made in testing the NRQCD/factorization formalism for onium production. In particular, I gather the evi
First principle quadratic and linear mass operators, quarkonium spectrum and Regge trajectories
hep-phM. Baldicchi
In previous works, a squared mass operator M^2 and a more common centre of frame Hamiltonian H_CM for the quark-antiquark system were obtained by using the only assumption that ln W (W being the Wilson loop correlator) can be written in QCD as the sum of its perturbative expression and an area term. We evaluated the spectrum of these operators by neglecting
Alessandro De Angelis
The DELPHI detector at LEP is particularly suited for hadron identification and for the identification of b-initiated jets. This note presents recent results based on such characteristics.
Bernard F Schutz
The first decade of the new millenium should see the first direct detections of gravitational waves. This will be a milestone for fundamental physics and it will open the new observational science of gravitational wave astronomy. But gravitational waves already play an important role in the modeling of astrophysical systems. I review here the present state o