March 2004 arXiv papers — page 5
Showing 401–500 of 3,458 papers
L. Harnau, F. Penna, S. Dietrich
Density functional theory is used to study colloidal hard-rod fluids near an individual right-angled wedge or edge as well as near a hard wall which is periodically patterned with rectangular barriers. The Zwanzig model, in which the orientations of the rods are restricted to three orthogonal orientations but their positions can vary continuously, is analyze
F. Rivadulla, M. Banobre-Lopez, M. A. Lopez-Quintela, J. Rivas
We report the divergence of the nonlinear component of the bulk susceptibility in NaxCoO2 (0.3<x<0.62) as T goes to 0 K. These experiments provide an striking evidence of the existence of a ferromagnetic phase transition at zero Kelvin (quantum phase transition). The possible role of magnetic fluctuations in the superconductivity is discussed to the light of
The origin of the glassy magnetic dynamics of the phase segregated state in perovskites
cond-mat.str-elF. Rivadulla, M. A. Lopez-Quintela, J. Rivas
In this paper we address many of the fundamental open questions regarding the glassy behavior of the magnetic/electronic phase segregated state in rare earth perovskites. In particular, magnetic relaxation experiments support that the collective effects (memory, ageing, etc.) are due to interparticle interactions, rather than the double-exchange vs. superexc
L. Chioncel, A. I. Lichtenstein
The electronic structure of Co/Cu(001) and Fe/Cr(001) magnetic multilayers has been investigated within the local density approximation combined with dynamical mean field theory. Our calculation shows enhanced density of states at the Fermi level, suggesting that electronic correlations might play an important role in the transport properties of multilayers.
M. E. Cates, M. Fuchs, K. Kroy, W. C. K. Poon
We present some recent theory and simulation results addressing the phenomena of colloidal gelation at both high and low volume fractions, in the presence of short-range attractive interactions. We discuss the ability of mode-coupling theory and its adaptations to address situations with strong heterogeneity in density and/or dynamics. We include a discussio
G. Rousseaux, H. Caps, J. -E. Wesfreid
We report an experimental study of a binary sand bed under an oscillating water flow. The formation and evolution of ripples is observed. The appearance of a granular segregation is shown to strongly depend on the sand bed preparation. The initial wavelength of the mixture is measured. In the final steady state, a segregation in volume is observed instead of
Long term memories of developed and emerging markets: using the scaling analysis to characterize their stage of development
cond-mat.stat-mechT. Di Matteo, T. Aste, M. M. Dacorogna
The scaling properties encompass in a simple analysis many of the volatility characteristics of financial markets. That is why we use them to probe the different degree of markets development. We empirically study the scaling properties of daily Foreign Exchange rates, Stock Market indices and fixed income instruments by using the generalized Hurst approach.
Santo Fortunato
The consensus model of Krause and Hegselmann can be naturally extended to the case in which opinions are integer instead of real numbers. Our algorithm is much faster than the original version and thus more suitable for applications. For the case of a society in which everybody can talk to everybody else, we find that the chance to reach consensus is much hi
Bo Reipurth, Colin Aspin
We present a study of McNeil's Nebula, a newly appeared reflection nebula in the L1630 cloud, together with photometry and spectroscopy of its source. New IR photometry compared to earlier 2MASS data shows that the star has brightened by about 3 magnitudes in the near-infrared, changing its location in a J-H/H-K diagram precisely along a reddening vector
A catalogue of the Chandra Deep Field South with multi-colour classification and photometric redshifts from COMBO-17
astro-phC. Wolf, K. Meisenheimer, M. Kleinheinrich, A. Borch
We present the COMBO-17 object catalogue of the Chandra Deep Field South for public use, covering a field which is 31.5' x 30' in size. This catalogue lists astrometry, photometry in 17 passbands from 350 to 930 nm, and ground-based morphological data for 63,501 objects. The catalogue also contains multi-colour classification into the categories '
R. Hoogerwerf, N. S. Brickhouse, C. W. Mauche
We present the first detection of orbital motion in the cataclysmic variable EX Hydrae based on X-ray data from the Chandra X-ray Observatory. The large collecting area of the telescope and the high resolution of the HETG spectrometers allow for an unprecedented velocity accuracy of ~15 km/s in the X-ray wavelength regime. We find an emission line velocity a
Supersoft X-ray sources in M31: II. ROSAT-detected supersoft sources in the ROSAT, Chandra and XMM eras
astro-phJ. Greiner, R. DiStefano, A. Kong, F. Primini
We have performed Chandra observations during the past 3 years of 5 of the M31 supersoft X-ray sources (SSS) discovered with ROSAT. Surprisingly, only one of these sources has been detected, despite a predicted detection of about 20-80 counts. This has motivated a thorough check of the ROSAT M31 survey I data, including a relaxation of the hardness ratio req
Jennifer E. Scott, Gerard A. Kriss, Michael Brotherton, Richard F. Green
The Far Ultraviolet Spectroscopic Explorer (FUSE) has surveyed a large sample (> 100) of active galactic nuclei in the low redshift universe (z < 1). Its response at short wavelengths makes it possible to measure directly the EUV spectral shape of QSOs and Seyfert 1 galaxies at z < 0.3. Using archival FUSE spectra, we form a composite extreme ultraviolet (EU
Sabrina Casanova, Peter L. Biermann, Ralph Engel, Athina Meli
The diffuse galactic gamma-ray spectrum measured by the EGRET experiment \citep{Hunter:1997} are interpreted within a scenario in which cosmic rays (CRs) are injected by three different kind of sources, (i) supernovae (SN) which explode into the interstellar medium (ISM), (ii) Red Supergiants (RSG), and (iii) Wolf-Rayet stars (WR), where the two latter explo
I. Trujillo, Peter Erwin, A. Asensio Ramos, Alister W. Graham
We fit the surface-brightness profiles of 21 elliptical galaxies using both the Sersic function and a new empirical model which combines an inner power law with an outer Sersic function. The profiles are combinations of deconvolved HST profiles from the literature and ellipse fits to the full WFPC2 mosaic images, and thus span a radial range from ~ 0.02 arcs
Spatial Locality of Galaxy Correlation Function in Phase Space: Samples from the 2MASS Extended Source Catalog
astro-phYicheng Guo, Yao-Quan Chu, Li-Zhi Fang
We analyze the statistical properties and dynamical implications of galaxy distributions in phase space for samples selected from the 2MASS Extended Source Catalog. The galaxy distribution is decomposed into modes $δ({\bf k, x})$ which describe the number density perturbations of galaxies in phase space cell given by scale band $\bf k$ to ${\bf k}+Δ{\bf k}$
J. P. Dietrich, D. Clowe, P. Schneider, J. Kerp
We present a weak lensing analysis and comparison to optical and X-ray maps of the close pair of massive clusters A222/223. Indications for a filamentary connection between the clusters are found and discussed.
Magnetic Fields and Ionized Gas in the inner Galaxy: An Outer Scale for Turbulence and the Possible Role of HII Regions
astro-phM. Haverkorn, B. M. Gaensler, N. M. McClure-Griffiths, John M. Dickey
We present an analysis of rotation measure (RM) fluctuations from the Test Region of the Southern Galactic Plane Survey (SGPS), along with emission measure (EM) fluctuations in the same field taken from the Southern H-Alpha Sky Survey Atlas. The structure function of RM fluctuations shows a relatively steep slope at small scales (1-5 arcmin), a break in slop
T. An, X. Y. Hong, T. Venturi, D. R. Jiang
In this paper we present a multifrequency and multiepoch study of \object{PKS 1502+106} at radio frequencies. The analysis is based on an EVN (European VLBI Network) dataset at 5 GHz and archive VLBA (Very Long Baseline Array) datasets at 2.3, 8.3, 24.4 and 43.1 GHz over a period of 8 years. The source is characterized by a multi--component one--sided jet at
B. Gerken, B. Ziegler, M. Balogh, D. Gilbank
We present a spectroscopic analysis of two galaxy clusters out to ~4Mpc at z~0.2. The two clusters VMF73 and VMF74 identified by Vikhlinin et al. (1998) were observed with MOSCA at the Calar Alto 3.5m telescope. Both clusters lie in the ROSAT PSPC field R285 and were selected from the X-ray Dark Cluster Survey (Gilbank et al. 2004) that provides optical V- a
Elena Jimenez-Bailon, Enrico Piconcelli, Matteo Guainazzi, Norbert Schartel
We present preliminary results of a systematic analysis of the XMM-Newton spectra of nearby optically-bright QSOs. The objects have been optically selected from the Bright Quasar Survey sample. The goal of this project is to characterise the X-ray spectral properties of optically selected QSOs in the 0.3-12 keV energy band. A power law component accounts the
Oliver Czoske
We are using VIMOS to conduct a wide-field spectroscopic survey covering fields of 0.5 x 0.5 sqdeg around the X-ray luminous clusters of galaxies Abell 1689 (z = 0.185) and Abell 1835 (z = 0.25). Here we describe the observations and first results on the redshift distribution of subsamples of cluster galaxies to R~22 for which we at present have obtained sec
A. Tiengo, S. Mereghetti, G. Ghisellini, E. Rossi
Thanks to its extraordinary brightness, the X-ray afterglow of GRB030329 could be studied by XMM-Newton up to two months after the prompt Gamma-ray emission. We present the results of two XMM-Newton observations performed on May 5 and 29, as well as an analysis of the Rossi-XTE data of the early part of the afterglow, discussing in particular the stability o
D. H. Lumb, A Finoguenov, R Saxton, B Aschenbach
We describe measurements of the mirror vignetting in the XMM-Newton Observatory made in-orbit, using observations of SNR G21.5-09 and SNR 3C58 with the EPIC imaging cameras. The instrument features that complicate these measurements are briefly described. We show the spatial and energy dependences of measured vignetting, outlining assumptions made in derivin
Sumit R. Das, Joshua L. Davis, Finn Larsen, Partha Mukhopadhyay
We consider cosmological particle production in 1+1 dimensional string theory. The process is described most efficiently in terms of anomalies, but we also discuss the explicit mode expansions. In matrix cosmology the usual vacuum ambiguity of quantum fields in time-dependent backgrounds is resolved by the underlying matrix model. This leads to a finite ener
Ralph L. Cohen
Let $M^n$ be a closed, connected $n$-manifold. Let $\mtm$ denote the Thom spectrum of its stable normal bundle. A well known theorem of Atiyah states that $\mtm$ is homotopy equivalent to the Spanier-Whitehead dual of $M$ with a disjoint basepoint, $M_+$. This dual can be viewed as the function spectrum, $F(M, S)$, where $S$ is the sphere spectrum. $F(M, S)$
M. Iskin, I. O. Kulik
Recent discovery of mesoscopic electronic structures, in particular the carbon nanotubes, made necessary an investigation of what effect may helical symmetry of the conductor (metal or semiconductor) have on the persistent current oscillations. We investigate persistent currents in helical structures which are non-decaying in time, not requiring a voltage bi
Utpal Sarkar
We considered parity breaking in some left-right symmetric models. We studied spontaneous and explicit parity violation in two cases with doublet and triplet Higgs scalars. The minimization condition in these two cases differ significantly. A comparative study of these models is presented emphasizing their phenomenological consequences.
Douglas Singleton
We extend a recently discovered, non-singular 6 dimensional brane, solution to D=4+n dimensions. As with the previous 6D solution the present solution provides a gravitational trapping mechanism for fields of spin 0, 1/2, 1 and 2. There is an important distinction between 2 extra dimensions and $n$ extra dimensions that makes this more than a trivial extensi
S. F. Sanchez, K. Jahnke, L. Wisotzki, D. H. McIntosh
We present the results from a study of the host galaxies of 15 optically selected AGNs with 0.5<z<1.1 from GEMS. GEMS is a Hubble Space Telescope imaging survey of a ~28"x28" contiguous field centered on the Chandra Deep Field South in the F606W and F850LP filter bands. It incorporates the SEDs and redshifts of ~10000 objects, obtained by the COMBO-1
Clifford M. Will
We estimate the rate at which the proposed space gravitational-wave interferometer LISA could detect intermediate-mass black-hole binaries, that is, binaries containing a black hole in the mass range 10 -- 100 Msun orbiting a black hole in the mass range 100 -- 1000 Msun. For one-year integrations leading up to the innermost stable orbit, and a signal-to-noi
Solvable multi-species reaction-diffusion processes, including the extended drop-push model
cond-mat.stat-mechMasoud Alimohammadi
By considering the master equation of asymmetric exclusion process on a one-dimensional lattice, we obtain the most general boundary condition of the multi-species exclusion processes in which the number of particles is constant in time. This boundary condition introduces the various interactions to the particles, including ones which have been studied yet a
David L. Johnson, Penelope Smith
Let B be a fiber bundle with compact fiber F over a compact Riemannian n-manifold M. There is a natural Riemannian metric on the total space B consistent with the metric on M. With respect to that metric, the volume of a rectifiable section s:M--> B is the mass of the image s(M) as a rectifiable n-current in B. Theorem: For any homology class of sections of
Lajos Diosi
We can uniquely calculate almost all entangled state vectors of tripartite systems ABC if we know the reduced states of any two bipartite subsystems, e.g., of AB and of BC. We construct the explicit solution.
Automatical generation of nonadiabatic conditional geometric phase shift via a noncoplanar fiber system
quant-phJian Qi Shen
A new scheme of realizing the nonadiabatic conditional geometric phase shift via a noncoplanar (and coiled) fiber system is presented in this Letter. It is shown that the effective Hamiltonian that describes the interaction of polarized photons with the fiber medium is just the Wang-Keiji type of Hamiltonian. This, therefore, means that the coiled fiber syst
Sandeep Krishna
I analyse a model of an evolving network represented as a directed graph; each node corresponds to one molecular species and the links to catalytic interactions between species. Over short timescales the graph remains fixed while relative populations of the molecular species change according to a set of coupled differential equations. Over long timescales th
Doug Pickrell
We use geometric arguments to derive a possible form for the radial part of the ``zero-mode Hamiltonian'' for the two dimensional sigma model with target space S^3, or more generally a compact simply connected Lie group.
Dmitri V. Vassilevich
We describe how spectral functions of differential operators appear in the quantum field theory context. We formulate consistency conditions which should be satisfied by the operators and by the boundary conditions. We review some modern developments in quantum field theory and strings and show which new spectral and boundary value problems arise.
Joan S. Birman
These notes were prepared to supplement the talk that I gave on Feb 19, 2004, at the First East Asian School of Knots and Related Topics, Seoul, South Korea. In this article I review aspects of the interconnections between braids, knots and contact structures on Euclidean 3-space. I discuss my recent work with William Menasco (arXiv math.GT/0310279)} and (ar
Alexander V. Karabegov
To each natural star product on a Poisson manifold $M$ we associate an antisymplectic involutive automorphism of the formal neighborhood of the zero section of the cotangent bundle of $M$. If $M$ is symplectic, this mapping is shown to be the inverse mapping of the formal symplectic groupoid of the star product. The construction of the inverse mapping involv
Alexander Stasinski
In a previous paper it was shown that a certain family of varieties suggested by Lusztig, is not enough to construct all irreducible complex representations of reductive groups over finite rings coming from the ring of integers in a local field, modulo a power of the maximal ideal. In this paper we define a generalisation of Lusztig's varieties, correspo
H. Hakopian
Here the polynomial interpolation approach is used to introduce the main results on multivariate normal algebraic systems. Next we bring a construction which shows that any standard algebraic system, with finite set of solutions, can be reduced to a normal type (total degree) algebraic system.
Robert L. Griess
We give a new existence proof for the rank 2^d even lattices usually called the Barnes-Wall lattices, and establish new results on uniqueness, structure and transitivity of the automorphism group on certain kinds of sublattices. Our proofs are relatively free of calculations, matrix work and counting, due to the uniqueness viewpoint. We deduce the labeling o
Narad Rampersad
This paper has been withdrawn by the author due to an error in the proof of Theorem 2.
A. Gerasimov, S. Kharchev, D. Lebedev
We describe new constructions of the infinite-dimensional representations of $U(\mathfrak{g})$ and $U_q(\mathfrak{g})$ for $\mathfrak{g}$ being $\mathfrak{gl}(N)$ and $\mathfrak{sl}(N)$. The application of these constructions to the quantum integrable theories of Toda type is discussed. With the help of these infinite-dimensional representations we manage to
The modular properties and the integral representations of the multiple elliptic gamma functions
math.QAAtsushi Narukawa
We show the modular properties of the multiple 'elliptic' gamma functions, which are an extension of those of the theta function and the elliptic gamma function. The modular property of the theta function is known as Jacobi's transformation, and that of the elliptic gamma function was provided by Felder and Varchenko. In this paper we deal with t
Kentaro Kawazu
We compute the perturbative tachyonic and massless spectra of Type II and Type 0 string theories on non-supersymmetric T^2/Z_N orbifolds, and those on T^4/Z_N ones. Comparing the spectra with one another, we obtain insight about the degeneracy of states and find several pairs of Type 0 orbifolds which could be identified with each other.
Chuan Miao, Xining Du, Guangwei Meng, Chuan Liu
Using the tadpole improved Wilson quark action on small, coarse and anisotropic lattices, $Kπ$ scattering length in the $I=3/2$ channel is calculated within quenched approximation. The results are extrapolated towards the chiral and physical kaon mass region. Finite volume and finite lattice spacing errors are also analyzed and a result in the infinite volum
Jerzy Matyjasek
The near horizon limit of the extreme nonlinear black hole is investigated. It is shown that resulting geometry belongs to the AdS2xS2 class with different modules of curvatures of subspaces and could be described in terms of the Lambert functions. It is demonstrated that the considered class of Lagrangians does not admit solutions of the Bertotti-Robinson t
E. Bouchbinder, D. Kessler, I. Procaccia
We address the velocity fluctuations of fastly moving cracks in stressed materials. One possible mechanism for such fluctuations is the interaction of the main crack with micro cracks (irrespective whether these are existing material defects or they form during the crack evolution). We analyze carefully the dynamics (in 2 space dimensions) of one macro and o
Andre X. C. N. Valente, Abhijit Sarkar, Howard A. Stone
A central issue in complex networks is tolerance to random failures and intentional attacks. Current literature emphasizes the dichotomy between networks with a power-law node connectivity distribution, which are robust to random failures but fragile to targeted attacks, versus networks with an exponentially decaying connectivity distribution, which are less
Marco Frasca
The aim of this review is to show how ``ferromagnetic'' states, that is, states having a fully polarization, can produce intrinsic decoherence by unitary evolution. This effect can give an understanding of recent experiments on mesoscopic devices as quantum point contacts showing the 0.7 conductance anomaly and the wide number of data about saturatio
S. V. Baoukina, S. I. Mukhin
We derived free energy functional of a bilayer lipid membrane from the first principles of elasticity theory. The model explicitly includes position-dependent mutual slide of monolayers and bending deformation. Our free energy functional of liquid-crystalline membrane allows for incompressibility of the membrane and vanishing of the in-plane shear modulus an
Scaling analysis of Schottky barriers at metal-embedded semiconducting carbon nanotube interfaces
cond-mat.mes-hallYongqiang Xue, Mark A. Ratner
We present an atomistic self-consistent tight-binding study of the electronic and transport properties of metal-semiconducting carbon nanotube interfaces as a function of the nanotube channel length when the end of the nanotube wire is buried inside the electrodes. We show that the lineup of the nanotube band structure relative to the metal Fermi-level depen
Nurith Schupper, Nadav M. Shnerb
A spin model that displays inverse melting and inverse glass transition is presented and analyzed. Strong degeneracy of the interacting states of an individual spin leads to entropic preference of the "ferromagnetic" phase, while lower energy associated with the non-interacting states yields a "paramagnetic" phase as temperature decreases. An
J. P. Pekola
We propose a scheme of measuring the non-Gaussian character of noise by a hysteretic Josephson junction in the macroscopic quantum tunnelling (MQT) regime. We model the detector as an (under)damped $LC$ resonator. It transforms Poissonian charge injection into current through the detector, which samples the injection statistics over a floating time window of
W. N. Brandt, D. M. Alexander, F. E. Bauer, C. Vignali
This "pedagogical" review describes the key Chandra and XMM-Newton extragalactic surveys to date and details some of their implications for AGN physics and evolution. We additionally highlight two topics of current widespread interest: (1) X-ray constraints on the AGN content of luminous submillimeter galaxies, and (2) the demography and physics of h
A. Ali, E. Lunghi, A. Ya. Parkhomenko
Measurements of the time-dependent CP asymmetry in the decay $B^0_d (t) \to π^+ π^-$ and its charge conjugate by the BELLE and BABAR collaborations currently yield $C_{ππ}^{+-} = -0.46 \pm 0.13$ and $S_{ππ}^{+-} = -0.74 \pm 0.16$, characterizing the direct and mixing-induced CP asymmetries, respectively. We study the implication of these measurements on the
Indications of suppressed high p_T hadron production in nucleus-nucleus collisions at CERN-SPS
nucl-exDavid d'Enterria
Inclusive pion production at high transverse momenta (p_T > 2 GeV/c) in nucleus-nucleus (A+A) collisions at CERN SPS (sqrt(s_NN)~20 GeV) is revisited and systematically compared to all existing proton-proton data in the same range of center-of-mass energies. The ratio of A+A to p+p pion cross-sections (nuclear modification factor) for 0-8% central Pb+Pb, Pb+
P. Bialas, A. Morel, B. Petersson
We analyze a two dimensional SU(3) gauge model of Wilson lines as a dimensionally reduced model of high temperature QCD_3. In contrast to perturbative dimensional reduction it has an explicit global Z(3) symmetry in the action. The phase diagram of the model is studied in the space of two free parameters used to describe the self interaction of the Wilson li
Je-An Gu, W-Y. P. Hwang, Jr-Wei Tsai
Evolution of a universe with homogeneous extra dimensions is studied with the benefit of a well-chosen parameter space that provides a systematic, useful, and convenient way for analysis. In this model we find a natural evolution pattern that entails not only stable extra dimensions in the radiation-dominated era, thereby preserving essential predictions in
Y. Yusa
We have searched for neutrinoless tau lepton decays into three charged leptons using an 87.1 fb^{-1} data sample collected with the Belle detector at the KEKB e^+e^- collider. Since the number of signal candidate events is compatible with that expected from the background, we set 90% confidence level upper limits on the branching fractions in the range (1.9-
Three-point Correlation Functions of SDSS Galaxies in Redshift Space: Morphology, Color, and Luminosity Dependence
astro-phIssha Kayo, Yasushi Suto, Robert C. Nichol, Jun Pan
We present measurements of the redshift--space three-point correlation function of galaxies in the Sloan Digital Sky Survey (SDSS). For the first time, we analyze the dependence of this statistic on galaxy morphology, color and luminosity. In order to control systematics due to selection effects, we used $r$--band, volume-limited samples of galaxies, constru
Optical properties of a spherical 2D electron gas in the presence of a uniform magnetic field
cond-mat.mes-hallAli Ihsan Goker, Peter Nordlander
This paper was withdrawn by the authors.
Kevin Cahill
Alternative splicing allows an organism to make different proteins in different cells at different times, all from the same gene. In a cell that uses alternative splicing, the total length of all the exons is much shorter than in a cell that encodes the same set of proteins without alternative splicing. This economical use of exons makes genes more stable du
Quantum computations with atoms in optical lattices: marker qubits and molecular interactions
quant-phT. Calarco, U. Dorner, P. Julienne, C. Williams
We develop a scheme for quantum computation with neutral atoms, based on the concept of "marker" atoms, i.e., auxiliary atoms that can be efficiently transported in state-independent periodic external traps to operate quantum gates between physically distant qubits. This allows for relaxing a number of experimental constraints for quantum computation
S. Sree Ranjani, A. K. Kapoor, P. K. Panigrahi
Various quasi-exact solvability conditions, involving the parameters of the periodic associated Lam{é} potential, are shown to emerge naturally in the quantum Hamilton-Jacobi approach. It is found that, the intrinsic nonlinearity of the Riccati type quantum Hamilton-Jacobi equation is primarily responsible for the surprisingly large number of allowed solvabi
On the momentum-space approach to calculation of one-electron energy spectra and wave functions of atomic clusters
quant-phV. F. Elesin, A. I. Podlivaev, L. A. Openov
Momentum-space approach to calculation of one-electron energies and wave functions proposed initially by Fock for a hydrogen atom and considered later by Shibuya, Wulfman, and Koga for diatomic molecules is applied to clusters composed of three and more atoms. The corresponding basis set in the coordinate space is of the Sturmian type since all the hydrogenl
Peter Wolf, Christian J. Borde
We present a theory of recoil effects in two zone Ramsey spectroscopy, particularly adapted to microwave frequency standards using laser cooled atoms. We describe the atoms by a statistical distribution of Gaussian wave packets which enables us to derive and quantify effects that are related to the coherence properties of the atomic source and that have not
Gatis Midrijanis
We will show that if there exists a quantum query algorithm that exactly computes some total Boolean function f by making T queries, then there is a classical deterministic algorithm A that exactly computes f making O(T^3) queries. The best know bound previously was O(T^4) due to Beals et al.
Dietrich Stauffer, Ambarish Kunwar, Debashish Chowdhury
We have generalized our ``unified'' model of evolutionary ecology by taking into account the possible movements of the organisms from one ``patch'' to another within the same eco-system. We model the spatial extension of the eco-system (i.e., the geography) by a square lattice where each site corresponds to a distinct ``patch''. A sel
K. Pomorski
The shell correction method is revisited. Contrary to the traditional Strutinsky method, the shell energy is evaluated by an averaging over the number of particles and not over the single-particle energies, which is more consistent with the definition of the macroscopic energy. In addition, the smooth background is subtracted before averaging the sum of sing
Ground-gamma band mixing and evolution of collectivity in even-even neutron-rich nuclei with 40<Z<50
nucl-thS. Lalkovski, N. Minkov
We propose an extended band mixing formalism capable of describing the ground-gamma band interaction in a wide range of collective spectra beyond the regions of well deformed nuclei. On this basis we explain the staggering effects observed in the gamma bands of Mo, Ru and Pd nuclei providing a consistent interpretation of new experimental data in the neutron
Lijuan Ruan
Open charm spectra at mid-rapidity from direct reconstruction of $D^{0}\to Kπ$ and indirect electron/positron measurements via charm semileptonic decay in p+p and d+Au collisions at $\sqrt{s_{_{\rm NN}}}$ = 200 GeV are reported. The combined spectra cover open charm transverse momentum range $0.1{}^{<}_{\sim}p_{T}{}^{<}_{\sim}6$ GeV/$c$. The electron spectra
Avinash Khare, Arul Lakshminarayan, Uday Sukhatme
Identities involving cyclic sums of terms composed from Jacobi elliptic functions evaluated at $p$ equally shifted points were recently found. The purpose of this paper is to re-express these cyclic identities in terms of ratios of Jacobi theta functions, since many physicists prefer using Jacobi theta functions rather than Jacobi elliptic functions.
Sam Nelson
We study virtual isotopy sequences with classical initial and final diagrams, asking when such a sequence can be changed into a classical isotopy sequence by replacing virtual crossings with classical crossings. An example of a sequence for which no such virtual crossing realization exists is given. A conjecture on conditions for realizability of virtual iso
Jeffrey D. Achter, Joshua Holden
We estimate the proportion of function fields satisfying certain conditions which imply a function-field analogue of the Fontaine-Mazur conjecture. As a byproduct, we compute the fraction of abelian varieties (or even Jacobians) over a finite field which have a rational point of order l.
Ron Donagi, Alon E. Faraggi
The data from collider experiments and cosmic observatories indicates the existence of three light matter generations. In some classes of string compactifications the number of generations is related to a topological quantity, the Euler characteristic. However, these do not explain the existence of three generations. In a class of free fermionic string model
Matthias R Gaberdiel, Terry Gannon, Daniel Roggenkamp
D-branes that appear to generate all the K-theory charges of string theory on SU(n) are constructed, and their charges are determined.
D. Peressounko, for WA98 collaboration
We present final results from the WA98 experiment which provide first measurements of Bose-Einstein correlations of direct photons in ultrarelativistic heavy ion collisions. Invariant interferometric radii were extracted in the range $100<K_T<300$ MeV/c and compared to interferometric radii of charged pions. The yield of direct photons for $100<p_T<300$ MeV/
Measurement of the W-pair Production Cross-section and W Branching Ratios in e+e- Collisions at sqrt(s) = 161-209 GeV
hep-exThe DELPHI Collaboration, J. Abdallah
These final results on e+e- -> W+W- production cross-section measurements at LEP2 use data collected by the DELPHI detector at centre-of-mass energies up to 209 GeV. Measurements of total cross-sections, W angular differential distributions and decay branching fractions, and the value of the CKM element |V_{cs}| are compared to the expectations of the Standa
Measurement of the Forward-Backward Asymmetries of e+e- -> Z -> b bbar and e+e- -> Z -> c cbar using prompt leptons
hep-exThe DELPHI Collaboration, J. Abdallah
The forward-backward asymmetries of the processes e+e- -> Z -> b bbar and e+e- -> Z -> c cbar were measured from a sample of hadronic Z decays collected by the DELPHI experiment between 1993 and 1995. Enriched samples of b bbar and c cbar events were obtained using lifetime information. The tagging of b and c quarks in these samples was based on the semilept
The DELPHI Collaboration, J. Abdallah
The form factor of Lambda_b^0 baryons is estimated using 3.46 10^6 hadronic Z decays collected by the DELPHI experiment between 1992 and 1995. Charmed Lambda_c^+ baryons fully reconstructed in the pK-pi+, pK0_S, and Lambda pi+pi+pi- modes, are associated to a lepton with opposite charge in order to select Lambda_b^0 -> Lambda_c^+ l^- anti-nu_l decays. From a
M. L. Kurnaz
Detrended fluctuation analysis is used to investigate power law relationship between the monthly averages of the maximum daily temperatures for different locations in the western US. On the map created by the power law exponents, we can distinguish different geographical regions with different power law exponents. When the power law exponents obtained from t
P. Bialas
We discuss the geometry of trees endowed with a causal structure using the conventional framework of equilibrium statistical mechanics. We show how this ensemble is related to popular growing network models. In particular we demonstrate that on a class of afine attachment kernels the two models are identical but they can differ substantially for other choice
Application of detrended fluctuation analysis to monthly average of the maximum daily temperatures to resolve different climates
cond-mat.stat-mechM. L. Kurnaz
Detrended fluctuation analysis is used to investigate correlations between the monthly average of the maximum daily temperatures for different locations in the continental US and the different climates these locations have. When we plot the scaling exponents obtained from the detrended fluctuation analysis versus the standard deviation of the temperature flu
B. R. Gadjiev
The theory of a sequence of phase transitions of high-symmetry-incommensurate-commensurate phase controlled by competing order parameters is investigated. The temperature dependence of dielectric constant is derived. The comparison of the obtained results with experimental data for layered crystals is discussed.
Broken symmetry and symmetry classification of magnetic ordering in doped crystals
cond-mat.stat-mechB. R. Gadjiev
The problem of the spontaneous breaking of the symmetry in the crystals with variable composition is discussed. The character of the variation of the inhomogeneous superstructure depending on the substitutional atom concentration has been considered. The genesis of the structure and magnetic ordering in the perovskite type compounds is discussed.
Effects of the Two- Gap Nature on the Microwave Conductivity of 39 K Polycrystalline MgB2 Films
cond-mat.supr-conSang Young Lee, J. H. Lee, Jung Hoon Han, S. H. Moon
The surface resistance (Rs) and the real part (sigma_1) of the microwave complex conductivity of a ~380 nm-thick polycrystalline MgB2 film with the critical temperature (Tc) of 39.3 K were investigated at ~8.5 GHz as a function of temperature. Two coherence peaks were observed in the sigma_1 versus temperature curve at temperatures of ~0.5 Tc and ~0.9 Tc, re
Exact Results for Spectra of Overdamped Brownian Motion in Fixed and Randomly Switching Potentials
cond-mat.stat-mechA. A. Dubkov, V. N. Ganin, B. Spagnolo
The exact formulae for spectra of equilibrium diffusion in a fixed bistable piecewise linear potential and in a randomly flipping monostable potential are derived. Our results are valid for arbitrary intensity of driving white Gaussian noise and arbitrary parameters of potential profiles. We find: (i) an exponentially rapid narrowing of the spectrum with inc
Plamen Ch. Ivanov, Ainslie Yuen, Boris Podobnik, Youngki Lee
We analyze the sequence of time intervals between consecutive stock trades of thirty companies representing eight sectors of the U. S. economy over a period of four years. For all companies we find that: (i) the probability density function of intertrade times may be fit by a Weibull distribution; (ii) when appropriately rescaled the probability densities of
Exchange coupling and enhancement of Curie temperature of the intergranular amorphous region in nano-crystalline duplex-phase alloys system
cond-mat.mtrl-sciY. Z. Shao, W. R. Zhong, G. M. Lin, X. D. Hu
We explored the magnetic behavior of a common two-phase nanomagnetic system by Monte Carlo computer simulation of a modified Heisenberg model on a 3D complex lattice with single- and cluster-spins. The effect of exchange coupling between two component magnetic phases was studied on the enhancement in Curie temperature (ECT) of the intergranular amorphous reg
Daniel B. Murray, Lucien Saviot
The spectrum of acoustic vibrational modes of an inhomogeneous elastic continuum are analyzed with application to a spherical nanoparticle embedded in an infinite glass block. The relationship of these modes to the discrete vibrational spectrum of a free sphere is studied. The vibrational modes of a sphere with a fixed surface are relevant in some situations
J. M. Wrobel, T. A. Rector, G. B. Taylor, S. T. Myers
We are using the NRAO VLBA at 5.0 GHz to image about 200 FIRST sources stronger than 10 mJy at 1.4 GHz in the NDWFS.
M. A. Garrett, J. M. Wrobel, R. Morganti
A 20-hour VLBI observation with the NRAO VLBA and GBT in the NOAO Bootes field reaches an rms noise of 9 microJy per beam at 1.4 GHz. Three sources were detected at 10-milliarcsecond resolution within the GBT primary beam of FWHM 8.6', including the 20-milliJy calibrator and two sub-milliJy sources. By tapering the visibility data, portions of the VLBA p
Janusz Bednarz
We present the model of cosmic rays acceleration at ultrarelativistic subshocks and confront it with the observations of gamma-ray bursts and blazars. We investigate cosmic rays acceleration in shocks with Lorentz factors in the range 3 - 40. We show that fluctuations of the magnetic field downstream of the shock do not play an important role in the accelera
W. P. Varricatt, P. M. Williams, N. M. Ashok
We present new spectra of WR 140 (HD 193793) in the JHK bands with some covering the 1.083-micron He I emission line at higher resolution, observed between 2000 October and 2003 May to cover its 2001 periastron passage. The WC7 + O4-5 spectroscopic binary WR 140 is the prototype of colliding-wind, episodic dust-making Wolf-Rayet systems which also show stron
uvby(-$β$) photometry of high-velocity and metal-poor stars X. Stars of very low metal abundance: observations, reddenings, metallicities, classifications, distances, and relative ages
astro-phW. J. Schuster, T. C. Beers, R. Michel, P. E. Nissen
uvby(--$β$) photometry has been obtained for an additional 411 very metal-poor stars selected from the HK survey, and used to derive basic parameters such as interstellar reddenings, metallicities, photometric classifications, distances, and relative ages... These very metal-poor stars are compared to M92 in the c_0,(b-y)_0 diagram, and evidence is seen for
Vahid Rezania, John C. Samson, Peter Dobias
In this study we propose a new generic model for QPOs based on oscillation modes of neutron star magnetospheres. We argue that the interaction of the accretion disk with the magnetosphere can excite resonant shear Alfven waves in a region of enhanced density gradients. We demonstrate that depending on the distance of this enhanced density region from the sta
Kari Enqvist
Curvaton is an effectively massless field whose energy density during inflation is negligible but which later becomes dominant. This is a novel mechanism to generate the scale invariant perturbations. I discuss the possibility that the curvaton could be found among the fields of the minimally supersymmetric standard model (MSSM), which contains a number of f