August 2003 arXiv papers — page 3
Showing 201–300 of 2,790 papers
N. A. Fortune, H. A. Radovan, S. T. Hannahs, T. P. Murphy
The Clogston estimate for the Pauli limit used in the original comment (and the paper to which it referred) neglects important effects that lead to a significant enhancement of the Pauli limit in CeCoIn5. The discussion in the original comment is therefore moot and the comment has been withdrawn.
Disorder Effect on the Vortex Pinning by the Cooling Process Control in the Organic Superconductor $κ$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Br
cond-mat.supr-conN. Yoneyama, T. Sasaki, T. Nishizaki, N. Kobayashi
We investigate the influence of disorders in terminal ethylene groups of BEDT-TTF molecules (ethylene-disorders) on the vortex pinning of the organic superconductor $κ$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Br. Magnetization measurements are performed under different cooling-processes. The second peak in the magnetization hysteresis curve is observed for all samples st
Antony A. Stark
A large single-dish submillimeter-wave telescope equipped with a focal plane array containing ~10^4 bolometers and costing about $120M could locate most protogalaxies in the southern sky within a year of operation.
Antony A. Stark
AST/RO is a 1.7m diameter submillimeter-wave telescope at the geographic South Pole. A key AST/RO project is the mapping of C I and CO J=4-3 and J=7-6 emission from the inner Milky Way (Martin et al. 2003). These data are released for general use.
High Resolution Images of Orbital Motion in the Trapezium Cluster: First Scientific Results from the MMT Deformable Secondary Mirror Adaptive Optics System
astro-phLaird M. Close, Francois Wildi, Michael Lloyd-Hart, Guido Brusa
We present the first scientific images obtained with a deformable secondary mirror adaptive optics system. We utilized the 6.5m MMT AO system to produce high-resolution (FWHM=0.07'') near infrared (1.6 um) images of the young (~1 Myr) Orion Trapezium theta 1 Ori cluster members. A combination of high spatial resolution and high signal to noise allowe
Andrew Gould, Julio Chaname
We present a catalog of 424 common proper motion companions to Hipparcos stars with good (>3 sigma) parallaxes, thereby effectively providing new parallaxes for these companions. Compared to stars in the Hipparcos catalog, these stars are substantially dimmer. The catalog includes 20 WDs and an additional 29 stars with M_V>14, the great majority of the latte
Sean Matt, Adam Frank, Eric Blackman
We discuss a mechanism by which a giant star can expel its envelope in an outburst, leaving its core exposed. The outburst is powered by rotational kinetic energy of the core, transferred to the envelope via the twisting of magnetic fields. We show that, if the core is magnetized, and if it has sufficient angular momentum, this mechanism may be triggered at
Eric L. Sandquist
We have calibrated an extensive set of BVI observations of M67. We have selected stars that are most likely to be single-star members of the cluster using proper motion, radial velocity, and variability information from the literature, and an examination of the most probable color-magnitude diagram locations of unresolved stellar blends. Observations of M67
Lorenzo Monaco, Michele Bellazzini, Francesco R. Ferraro, Elena Pancino
We report on the recovery of a Blue Horizontal Branch (BHB) population belonging to the Sagittarius Dwarf Spheroidal Galaxy (Sgr). The sequence is clearly identified in the (V, V-I) Color Magnitude Diagram (CMD) obtained for about 500,000 stars in the region of the globular cluster M~54. The BHB morphology is similar to the analogous sequence in M~54, but it
The Mass Function of Super Giant Molecular Complexes and Implications for Forming Young Massive Star Clusters in the Antennae (NGC 4038/39)
astro-phC. D. Wilson, N. Z. Scoville, S. C. Madden, V. Charmandaris
We have used previously published observations of the CO emission from the Antennae (NGC 4038/39) to study the detailed properties of the super giant molecular complexes with the goal of understanding the formation of young massive star clusters. Over a mass range from 5E6 to 9E8 solar masses, the molecular complexes follow a power-law mass function with a s
Photorecombination and Photoionization Experiments at Heavy-Ion Storage-Rings and Synchrotron-Light Sources
astro-phStefan Schippers
Recent experimental work on the photorecombination and the photoionization of astrophysically relevant atomic ions employing the merged-beams technique at heavy-ion storage-rings and synchrotron-light sources, respectively, is summarized. The resulting absolute photoionization cross sections and recombination rate coefficients benchmark corresponding theoret
J. Richard, R. Pello, J. -P. Kneib, D. Schaerer
We present different methods used to identify high redshift (z>5) objects in the high-magnification regions of lensing galaxy clusters, taking advantage of very well constrained lensing models. The research procedures are explained and discussed. The detection of emission lines in the optical/NIR spectra, such as Lyman-alpha, allows us to determine the redsh
Gopal-Krishna, Amit R. Dhakulkar, Paul J. Wiita, Samir Dhurde
Using the surface photometric analysis data for a well defined sample of 79 nearby radio galaxies (z < 0.12), it is shown that the level of radio emission associated with an elliptical galaxy during the radio-loud phase is related to the presence of large amounts of isophotal twist in its optical image. In particular, radio galaxies with P_408 > 3 x 10^{25}
Rafal Idzi, Rachel Somerville, Casey Papovich, Henry C. Ferguson
We investigate several fundamental properties of z ~ 4 Lyman-break galaxies by comparing observations with the predictions of a semi-analytic model based on the Cold Dark Matter theory of hierarchical structure formation. We use a sample of B_{435}-dropouts from the Great Observatories Origins Deep Survey, and complement the ACS optical B_{435}, V_{606}, i_{
Intrinsic and dust-induced polarization in gamma-ray burst afterglows: the case of GRB 021004
astro-phD. Lazzati, S. Covino, S. di Serego Alighieri, G. Ghisellini
Polarization measurements for the optical counterpart to GRB 021004 are presented and discussed. Our observations were performed with the TNG and the VLT-UT3 (Melipal) during the first and fourth night after the gamma-ray burst discovery. We find robust evidence of temporal evolution of the polarization, which is therefore, at least partially, intrinsic to t
A. Martocchia, G. Matt, V. Karas, T. Belloni
The properties of the broad Fe line detected in two BeppoSAX observations of the microquasar GRS 1915+105 are summarized.
H. J. A. Rottgering, L. d'Arcio, C. Eiroa, I. Labbe
The proposed infrared space interferometry mission Darwin has two main aims: (i) to detect and characterize exo-planets similar to the Earth, and (ii) to carry out astrophysical imaging in the wavelength range 6 - 20 micron at a sensitivity similar to JWST, but at an angular resolution up to 100 times higher. In this contribution we will first briefly discus
Carlo Broggini
LUNA, Laboratory for Underground Nuclear Astrophysics at Gran Sasso, is measuring fusion cross sections down to the energy of the nucleosynthesis inside stars. Outstanding results obtained up to now are the cross-section measurements within the Gamow peak of the Sun of $^{3}He(^{3}He,2p)^{4}He$ and the $D(p,γ)^{3}He$. The former plays a big role in the proto
G. Risaliti, R. Maiolino, A. Marconi, L. Bassani
We present an L-band spectrum of the Ultraluminous Infrared Galaxy IRAS 19254-7245 (the Superantennae), obtained with VLT-ISAAC. The high signal to noise ratio allows a study of the main spectral features with unprecedented detail for an extragalactic source. We argue that the main energy source in the IR is an obscured AGN. This is indicated by the low equi
Thierry Foglizzo, Pascal Galletti
The linear stability of stalled accretion shocks is investigated in the context of core collapse of type II supernovae. We focus on a particular instability mechanism based on the coupling of acoustic perturbations with advected ones (vorticity, entropy). This advective-acoustic cycle takes place between the shock and the nascent neutron star. Both adiabatic
S. Mattila, P. Lundqvist, P. Meikle, R. Stathakis
We present a spectroscopic study of the inner circumstellar ring around SN 1987A. The aim is to determine the elemental abundances and density structure, with particular emphasis on the abundance of iron. We acquired and analysed optical spectra at the Anglo-Australian Telescope (AAT) between 1400 and 4300 days post-explosion. We also assembled from the lite
UHECR Anisotropy from Luminous Infrared Galaxies - Predictions for the Pierre Auger Observatory
astro-phGiller Maria, Michalak Wojciech, Smialkowski Andrzej
We consider the hypothesis that luminous infrared galaxies (LIRGs) are sources of the UHECRs. By associating the AGASA triplet with the Arp 299 galaxy we obtain reasonable values for Galactic and extragalactic magnetic fields. We predict what the southern sky, to be seen by the Auger experiment, should look like, so that the LIRG hypothesis could be verified
Hiroyuki Hirashita, Veronique Buat, Akio K. Inoue
Infrared (IR) luminosity of galaxies originating from dust emission can be used as an indicator of the star formation rate (SFR). Inoue et al. (2000, IHK) have derived a formula for the conversion from IR luminosity to SFR by using the following three quantities: the fraction of Lyman continuum luminosity absorbed by gas (f), the fraction of UV luminosity ab
Dovi Poznanski, Avishay Gal-Yam, Dan Maoz, Alexei V. Filippenko
Large numbers of supernovae (SNe) have been discovered in recent years, and many more will be found in the near future. Once discovered, further study of a SN and its possible use as an astronomical tool (e.g., as a distance estimator) require knowledge of the SN type. Current classification methods rely almost solely on the analysis of SN spectra to determi
M. A. T. Groenewegen, M. Salaris
(abridged) Recent investigations aimed at estimating the distance to the young LMC cluster NGC1866 have made use of Red Clump stars in the surrounding LMC field, together with empirical and theoretical Main-Sequence fitting methods, and have found significantly different distances for the field and the cluster, the latter being closer by in distance modulus
Richard de Grijs
Young, massive star clusters are the most notable and significant end products of violent star-forming episodes triggered by galaxy collisions, mergers, and close encounters. Their contribution to the total luminosity induced by such extreme conditions dominates, by far, the overall energy output due to the gravitationally-induced star formation. The general
J. R. Rizzo, J. Martin-Pintado, J. -F. Desmurs
NGC 2359 is a Wolf-Rayet (W-R) nebula partially bound by a rather dense and warm molecular cloud. We present the results derived from CO and $^{13}$CO fully sampled maps of the molecular material with angular resolutions up to 12". We have detected three different velocity components, and determined their spatial distribution and physical properties. The
Gabriele Ghisellini
Beppo}SAX contributed substantially to our understanding of the physics of blazars. This has been made possible mainly by its wide energy range and especially by its high energy detector. Together with the information coming from still higher energies we know at last the entire spectral energy distribution (SED) of blazars. Different subclasses of blazars ha
Istvan Szapudi, Jun Pan
We present a simple and accurate method to constrain galaxy bias based on the distribution of counts in cells. The most unique feature of our technique is that it is applicable to non-linear scales, where both dark matter statistics and the nature of galaxy bias are fairly complex. First, we estimate the underlying continuous distribution function from preci
Xinwu Cao
We estimate the masses of massive black holes in BL Lac objects from their host galaxy luminosity. The power of jets and central optical ionizing luminosity for a sample of BL Lac objects are derived from their extended radio emission and the narrow-line emission, respectively. The maximal jet power can be extracted from a standard thin accretion disk/spinni
M. Ave
The Engineering Array of the Auger Observatory has been running successfully since 2001 and inclined showers have been recorded from the start. We have analysed the events with zenith angle $>$ 70$^0$ recorded between May and November 2002. The different algorithms developed to analyze these showers are also discussed. An preliminary discussion of a reconstr
G. W. Doppmann, D. T. Jaffe, R. J. White
We present high resolution (R=50,000) spectra at 2.2 um of 16 young stars in the rho Ophiuchi dark cloud. Photospheric features are detected in the spectra of 11 of these sources, all Class II young stellar objects. In 10 of these sources, we measure effective temperatures, continuum veiling, and vsini rotation from the shapes and strengths of atomic photosp
G. W. Doppmann, D. T. Jaffe
We describe a technique for deriving effective temperatures, surface gravities, rotation velocities, and radial velocities from high resolution near-IR spectra. The technique matches the observed near-IR spectra to spectra synthesized from model atmospheres. For pre-main sequence stars, we use the same matching process to also measure the amount of excess ne
Ivan Veselic'
We consider the quantum site percolation model on graphs with an amenable group action. It consists of a random family of Hamiltonians. Basic spectral properties of these operators are derived: non-randomness of the spectrum and its components, existence of an self-averaging integrated density of states and an associated trace-formula.
C. Dariescu, M. A. Dariescu, N. G. Deshpande, Dilip Kumar Ghosh
Recent measurement of time dependent asymmetries in $B \to ϕK$ are indicative of a new source of CP violation. We examine squark mixing in SUSY as this new source, and using QCD improved factorization method to describe $B \to ϕK $ decay, find the allowed range of parameter space for $ρ$ and $ψ$, the magnitude and phase of the down type LR(RL) squark mixing
J. E. Hirsch
The theory of hole superconductivity predicts that when a metal goes superconducting negative charge is expelled from its interior towards the surface. As a consequence the superconductor in its ground state is predicted to have a non-homogeneous charge distribution and an outward pointing electric field in its interior. Here we propose equations to describe
Noam Berger, Claire Kenyon, Elchanan Mossel, Yuval Peres
We study continuous time Glauber dynamics for random configurations with local constraints (e.g. proper coloring, Ising and Potts models) on finite graphs with $n$ vertices and of bounded degree. We show that the relaxation time (defined as the reciprocal of the spectral gap $|λ_1-λ_2|$) for the dynamics on trees and on planar hyperbolic graphs, is polynomia
Alfonso García-Parrado, José M. M. Senovilla
We fully develop the concept of causal symmetry introduced in Class. Quant. Grav. 20 (2003) L139. A causal symmetry is a transformation of a Lorentzian manifold (V,g) which maps every future-directed vector onto a future-directed vector. We prove that the set of all causal symmetries is not a group under the usual composition operation but a submonoid of the
Vlada Limic, Robin Pemantle
The purpose of this note is to provide proofs for some facts about the NK model of evolution proposed by Kauffman and Levin. In the case of normally distributed fitness summands, some of these facts have been previously conjectured and heuristics given. In particular, we provide rigorous asymptotic estimates for the number of local fitness maxima in the case
One-dimensional models for atoms in strong magnetic fields, II: Anti-Symmetry in the Landau Levels
math-phRaymond Brummelhuis, Mary Beth Ruskai
Electrons in strong magnetic fields can be described by one-dimensional models in which the Coulomb potential and interactions are replaced by regularizations associated with the lowest Landau band. For a large class of models of these type, we show that the maximum number of electrons that can be bound is less than a Z + Z f(Z). The function f(Z) represents
Gene F. Mazenko
The calculation of the point vortex velocity probability distribution function (vvpdf) is extended to a larger class of systems beyond the nonconserved TDGL model treated earlier. The range is extended to include certain anisotropic models and the conserved order parameter case. The vvpdf still satisfies scaling with large velocity tails as for the nonconser
Stephen F. Sawin
For each compact, simple, simply-connected Lie group and each integer level we construct a modular tensor category from a quotient of a certain subcategory of the category of representations of the corresponding quantum group. We determine when at fractional levels the corresponding category is modular. We also give a quantum version of the Racah formula for
Anna Pratoussevitch
We consider discrete subgroups Gamma of the simply connected Lie group SU~(1,1), the universal cover of SU(1,1), of finite level, i.e. the subgroup intersects the centre of SU~(1,1) in a subgroup of finite index, this index is called the level of the group. The Killing form induces a Lorentzian metric of constant curvature on the Lie group SU~(1,1). The disc
John Robert Burger
Introduced below is a quantum database method, not only for retrieval but also for creation. It uses a particular structure of true's and false's in a state vector of n qubits, permitting up to 2**2**n words, vastly more than for classical bits. Several copies are produced so that later they can be destructively observed and a word determined with hi
V. Elias, R. B. Mann, D. G. C. McKeon, T. G. Steele
In the absence of a tree-level scalar-field mass, renormalization-group (RG) methods permit the explicit summation of leading-logarithm contributions to all orders of the perturbative series for the effective-potential functions utilized in radiative symmetry breaking. For scalar-field electrodynamics, such a summation of leading logarithm contributions lead
Alan Kostelecky, Matthew Mewes
We consider neutrino oscillations in the minimal Standard-Model Extension describing general Lorentz and CPT violation. Among the models without neutrino mass differences is one with two degrees of freedom that reproduces most major observed features of neutrino behavior.
A. Mishra, E. L. Bratkovskaya, J. Schaffner-Bielich, S. Schramm
We evaluate the in-medium $D$ and $\bar D$-meson masses in hot hadronic matter induced by interactions with the light hadron sector described in a chiral SU(3) model. The effective Lagrangian approach is generalized to SU(4) to include charmed mesons. We find that the D-mass drops substantially at finite temperatures and densities, which open the channels of
A Spontaneous Generation of the Magnetic Field and Suppression of the Heat Conduction in Cold Fronts
astro-phNobuhiro Okabe, Makoto Hattori
We have determined the physical mechanism responsible for the plasma instabilities, which was first found by Ramani and Laval (1978), associated with anisotropic velocity distributions induced by the temperature gradient in which there are growing low frequency transverse magnetic waves, even in the absence of background magnetic fields. We have shown that t
V. V. Varlamov
The Biedenharn type relativistic wavefunctions are considered on the group manifold of the Poincaré group. It is shown that the wavefunctions can be factorized on the group manifold into translation group and Lorentz group parts. A Lagrangian formalism and field equations for such factorizations are given. Parametrizations of the functions obtained are studi
John Robert Burger
Procedures are given below to construct symmetric and anti-symmetric quantum functions. If hidden in an oracle, such functions can be identified exactly, without iterative interrogation. This is another example of quantum search. The resulting positive (or negative) functions also serve to uniquely reorganize a superposition of states to give a basis state f
$\bar B^0\to ϕK_S$ and $\bar K^{*0}γ$ CP Asymmetries from Supersymmetric Right-handed Flavor Mixing: Implications for Heavy Quark Phenomenology
hep-phChun-Khiang Chua, Wei-Shu Hou, Makiko Nagashima
Two recent experimental developments, when combined, may have far reaching implications. $S_{ϕK_S} < 0$, if confirmed, would imply large $s$-$b$ mixing, a new CP phase, and right-handed dynamics. Large $Δm_{B_s}$ would be likely, making the $B_s$ program at hadron machines difficult. Reconstruction of $B$ vertex from $K_S$ at B factories, as shown by BaBar&#
NEXXUS: A comprehensive ROSAT survey of coronal X-ray emission among nearby solar-like stars
astro-phJ. H. M. M. Schmitt, C. Liefke
We present a final summary of all ROSAT X-ray observations of nearby stars. All available ROSAT observations with the ROSAT PSPC, HRI and WFC have been matched with the CNS4 catalog of nearby stars and the results gathered in the Nearby X-ray and XUV-emitting Stars data base, available via www from the Home Page of the Hamburger Sternwarte at http://www.hs.u
Daeho Lee, Ee Chang-Young
In order to understand the characteristics of quantum entanglement of massive particles under Lorentz boost, we first introduce a relevant relativistic spin observable, and evaluate its expectation values for the Bell states under Lorentz boost. Then we show that maximal violation of the Bell's inequality can be achieved by properly adjusting the directi
Liudmila Joukovskaya, Yaroslav Volovich
We study the toy model of interacting open and closed string tachyons which demonstrates some interesting properties of the unstable D-brane decay scenario. We compute a stress tensor of the system and study the energy and pressure dynamics. We show that the total energy of the system is conserved. We separate the stress tensor into two parts corresponding t
Alain Connes, Michel Dubois-Violette
We analyse the moduli space and the structure of noncommutative 3-spheres. We develop the notion of central quadratic form for quadratic algebras, and prove a general algebraic result which considerably refines the classical homomorphism from a quadratic algebra to a cross-product algebra associated to the characteristic variety and lands in a richer cross-p
Alexander Khodjamirian, Thomas Mannel, Martin Melcher
QCD sum rules are used to estimate the flavour SU(3)-symmetry violation in two-body B decays to pions and kaons. In the factorizable amplitudes the SU(3)-violation manifests itself in the ratio of the decay constants f_K/f_pi and in the differences between the B->K, B_s->K and B->pi form factors. These effects are calculated from the QCD two-point and light-
ZEUS Collaboration
Inclusive production of $D^*(2010)$ mesons in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 81.9 pb$^{-1}$. The decay channel $D^{* +}\to D^0 π^+ $ with $D^0\to K^-π^+$ and corresponding antiparticle decay were used to identify $D^*$ mesons. Differential $D^*$ cross sections with $1.5<Q^2<1000$ G
John McDonald
The curvaton scenario predicts an almost scale-invariant spectrum of perturbations in most inflation models. We consider the possibility that renormalisable phi^4 or Planck scale-suppressed non-renormalisable curvaton potential terms may result in an observable deviation from scale-invariance. We show that if the curvaton initially has a large amplitude and
Koji Fujiwara, Takashi Shioya, Saeko Yamagata
We study discrete groups from the view point of a dimension gap in connection to CAT(0) geometry. Developing studies by Brady-Crisp and Bridson, we show that there exist finitely presented groups of geometric dimension 2 which do not act properly on any proper CAT(0) spaces of dimension 2 by isometries, although such actions exist on CAT(0) spaces of dimensi
A. Ossipov, Tsampikos Kottos
We study the proximity effect of a superconductor to a normal system with fractal spectrum. We find that there is no gap in the excitation spectrum, even in the case where the underlying classical dynamics of the normal system is chaotic. An analytical expression for the distribution of the smallest excitation eigenvalue $E_g$ of the hybrid structure is obta
T. Baier, E. Bick, C. Wetterich
We compute the temperature dependence of the antiferromagnetic order parameter and the gap in the two dimensional Hubbard model at and close to half filling. Our approach is based on truncations of an exact functional renormalization group equation. The explicit use of composite bosonic degrees of freedom permits a direct investigation of the ordered low tem
Anais Smailagic, Euro Spallucci
We formulate Noncommutative Qauntum Field Theory in terms of fields defined as mean value over coherent states of the noncommutative plane. No *-product is needed in this formulation and noncommutativity is carried by a modified Fourier transform of fields. As a result the theory is UV finite and the cutoff is provided by the noncommutative parameter theta.
Torsten Bringmann, Martin Eriksson
We investigate cosmologies with homogeneous extra dimensions that can be described by generalised Friedmann-Robertson-Walker metrics and give a brief review on a general setup to describe a broad range of standard stabilization and compactification mechanisms. These mechanisms allow for solutions to the field equations with static extra dimensions if the uni
Kumar S. Gupta
Hamiltonians with inverse square interaction potential occur in the study of a variety of physical systems and exhibit a rich mathematical structure. In this talk we briefly mention some of the applications of such Hamiltonians and then analyze the case of the N-body rational Calogero model as an example. This model has recently been shown to admit novel sol
Towards a sensitive search for variation of the fine structure constant using radio-frequency E1 transitions in atomic dysprosium
physics.atom-phA. T. Nguyen, D. Budker, S. K. Lamoreaux, J. R. Torgerson
It has been proposed that the radio-frequency electric-dipole (E1) transition between two nearly degenerate opposite-parity states in atomic dysprosium should be highly sensitive to possible temporal variation of the fine structure constant ($α$) [V. A. Dzuba, V. V. Flambaum, and J. K. Webb, Phys. Rev. A {\bf 59}, 230 (1999)]. We analyze here an experimental
Logarithmic corrections to the Bekenstein_Hawking entropy for five-dimensional black holes and de Sitter spaces
hep-thY. S. Myung
We calculate corrections to the Bekenstein-Hawking entropy formula for the five-dimensional topological AdS (TAdS)-black holes and topological de Sitter (TdS) spaces due to thermal fluctuations. We can derive all thermal properties of the TdS spaces from those of the TAdS black holes by replacing $k$ by $-k$. Also we obtain the same correction to the Cardy-V
M. Asakawa, T. Hatsuda
Analyzing correlation functions of charmonia at finite temperature ($T$) on $32^3\times(32-96)$ anisotropic lattices by the maximum entropy method (MEM), we find that $J/ψ$ and $η_c$ survive as distinct resonances in the plasma even up to $T \simeq 1.6 T_c$ and that they eventually dissociate between $1.6 T_c$ and $1.9 T_c$ ($T_c$ is the critical temperature
Xiaodong Zhu, Francis Bonahon
We consider the space of geodesic laminations on a surface, endowed with the Hausdorff metric d_H and with a variation of this metric called the d_log metric. We compute and/or estimate the Hausdorff dimensions of these two metrics. We also relate these two metrics to another metric which is combinatorially defined in terms of train tracks.
Francis Bonahon, Xiaodong Zhu
We continue our investigation of the space of geodesic laminations on a surface, endowed with the Hausdorff topology. We determine the topology of this space for the once-punctured torus and the 4-times-punctured sphere. For these two surfaces, we also compute the Hausdorff dimension of the space of geodesic laminations, when it is endowed with the natural m
W. H. Zurek
Effective classicality of a property of a quantum system can be defined using redundancy of its record in the environment. This allows quantum physics to approximate the situation encountered in the classical world: The information about a classical system can exist independently from its state. In quantum theory this is no longer possible: In an isolated qu
A. C. Sicardi Shifino, G. Abal, R. Siri, A. Romanelli
We show that some classically chaotic quantum systems uncoupled from noisy environments may generate intrinsic decoherence with all its associated effects. In particular, we have observed time irreversibility and high sensitivity to small perturbations in the initial conditions in a quasiperiodic version of the kicked rotor. The existence of simple quantum s
A. T. Avelar, B. Baseia, J. M. C. Malbouisson
We consider experimental routes to determine the nonclassical degree of states of a field mode. We adopt a distance-type criterium based on the Hilbert-Schmidt metric to quantify the nonclassicality. The concept of nonclassical degree is extended for states of bipartite systems, allowing us to discuss a possible connection between nonclassicality and entangl
S. M. Fei, X. H. Gao, X. H. Wang, Z. X. Wang
The separability and entanglement of quantum mixed states in $\Cb^2 \otimes \Cb^3 \otimes \Cb^N$ composite quantum systems are investigated. It is shown that all quantum states $ρ$ with positive partial transposes and rank $r(ρ)\leq N$ are separable.
John Robert Burger
Classical simulation is important because it sets a benchmark for quantum computer performance. Classical simulation is currently the only way to exercise larger numbers of qubits. To achieve larger simulations, sparse matrix processing is emphasized below while trading memory for processing. It performed well within NCSA supercomputers, giving a state vecto
Crossover from classical to quantum behavior of Duffing oscillator through "pseudo-Lyapunov exponent"
quant-phYukihiro Ota, Ichiro Ohba
We discuss the quantum--classical correspondence in a specific dissipative chaotic system, Duffing oscillator. We quantize it on the basis of quantum state diffusion (QSD) which is a certain formulation for open quantum systems and an effective tool for analyzing complex problems numerically. We consider a sensitivity to initial conditions, `` pseudo-Lyapuno
J. J. Hope, J. D. Close
All optical techniques used to probe the properties of Bose-Einstein condensates have been based on dispersion and absorption that can be described by a two-level atom. Both phenomena lead to spontaneous emission that is destructive. Recently, both were shown to lead to the same limit to the signal to noise ratio for a given destruction. We generalise this r
Solvejg Jorgensen, Ronnie Kosloff
A pulse shaping algorithm for a matter wave with the purpose of controlling a binary reaction has been designed. The scheme is illustrated for an Eley-Rideal reaction where an impinging matter-wave atom recombines with an adsorbed atom on a metal surface. The wave function of the impinging atom is shaped such that the desorbing molecule leaves the surface in
Salomon Itza-Ortiz, N. Sanjay Rebello, Dean A. Zollman
We investigated students' use of Newton's second law in mechanics and electromagnetism contexts by interviewing students in a two-semester calculus-based physics course. We observed that students' responses are consistent with three mental models. These models appeard in mechanics contexts and were transferred to electromagnetism contexts. We dev
R. S. Conroy, Y. Xiao, M. Vengalattore, W. Rooijakkers
We report a compact (<20cm3), robust source for producing a bright flux of cold atoms, which can be loaded efficiently into a magnetic guide. A continuous flux of up to 8 x 109 87Rb atoms/s have been produced from this 2D+ vapor cell MOT. The flux had a divergence of 12.5 mrad and velocity could be controlled in the range 2-15 m/s. This flux was coupled cont
E. R. Prakasan, Anil Kumar, Anil Sagar, Lalit Mohan
The frontiers of physics related e-print archives (1994-2002) at http://www.arxiv.org/archives/physics web service are explored from 7770 submissions. No. of e-prints in the six research disciplines besides physics (5390) were: Condensed matter(754), Quantum physics(279), Astrophysics(222), Chemical physics(129), High energy physics Phenomenology(118), and H
T. A. Nieminen, H. Rubinsztein-Dunlop, N. R. Heckenberg, A. I. Bishop
Optical trapping is a widely used technique, with many important applications in biology and metrology. Complete modelling of trapping requires calculation of optical forces, primarily a scattering problem, and non-optical forces. The T-matrix method is used to calculate forces acting on spheroidal and cylindrical particles.
S. Bayoudh, T. A. Nieminen, N. R. Heckenberg, H. Rubinsztein-Dunlop
Optical tweezers are widely used for the manipulation of cells and their internal structures. However, the degree of manipulation possible is limited by poor control over the orientation of trapped cells. We show that it is possible to controllably align or rotate disc shaped cells - chloroplasts of Spinacia oleracea - in a plane polarised Gaussian beam trap
T. A. Nieminen, N. R. Heckenberg, H. Rubinsztein-Dunlop
In recent years there has been an explosive development of interest in the measurement of forces at the microscopic level, such as within living cells, as well as the properties of fluids and suspensions on this scale, using optically trapped particles as probes. The next step would be to measure torques and associated rotational motion. This would allow mea
A Conjugation Symmetry in Linear Electromagnetism, in Extension of Materials with Negative Real Permittivity and Permeability Scalars
physics.opticsA. Lakhtakia
If all space is occupied by a linear bianisotropic material--whether homogeneous or not--then the concurrent replacements of the permittivity and the impermeability tensors by the negatives of their respective complex conjugates and of the magnetoelectric tensors by their respective complex conjugates (in the Boys-Post representation) imply the conjugation o
Description of Chiral Doublets in $A\sim130$ Nuclei and the Possible Chiral Doublets in $A\sim100$ Nuclei
nucl-thJ. Peng, J. Meng, S. Q. Zhang
The chiral doublets for nuclei in $A\sim100$ and $A\sim130$ regions have been studied with the particle-rotor model. The experimental spectra of chiral partners bands for four N=75 isotones in $A\sim130$ region have been well reproduced by the calculation with the configuration $πh_{11/2}\otimesνh_{11/2}^{-1}$. The possible chiral doublets in $A\sim100$ regi
Nucleus-nucleus reaction cross-sections calculated for realistic nuclear matter distributions within the Glauber-Sitenko approach
nucl-thV. Lukyanov, E. Zemlyanaya, B. Slowinski
Basing on the thickness (profile) function, previously obtained for the realistic Fermi type distribution of nucleons in nuclei, calculations are made of the microscopic eikonal phases of the nucleus-nucleus scattering and the total reaction cross- sections. In so doing, the phase is deduced to the one-dimensional integral provided that the Gaussian density
S. Strauch
Two-pion photoproduction in the reaction gamma + p -> p + pi^+ + pi^- has been studied at Jefferson Lab Hall B using a circularly-polarized tagged photon beam in the energy range between 0.6 GeV and 2.3 GeV. Owing to the large angular acceptance of the CLAS detector, complete beam-helicity-dependent angular distributions of the final-state particles were mea
Guy Katriel
We derive simple conditions for the stability or instability of the synchronized oscillation of a class of networks of coupled phase-oscillators, which includes many of the systems used in neural modelling.
R. F. Streater
We consider the quantum information manifold whose underlying set M consists of density operators rho with the extra property that some fractional power of rho is of trace class. The topology is defined by defining a neighbourhood of a point rho to be all density operators that dominate rho and are dominated by rho. We show that this is the same set as that
Discrete Painlevé equations, Orthogonal Polynomials on the Unit Circle and $N$-recurrences for averages over U(N) -- \PVI $τ$-functions
math-phP. J. Forrester, N. S. Witte
The theory of orthogonal polynomials on the unit circle is developed for a general class of weights leading to systems of recurrence relations and derivatives of the polynomials and their associated functions, and to functional-difference equations of certain coefficient functions appearing in the theory. A natural formulation of the Riemann-Hilbert problem
Mike Develin, Seth Sullivant
This paper is concerned with the topological invariant of a graph given by the maximum degree of a Markov basis element for the corresponding graph model for binary contingency tables. We describe a degree four Markov basis for the model when the underlying graph is a cycle and generalize this result to the complete bipartite graph $K_{2,n}$. We also give a
Andrew Hassell, Jared Wunsch
We discuss the form of the propagator $U(t)$ for the time-dependent Schrödinger equation on an asyptotically Euclidean, or, more generally, asymptotically conic, manifold with no trapped geodesics. In the asymptotically Euclidean case, if $χ\in \mathcal{C}_0^\infty$, and with $\mathcal{F}$ denoting Fourier transform, $\mathcal{F}\circ e^{-ir^2/2t} U(t) χ$ is
Tolga Etgü, B. Doug Park
Let E(1)_p denote the rational elliptic surface with a single multiple fiber f_p of multiplicity p. We construct an infinite family of homologous non-isotopic symplectic tori representing the primitive class [f_p] in E(1)_p when p>1. As a consequence, we get infinitely many non-isotopic symplectic tori in the fiber class of the rational elliptic surface E(1)
Sever Silvestru Dragomir
Reverses of Schwarz, triangle and Bessel inequalities in inner product spaces that improve some earlier results are pointed out. They are applied to obtain new Gruss type inequalities in inner product spaces. Some natural applications for integral inequalities are also pointed out.
Jooyoun Hong
We deal with classes of prime ideals whose associated graded ring is isomorphic to the Rees algebra of the conormal module in order to describe the divisor class group of the Rees algebra and to examine the normality of the conormal module.
S. S. Dragomir, Y. J. Cho, S. S. Kim, A. Sofo
Some inequalities in 2-inner product spaces generalizing Bessel's result that are similar to the Boas-Bellman inequality from inner product spaces, are given. Applications for determinantal integral inequalities are also provided.
Alan L. Carey, John Phillips
We give a comprehensive account of an analytic approach to spectral flow along paths of self-adjoint Breuer-Fredholm operators in a type $I_{\infty}$ or $II_\infty$ von Neumann algebra ${\mathcal N}$. The framework is that of {\it odd unbounded} $θ$-{\it summable} {\it Breuer-Fredholm modules} for a unital Banach *-algebra, $\mathcal A$. In the type $II_{\in
S. F. Hassan
A systematic construction is given for N=1 open string boundary coupling to Abelian and non-Abelian Dp-brane worldvolume fields, in general curved backgrounds. The basic ingredient is a set of four ``boundary vectors'' that provide a unified description of boundary conditions and boundary couplings. We then turn to the problem of apparent inconsisten
G. W. Gibbons, C. E. Patricot
We show explicitly how the Newton-Hooke groups act as symmetries of the equations of motion of non-relativistic cosmological models with a cosmological constant. We give the action on the associated non-relativistic spacetimes and show how these may be obtained from a null reduction of 5-dimensional homogeneous pp-wave Lorentzian spacetimes. This allows us t
Domingo J. Louis-Martinez
Exact solutions of the relativistic many-body problem are presented