March 2006 arXiv papers — page 8
Showing 701–800 of 4,608 papers
On the computation of the entropy in the microcanonical ensemble for mean-field-like systems
cond-mat.stat-mechAlessandro Campa
Two recently proposed expressions for the computation of the entropy in the microcanonical ensemble are compared, and their equivalence is proved. These expressions are valid for a certain class of statistical mechanics systems, that can be called mean-field-like systems. Among these, this work considers only the systems with the most usual hamiltonian struc
M. F. Smith
The phonon contribution to the thermal conductivity at low temperature in superconductors with line nodes is calculated assuming that scattering by both nodal quasiparticles and the sample boundaries is significant. It is determined that, within the regime in which the quasiparticles are in the universal limit and the phonon attenuation is in the hydrodynami
The Origin of Anomalous Low-Temperature Downturns in the Thermal Conductivity of Cuprates
cond-mat.supr-conM. F. Smith, Johnpierre Paglione, M. B. Walker, Louis Taillefer
We show that the anomalous decrease in the thermal conductivity of cuprates below 300 mK, as has been observed recently in several cuprate materials including Pr$_{2-x}$Ce$_x$CuO$_{7-δ}$ in the field-induced normal state, is due to the thermal decoupling of phonons and electrons in the sample. Upon lowering the temperature, the phonon-electron heat transfer
Jisang Hong
Using the full potential linearized augmented plane wave (FLAPW) method, we have explored the magnetic properties of one dimensional (1D) Ti atomic chain. Astonishingly, we for the first time observed that the 1D Ti atomic chain has ferromagnetic ground state even on NiAl(110) surface although the Ti has no magnetic moment in bulk or macroscopic state. It wa
G. C. Lau, B. D. Muegge, T. M. McQueen, E. L. Duncan
Synthesis and crystal structures are described for the compounds Ln2(Ti2-xLnx)O7-x/2, where Ln = Tb, Dy, Ho, Er, Tm, Yb, Lu, and x ranges from 0 to 0.67. Rietveld refinements on X-ray powder diffraction data indicate that in Tb and Dy titanate pyrochlores, extra Ln3+ cations mix mainly on the Ti4+ site with little disorder on the original Ln3+ site. For the
P. G. Mather, J. C. Read, R. A. Buhrman
We report scanning tunneling spectroscopy studies of the electronic structure of 1.5 to 3 nm (001) textured MgO layers grown on (001) Fe. Thick MgO layers exhibit a bulk-like band gap, approximately 5-7 eV, and sparse, localized defect states with characteristics attributable to oxygen and, in some cases, Mg vacancies. Thin MgO layers exhibit electronic stru
Shell Structure and Strengthening of Superconducting Pair Correlation in Nanoclusters
cond-mat.supr-conVladimir Z. Kresin, Yurii N. Ovchinnikov
The existence of shell structure and the accompanying high degeneracy of electronic levels leads to the possibility of strong superconducting pairing in metallic nanoclusters with N~100-1000 delocalized electrons. The most favorable cases correspond to (a) "magic" clusters with strongly degenerate highest occupied and lowest unoccupied shells and a r
A basis-set based Fortran program to solve the Gross-Pitaevskii Equation for dilute Bose gases in harmonic and anharmonic traps
cond-mat.otherRakesh P. Tiwari, Alok Shukla
Inhomogeneous boson systems, such as the dilute gases of integral spin atoms in low-temperature magnetic traps, are believed to be well described by the Gross-Pitaevskii equation (GPE). GPE is a nonlinear Schroedinger equation which describes the order parameter of such systems at the mean field level. In the present work, we describe a Fortran 90 computer p
Signature of the electron-electron interaction in the magnetic field dependence of nonlinear I-V characteristics in mesoscopic conductors
cond-mat.mes-hallE. Deyo, B. Spivak, A. Zyuzin
The nonlinear I-V characteristics of mesoscopic samples contain parts which are linear in the magnetic field and quadratic in the electric field. These contributions to the current are entirely due to the electron-electron interaction and consequently they are proportional to the electron-electron interaction constant. We present detailed calculations of the
Reply to the comment on "Theoretical analysis of the transmission phase shift of a quantum dot in the presence of Kondo correlations"
cond-mat.mes-hallM. Lavagna, P. Vitushinsky, A. Jerez
In their comment, Aharony, Entin-Wohlman, Oreg and von Delft claimed that the expression we obtained for the phase of the S-matrix does not give back the correct result notably in the U=0 limit of the single level Anderson model (SLAM). Their comment, however, misses the point of our argument, namely, that the SLAM is insufficient to describe the interferome
Static and dynamic properties of crystalline phases of two-dimensional electrons in a strong magnetic field
cond-mat.mes-hallA. M. Ettouhami, F. D. Klironomos, Alan T. Dorsey
We study the cohesive energy and elastic properties as well as normal modes of the Wigner and bubble crystals of the two-dimensional electron system (2DES) in higher Landau levels. Using a simple Hartree-Fock approach, we show that the shear moduli ($c_{66}$'s) of these electronic crystals show a non-monotonic behavior as a function of the partial fillin
Charge and Spin Ordering in Insulating Na$_{0.5}$CoO$_2$: Effects of Correlation and Symmetry
cond-mat.str-elK. -W. Lee, W. E. Pickett
Ab initio band theory including correlations due to intra-atomic repulsion is applied to study charge disproportionation and charge- and spin-ordering in insulating Na$_{0.5}$CoO$_2$. Various ordering patterns (zigzag and two striped) for four-Co supercells are analyzed before focusing on the observed "out-of-phase stripe" pattern of antiferromagneti
X. G. Luo, H. Li, X. H. Chen, Y. M. Xiong
Magnetic and transport properties of polycrystalline Gd$_{1-x}$Sr$_x$CoO$_{3}$ ($x$= 0.10-0.70) are investigated systemically. Cluster-glass magnetism for $x \leq$ 0.45 and long-range ferromagnetic order in higher doping level are observed. Transport measurements indicate insulator-like behaviors for the samples with $x \leq$ 0.30, and an insulator-metal (IM
Stéphane Ancey, Yves Décanini, Antoine Folacci, Paul Gabrielli
We consider the scattering of electromagnetic waves by a left-handed cylinder -- i.e., by a cylinder fabricated from a left-handed material -- in the framework of complex angular momentum techniques. We discuss both the TE and TM theories. We emphasize more particularly the resonant aspects of the problem linked to the existence of surface polaritons. We pro
J. W. Moffat
The inhomogeneous distribution of matter in the non-linear regime of galaxies, clusters of galaxies and voids is described by an exact, spherically symmetric inhomogeneous solution of Einstein's gravitational field equations, corresponding to an under-dense void. The solution becomes the homogeneous and isotropic Einstein-de Sitter solution for a red shi
L. Saleh, T. C. Beers, G. J. Mathews
We present numerical simulations to describe the nucleosynthesis and evolution of pre-Galactic clouds in a model which is motivated by cold dark matter simulations of hierarchical galaxy formation. We adopt a SN-induced star-formation mechanism and follow the chemical enrichment and energy input by Type II and Type Ia SNe. We utilize metallicity-dependent yi
Mukremin Kilic, Ted von Hippel, S. K. Leggett, D. E. Winget
We present near-infrared spectroscopic observations of 20 previously known DAZ white dwarfs obtained at the NASA Infrared Telescope Facility. Two of these white dwarfs (G29-38 and GD362) are known to display significant K-band excesses due to circumstellar debris disks. Here we report the discovery of excess K-band radiation from another DAZ white dwarf, WD0
Manfred W. Pakull, Fabien Grise, Christian Motch
Optical studies of ultraluminous X-ray sources (ULX) in nearby galaxies have turned out to be instrumental in discriminating between various models including the much advertised intermediate mass black hole hypothesis and various beaming scenarios. Here we report on ESO VLT and SUBARU observations of ULX that have revealed the parent stellar clusters with ag
Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
astro-phR. O. Gray, C. J. Corbally, R. F. Garrison, M. T. McFadden
We are obtaining spectra, spectral types and basic physical parameters for the nearly 3600 dwarf and giant stars earlier than M0 in the Hipparcos catalog within 40pc of the Sun. Here we report on results for 1676 stars in the southern hemisphere observed at Cerro Tololo Interamerican Observatory and Steward Observatory. These results include new, precise, ho
Fabien Grise, Manfred W. Pakull, Christian Motch
We present optical observations of a ULX in the nearby spiral galaxy IC 342. This variable source has an average X-ray luminosity of some 10^{40} erg/s. At the position of the source there is an ionized nebula (the "Tooth") having huge dimensions (280 x 130 pc), much larger than normal supernova remnants. Our optical spectra reveal highly supersonic
Fabien Grise, Manfred W. Pakull, Christian Motch
We present optical observations of an ultraluminous X-ray source (ULX) in Holmberg IX, a dwarf galaxy near M81. The ULX has an average X-ray luminosity of some 10^{40} erg/s. It is located in a huge (400pc x 300pc) ionized nebula being much larger than normal supernova remnants. From the observed emission lines (widths and ratios) we find that the structure
Raffaella Schneider, Kazuyuki Omukai, Akio Inoue, Andrea Ferrara
The thermal and fragmentation properties of star-forming clouds have important consequences on the corresponding characteristic stellar mass. The initial composition of the gas within these clouds is a record of the nucleosynthetic products of previous stellar generations. In this paper we present a model for the evolution of star-forming clouds enriched by
J. Einasto, M. Einasto, E. Tago, E. Saar
We use the 2dF Galaxy Redshift Survey data to compile catalogues of superclusters for the Northern and Southern regions of the 2dFGRS, altogether 543 superclusters at redshifts 0.009 < z < 0.2. We analyse methods of compiling supercluster catalogues and use results of the Millennium Simulation to investigate possible selection effects and errors. We find tha
P. Spanò, F. M. Zerbi, C. J. Norrie, C. R. Cunningham
We describe and summarize the optical challenges for future instrumentation for Extremely Large Telescopes (ELTs). Knowing the complex instrumental requirements is crucial for the successful design of 30-60m aperture telescopes. After all, the success of ELTs will heavily rely on its instrumentation and this, in turn, will depend on the ability to produce la
Prado Martin-Moruno, Jose A. Jimenez Madrid, Pedro F. Gonzalez-Diaz
The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable v
New methods for approximating general relativity in numerical simulations of stellar core collapse
astro-phHarald Dimmelmeier, Pablo Cerda-Duran, Andreas Marek, Guillaume Faye
We review various approaches to approximating general relativistic effects in hydrodynamic simulations of stellar core collapse and post-bounce evolution. Different formulations of a modified Newtonian gravitational potential are presented. Such an effective relativistic potential can be used in an otherwise standard Newtonian hydrodynamic code. An alternati
A Comprehensive Study of 2 000 Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey: I. The Sample
astro-phHongyan Zhou, Tinggui Wang, Weimin Yuan, Honglin Lu
This is the first paper in a series dedicated to the study of the emission-line and continuum properties of narrow line Seyfert 1 galaxies (NLS1s). We carried out a systematic search for NLS1s from objects assigned as ``QSOs'' or ``galaxies'' in the spectroscopic sample of the Sloan Digital Sky Survey Data Release 3 (SDSS DR3) by a careful mo
V. Sguera, A. Bazzano, A. J. Bird, A. J. Dean
Supergiant high mass X-ray binaries (SGXBs) are believed to be rare objects, as stars in the supergiant phase have a very short lifetime and to date only about a dozen of them have been discovered. They are known to be persistent and bright X-ray sources. INTEGRAL is changing this classical picture as its observations are revealing the presence of a new subc
Robert G. Izzard, Arend Jan T. Poelarends
We describe our first attempt at modelling nucleosynthesis in massive AGB stars which have undergone core carbon burning, the super-AGB stars. We fit a synthetic model to detailed stellar evolution models in the mass range 9<=M/Msun<=11.5 (Z=0.02), and extrapolate these fits to the end of the AGB. We determine the number of thermal pulses and AGB lifetime as
R. R. Shobbrook, G. Handler, D. Lorenz, D. Mogorosi
We have carried out single and multi-site photometry of the three Beta Cephei stars Beta and 15 CMa as well as KZ Mus. For the two stars in CMa, we obtained 270 h of measurement in the Stromgren uvy and Johnson V filters, while 150 h of time-resolved Stromgren uvy photometry was acquired for KZ Mus. All three stars are multi-periodic variables, with three (B
Woong-Tae Kim, Eve C. Ostriker
(Abridged) We investigate the growth of spiral-arm substructure in vertically stratified, self-gravitating, galactic gas disks, using local numerical MHD simulations. Our new models extend our previous 2D studies (Kim & Ostriker 2002), which showed that a magnetized spiral shock in a thin disk can undergo magneto-Jeans instability (MJI), resulting in interar
E. L. Wright
In the century since Einstein's anno mirabilis of 1905, our concept of the Universe has expanded from Kapteyn's flattened disk of stars only 10 kpc across to an observed horizon about 30 Gpc across that is only a tiny fraction of an immensely large inflated bubble. The expansion of our knowledge about the Universe, both in the types of data and the s
Earth azimuth effect in the bank of search templates for an all sky search of the continuous gravitational wave
astro-phS. K. Sahay
We study the problem of all sky search in reference to continuous gravitational wave (CGW) whose wave-form are known in advance. We employ the concept of Fitting Factor and study the variation in the bank of search templates with different Earth azimuth at t=0. We found that the number of search templates varies significantly. Hence, accordingly, the computa
Mercedes Lopez-Morales, J. Scott Shaw
Full tests to stellar models below 1 Msun have been hindered until now by the scarce number of precise measurements of the stars' most fundamental parameters: their masses and radii. With the current observational techniques, the required precision to distinguish between different models (errors < 2-3 %) can only be achieved using detached eclipsing bina
Priscilla C. Frisch
Several sets of data show that small interstellar grains captured in interstellar magnetic fields draped over the heliosphere appear to polarize the light of nearby stars. The maximum polarization direction is offset in ecliptic longitude by about +35 from the upwind direction, and the polarization peak is enhanced for stars near the ecliptic plane. A band o
J. Scott Shaw, Mercedes Lopez-Morales
We present new observations of cool <6000K and low mass <1Msun binary systems that have been discovered by searching several modern stellar photometric databases. The search has led to a factor of 10 increase in the number of known cool close eclipsing binary systems.
Jan Staff, Rachid Ouyed, Prashanth Jaikumar
We study the role of spin-down in driving quark deconfinement in the high density core of isolated neutron stars. Assuming spin-down to be solely due to magnetic braking, we obtain typical timescales to quark deconfinement for neutron stars that are born with Keplerian frequencies. Employing different equations of state (EOS), we determine the minimum and ma
Magnetic Field Decay and Period Evolution of Anomalous X-Ray Pulsars in the Context of Quark Stars
astro-phBrian Niebergal, Rachid Ouyed, Denis Leahy
We discuss a model wherein soft gamma-ray repeaters (SGRs), anomalous X-ray pulsars (AXPs), and radio quiet isolated neutron stars (RQINSs) are all compact objects exhibiting superconductivity, namely color-flavor locked quark stars. In particular we calculate the magnetic field decay due to the expulsion of spin-induced vortices from the star's superflu
Baris Coskunuzer
Because of the relevance of the results, this paper is merged into the paper titled "On the Number of Solutions to Asymptotic Plateau Problem" (arXiv:math.DG/0505593) as a new section.
Ground-State and Domain-Wall Energies in the Spin-Glass Region of the 2D $\pm J$ Random-Bond Ising Model
cond-mat.dis-nnRonald Fisch, Alexander K. Hartmann
The statistics of the ground-state and domain-wall energies for the two-dimensional random-bond Ising model on square lattices with independent, identically distributed bonds of probability $p$ of $J_{ij}= -1$ and $(1-p)$ of $J_{ij}= +1$ are studied. We are able to consider large samples of up to $320^2$ spins by using sophisticated matching algorithms. We s
Igor Bayak
In this paper we investigate the relation between Abelian and non-Abelian groups of parity. The Abelian groups of parity are formed as kernels of homomorphisms of parity in group $\mmathbb{Z}^{n}$ and the non-Abelian groups of parity are formed as kernels of homomorphisms of parity in group $S_{2}\wr S_{n}$. It is shown that the group of isomorphisms of the
Cross-correlation of WMAP 3rd year and the SDSS DR4 galaxy survey: new evidence for Dark Energy
astro-phA. Cabre, E. Gaztanaga, M. Manera, P. Fosalba
We cross-correlate the third-year WMAP data with galaxy samples extracted from the SDSS DR4 (SDSS4) covering 13% of the sky, increasing by a factor of 3.7 the volume sampled in previous analyses. The new measurements confirm a positive cross-correlation with higher significance (total signal-to-noise of about 4.7). The correlation as a function of angular sc
Ludovic Van Waerbeke, Martin White, Henk Hoekstra, Catherine Heymans
The cosmological interpretation of weak lensing by large-scale structures requires knowledge of the redshift distribution of the source galaxies. Current lensing surveys are often calibrated using external redshift samples which span a significantly smaller sky area in comparison to the lensing survey, and are thus subject to sample variance. Some future len
Satoshi Yamaguchi
We use a D5-brane with electric flux in AdS_5 x S^5 background to calculate the circular Wilson loop of anti-symmetric representation in N=4 super Yang-Mills theory in 4 dimensions. The result agrees with the Gaussian matrix model calculation.
Stretched exponential relaxation in three dimensional short-range spin glass Cu$_{0.5}$Co$_{0.5}$Cl$_{2}$-FeCl$_{3}$ graphite bi-intercalation compound
cond-mat.dis-nnItsuko S. Suzuki, Masatsugu Suzuki
Cu$_{0.5}$Co$_{0.5}$Cl$_{2}$-FeCl$_{3}$ graphite bi-intercalation compound is a three-dimensional short-range spin glass with a spin freezing temperature $T_{SG}$ ($= 3.92 \pm 0.11$ K). The time evolution of the zero-field cooled magnetization $M_{ZFC}(t)$ has been measured under various combinations of wait time ($t_{w}$), temperature ($T$), temperature-shi
Xiang-Yu Wang, Peter Meszaros
Shock breakout X-ray emission has been reported for the first time from a supernova connected with a gamma-ray burst, namely GRB060218/SN2006aj. The gamma-ray emission and the power-law decaying X-ray afterglow are ascribed to a highly relativistic jet, while the thermal soft X-rays are thought to be produced when the radiation-dominated shock breaks from th
Jesús A. Maytorena, Catalina López-Bastidas, Francisco Mireles
We study the frequency dependent spin- and charge- conductivity tensors of a two-dimensional electron gas (2DEG) with Rashba and Dresselhaus spin-orbit interaction. We show that the angular anisotropy of the spin-splitting energy induced by the interplay between the Rashba and Dresselhaus couplings gives rise to a characteristic spectral behavior of the spin
C. Kollath, A. Iucci, T. Giamarchi, W. Hofstetter
We present a non-perturbative analysis of a new experimental technique for probing ultracold bosons in an optical lattice by periodic lattice depth modulations. This is done using the time-dependent density-matrix renormalization group method. We find that sharp energy absorption peaks are not unique to the Mott insulating phase at commensurate filling, but
Vanessa Mangano, Valentina La Parola, Giancarlo Cusumano, Teresa Mineo
Swift discovered XRF 050416A with the BAT and began observing it with its narrow field instruments only 64.5 s after the burst onset. Its very soft spectrum classifies this event as an X-ray flash. The afterglow X-ray emission was monitored up to 74 days after the burst. The X-ray light curve initially decays very fast, subsequently flattens and eventually s
Edward M. Cackett, Rudy Wijnands, Ron Remillard
We report the discovery of an X-ray transient, observed in outburst with XMM-Newton on March 20, 2003, and with position 18h12m27.8s, -18 12 34 (J2000, approximate positional error 2"). No known source is present at this position and the source was not detected during published ROSAT or ASCA observations of that region. However, the source may be associa
Jure Leskovec, Jon Kleinberg, Christos Faloutsos
How do real graphs evolve over time? What are ``normal'' growth patterns in social, technological, and information networks? Many studies have discovered patterns in static graphs, identifying properties in a single snapshot of a large network, or in a very small number of snapshots; these include heavy tails for in- and out-degree distributions, com
Chong-Sun Chu, Valentin V. Khoze
We consider the AdS/CFT correspondence between the beta-deformed supersymmetric gauge theory and the type IIB string theory on the Lunin-Maldacena background. Guided by gauge theory results, we modify and extend the supergravity solution of Lunin and Maldacena in two ways. First we make it to be doubly periodic in the deformation parameter, beta -> beta+1 an
Martin Kruczenski
We consider the open string vacuum amplitude determining the interaction between a stack of N D3-branes and a single probe brane. When using light cone gauge, it is clear that the sum of planar diagrams (relevant in the large-N limit) is described by the free propagation of a closed string. A naive calculation suggests that the Hamiltonian of the closed stri
R. G. Pereira, J. Sirker, J. -S. Caux, R. Hagemans
The longitudinal spin structure factor for the XXZ-chain at small wave-vector q is obtained using Bethe Ansatz, field theory methods and the Density Matrix Renormalization Group. It consists of a peak with peculiar, non-Lorentzian shape and a high-frequency tail. We show that the width of the peak is proportional to q^2 for finite magnetic field compared to
Angik Sarkar, T. K. Bhattacharyya, Ajay Patwardhan
Quantum Logic Processors can be implemented with Mach Zehnder Interferometer(MZI) configurations for the Quantum logic operations and gates. In this paper, its implementation for both optical and electronic system has been presented. The correspondence between Jones matrices for photon polarizations and Pauli spin matrices for electrons gives a representatio
Gregory Gabadadze, Alberto Iglesias
We investigate the decoupling limit in the DGP model of gravity by studying its nonlinear equations of motion. We show that, unlike 4D massive gravity, the limiting theory does not reduce to a sigma model of a single scalar field: Non-linear mixing terms of the scalar with a tensor also survive. Because of these terms physics of DGP is different from that of
Athanasios Dedes, Steven Rimmer, Janusz Rosiek
We consider the most general supersymmetric model with minimal particle content and an additional discrete Z_3 symmetry (instead of R-parity), which allows lepton number violating terms and results in non-zero Majorana neutrino masses. We investigate whether the currently measured values for lepton masses and mixing can be reproduced. We set up a framework i
J. Baines, S. P. Baranov, O. Behnke, J. Bracinik
The present status of the heavy-quark production theory is critically reviewed in the first contribution. The second contribution summarises the present heavy flavour data from HERA and gives an outlook of what can be expected from HERA-II. The potential of the LHC experiments for charm and beauty physics is reviewed in the 3rd contribution. Then the relevan
B. Siudeja
Let $α\in(0,2)$ and $X_t$ be a symmetric $α$-stable process. We define the scattering length $Γ(v)$ of the positive potential $v$ and prove several of its basic properties. We use the scattering length to findestimates for the first eigenvalue of the Schrödinger operator of the ``Neumann'' fractional Laplacian in a cube with potential $v$.
Magdalena Djordjevic
Computation of collisional energy loss in a finite size QCD medium has become crucial to obtain reliable predictions for jet quenching in ultra-relativistic heavy ion collisions. We here compute this energy loss up to the zeroth order in opacity. Our approach consistently treats both soft and hard contributions to the collisional energy loss. Consequently, i
Rafael Hernandez, Esperanza Lopez
One-loop corrections to the energy of semiclassical rotating strings contain both analytic and non-analytic terms in the 't Hooft coupling. Analytic contributions agree with the prediction from the string Bethe ansatz based on the classical S-matrix, but in order to include non-analytic contributions quantum corrections are required. We find a general ex
M. Pustilnik
We evaluate the dynamic structure factor $S(q,ω)$ of a one-dimensional quantum Hamiltonian with the inverse-square interaction (Calogero-Sutherland model). For a fixed small $q$, the structure factor differs from zero in a finite interval of frequencies of the width $δω\propto q^2/m$. At the borders of this interval $S(q,ω)$ exhibits power-law singularities
The multiwavelength afterglow of GRB 050721: a puzzling rebrightening seen in the optical but not in the X-ray
astro-phL. A. Antonelli, V. Testa, P. Romano, D. Guetta
Context. GRB050721 was detected by Swift and promptly followed-up, in the X-ray by Swift itself and, in the optical band, by the VLT operated, for the first time, in rapid response mode. A multiwavelength monitoring campaign was performed in order to study its afterglow behavior. Aims. We present the analysis of the early and late afterglow emission in both
Ko Honda, William H. Kazez, Gordana Matic
We continue our study of the monoid of right-veering diffeomorphisms on a compact oriented surface with nonempty boundary, introduced in [HKM2]. We conduct a detailed study of the case when the surface is a punctured torus; in particular, we exhibit the difference between the monoid of right-veering diffeomorphisms and the monoid of products of positive Dehn
Axel Kleinschmidt, Hermann Nicolai
We analyze the decomposition of recently constructed unfaithful spinor representations of K(E10) under its SO(9) x SO(9), and SO(9) x SO(2) subgroups, respectively, where K(E10) is the `maximal compact' subgroup of the hyperbolic Kac--Moody group E(10). We show that under these decompositions, respectively, one and the same K(E10) spinor gives rise to bo
Eduardo S. Cypriano, Claudia L. Mendes de Oliveira, Laerte Sodré
We study the properties of the fossil cluster RX J1416.4+2315 through g' and i'-band imaging and spectroscopy of 25 member galaxies. The system is at a mean redshift of 0.137 and has a velocity dispersion of 584 km s^-1. Superimposed onto one quadrant of the cluster field there is a group of five galaxies at a mean redshift of 0.131, which, if includ
Alberto Cortijo, Maria A. H. Vozmediano
A model is proposed to study the electronic structure of slightly curved graphene sheets with an arbitrary number of pentagon-heptagon pairs and Stone-Wales defects based on a cosmological analogy. The disorder induced by curvature produces characteristic patterns in the local density of states that can be observed in scanning tunnel and transmission electro
The NOAO Fundamental Plane Survey - III. Variations in the stellar populations of red-sequence galaxies from the cluster core to the virial radius
astro-phRussell J. Smith, Michael J. Hudson, John R. Lucey, Jenica E. Nelan
We analyse absorption line-strength indices for ~3000 red-sequence galaxies in 94 nearby clusters, to investigate systematic variations of their stellar content with location in the host cluster. The data are drawn from the NOAO Fundamental Plane Survey. Our adopted method is a generalization of that introduced by Nelan et al. to determine the global age-mas
A. Moor, P. Abraham, A. Derekas, Cs. Kiss
By searching the IRAS and ISO databases we compiled a list of 60 debris disks which exhibit the highest fractional luminosity values (fd>10^-4) in the vicinity of the Sun (d<120pc). Eleven out of these 60 systems are new discoveries. Special care was taken to exclude bogus disks from the sample. We computed the fractional luminosity values using available IR
Andreas Hartmann
Free interpolation in Hardy spaces is caracterized by the well-known Carleson condition. The result extends to Hardy-Orlicz spaces contained in the scale of classical Hardy spaces $H^p$, $p>0$. For the Smirnov and the Nevanlinna classes, interpolating sequences have been characterized in a recent paper in terms of the existence of harmonic majorants (quasi-b
F. Q. Wu, B. S. Zou
We carry out a theoretical and Monte Carlo study on the $J/ψ$ decays into $ωππ$ and $K\bar{K}π$ through intermediate subthreshold $ρ$ meson by using SU(3)-symmetric Lagrangian approach. It is found that the subthreshold $ρ$ contribution is not negligible and may have significant influence on partial wave analysis of resonances in these channels, especially n
Study of time lags in HETE-2 Gamma-Ray Bursts with redshift: search for astrophysical effects and Quantum Gravity signature
astro-phJ. Bolmont, J. -L. Atteia, A. Jacholkowska, F. Piron
The study of time lags between spikes in Gamma-Ray Burst light curves in different energy bands as a function of redshift may lead to the detection of effects due to Quantum Gravity. We present an analysis of 15 Gamma-Ray Bursts with measured redshift, detected by the HETE-2 mission in order to measure time lags related to astrophysical effects and search fo
Existence of Negative Gravity Material Identification of Dark Energy Dark Matter Isothermal Gravitational Equilibrium and Galactic Rotation Theory
physics.gen-phJames G. Gilson
A solution to Einstein's field equations via the Friedman equations is shown to produce a cosmological model that is in exact agreement with the measurements made by the dark energy astronomers. All the essential physical parameters are obtained as epoch dependent functions all in closed form. The equations of state are obtained for total density, non-da
Morihiko Saito
Using the theory of mixed perverse sheaves, we extend arguments on the Hodge conjecture initiated by Lefschetz and Griffiths to the case of the Tate conjecture, and show that the Tate conjecture for divisors is closely related to the de Rham conjecture for nonproper varieties, finiteness of the Tate-Shafarevich groups, and also to some conjectures in the ana
J. Brodzki, G. A. Niblo, N. J. Wright
We define the concept of a partial translation structure T on a metric space X and we show that there is a natural C*-algebra C*(T) associated with it which is a subalgebra of the uniform Roe algebra C*_u(X). We introduce a coarse invariant of the metric which provides an obstruction to embedding the space in a group. When the space is sufficiently group-lik
(p,q)-string in the wrapped supermembrane on 2-torus -- A classical analysis of the bosonic sector --
hep-thHiroyuki Okagawa, Shozo Uehara, Satoshi Yamada
We consider a wrapped supermembrane on $\R^9\times T^2$. We examine a double dimensional reduction to deduce a $(p,q)$-string in type IIB superstring theory from the wrapped supermembrane. In particular, directly from the wrapped supermembrane action, we explicitly derive the action of a string which carries the RR 2-form charge as well as the NSNS 2-form ch
Mireille Bousquet-Mélou, Steven Butler
Given a permutation $π\in \Sn\_n$, construct a graph $G\_π$ on the vertex set $\{1,2, ..., n\}$ by joining $i$ to $j$ if (i) $i<j$ and $π(i)<π(j)$ and (ii) there is no $k$ such that $i < k < j$ and $π(i)<π(k)<π(j)$. We say that $π$ is forest-like if $G\_π$ is a forest. We first characterize forest-like permutations in terms of pattern avoidance, and then by
L. Lamata, J. Leon, D. Salgado, E. Solano
We propose an inductive procedure to classify N-partite entanglement under stochastic local operations and classical communication (SLOCC) provided such a classification is known for N-1 qubits. The method is based upon the analysis of the coefficient matrix of the state in an arbitrary product basis. We illustrate this approach in detail with the well-known
Konrad J Swanepoel
We develop a general method of proving that certain star configurations in finit e-dimensional normed spaces are Steiner minimal trees. This method generalizes the results of Lawlor and Morgan (1994) that could only be applied to differentiable norms. The generalization uses the subdifferential calculus from convex analysis. We apply this method to two speci
Hwajeong Kim
Unstable minimal surfaces are the unstable stationary points of the Dirichlet-Integral. In order to obtain unstable solutions, the method of the gradient flow together with the minimax-principle is generally used. The application of this method for minimal surfaces in the Euclidean spacce was presented in \cite{s3}. We extend this theory for obtaining unstab
A. O. Sboychakov, K. I. Kugel, A. L. Rakhmanov
A "minimal model" of the Kondo-lattice type is used to describe a competition between the localization and metallicity in doped manganites and related magnetic oxides with Jahn-Teller ions. It is shown that the number of itinerant charge carriers can be significantly lower than that implied by the doping level x. A strong tendency to the phase separa
S. J. Goldstein, L. E. Labuschagne
Building on the ideas in L E Labuschagne, Composition Operators on Non-commutative $L^p$-spaces, \textit{Expo. Math} \textbf{17}(1999), 429--468, we indicate how the concept of a composition operator may be extended to the context of Haagerup $L^p$-spaces.
I. Zborovsky, M. Tokarev
New generalization of z-scaling in inclusive particle production is proposed. The scaling variable z is fractal measure which depends on kinematical characteristics of the underlying sub-process expressed in terms of the momentum fractions x1 and x2 of the incoming protons. In the generalized approach, the x1 and x2 are functions of the momentum fractions ya
M. S. Clemens, A. Bressan, B. Nikolic, P. Alexander
Using the third data release of the Sloan Digital Sky Survey (SDSS) we have rigorously defined a volume limited sample of early-type galaxies in the redshift range z < 0.1. We have defined the density of the local environment for each galaxy using a method which takes account of the redshift bias introduced by survey boundaries if traditional methods are use
S. Groote, J. G. Körner, A. A. Pivovarov
Using configuration space techniques, we calculate next-to-leading order (NLO) five-loop QCD corrections to the correlators of interpolating pentaquark currents in the limit of massless quarks. We obtain very large NLO corrections to the spectral density which makes a standard sum rule analysis problematic. However, the NLO corrections to the correlator in c
Spinning String and Giant Graviton in Electric/Magnetic Field Deformed $AdS_3 \times S^3 \times T^4$
hep-thWung-Hong Huang
We apply the transformation of mixing azimuthal and internal coordinate or mixing time and internal coordinate to the 11D M-theory with a stack of M2-branes $\bot$ M2-branes, then, through the mechanism of Kaluza-Klein reduction and a series of the T duality we obtain the corresponding background of a stack of D1-branes $\bot$ D5-branes which, in the near-ho
Debabrata Biswas
The classical Liouville density on the constant energy surface reveals a number of interesting features when the initial density has no directional preference. It has been shown (Physical Review Letters, 93 (2004) 204102) that the eigenvalues and eigenfunctions of the momentum-projected density evolution operator have a correspondence with the quantum Neuman
Visualizing high-temperature spin dynamics in La1-xCaxMnO3 from a mapping of EPR linewidth and g factor
cond-mat.str-elY. Liu, S. L. Wan, X. G. Li
This paper presents an analysis of electron paramagnetic resonance parameters, i.e., g factor, linewidth, and intensity on powder samples of La1-xCaxMnO3 at the commensurate carrier concentrations of x = N/8 (N = 1, 2, 3, 4, 5, 6, and 7). We demonstrate that the mapping of EPR parameters offers a powerful tool to investigate high-temperature spin dynamics in
Hagai Netzer, V. Mainieri, P. Rosati, Benny Trakhtenbrot
We combine emission line and X-ray luminosities for 45 sources from the Chandra Deep Field South (CDF-S), and seven HELLAS sources, to obtain a new sample of 52 X-ray selected type-II active galactic nuclei (AGNs). Eighteen of our sources are very luminous with a typical, absorption-corrected 2-10 keV luminosity of few 10^{44} erg/sec (type-II QSOs). We comp
Mechanism and kinetics of phase formation of cobalt oxyhydrates (Na,K)x(H2O)yCoO2-delta synthesized using aqueous permanganate solution route
cond-mat.supr-conChia-Jyi Liu, Wen-Chin Hung, Chia-Yuan Liao, Jung-Sheng Wang
This paper has been withdrawn by the author due to a data error in Fig 5.
Katsuichi Higuchi, Masato Senami, Katsuji Yamamoto
We investigate the quark masses and mixings by including vector-like down-type quark singlets in universality of strength for Yukawa couplings (USY). In contrast with the standard model with USY, the sufficient $ CP $ violation is obtained for the Cabibbo-Kobayashi-Maskawa matrix through the mixing between the ordinary quarks and quark singlets. The top-bott
Relative spectral lag: an new redshift indicator to measure the cosmos with gamma-ray bursts
astro-phZhi-Bin Zhang, Jia-Gan Deng, Rui-Jing Lu, Hai-Feng Gao
Using 64 ms count data for long gamma-ray bursts ($T_{90}>$2.6s), we analyze the quantity, relative spectral lag (RSL), which is defined as $τ_{31}/FWHM_{(1)}$, where $τ_{31}$ is the spectral lag between energy bands 1 and 3, and $FWHM_{(1)}$ denotes full width at half maximum of the pulse in energy channel 1. To get insights into features of the RSLs, we in
Luca Amendola, David Polarski, Shinji Tsujikawa
All $f(R)$ modified gravity theories are conformally identical to models of quintessence in which matter is coupled to dark energy with a strong coupling. This coupling induces a cosmological evolution radically different from standard cosmology. We find that in all $f(R)$ theories that behave as a power of $R$ at large or small $R$ (which include most of th
Using Phenomenological Formulae,Deducing the Masses and Flavors of the Quarks, Baryons and Mesons from Two Elementary Quarks
hep-phJiao-Lin Xu
Using phenomenological formulae, we deduce the masses and quantum numbers of the quarks from two elementary quarks ($ε_{u}$ and $ε_{d}$) first. Then using the sum laws and a binding energy formula, in terms of the qqq baryon model and SU(4), we deduce the masses and quantum numbers of the important baryons from the deduced quarks. At the same time, using the
Vortex creation during magnetic trap manipulations of spinor Bose-Einstein condensates
cond-mat.otherA. P. Itin, T. Morishita, M. Satoh, O. I. Tolstikhin
We investigate several mechanisms of vortex creation during splitting of a spinor BEC in a magnetic trap controlled by a pair of current carrying wires and bias magnetic fields. Our study is motivated by a recent MIT experiment on splitting BECs with a similar trap, where unexpected fork-like structure appeared in the interference fringes corresponding to in
E. Knill
There are two complementary approaches to realizing quantum information so that it is protected from a given set of error operators. Both involve encoding information by means of subsystems. One is initialization-based error protection, which involves a quantum operation that is applied before error events occur. The other is operator quantum error correctio
Stefano Zippilli, Giovanna Morigi, Wolfgang P. Schleich
We study the mechanical effects of light on an atom trapped in a harmonic potential when an atomic dipole transition is driven by a laser and it is strongly coupled to a mode of an optical resonator. We investigate the cooling dynamics in the bad cavity limit, focussing on the case in which the effective transition linewidth is smaller than the trap frequenc
Mahmoud Abdel-Aty
With the reliance in the processing of quantum information on a cold trapped ion, we analyze the entanglement entropy in the ion-field interaction with pair cat states. We investigate a long-living entanglement allowing the instantaneous position of the center-of-mass motion of the ion to be explicitly time dependent. An analytic solution for the system oper
C. Negrevergne, T. S. Mahesh, C. A. Ryan, M. Ditty
In this letter, we present an experimental benchmark of operational control methods in quantum information processors extended up to 12 qubits. We implement universal control of this large Hilbert space using two complementary approaches and discuss their accuracy and scalability. Despite decoherence, we were able to reach a 12-coherence state (or 12-qubits
G. Brida, M. V. Chekhova, M. Genovese, M. Gramegna
We present the first observation of two-photon polarization interference structure in the second-order Glauber's correlation function of two-photon light generated via type-II spontaneous parametric down-conversion. In order to obtain this result, two-photon light is transmitted through an optical fibre and the coincidence distribution is analyzed by mea