June 2004 arXiv papers — page 11
Showing 1,001–1,100 of 3,692 papers
Mark Slater
The first observations of the rare decays KS->pi0e+e- and KS->pi0mu+mu- have been made by the NA48/1 collaboration at the CERN SPS accelerator. From high intensity KS data collected during the 2002 run, clean signals of 7 KS->pi0e+e- events and 6 KS->pi0mu+mu- events were observed, giving branching ratio measurements of BR(KS->pi0e+e-) = 5.8 +2.9 -2.4 x 10^-
J. G. Smith
We report results from five analyses based on data taken with the BABAR detector at the PEP-II asymmetric e+e- collider. Included are branching fraction measurements for many B-meson decays involving eta, eta', omega, phi or a0 mesons and the final state Kspi+pi-, and a full angular analysis of the decay B->phiK*0.
Krzysztof Sliwa
Measurements of the top quark mass and the t-tbar and single top production cross sections, obtained by CDF and D0 Collaboration at the Tevatron, are presented. The methodology of the CDF and D0 analyses and their underlying assumptions are summarized. In anticipation of the increased amount of data in Run-II, prospects are presented. The fact that top quark
Measurement of the Ratio of the Vector to Pseudoscalar Charm Semileptonic Decay Rate Γ(D+ > ANTI-K*0 mu+ nu)/Γ(D+ > ANTI-K0 mu+ nu)
hep-exThe FOCUS Collaboration
Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report on the measurement of the ratio of semileptonic rates Γ(D+ > ANTI-K pi mu+ nu)/Γ(D+ > ANTI-K0 mu+ nu)= 0.625 +/- 0.045 +/- 0.034. Allowing for the K pi S-wave interference measured previously by FOCUS, we extract the vector to pseudoscalar ratio
A. D. Speliotopoulos, R. Y. Chiao
There now exists in the literature two different expressions for the phase shift of a matter-wave interferometer caused by the passage of a gravitation wave. The first, a commonly accepted expression that was first derived in the 1970s, is based on the traditional geodesic equation of motion (EOM) for a test particle. The second, a more recently derived expr
B. Kleihaus, J. Kunz, F. Navarro-Lerida
We study rotating black holes in Einstein-Yang-Mills-Higgs theory. These black holes emerge from static black holes with monopole hair when a finite horizon angular velocity is imposed. At critical values of the horizon angular velocity and the horizon radius, they bifurcate with embedded Kerr-Newman black holes. The non-Abelian black holes possess an electr
Otakar Svitek, Jiri Podolsky
The Efroimsky perturbation scheme for consistent treatment of gravitational waves and their influence on the background is summarized and compared with classical Isaacson's high-frequency approach. We demonstrate that the Efroimsky method in its present form is not compatible with the Isaacson limit of high-frequency gravitational waves, and we propose i
Andrew C. Huang, Armando Fox
Cluster hash tables (CHTs) are a key persistent-storage component of many large-scale Internet services due to their high performance and scalability. We show that a correctly-designed CHT can also be as easy to manage as a farm of stateless servers. Specifically, we trade away some consistency to obtain reboot-based recovery that is simple, maintains full d
Diluted planar ferromagnets: nonlinear excitations on a non-simply connected manifold
cond-mat.str-elFagner M. Paula, Afranio R. Pereira, Lucas A. S. Mól
We study the behavior of magnetic vortices on a two-dimensional support manifold being not simply connected. It is done by considering the continuum approach of the XY-model on a plane with two disks removed from it. We argue that an effective attractive interaction between the two disks may exist due to the presence of a vortex. The results can be applied t
Srikant Marakani, Gene F. Mazenko
Using a hydrodyamic model of granular flows, we present very long time simulations of a granular fluid in two dimensions without gravity and with periodic boundary conditions in a square domain. Depending upon the values of the viscosity, thermal conductivity and dissipation, we find for intermediate times a metastable clustering state. For longer times the
Bakir Babic, Christian Schonenberger
We have explored the low-temperature linear and non-linear electrical conductance $G$ of metallic carbon nanotubes (CNTs), which were grown by the chemical-vapor deposition method. The high transparency of the contacts allows to study these two-terminal devices in the high conductance regime. We observe the expected four-fold shell pattern together with Kond
Coupling between electronic and structural degrees of freedom in the triangular lattice conductor NaxCoO2
cond-mat.str-elQ. Huang, M. L. Foo, R. A. Pascal, J. W. Lynn
The determination by powder neutron diffraction of the ambient temperature crystal structures of compounds in the NaxCoO2 family, for 0.3 < x <= 1.0, is reported. The structures consist of triangular CoO2 layers with Na ions distributed in intervening charge reservoir layers. The shapes of the CoO6 octahedra that make up the CoO2 layers are found to be criti
W. Nolting, T. Hickel, A. Ramakanth, G. G. Reddy
For modeling the magnetic properties of concentrated and diluted magnetic semiconductors, we use the Kondo-lattice model. The magnetic phase diagram is derived by inspecting the static susceptibility of itinerant band electrons, which are exchange coupled to localized magnetic moments. It turns out that rather low band occupations favour a ferromagnetic orde
T. Tanizawa, G. Paul, R. Cohen, S. Havlin
We study the robustness of complex networks to multiple waves of simultaneous (i) targeted attacks in which the highest degree nodes are removed and (ii) random attacks (or failures) in which fractions $p_t$ and $p_r$ respectively of the nodes are removed until the network collapses. We find that the network design which optimizes network robustness has a bi
Conductivity of Silicon Inversion Layers: comparison with and without in-plane magnetic field
cond-mat.str-elYeekin Tsui, S. A. Vitkalov, M. P. Sarachik, T. M. Klapwijk
A detailed comparison is presented of the temperature dependence of the conductivity of dilute, strongly interacting electrons in two-dimensional silicon inversion layers in the metallic regime in the presence and in the absence of a magnetic field. We show explicitly and quantitatively that a magnetic field applied parallel to the plane of the electrons red
Reply to Comment on "Why is the DNA Transition First Order?" and "Griffiths Singularities in Unbinding of Strongly Disordered Polymers" by M. Ya. Azbel
cond-mat.softY. Kafri, D. Mukamel, L. Peliti
It is shown that the various claims made in the comment by M. Ya. Azbel (physics/0403106) on the two publications Phys. Rev. Lett. 91, 055502 (2003) and Phys. Rev. Lett. 85, 4988 (2000) are invalid. They are a result of a misinterpretation of the main points of both papers.
J. Graetz, C. C. Ahn, H. Ouyang, P. Rez
Electron energy-loss spectrometry was employed to measure the white lines at the L23 absorption edges of the 3d transition-metal oxides and lithium transition-metal oxides. The white-line ratio (L3/L2) was found to increase between d^0 and d^5 and decrease between d^5 and d^10, consistent with previous results for the transition metals and their oxides. The
Magnetization, thermoelectric, and pressure studies of the magnetic field-induced metal to insulator transition in tau phase organic conductors
cond-mat.str-elD. Graf, E. S. Choi, J. S. Brooks, N. Harrison
We have investigated the magnetic field-induced metal-insulator transition in the tau-phase organic conductors, which occurs in fields above 35 T, and below 14 K, by magnetization, thermoelectric, and pressure dependent transport methods. Our results show that the transition is a bulk thermodynamic process where a magnetic field-dependent gap opens upon entr
C. Buzano, E. de Stefanis, A. Pelizzola, M. Pretti
We investigate a lattice-fluid model defined on a two-dimensional triangular lattice, with the aim of reproducing qualitatively some anomalous properties of water. Model molecules are of the "Mercedes Benz" type, i.e., they possess a D3 (equilateral triangle) symmetry, with three bonding arms. Bond formation depends both on orientation and local dens
H. -J. Lee, R. Bulla
The numerical renormalization group method is used to investigate zero temperature phase transitions in quantum impurity systems, in particular in the soft-gap Anderson model, where an impurity couples to a non-trivial fermionic bath. In this case, zero temperature phase transitions occur between two different phases whose fixed points can be built up of non
Jaume Masoliver, Miquel Montero, Josep Perello
We apply the theory of continuous time random walks to study some aspects of the extreme value problem applied to financial time series. We focus our attention on extreme times, specifically the mean exit time and the mean first-passage time. We set the general equations for these extremes and evaluate the mean exit time for actual data.
Dressed atom versus exciton polariton: From Rabi oscillations to the Fermi Golden rule
cond-mat.str-elFrancois Dubin, Monique Combescot, Bernard Roulet
We rederive the dressed atom and the exciton polariton within the {\it same} framework to make clear that their difference only comes from the number of electrons available for photoexcitations. Using it, we analytically show how the time dependence of the photon number transforms from an oscillating behavior (at the stimulated or vacuum Rabi frequency) to a
M. El-Hagary, H. Michor, E. Bauer, R. Groessinger
The novel ternary compound CeCo$_9$Si$_4$ has been studied by means of specific heat, magnetisation, and transport measurements. Single crystal X-ray Rietveld refinements reveal a fully ordered distribution of Ce, Co and Si atoms with the tetragonal space group I4/mcm isostructural with other RCo9Si4. The smaller lattice constants of CeCo9Si4 in comparison w
van der Waals interactions of the benzene dimer: towards treatment of polycyclic aromatic hydrocarbon dimers
cond-mat.softS. D. Chakarova, E. Schroder
Although density functional theory (DFT) in principle includes even long-range interactions, standard implementations employ local or semi-local approximations of the interaction energy and fail at describing the van der Waals interactions. We show how to modify a recent density functional that includes van der Waals interactions in planar systems [Phys. Rev
H. Michor, M. El-Hagary, S. Oezcan, A. Horyn
Weak itinerant ferromagnetism in YCo9Si4 below about 25 K is studied by means of magnetisation, specific heat, and resistivity measurements. Single crystal X-ray Rietveld refinements at room temperature reveal a fully ordered distribution of Y, Co and Si atoms within the tetragonal space group I4/mcm isostructural with LaCo9Si4. The latter exhibits itinerant
Nonlinear atom-optical delta-kicked harmonic oscillator using a Bose-Einstein condensate
cond-mat.softG. J. Duffy, A. S. Mellish, K. J. Challis, A. C. Wilson
We experimentally investigate the atom-optical delta-kicked harmonic oscillator for the case of nonlinearity due to collisional interactions present in a Bose-Einstein condensate. A Bose condensate of rubidium atoms tightly confined in a static harmonic magnetic trap is exposed to a one-dimensional optical standing-wave potential that is pulsed on periodical
Shin-ichi Kimura, Mitsuru Okuno, Hideaki Kitazawa, Fumihiko Ishiyama
The temperature dependence of the electronic structure of CeBi arising from two types of antiferromagnetic transitions based on optical conductivity ($σ(ω)$) was observed. The $σ(ω)$ spectrum continuously and discontinuously changes at 25 and 11 K, respectively. Between these temperatures, two peaks in the spectrum rapidly shift to the opposite energy sides
Emil A. Yuzbashyan, Alexander A. Baytin, Boris L. Altshuler
We study the effects of superconducting pairing in small metallic grains. We show that in the limit of large Thouless conductance one can explicitly determine the low energy spectrum of the problem as an expansion in the inverse number of electrons on the grain. The expansion is based on the formal exact solution of the Richardson model. We use this expansio
Yunsic Shim, Jacques G. Amar
We investigate the applicability of the synchronous relaxation (SR) algorithm to parallel kinetic Monte Carlo simulations of simple models of thin-film growth. A variety of techniques for optimizing the parallel efficiency are also presented. We find that the parallel efficiency is determined by three main factors $-$ the calculation overhead due to relaxati
Gaurav Arya, Athanassios Z. Panagiotopoulos
The behavior of confined cylindrical micelle-forming surfactants under the influence of shear has been investigated using Monte Carlo simulations. The surfactants are modeled as coarse-grained lattice polymers, while the Monte Carlo shear flow is implemented with an externally imposed potential energy field which induces a linear drag velocity on the surfact
S. Di Matteo, G. Jackeli, C. Lacroix, N. B. Perkins
We discuss the ground state of a pyrochlore lattice of threefold-orbitally-degenerate $S=1/2$ magnetic ions. We derive an effective spin-orbital Hamiltonian and show that the orbital degrees of freedom can modulate the spin exchange, removing the infinite spin-degeneracy characteristic of pyrochlore structures. The resulting state is a collection of spin-sin
Sébastien Camalet, Sigmund Kohler, Peter Hänggi
We derive within a time-dependent scattering formalism expressions for both the current through ac-driven nanoscale conductors and its fluctuations. The results for the time-dependent current, its time average, and, above all, the driven shot noise properties assume an explicit and serviceable form by relating the propagator to a non-Hermitian Floquet theory
Conversion of phase-slip lines into elementary resistive domains in a current-carrying superconducting thin film
cond-mat.supr-conE. V. Il'ichev, V. I. Kuznetsov, V. A. Tulin
A nonmonotonic dependence of the differential resistance of the first step of a phase-slip line on the heat-reservoir temperature near Tc has been observed experimentally for the first time in a superconducting tin film. This behavior is interpreted as a conversion of the phase-slip line into an elementary resistive domain as the result of a deviation from t
Observation of a nonmonotonic transverse voltage induced by vortex motion in a superconducting thin film
cond-mat.supr-conI. Yu. Antonova, V. M. Zakosarenko, E. V. Il'ichev, V. I. Kuznetsov
A vortex-induced transverse voltage in a superconducting film, previously predicted theoretically, has been seen experimentally for the first time. The magnitude of this voltage and its nonmonotonic current dependence are explained on the basis of a curvature of the trajectory of vortices resulting from their interaction. A good agreement between theory and
Charles F. Gammie
The magnetorotational instability (MRI) is the leading candidate for driving turbulence, angular momentum transport, and accretion in astrophysical disks. I consider the linear theory of the MRI in a thin, equatorial disk in the Kerr metric. I begin by analyzing a mechanical model for the MRI that consists of two point masses on nearly circular orbits connec
Kaisa E. Young, Jeong-Eun Lee, Neal J. Evans, Paul F. Goldsmith
We present maps of the 6 cm and 1.3 mm transitions of formaldehyde toward three cold, dense pre-protostellar cores: L1498, L1512, and L1544. The 6 cm transition is a unique probe of high density gas at low temperature. However, our models unequivocally indicate that H2CO is depleted in the interiors of PPCs, and depletion significantly affects how H2CO probe
Eric D. Feigelson, Warrick A. Lawson
Sensitive X-ray imaging surveys provide a new and effective tool to establish the census of pre-main sequence (PMS) stars in nearby young stellar clusters. We report here a deep Chandra X-ray Observatory observation of PMS stars in the Chamaeleon I North cloud, achieving a limiting luminosity of log L_t ~ 27 erg/s (0.5-8 keV band) in a 0.8x0.8 pc region. Of
F. Camilo, R. N. Manchester, A. G. Lyne, B. M. Gaensler
We report the discovery of a radio pulsar with a characteristic age of 7300 years, making it one of the 10 apparently youngest Galactic pulsars known. PSR J1357-6429, with a spin period of P = 166 ms and spin-down luminosity of 3.1e36 ergs/s, was detected during the Parkes multibeam survey of the Galactic plane. We have measured a large rotational glitch in
D. N. McKinsey, C. Orzel
The beta-decay of $\rm^{85}Kr$ is a significant radioactive background for experiments that use liquified noble gases to search for dark matter and measure the low-energy solar neutrino flux. While there are several proposed methods for reducing Kr levels in these experiments, an independent technique is needed for measuring very low Kr levels. By selectivel
F. Heitsch, P. S. Li
The currently most viable methods to estimate magnetic field strengths in molecular cloud cores are Zeeman measurements and the Chandrasekhar-Fermi (CF) method. The CF-method estimates magnetic field strengths from polarimetry and relies on equipartition between the turbulent kinetic and turbulent magnetic energy in the observed region. Thus, its application
Nader Haghighipour
A summary of the results of a numerical study of the growth of solid particles in the vicinity of an azimuthally symmetric density enhancement of a protostellar disk are presented. The effects of gas drag and pressure gradients on the rate of growth of dust particles and their settling on the midplane of the nebula are also discussed.
Nathan Smith
High-resolution spectra of molecular hydrogen in the Homunculus nebula allow for the first direct measurement of the systemic velocity of Eta Carinae. Near-infrared long-slit data for H2 1-0 S(1) lambda 21218 obtained with the Phoenix spectrometer on the Gemini South telescope give Vsys=-8.1pm1 km/s (heliocentric), or VLSR=-19.7pm1 km/s, from the average of
Joeri van Leeuwen
The thesis focuses on different aspects of radio pulsars: on the one hand it describes research on the pulsar emission mechanism (nulling, drifting subpulses, single-pulse polarisation and their mutual interaction). On the other it gives an account of investigations into the evolution of the pulsar population as a whole (birthrates, velocities, magnetic fiel
Jeremiah Murphy, Adam Burrows, Alexander Heger
The mechanism responsible for the natal kicks of neutron stars continues to be a challenging problem. Indeed, many mechanisms have been suggested, and one hydrodynamic mechanism may require large initial asymmetries in the cores of supernova progenitor stars. Goldreich, Lai, & Sahrling (1997) suggested that unstable g-modes trapped in the iron (Fe) core by t
M. I. Wilkinson, J. T. Kleyna, N. W. Evans, G. F. Gilmore
We present projected velocity dispersion profiles for the Draco and Ursa Minor (UMi) dwarf spheroidal galaxies based on 207 and 162 discrete stellar velocities, respectively. Both profiles show a sharp decline in the velocity dispersion outside ~30 arcmin (Draco) and ~40 arcmin (UMi). New, deep photometry of Draco reveals a break in the light profile at ~25
Patricia A. Henning, Renee C. Kraan-Korteweg, Lister Staveley-Smith
The 64-m Parkes telescope, equipped with the 21-cm multibeam receiver, has completed a sensitive survey (typically 6 mJy per beam rms) for HI galaxies in the Zone of Avoidance accessible to the telescope, 196 < l < 52 deg, and |b| < 5 deg. While the galaxy candidate inspection is not yet quite complete, and final number not yet determined, the survey has yie
M. V. Sazhin, O. S. Khovanskaya, M. Capaccioli, G. Longo
CSL1 is a peculiar object discovered in the OACDF. Photometric and spectroscopic investigation strongly suggest that it may be the first case of gravitational lensing by cosmic string. In this paper we derive and discuss a statistical excess of a gravitational lens candidates present in OACDF region surrounding CSL1. This excess cannot be explained on the ba
Pisin Chen
While there exist various candidates, the identification of dark matter remains unresolved. Recently it was argued that the generalized uncertainty principle (GUP) may prevent a black hole from evaporating completely, and as a result there should exist a Planck-size BHR at the end of its evaporation. We speculate that the stability of BHR may be further prot
The 2dF Galaxy Redshift Survey: Spherical Harmonics analysis of fluctuations in the final catalogue
astro-phWill J. Percival, Daniel Burkey, Alan Heavens, Andy Taylor
We present the result of a decomposition of the 2dFGRS galaxy overdensity field into an orthonormal basis of spherical harmonics and spherical Bessel functions. Galaxies are expected to directly follow the bulk motion of the density field on large scales, so the absolute amplitude of the observed large-scale redshift-space distortions caused by this motion i
Abhijit Bhattacharyya, Sanjay K. Ghosh, Matthias Hanauske, Sibaji Raha
The quark hadron phase transition in a rotating compact star has been studied. The NLZ-model has been used for the hadronic sector and the MIT Bag model has been used for the quark sector. It has been found that rotating twin star (third family) solutions are obtained upto $Ω\approx 4000 s^{-1}$. Stars which are rotating faster than this limit do not show an
Mitsuhiko Honda, Hirokazu Kataza, Yoshiko K. Okamoto, Takashi Miyata
We have observed the 8-13 $μ$m spectrum (R$\sim$250) of the Vega-like star candidate HD145263 using Subaru/COMICS. The spectrum of HD145263 shows the broad trapezoidal silicate feature with the shoulders at 9.3 $μ$m and 11.44 $μ$m, indicating the presence of crystalline silicate grains. This detection implies that crystalline silicate may also be commonly pr
The progenitor of the 'born-again' core V605 Aql and the relation to its younger twin V4334 Sgr
astro-phM. F. M. Lechner, S. Kimeswenger
We derived the properties of V605 Aql before the final helium flash pulse by studying its surrounding PN A58. Photoionizing models of our spectral data together with a new distance estimate and a closer look at the recombination timescales lead to a consistent model. Comparing our findings with the only hydrogen-poor twin, namely Sakurai's Object, we con
L. M. Buson, F. Bertola, A. Bressan, D. Burstein
NGC5018, one of the weakest UV emitters among giant ellipticals (gE) observed with IUE, appears to consist of an optical stellar population very similar to that of the compact, dwarf elliptical M32, which is several magnitudes fainter in luminosity than NGC5018 and whose stellar population is know to be ~3 Gyr old. Here we show that the mid-UV spectra of the
A new HI catalog of Low Surface Brightness galaxies out to z=0.1 - Tripling the number of massive LSB galaxies Known
astro-phK. O'Neil, G. Bothun, W. van Driel, D. Monnier Ragaigne
Using both the Arecibo 305m and the Nancay decimetric 100-m class radio telescopes, we have observed the HI line of 116 Low Surface Brightness (LSB) galaxies from the Bothun et al. 1985 subset of LSB galaxies in the Uppsala General Catalog. The observations had a detection rate of 70%, resulting in the new determination of HI properties for 81 galaxies. Surp
Deuterated hydrogen chemistry: Partition functions, Equilibrium constants and Transition intensities for the H3+ system
astro-phJayesh Ramanlal, Jonathan Tennyson
H3+ and the deuterated isotopomers are thought to play an important role in interstellar chemistry. The partition functions of H3+, D2H+ and D3+ are calculated to a temperature of 800 K by explicitly summing the ab initio determined rotation-vibration energy levels of the respective species. These partition functions are used to calculate the equilibrium con
Paolo Padoan, Karen Willacy, William Langer, Mika Juvela
The determination of the fractional electron abundance, Xe, in protostellar cores relies on observations of molecules, such as DCO+, H13CO+ and CO, and on chemical models to interpret their abundance. Studies of protostellar cores have revealed significant variations of Xe from core to core within a range 10^-8<Xe<10^-6. The physical origin of these large va
Michael Truss, Graham Wynn
We present very high resolution hydrodynamical simulations of accretion discs in black hole X-ray binaries accreting near the Eddington limit. The results show that mass loss, irradiation and tidal interactions all have a profound effect on the observed behaviour of long period X-ray transients. In particular, the interplay of all of these effects in the out
Dmitry Bizyaev, Serafim Kajsin
We present surface photometry results for a sample of eleven edge-on galaxies observed with the 6m telescope at the Special Astrophysical Observatory (Russia). The photometric scale length, scale height, and central surface brightness of the stellar disks of our sample galaxies are estimated. We show that four galaxies in our sample, which are visually refer
Jeffrey E. McClintock, Ronald A. Remillard
We review the properties of 40 X-ray binaries that contain either a confirmed black hole or a black hole candidate. After discussing briefly the significance of these Galactic black holes to both astronomy and physics, we present basic data for all 40 systems, review the physics of mass accretion onto black holes, and then show seven-year light curves of 20
J. M. Castro Cerón, A. J. Castro-Tirado, J. Gorosabel, J. Hjorth
We present optical follow up observations of the long GRB 001007 between 6.14 hours and ~468 days after the event. An unusually bright optical afterglow (OA) was seen to decline following a steep power law decay with index alpha = -2.03 +/- 0.11, possibly indicating a break in the light curve at t - to < 3.5 days, as found in other bursts. Upper limits impos
Christopher Gordon, Wayne Hu
We explicate the origin of the temperature quadrupole in the adiabatic dark energy model and explore the mechanism by which scale invariant isocurvature dark energy perturbations can lead to its sharp suppression. The model requires anticorrelated curvature and isocurvature fluctuations and is favored by the WMAP data at about the 95% confidence level in a f
Xingang Chen
We discuss a scenario where at least part of the homogeneity on a brane world can be directly related to the hierarchy problem through warped space. We study the dynamics of an anti-D3-brane moving toward the infrared cut-off of a warped background. After a region described by the DBI action, the self-energy of the anti-D3-brane will dominate over the backgr
R. D. Matheus, F. S. Navarra, M. Nielsen, R. Rodrigues da Silva
In a diquark-diquark-antiquark picture of pentaquarks, we use two interpolating currents to calculate the mass of the recently measured $Ξ^{--}$ state in the framework of QCD sum rules. We show that, even though yielding similar values for $m_{Ξ^{--}}$ (and close to the experimental value), these currents differ from each other in what concerns the strength
The laplacian of a graph as a density matrix: a basic combinatorial approach to separability of mixed states
quant-phSamuel L. Braunstein, Sibasish Ghosh, Simone Severini
We study entanglement properties of mixed density matrices obtained from combinatorial Laplacians. This is done by introducing the notion of the density matrix of a graph. We characterize the graphs with pure density matrices and show that the density matrix of a graph can be always written as a uniform mixture of pure density matrices of graphs. We consider
M. Kruczenski, A. Tseytlin
We consider the low energy effective action corresponding to the 1-loop, planar, dilatation operator in the scalar sector of N=4 SU(N) SYM theory. For a general class of non-holomorphic ``long'' operators, of bare dimension L>>1, it is a sigma model action with 8-dimensional target space and agrees with a limit of the phase-space string sigma model a
Anjana Bagga, P. K. Chattopadhyay, Subhasis Ghosh
Formation of excitonic states in quantum dots of nitride based III-V semiconductors GaN and AlN including coulomb and exchange interactions are investigated. Dark exciton formation is found to occur for both GaN quantum dots(QDs) with wurtzite structure having positive crystal field splitting and GaN and AlN QDs with zero crystal field splitting with a trans
Sadhan K. Adhikari
Using the numerical solution of the nonlinear Schrödinger equation and a variational method it is shown that (3+1)-dimensional spatiotemporal optical solitons, known as light bullets, can be stabilized in a layered Kerr medium with sign-changing nonlinearity along the propagation direction.
Joris Raeymaekers
We analyze observational constraints on the parameter space of tachyonic inflation with a Gaussian potential and discuss some predictions of this scenario. As was shown by Kofman and Linde, it is extremely problematic to achieve the required range of parameters in conventional string compactifications. We investigate if the situation can be improved in more
G. Cella, V. Sannibale, R. DeSalvo, S Márka
In this article we investigate the principle and properties of a vertical passive seismic noise attenuator conceived for ground based gravitational wave interferometers. This mechanical attenuator based on a particular geometry of cantilever blades called monolithic geometric anti springs (MGAS) permits the design of mechanical harmonic oscillators with very
D. M. Tong, K. Singh, L. C. Kwek, C. H. Oh
The adiabatic theorem shows that the instantaneous eigenstate is a good approximation of the exact solution for a quantum system in adiabatic evolution. One may therefore expect that the geometric phase calculated by using the eigenstate should be also a good approximation of exact geometric phase. However, we find that the former phase may differ appreciabl
Sean Cleary, Tim R. Riley
The dead-end depth of an element g of a group G, with respect to a generating set A is the distance from g to the complement of the radius $d_A(1,g)$ closed ball, in the word metric $d_A$ defined with respect to A. We exhibit a finitely presented group G with a finite generating set with respect to which there is no upper bound on the dead-end depth of eleme
M. J. Tannenbaum
Measurements using the finely segmented EM Calorimeter in PHENIX are presented. The issue of whether these are sufficient to claim discovery of the Quark Gluon Plasma is discussed.
J. -F. Fortin, P. Jacob, P. Mathieu
A derivation of the basis of states for the $SM(2,4k)$ superconformal minimal models is presented. It relies on a general hypothesis concerning the role of the null field of dimension $2k-1/2$. The basis is expressed solely in terms of $G_r$ modes and it takes the form of simple exclusion conditions (being thus a quasi-particle-type basis). Its elements are
Condensation energy of the homogeneous electron gas from the density functional theory for superconductors
cond-mat.supr-conM. Wierzbowska, J. W. Krogh
The condensation energy of the homogeneous electron gas is calculated within the density functional theory for superconductors. Purely electronic considerations include the exchange energy exactly and the correlation energy on a level of the random phase approximation. The singlet superconductivity is assumed, and the Coulomb interaction is studied with a mo
Glenn Barnich, Maxim Grigoriev, Alexei Semikhatov, Ilya Tipunin
For free-field theories associated with BRST first-quantized gauge systems, we identify generalized auxiliary fields and pure gauge variables already at the first-quantized level as the fields associated with algebraically contractible pairs for the BRST operator. Locality of the field theory is taken into account by separating the space--time degrees of fre
Shin Nakamura
We propose a new method to describe a recoiling D-brane that is elastically scattered by closed strings in the non-relativistic region. We utilize the low-energy effective field theory on the worldvolume of the D-brane, and the velocity of the D-brane is described by the time derivative of the expectation values of the massless scalar fields on the worldvolu
Rob Fender, Tomaso Belloni
GRS 1915+105 - the first stellar-scale, highly relativistic jet source identified - is a key system for our understanding of the disc-jet coupling in accreting black hole systems. Comprehending the coupling between inflow and outflow in this source is important not only for X-ray binary systems but has a broader relevance for studies of active galactic nucle
R. T. Clay, S. Mazumdar
Strong co-operative interactions occur between four different broken symmetries involving charge-ordering and bond distortions in the quarter-filled correlated zigzag electron ladder. The ground state is singlet, with spin gap several times larger than in the spin-Peierls state of the one-dimensional quarter-filled chain with the same parameters. We propose
Rotational cooling of heteronuclear molecular ions with ^1-Sigma, ^2-Sigma, ^3-Sigma and ^2-Pi electronic ground states
physics.atom-phI. S. Vogelius, L. B. Madsen, M. Drewsen
The translational motion of molecular ions can be effectively cooled sympathetically to translational temperatures below 100 mK in ion traps through Coulomb interactions with laser-cooled atomic ions. The ro-vibrational degrees of freedom, however, are expected to be largely unaffected during translational cooling. We have previously proposed schemes for coo
Saharon Shelah
A dependent theory is a (first order complete theory) T which does not have the independence property. A main result here is: if we expand a model of T by the traces on it of sets definable in a bigger model then we preserve its being dependent. Another one justifies the cofinality restriction in the theorem (from a previous work) saying that pairwise perpen
Toshihiro Matsuo, So Matsuura, Kazutoshi Ohta
We examine the two-dimensional U(N) Yang-Mills theory by using the technique of random partitions. We show that the large N limit of the partition function of the 2D Yang-Mills theory on S^2 reproduces the instanton counting of 4D N=2 supersymmetric gauge theories introduced by Nekrasov. We also discuss that we can take the ``double scaling limit'' b
The influence of rotation in radiation driven wind from hot stars: New solutions and disk formation in Be stars
astro-phMichel Curé
The theory of radiation driven wind including stellar rotation is re-examined. After a suitable change of variables, a new equation for the mass loss rate is derived analytically. The solution of this equation remains within 1% confidence when compared with numerical solutions. Also, a non-linear equation for the position of the critical (singular) point is
Classification of the scalar mesons: a strange pole expedition into charm and beauty territory
hep-phEef van Beveren, George Rupp
The classification of scalar and vector mesons is reviewed within the framework of the Resonance-Spectrum Expansion (RSE). This method allows a simple and straightforward description of non-exotic meson-meson scattering, incorporating the effects of quark confinement and OZI-allowed decay in a fully nonperturbative way. Results for resonances and bound state
Taksu Cheon
We examine the classical contents of quantum games. It is shown that a quantum strategy can be interpreted as a classical strategies with effective density-dependent game matrices composed of transposed matrix elements. In particular, successful quantum strategies in dilemma games are interpreted in terms of a symmetrized game matrix that corresponds to an a
Jerome P. Gauntlett, Jan B. Gutowski, Nemani V. Suryanarayana
We analyse a one parameter family of supersymmetric solutions of type IIB supergravity that includes AdS_5 x S^5. For small values of the parameter the solutions are causally well-behaved, but beyond a critical value closed timelike curves (CTC's) appear. The solutions are holographically dual to N=4 supersymmetric Yang-Mills theory on a non-conformally
Nonlinear Couplings of R-modes: Energy Transfer and Saturation Amplitudes at Realistic Timescales
gr-qcJeandrew Brink, Saul A Teukolsky, Ira Wasserman
Non-linear interactions among the inertial modes of a rotating fluid can be described by a network of coupled oscillators. We use such a description for an incompressible fluid to study the development of the r-mode instability of rotating neutron stars. A previous hydrodynamical simulation of the r-mode reported the catastrophic decay of large amplitude r-m
J. Ambjorn, A. Dubin, Y. Makeenko
We calculate quantum averages of Wilson loops (holonomies) in gauge theories on the Euclidean noncommutative plane, using a path-integral representation of the star-product. We show how the perturbative expansion emerges from a concise general formula and demonstrate its anomalous behavior at large parameter of noncommutativity for the simplest nonplanar dia
J. Wooldridge, D. McK Paul, G. Balakrishnan, M. R. Lees
Magnetic susceptibility, transport and heat capacity measurements of single crystal NaxCoO2 (x=0.71) are reported. A transition to a spin density wave (SDW) state at Tmag = 22 K is observable in all measurements, except chi(ac) data in which a cusp is observed at 4 K and attributed to a low temperature glassy phase. M(H) loops are hysteretic below 15 K. Both
Algebraic Bethe Ansatz for the Zamolodchikov-Fateev and Izergin-Korepin models with open boundary conditions
nlin.SIV. Kurak, A. Lima-Santos
We have considered the Zamolodchikov-Fateev and the Izergin-Korepin models with diagonal reflection boundaries. In each case the eigenspectrum of the transfer matrix is determined by application of the algebraic Bethe Ansatz.
M. Lüders, A. Ernst, M. Däne, Z. Szotek
We propose a simplified version of self-interaction corrected local spin-density (SIC-LSD) approximation, based on multiple scattering theory, which implements self-interaction correction locally, within the KKR method. The multiple scattering aspect of this new SIC-LSD method allows for the description of crystal potentials which vary from site to site in a
Giovanni Villadoro, Fabio Zwirner
We consider the generalized dimensional reduction of pure ungauged N=4, D=5 supergravity, where supersymmetry is spontaneously broken to N=2 or N=0 with identically vanishing scalar potential. We explicitly construct the resulting gauged D=4 theory coupled to a single vector multiplet, which provides the minimal N=4 realization of a no-scale model. We discus
M. Cvitan, S. Pallua, P. Prester
We show that microscopic black hole entropy formula based on Virasoro algebra can be derived from usual properties of stationary Killing horizons alone and absence of singularities of curvature invariants on them. In such a way some usual additional assumptions are shown to be fulfilled. In addition, for all quantities power expansion near horizon and thus e
Deconfined quantum criticality of the O(3) nonlinear $σ$ model in two spacial dimensions: A renormalization group study
cond-mat.str-elKi-Seok Kim
We investigate the quantum phase transition of the O(3) nonlinear $σ$ model {\it without Berry phase} in two spacial dimensions. Utilizing the $CP^{1}$ representation of the nonlinear $σ$ model, we obtain an effective action in terms of bosonic spinons interacting via compact U(1) gauge fields. Based on the effective field theory, we find that the bosonic sp
Jerzy Kijowski, Roman Werpachowski
Affine variational principle for General Relativity, proposed in 1978 by one of us (J.K.), is a good remedy for the non-universal properties of the standard, metric formulation, arising when the matter Lagrangian depends upon the metric derivatives. Affine version of the theory cures the standard drawback of the metric version, where the leading (second orde
S. A. Alavi, Forough Nasseri
We study the cosmological implications of the space-space noncommutative inflation and present formulae for the spectral index and its running. Our results show that deviations from the spectral index and its running depend on the space-space noncommutativity length scale. We conclude that in the slow-roll regime of a typical inflationary scenario, space-spa
Dhrubaditya Mitra, Jeremie Bec, Rahul Pandit, Uriel Frisch
We study turbulence in the one-dimensional Burgers equation with a white-in-time, Gaussian random force that has a Fourier-space spectrum $\sim 1/k$, where $k$ is the wave number. From very-high-resolution numerical simulations, in the limit of vanishing viscosity, we find evidence for multiscaling of velocity structure functions which cannot be falsified by
Toshikazu Ito, Bruno Scardua
We study the classification of singularities of holomorphic foliations and non-integrable one-forms under the hypothesis of transversality with real hypersurfaces.
Kazunari Shima, Motomu Tsuda
We discuss further the universality of the Volkov-Akulov (V-A) action of a Nambu-Goldstone (N-G) fermion for the spontaneous breaking of supersymmetry (SUSY). We show general relations between the standard V-A action and nonlinear (NL) SUSY actions including apparently (pathological) higher derivatives of the N-G fermion. Composite fields of the N-G fermions
New measurement on photon yields from air and the application to the energy estimation of primary cosmic rays
astro-phM. Nagano, K. Kobayakawa, N. Sakaki, K. Ando
The air fluorescence technique is used to detect ultra-high energy cosmic rays (UHECR), and to estimate their energy. Of fundamental importance is the photon yield due to excitation by electrons, in air of various densities and temperatures. After our previous report, the experiment has been continued using a Sr90 $β$ source to study the pressure dependence
Tetsuya Shiromizu, Shinya Tomizawa, Yuki Uchida, Shinji Mukohyama
We consider five dimensional deSitter spacetimes with a deficit angle due to the presence of a closed 2-brane and identify one dimension as an extra dimension. From the four dimensional viewpoint we can see that the spacetime has a structure similar to a Kaluza-Klein bubble of nothing, that is, four dimensional spacetime ends at the 2-brane. Since a spatial