March 2002 arXiv papers — page 8
Showing 701–800 of 2,674 papers
K. Okazaki, T. Mizokawa, A. Fujimori, E. V. Sampathkumaran
We have measured the photoemission spectra of Nd$_{1-x}$Sm$_{x}$NiO$_{3}$, where the metal-insulator transition and the Néel ordering occur at the same temperature for $x \lesssim 0.4$ and the metal-insulator transition temperature ($T_{MI}$) is higher than the Néel temperature for $x \gtrsim 0.4$. For $x \le 0.4$, the spectral intensity at the Fermi level i
Study of Ag and Cu / MgB2 powder-in-tube composite wires fabricated by in-situ reaction at low temperature
cond-mat.supr-conE. Martinez, L. A. Angurel, R. Navarro
Superconducting Ag or Cu sheathed MgB2 wires have been fabricated by conventional powder-in-tube techniques. The in-situ reaction of Mg and B powders with atomic proportions of 1:2 and 1.33:2 inside Ag or Cu tubes at low temperatures have been searched. An active alloying of Mg with Ag or Cu sheaths at temperatures below 660 C has been observed. For Ag sheat
Jan Freund, Thorsten Poeschel
A two-dimensional cellular automaton is introduced to model the flow and jamming of vehicular traffic in cities. Each site of the automaton represents a crossing where a finite number of cars can wait approaching the crossing from each of the four directions. The flow of cars obeys realistic traffic rules. We investigate the dependence of the average velocit
Itinerant metamagnetism of CeRu2Si2 : bringing out the dead. Comparison with the new Sr3Ru2O7 case
cond-mat.str-elJ. Flouquet, P. Haen, S. Raymond, D. Aoki
Focus is given on the macroscopic and microscopic experimental works realized during a decade on the clear case of itinerant metamagnetism in the heavy fermion paramagnetic compound CeRu2Si2 . Emphasis is made on the feedback between the band structure, the exchange coupling and the lattice instability. Sweeps in magnetic field, pressure and temperature feel
Simulation of evacuation processes using a bionics-inspired cellular automaton model for pedestrian dynamics
cond-mat.stat-mechAnsgar Kirchner, Andreas Schadschneider
We present simulations of evacuation processes using a recently introduced cellular automaton model for pedestrian dynamics. This model applies a bionics approach to describe the interaction between the pedestrians using ideas from chemotaxis. Here we study a rather simple situation, namely the evacuation from a large room with one or two doors. It is shown
K. A. Muller, C. W. Chu
Superconductivity in the electric field-effect doped infinite layer compound CaCuO2 is considered. It is argued that in the superconducting CuO2 layer, next to the insulating Al2O3 overlayer, the coordination of the Cu2+ ions by oxygens is pyramidal rather than square planar. This view stems from existing NEXAFS and the analysis of HRETM results, as well as
Probability-Changing Cluster Algorithm: Study of Three-Dimensional Ising Model and Percolation Problem
cond-mat.stat-mechYusuke Tomita, Yutaka Okabe
We present a detailed description of the idea and procedure for the newly proposed Monte Carlo algorithm of tuning the critical point automatically, which is called the probability-changing cluster (PCC) algorithm [Y. Tomita and Y. Okabe, Phys. Rev. Lett. {\bf 86} (2001) 572]. Using the PCC algorithm, we investigate the three-dimensional Ising model and the
Duality between existence condition and construction procedure for interface states in a class of narrow-gap heterostructures
cond-mat.mtrl-sciB. D. Kandilarov, V. Detcheva
The problem for interface solutions in the quantum theory of heterostructures comprising narrow-gap semiconductors is reformulated in the language of commutative diagrams. By this way the theory of interface states in such heterostructures is naturally factorized in the two subproblems: (i) Criterion for the existence of interface states, (ii) Their localiza
Hajime Yoshino, Koji Hukushima, Hajime Takayama
We extend the standard droplet scaling theory for isothermal aging in spin glasses assuming that the effective stiffness constant of droplets as large as extended defects is vanishingly small. A novel dynamical order parameter and the associated dynamical susceptibility emerge. Breaking of the fluctuation dissipation theorem takes place at the dynamical orde
HI Absorption in the Gigamaser Galaxy TXS 2226-184 and the Relation between HI Absorption and Water Emission
astro-phG. B. Taylor, A. B. Peck, C. Henkel, H. Falcke
We report on the discovery of HI in absorption toward the gigamaser galaxy TXS2226-184 using the VLA. The absorption appears to consist of two components -- one with a width of 125 km/s, and one broader (420 km/s), both toward the compact radio source in the nucleus of the galaxy. Based on these large velocity widths we suggest that the HI absorption is prod
Curtis J. Saxton, Ralph S. Sutherland, Geoffrey V. Bicknell, Gwendoline Blanchet
We have carried out simulations of supersonic light jets in order to model the features observed in optical and radio images of the western hot-spot in the radio galaxy Pictor A. We have considered jets with density ratios eta=1e-2 - 1e-4, and Mach numbers ranging between 5 and 50. From each simulation, we have generated ray-traced maps of radio surface brig
Curtis J. Saxton
Thermal instabilities can cause a radiative shock to oscillate, thereby modulating the emission from the post-shock region. The mode frequencies are approximately quantised in analogy to those of a vibrating pipe. The stability properties depend on the cooling processes, the electron-ion energy exchange and the boundary conditions. This paper considers the e
N. Kameswara Rao, Aruna Goswami, David L. Lambert
The first high-resolution optical spectra of QY Sge are presented and discussed. Menzies & Whitelock (1988) on the basis of photometry and low-resolution spectra suggested that this G0I supergiant was obscured by dust and seen only by scattered light from a circumstellar reflection nebula. The new spectra confirm and extend this picture. Photospheric lines a
Patrick Cote, S. G. Djorgovski, Georges Meylan, S. Castro
We have measured Keck/HIRES radial velocities for 30 candidate red giants in the direction of Palomar 13: an object traditionally cataloged as a compact, low-luminosity globular cluster. From a sample of 21 confirmed members, we find a systemic velocity of 24.1 km/s and a projected, intrinsic velocity dispersion of 2.2 km/s. Although small, this dispersion i
Fabrizio Brighenti, William G. Mathews
In conventional models of galactic and cluster cooling flows widespread cooling (mass dropout) is assumed to avoid accumulation of unacceptably large central masses. However, recent XMM observations have failed to find spectral evidence for locally cooling gas. This has revived the notion that cooling flows are heated by some process such as an intermittent,
L. R. Jones, I. McHardy, A. Newsam, K. Mason
We describe some of the first X-ray detections of groups of galaxies at high redshifts (z~0.4), based on the UK deep X-ray survey of McHardy et al (1998). Combined with other deep ROSAT X-ray surveys with nearly complete optical identifications, we investigate the X-ray evolution of these systems. We find no evidence for evolution of the X-ray luminosity fun
M. A. P. Torres, J. Casares, I. G. Martinez-Pais, P. A. Charles
We present high and intermediate resolution spectroscopy of the X-ray nova Centaurus X-4 during its quiescent phase. Our analysis of the absorption features supports a K3-K5V spectral classification for the companion star, which contributes approximately 75 % of the total flux at Halpha. Using the high resolution spectra we have measured the secondary star&#
Filippo Fraternali, Gustaaf van Moorsel, Renzo Sancisi, Tom Oosterloo
High sensitivity H I observations of the nearby spiral galaxy NGC 2403 obtained with the VLA are presented and discussed. The properties of the extended, differentially rotating H I layer with its H I holes, spiral structure and outer warp are described. In addition, these new data reveal the presence of a faint, extended and kinematically anomalous componen
Jose A. Font
Numerical schemes for the general relativistic hydrodynamic equations are discussed. The use of conservative algorithms based upon the characteristic structure of those equations, developed during the last decade building on ideas first applied in Newtonian hydrodynamics, provides a robust methodology to obtain stable and accurate solutions even in the prese
The runaway instability of thick discs around black holes. I. The constant angular momentum case
astro-phJose A. Font, Frederic Daigne
We present results from a numerical study of the runaway instability of thick discs around black holes. This instability is an important issue for most models of cosmic gamma-ray bursts, where the central engine responsible for the initial energy release is such a system consisting of a thick disc surrounding a black hole. We have carried out a comprehensive
A Hubble Space Telescope Lensing Survey of X-ray Luminous Galaxy Clusters: III. A Multiply-imaged Extremely Red Galaxy at z=1.6
astro-phGraham P. Smith, Ian Smail, J. -P. Kneib, C. J. Davis
We present near-infrared spectroscopy and Hubble Space Telescope (HST) imaging of EROJ003707+0909.5, the brightest of three gravitationally-lensed images of an Extremely Red Object (ERO) at z=1.6, in the field of the massive cluster A68 (z=0.255). We exploit the superlative resolution of our HST data and the enhanced spatial resolution and sensitivity afford
M. Molla, A. I. Diaz, F. Ferrini
We have computed a set of multiphase chemical evolution models in which the radial mass distribution of each theoretical galaxy is calculated using the Universal Rotation Curve from Persic, Salucci & Steel (1996). We obtain the chemical evolution for galaxies of different masses and morphological types by changing the efficiencies to form molecular clouds an
M. Molla, E. Hardy
We study the old problem of the uniqueness of chemical evolution models. We showed in Molla et al. (1999) that multiphase models for three Virgo cluster galaxies were able to reproduce the observed radial distributions of spectral indices Mg2 and Fe52. But those models may fit the present-epoch radial distributions with different star formation histories. Th
Mercedes Molla, Eduardo Hardy
We study the old problem of the uniqueness of chemical evolution models by analyzing a set of multiphase models for the galaxy NGC 4303 computed for a variety of plausible physical input parameters. Our aim is to determine if the input parameters may be strongly constrained when nebular abundances and stellar spectral indices radial distributions are used. W
I. Marquez, J. Maegosa
We present our preliminary results on the study of the high luminosity ULIRGs (log(LFIR) > 12.3) in the 1Jy sample. Deep, high resolution optical R images with 7 arcmin x 7 arcmin field of view for 2/3 of the whole sample, show that they are generally found in very rich environments, they seem to be late stage merger products (long tidal tails are found in o
L. Terenzi, M. Bersanelli, C. Burigana, R. C. Butler
Planck LFI (Low Frequency Instrument) will produce a complete survey of the sky at millimeter wavelengths. Data stream analysis will provide the possibility to reveal unexpected millimeter sources and to study their flux evolution in time at different frequencies. We describe here the main implications and discuss data analysis methods. Planck sensitivities
M. J. Page, A. A. Breeveld, R. Soria, K. Wu
We present the soft X-ray spectrum of the LINER galaxy M81 from a long observation with the XMM-Newton RGS. As well as continuum emission from the active nucleus, the spectrum shows emission lines from multi temperature collisionally ionized gas. The emission lines are significantly broader than the RGS point-source spectral resolution, and in the cross disp
M. Rodriguez
Optical CCD spectra are used to determine the Fe abundances at several positions inside seven bright Galactic HII regions. The observed [FeIII] line ratios are compared with the predictions of different sets of collision strengths and transition probabilities for this ion to select the atomic data providing the best fit to the observations. The values found
M. Catelan, J. Borissova, F. R. Ferraro, T. M. Corwin
Deep UBVI photometry for a large field covering the distant globular cluster M75 (NGC 6864) is presented. We confirm a previous suggestion (Catelan et al. 1998a) that M75 possesses a bimodal horizontal branch (HB) bearing striking resemblance to the well-known case of NGC 1851. In addition, we detect a third, smaller grouping of stars on the M75 blue tail, s
SPICES II. Optical and Near-Infrared Identifications of Faint X-Ray Sources from Deep Chandra Observations of Lynx
astro-phDaniel Stern, Paolo Tozzi, S. A. Stanford, Piero Rosati
We present our first results on field X-ray sources detected in a deep, 184.7 ks observation with the ACIS-I camera on Chandra. The observations target the Lynx field of SPICES, and contains three known X-ray-emitting clusters out to z=1.27. Not including the known clusters, in the 17'x17' ACIS-I field we detect 132 sources in the 0.5-2 keV (soft) X-
Metallicity and Kinematics of M31's Outer Stellar Halo from a Keck Spectrocscopic Survey
astro-phDavid B. Reitzel, Puragra Guhathakurta
We present multislit CaII near-infrared triplet spectroscopy with the Keck 10-m telescope/LRIS of 99 M31 halo red giant candidates in the apparent mag range 20<I<22 in a SE minor axis field at R=19kpc. The spectra are used to isolate M31 halo red giants from foreground Milky Way dwarf stars, background compact field galaxies and M31 disk giants. The observed
Christian Zier, Peter L. Biermann
We determine the properties of the stellar torus that we showed in a previous paper to result as a product of two merging black holes. If the surrounding stellar cluster is as massive as the binary black hole, the torque acting on the stars ejects a fraction which extracts all the binary's angular momentum on scales of ~10^7 yr, and a geometrically thick
C. Chicone, B. Mashhoon
The Jacobi equation in pseudo-Riemannian geometry determines the linearized geodesic flow. The linearization ignores the relative velocity of the geodesics. The generalized Jacobi equation takes the relative velocity into account; that is, when the geodesics are neighboring but their relative velocity is arbitrary the corresponding geodesic deviation equatio
George Siopsis
The motion of a scalar particle in (d+1)-dimensional AdS space may be described in terms of the Cartesian coordinates that span the (d+2)-dimensional space in which the AdS space is embedded. Upon quantization, the mass hyperboloid defined in terms of the conjugate momenta turns into the wave equation in AdS space. By interchanging the roles of coordinates a
P. F. Harrison, W. G. Scott
Tri-bimaximal mixing is a specific lepton mixing ansatz, which has been shown to account very successfully for the established neutrino oscillation data. Working in a particular basis (the `circulant basis'), we identify three independent symmetries of tri-bimaximal mixing, which we exploit to set the tri-bimaximal hypothesis in context, alongside some s
L. Andrianopoli, R. D'Auria, S. Ferrara, M. A. Lledo
We show that N=8 spontaneously broken supergravity in four dimensions obtained by Scherk-Schwarz generalized dimensional reduction can be obtained from a pure four dimensional perspective by gauging a suitable electric subgroup of E_{7,7}. Owing to the fact that there are non isomorphic choices of maximal electric subgroups of the U-duality group their gaugi
PSR J1740-5340: accretion inhibited by radio-ejection in a binary millisecond pulsar in the Globular Cluster NGC 6397
astro-phLuciano Burderi, Francesca D'Antona, Marta Burgay
We present an evolutionary scenario for the spin-up and evolution of binary millisecond pulsars, according to which the companion of the pulsar PSR J 1740-5340, recently discovered as a binary with orbital period of 32.5 hr in the Globular Cluster NGC 6397, is presently in a phase of ``radio-ejection'' mass loss from the system. At present, Roche lob
F. Krzakala, O. C. Martin
We address the problem of chaotic temperature dependence in disordered glassy systems at equilibrium by following states of a random-energy random-entropy model in temperature; of particular interest are the crossings of the free-energies of these states. We find that this model exhibits strong, weak or no temperature chaos depending on the value of an expon
Derek Teaney, Raju Venugopalan
We compute the contribution of classical fields to the second Fourier coefficient (v_2) of the azimuthal gluon distribution at large transverse momentum in heavy ion collisions. We find that the classical contribution to the flow alone cannot account for the experimentally observed behavior of v_2(p_t) at large transverse momentum p_t.
Bin Chen, Feng-Li Lin
In this paper we calculate the spectrum of Neumann matrix with zero modes in the presence of the constant B field in Witten's cubic string field theory. We find both the continuous spectrum inside $[{-1\over3}, 0)$ and the constraint on the existence of the discrete spectrum. For generic $θ$, -1/3 is not in the discrete spectrum but in the continuous spe
Continuum quasiparticle random phase approximation and the time dependent Hartree-Fock-Bogoliubov approach
nucl-thE. Khan, N. Sandulescu, M. Grasso, Nguyen Van Giai
Quadrupole excitations of neutron-rich nuclei are analyzed by using the linear response method in the Quasiparticle Random Phase Approximation (QRPA). The QRPA response is derived starting from the time-dependent Hartree-Fock-Bogoliubov (HFB) equations. The residual interaction between the quasiparticles is determined consistently from the two-body force use
Qiuping A. Wang, Alain Le Mehaute
It is argued that the factorization of compound probability over subsystems is a consequence of the existence of thermodynamic equilibrium in the composite system having Tsallis entropy. So it should be respected by all exact calculations concerning interacting nonextensive subsystems. Using nonextensive energy satisfying the factorization, we propose an add
E. Bergshoeff, U. Gran, D. Roest
We investigate half-supersymmetric domain wall solutions of four maximally supersymmetric D=9 massive supergravity theories obtained by Scherk-Schwarz reduction of D=10 IIA and IIB supergravity. One of the theories does not have a superpotential and does not allow domain wall solutions preserving any supersymmetry. The other three theories have superpotentia
Yves Le Jan, Olivier Raimond
We are interested in stationary "fluid" random evolutions with independent increments. Under some mild assumptions, we show they are solutions of a stochastic differential equation (SDE). There are situations where these evolutions are not described by flows of diffeomorphisms, but by coalescing flows or by flows of probability kernels. In an interme
N. Evans, M. Petrini, A. Zaffaroni
Starting from the Maldacena-Nunez supergravity dual of N=1 super Yang-Mills theory we study the inclusion of a supersymmetry breaking gaugino mass term. We consider a class of non supersymmetric deformations of the MN solutions which have been recently proposed in the literature. We show that they can be interpreted as corresponding to the inclusion of both
Ali Mostafazadeh
We examine the properties and consequences of pseudo-supersymmetry for quantum systems admitting a pseudo-Hermitian Hamiltonian. We explore the Witten index of pseudo-supersymmetry and show that every pair of diagonalizable (not necessarily Hermitian) Hamiltonians with discrete spectra and real or complex-conjugate pairs of eigenvalues are isospectral and ha
Symmetrical Temperature-Chaos Effect with Positive and Negative Temperature Shifts in a Spin Glass
cond-mat.dis-nnP. E. Jönsson, H. Yoshino, P. Nordblad
The aging in a Heisenberg-like spin glass Ag(11 at% Mn) is investigated by measurements of the zero field cooled magnetic relaxation at a constant temperature after small temperature shifts $|ΔT/T_g| < 0.012$. A crossover from fully accumulative to non-accumulative aging is observed, and by converting time scales to length scales using the logarithmic growth
Omer Blaes, Man Hoi Lee, Aristotle Socrates
We consider the dynamical evolution of bound, hierarchical triples of supermassive black holes that might be formed in the nuclei of galaxies undergoing sequential mergers. The tidal force of the outer black hole on the inner binary produces eccentricity oscillations through the Kozai mechanism, and this can substantially reduce the gravitational wave merger
Joan Simon
The geometry of flat spacetime modded out by a null rotation (boost+rotation) is analysed. When embedding this quotient spacetime in String/M-theory, it still preserves one half of the original supersymmetries. Its connection with the BTZ black hole, supersymmetric dilatonic waves and one possible resolution of its singularity in terms of nullbranes are also
Ruggero Ferrari, Marco Picariello, Andrea Quadri
We discuss the Equivalence Theorem (ET) in the BRST formalism. The existence of a local inverse of the field transformation (at least as a formal power expansion) suggests a formulation of the ET, which allows a nilpotent BRST symmetry. This strategy cannot be implemented at the quantum level if the inverse is non-local. In this case we propose an alternativ
Rabin Banerjee, Biswajit Chakraborty, Subir Ghosh
Noncommutativity in an open string moving in a background Neveu-Schwarz field is investigated in a gauge independent Hamiltonian approach, leading to new results. The noncommutativity is shown to be a direct consequence of the non-trivial boundary conditions, which, contrary to several approaches, are not treated as constraints. We find that the noncommutati
Ulf H. Danielsson
In this paper we consider the influence of transplanckian physics on the CMBR anisotropies produced by inflation. We consider a simple toy model that allows for analytic calculations and argue on general grounds, based on ambiguities in the choice of vacuum, that effects are expected with a magnitude of the order of $H/Λ$, where $H$ is the Hubble constant du
Eduardo J. S. Villaseñor
We carry out the extension of the covariant Ostrogradski method to fermionic field theories. Higher-derivative Lagrangians reduce to second order differential ones with one explicit independent field for each degree of freedom.
J. Merikoski, J. Maunuksela, M. Myllys, J. Timonen
The spatial and temporal persistence, or first-return distributions are measured for slow combustion fronts in paper. The stationary temporal and (perhaps less convincingly) spatial persistence exponents agree with the predictions based on the front dynamics, which asymptotically belongs to the Kardar-Parisi-Zhang (KPZ) universality class. The stationary sho
Angular correlation theory for double photoionization in a rare gas atom : ionization by polarized photons
physics.atom-phChiranjib Sur, Dipankar Chattarji
This is a sequel to an earlier article on the theory of angular correlation for double photoionization. Here we consider the two-step double photoionization of a rare gas atom under the influence of a polarized photon beam described by appropriate Stokes parameters. Cylindrical mirror analysers (CMA) are used to detect the outgoing electrons. Theoretical val
Stability of quantum states of finite macroscopic systems against classical noises, perturbations from environments, and local measurements
quant-phAkira Shimizu, Takayuki Miyadera
We study the stability of quantum states of macroscopic systems of finite volume V, against weak classical noises (WCNs), weak perturbations from environments (WPEs), and local measurements (LMs). We say that a pure state is `fragile' if its decoherence rate is anomalously great, and `stable against LMs' if the result of a LM is not affected by anoth
J. Hwang, H. Noh
If the linear perturbation theory is valid through the bounce, the surviving fluctuations from the ekpyrotic scenario (cyclic one as well) should have very blue spectra with suppressed amplitude for the scalar-type structure. We derive the same (and consistent) result using the curvature perturbation in the uniform-field (comoving) gauge and in the zero-shea
Melvyn B. Nathanson
For the quantum integer $[n]_q = 1+q+...+q^{n-1}$ there is a natural polynomial multiplication $*_q$ such that $[m]_q *_q [n]_q = [mn]_q$. This multiplication leads to the functional equation $f_{mn}(q) = f_m(q)f_n(q^m),$ defined on a given sequence $\mathcal(F)=\{f_n(q)\}_{n=1}^{\infty}$ of polynomials. This paper contains various results concerning the cla
A. J. M. Medved
Observational evidence suggests that our universe is currently evolving towards an asymptotically de Sitter future. Unfortunately and in spite of much recent attention, various quantum, holographic and cosmological aspects of de Sitter space remain quite enigmatic. With such intrigue in mind, this paper considers the ``construction'' of a toy model t
Carlos Contreras, Gorazd Cvetic, Kwang Sik Jeong, Taekoon Lee
Using the CCFR data for the Gross--Llewellyn Smith (GLS) sum rule, we extract the strong coupling constant via Borel resummation of the perturbative QCD calculation. The method incorporates the correct nature of the first infrared renormalon singularity, and employs a conformal mapping to improve the convergence of the QCD perturbation expansion. The importa
Greg Kuperberg
The general stable quantum memory unit is a hybrid consisting of a classical digit with a quantum digit (qudit) assigned to each classical state. The shape of the memory is the vector of sizes of these qudits, which may differ. We determine when N copies of a quantum memory A embed in N(1+o(1)) copies of another quantum memory B. This relationship captures t
Structural and electronic properties of Al nanowires: an ab initio pseudopotential study
cond-mat.mtrl-sciJin-Cheng Zheng, Hui-Qiong Wang, A. T. S. Wee, C. H. A. Huan
The stability and electronic structure of a single monatomic Al wire has been studied using the ab initio pseudopotential method. The Al wire undergoes two structural rearrangements under compression, i.e., zigzag configurations at angles of $140^o$ and $60^o$. The evolution of electronic structures of the Al chain as a function of structural phase transitio
Jin-Cheng Zheng, Hui-Qiong Wang, A. T. S. Wee, C. H. A. Huan
The stabilities of $(BN)_x(C_2)_{1-x}$ alloys and related superlattices are investigated by ab initio pseudopotential calculations. We find that the $(BN)_1/(C_2)_1$ superlattices in (111) orientations have the lowest formation energy among many short-range ordered $BNC_2$ structures due to the smallest number of B-C and C-N bonds. Based on the calculated fo
A Quantum Measurement Scenario which Requires Exponential Classical Communication for Simulation
quant-phAllison Coates
In this paper we consider the following question: how many bits of classical communication and shared random bits are necessary to simulate a quantum protocol involving Alice and Bob where they share k entangled quantum bits and do not communicate at all. We prove that 2^k classical bits are necessary, even if the classical protocol is allowed an εchance of
B. Militello, A. Messina, A. Napoli
The theoretical foundations of a new general approach to the measurement problem of vibrational observables in trapped ion systems is reported. The method rests upon the introduction of a simple vibronic coupling structure appropriately conceived to link the internal ionic state measurement outcomes to the mean value of a motional variable of interest. Some
V. G. Benza, G. Strini
We study the dynamics of a spin coupled to an oscillating magnetic field, in the presence of decoherence and dissipation. In this context we solve the master equation for the Landau-Zener problem, both in the unitary and in the irreversible case. We show that a single spin can be "magnetized" in the direction parallel to the oscillating bias. When de
C. R. Hagen
The second central extension of the planar Galilei group has been alleged to have its origin in the spin variable. This idea is explored here by considering local Galilean covariant field theory for free fields of arbitrary spin. It is shown that such systems generally display only a trivial realization of the second central extension. While it is possible t
P. Deuar, P. D. Drummond
Quantum dynamics simulations can be improved using novel quasiprobability distributions based on non-orthogonal hermitian kernel operators. This introduces arbitrary functions (gauges) into the stochastic equations, which can be used to tailor them for improved calculations. A possible application to full quantum dynamic simulations of BEC's is presented
G. Vidal
We show that, in any open set of distillable states, all asymptotic entanglement measures $E(ρ)$ are continuous as a function of (a single copy of) $ρ$, even though they quantify the entanglement properties of $ρ^{\otimes N}$ is the large $N$ limit.
G. Suryan
The National Academy of Sciences USA has posed eleven important questions about the Cosmos. This paper answers most of the questions based on the new concepts about "What is Time - A New Mathematico Physical And Information Theoretic Approach" [physics/0106073] and "Estimation of Gravitational Constant from CMBR data and Hubble's parameter
M. Hentschel, J. U. Nockel
The stationary states of a microlaser are related to the decaying quasibound states of the corresponding passive cavity. These are interpreted classically as originating from sequential escape attempts of an ensemble of rays obeying a curvature-corrected Fresnel formula. Polarization-dependent predictions of this model, and its limitations for stable orbits
Jens U. Nockel, A. D. Stone
Spherical and cylindrical dielectric cavities support high Q whispering gallery modes due to total internal reflection of the trapped light. When such a cavity is deformed smoothly the ray dynamics of these modes becomes chaotic in a manner determined by the KAM theory of classical hamiltonian dynamics. The universal properties of the ray dynamics predicted
J. Dobaczewski, W. Nazarewicz, M. V. Stoitsov
The volume and surface effects in the nuclear local energy density and the volume and surface components of the pairing interaction are discussed in the context of the mean-field, Hartree-Fock-Bogoliubov description of atomic nuclei. Predictions of properties of exotic nuclei close to the particle drip lines are presented.
A. S. Botvina, I. N. Mishustin
We show that the statistical multifragmentation model with the standard parameterization of the free volume predicts a constant pressure as density approaches the normal nuclear density. This is contrary to the Raduta&Raduta result obtained by disregarding the center of mass constraint. It is demonstrated that in finite nuclear systems the partitions with sm
Wojciech Florkowski, Wojciech Broniowski
The pt-spectra of hadrons measured at RHIC are very well described in a model which assumes that the chemical and thermal freeze-outs occur simultaneously. The model calculation includes all hadronic resonances and uses a simple parametrization of the freeze-out hypersurface.
M. Warda, J. L. Egido, L. M. Robledo, K. Pomorski
The fission barriers of the nuclei 254Fm, 256Fm, 258Fm, 258No and 260Rf are investigated in a fully microscopic way up to the scission point. The analysis is based on the constrained Hartree-Fock-Bogoliubov theory and Gogny's D1S force. The quadrupole, octupole and hexadecapole moments as well as the number of nucleons in the neck region are used as cons
K. Adcox
Data from Au + Au interactions at sqrt(s_NN) = 130 GeV, obtained with the PHENIX detector at RHIC, are used to investigate local net charge fluctuations among particles produced near mid-rapidity. According to recent suggestions, such fluctuations may carry information from the Quark Gluon Plasma. This analysis shows that the fluctuations are dominated by a
J. R. Dorfman, P. Gaspard, T. Gilbert
This paper presents an {\it ab initio} derivation of the expression given by irreversible thermodynamics for the rate of entropy production for different classes of diffusive processes. The first class are Lorentz gases, where non-interacting particles move on a spatially periodic lattice, and collide elastically with fixed scatterers. The second class are p
A. Yu. Shahverdian, A. V. Apkarian
The work relates to a new way for analysis of one-dimensional stochastic systems, based on consideration of its higher order difference structure. From this point of view, the deterministic and random processes are analyzed. A new numerical characteristic for one-dimensional stochastic systems is introduced. The applications to single neuron models and neura
G. Boffetta, F. De Lillo, S. Musacchio
The inverse energy cascade in Charney-Hasegawa-Mima turbulence is investigated. Kolmogorov law for the third order velocity structure function is shown to be independent on the Rossby number, at variance with the energy spectrum, as shown by high resolution direct numerical simulations. In the asymptotic limit of strong rotation, coherent vortices are observ
Scalar second order evolution equations possessing an irreducible sl$_2$-valued zero curvature representation
nlin.SIMichal Marvan
We find all scalar second order evolution equations possessing an sl$_2$-valued zero curvature representation that is not reducible to a proper subalgebra of sl$_2$. None of these zero-curvature representations admits a parameter.
Geometric Phase and Modulo Relations for Probability Amplitudes as Functions on Complex Parameter Spaces
math-phAlonso Botero
We investigate general differential relations connecting the respective behavior s of the phase and modulo of probability amplitudes of the form $\amp{ψ_f}ψ$, where $\ket{ψ_f}$ is a fixed state in Hilbert space and $\ketψ$ is a section of a holomorphic line bundle over some complex parameter space. Amplitude functions on such bundles, while not strictly holo
F. Moulin
The formulation of a generalized classical electromagnetism that includes both electric and magnetic charges, is explored in the framework of two potential approach. It is shown that it is possible to write an action integral from which one can derive, by least action principle, the symmetrized set of Maxwell's equations, but also the Lorentz force law b
T. Prosen, T. H. Seligman, H. A. Weidenmueller
We present a method to calculate integrals over monomials of matrix elements with invariant measures in terms of Wick contractions. The method gives exact results for monomials of low order. For higher--order monomials, it leads to an error of order 1/N^alpha where N is the dimension of the matrix and where alpha is independent of the degree of the monomial.
Alan Carey, Matilde Marcolli, Bai-Ling Wang
We establish a surgery formula for 3-dimensional Seiberg-Witten monopoles under (+1) Dehn surgery on a knot in a homology 3-sphere. (substantial revision)
Eduardo D. Sontag
This note provides a simple result showing, under suitable technical assumptions, that if a system S adapts to a class of external signals U, then S must necessarily contain a subsystem which is capable of generating all the signals in U. It is not assumed that regulation is robust, nor is there a prior requirement for the system to be partitioned into separ
Eric S. Egge, Toufik Mansour
A permutation $π\in S_n$ is said to {\it avoid} a permutation $σ\in S_k$ whenever $π$ contains no subsequence with all of the same pairwise comparisons as $σ$. For any set $R$ of permutations, we write $S_n(R)$ to denote the set of permutations in $S_n$ which avoid every permutation in $R$. In 1985 Simion and Schmidt showed that $|S_n(132, 213, 123)|$ is equ
Boris Apanasov, Inkang Kim
We develop and study quaternionic and octonionic analogies of Cartan angular and Toledo invariants that are well known in the complex hyperbolic space. Using such invariants we study quasifuchsian deformations (including bendings) of quaternionic and octonionic hyperbolic manifolds.
Anthony Small
The geometry of minimal surfaces generated by charge 2 Bogomolny monopoles on 3-dimensional Euclidean space is described in terms of the moduli parameter k. We find that the distribution of Gaussian curvature on the surface reflects the monopole structure. This is elucidated by the behaviour of the Gauss maps of the minimal surfaces.
J. Colliander, M. Keel, G. Staffilani, H. Takaoka
We prove an "almost conservation law" to obtain global-in-time well-posedness for the cubic, defocussing nonlinear Schrödinger equation in H^s(R^n) when n = 2, 3 and s > 4/7, 5/6, respectively.
Espace de modules des courbes hyperelliptiques stables et une inégalité de Cornalba-Harris-Xiao
math.AGSylvain Maugeais
In this paper, we show an inequality between the degrees of the conductor and the Hodge fiber of a hyperelliptic curve above a discrete valuation ring. For that we have to show theorems about the lifting of $p$-cyclic covers in order to obtain informations on the edge of the moduli space of hyperelliptic stable curves. The inequality then comes from the geom
I. I. Kogan, A. Nichols
We discuss the partners of the stress energy tensor and their structure in Logarithmic conformal field theories. In particular we draw attention to the fundamental differences between theories with zero and non-zero central charge. We analyze the OPE for T, \bar{T} and the logarithmic partners t and \bar{t} for c=0 theories.
Ashok Das, Alexander Mitov
We systematically study the question of identification and consistent inclusion of the radion, within the Lagrangian approach, in a two brane Randall-Sundrum model. Exploiting the symmetry properties of the theory, we show how the radion can be identified unambiguously and give the action to all orders in the radion field and the metric. Using the background
Absence of a charge renormalization in the Higgs model interacting with conformal two-dimensional gravity
hep-thZ. Haba
We discuss D-dimensional scalar and electromagnetic fields interacting with a quantized metric. The gravitons depend solely on twodimensional coordinates. We consider a conformal field theory model for the metric tensor. We show that an interaction with gravity improves the short distance behaviour. As a result there is no charge renormalization in the fourd
Elliptic Families of Solutions of the Kadomtsev-Petviashvili Equation and the Field Elliptic Calogero-Moser System
hep-thA. Akhmetshin, I. Krichever, Yu. Volvovski
We present the Lax pair for the field elliptic Calogero-Moser system and establish a connection between this system and the Kadomtsev-Petviashvili equation. Namely, we consider elliptic families of solutions of the KP equation, such that their poles satisfy a constraint of being balanced. We show that the dynamics of these poles is described by a reduction o
K. Van Acoleyen, H. Verschelde
We propose an alternative perturbative expansion for QCD. All scheme and scale dependence is reduced to one free parameter. Fixing this parameter with a fastest apparent convergence criterion gives sensible results in the whole energy region. We apply the expansion to the calculation of the zero flavor triple gluon vertex, the quark gluon vertex, the gluon p
Apostolos Pilaftsis
We revisit the issue of mixing matrix renormalization in theories that include Dirac or Majorana fermions. We show how a gauge-variant on-shell renormalized mixing matrix can be related to a manifestly gauge-independent one within a generalized ${\bar {\rm MS}}$ scheme of renormalization. This scheme-dependent relation is a consequence of the fact that in an
J. Conway, K. Desch, J. F. Gunion, S. Mrenna
The prospects for a precise exploration of the properties of a single or many observed Higgs bosons at future accelerators are summarized, with particular emphasis on the abilities of a Linear Collider (LC). Some implications of these measurements for discerning new physics beyond the Standard Model (SM) are also discussed.
Alberto Giovannini, Sergio Lupia, Roberto Ugoccioni
Scenarios for particle production in the GeV and TeV regions are reviewed. The expected increase with c.m. energy of the average number of clans for the soft component and the decrease for the semihard one indicate possible classical and quantum behaviour of gluons, respectively. Clan thermodynamics, discussed in the paper, appears as the natural framework t
T. Csorgo, F. Grassi, Y. Hama, T. Kodama
Simple, self-similar, analytic solutions of 1+1 dimensional relativistic hydrodynamics are presented, generalizing Bjorken's solution to inhomogeneous rapidity distribution.