October 2006 arXiv papers — page 9
Showing 801–900 of 5,236 papers
Exciton dissociation at donor-acceptor polymer heterojunctions: quantum nonadiabatic dynamics and effective-mode analysis
cond-mat.mtrl-sciHiroyuki Tamura, Eric R. Bittner, Irene Burghardt
The quantum-dynamical mechanism of photoinduced subpicosecond exciton dissociation and the concomitant formation of a charge-separated state at a TFB:F8BT polymer heterojunction is elucidated. The analysis is based upon a two-state vibronic coupling Hamiltonian including an explicit 24-mode representation of a phonon bath comprising high-frequency (C$=$C str
M. Acquarone, C. I. Ventura
We focus on the definition of the unitary transformation leading to an effective second order Hamiltonian, inside degenerate eigensubspaces of the non-perturbed Hamiltonian. We shall prove, by working out in detail the Su-Schrieffer-Heeger Hamiltonian case, that the presence of degenerate states, including fermions and bosons, which might seemingly pose an o
Eric R. Bittner
Recent ultrafast experiments have implicated intrachain base-stacking rather than base-pairing as the crucial factor in determining the fate and transport of photoexcited species in DNA chains. An important issue that has emerged concerns whether or not a Frenkel excitons is sufficient one needs charge-transfer states to fully account for the dynamics. In we
A Pugzlys, P J Rizo, K Ivanin, A Slachter
A number of time resolved optical experiments probing and controlling the spin and charge dynamics of the high mobility two-dimensional electron gas in a GaAs/AlGaAs heterojunction are discussed. These include time resolved reflectivity, luminescence, transient grating, magneto-optical Kerr effect, and electro-optical Kerr effect experiments. The optical exp
O. I. Velichko
The stress-mediated diffusion of nonequilibrium point defects from the surface to the bulk of the semiconductor is investigated by computer simulation. It is supposed that point defects are generated in the surface region by ion implantation and during diffusion pass over the local region of elastic stresses because the average defect migration length is gre
Tunnelling spectroscopy of the interface between Sr2RuO4 and a single Ru micro-inclusion in eutectic crystals
cond-mat.supr-conHiroshi Yaguchi, Keiichi Takizawa, Minoru Kawamura, Naoki Kikugawa
The understanding of the zero bias conductance peak (ZBCP) in the tunnelling spectra of S/N junctions involving d-wave cuprate superconductors has been important in the determination of the phase structure of the superconducting order parameter. In this context, the involvement of a p-wave superconductor such as Sr2RuO4 in tunnelling studies is indeed of gre
Deformation Potential Carrier-Phonon Scattering in Semiconducting Carbon Nanotube Transistors
cond-mat.mtrl-sciG. Pennington, A. Akturk, N. Goldsman, A. Wickenden
Theoretical calculations of carrier transport in single-walled carbon nanotubes are compared with recent experiments. Carrier-phonon scattering is accounted for using the deformation potential approximation. Comparing with experiments, a deformation potential coupling constant of 14eV is determined for semiconducting carbon nanotubes. Theory is shown to clos
A. Dupuis, E. M. Kotsalis, P. Koumoutsakos
We propose a hybrid model, coupling Lattice Boltzmann and Molecular Dynamics models, for the simulation of dense fluids. Time and length scales are decoupled by using an iterative Schwarz domain decomposition algorithm. The MD and LB formulations communicate via the exchange of velocities and velocity gradients at the interface. We validate the present LB-MD
Time-convolutionless master equation dynamics for charge-transfer processes between semiconducting polymers
cond-mat.mtrl-sciEric R. Bittner, Andrey Pereverzev
We present here a brief overview of our work in developing a convolutionless quantum master equation approach suitable for mesoscopic sized systems. Our final equation can be used in the regimes where the golden rule approach is not applicable. Here we apply the approach to study the electronic relaxation in several models with the finite number of normal mo
Carl McBride
The advent of electronic computers has revolutionised the application of statistical mechanics to the liquid state. Computers have permitted, for example, the calculation of the phase diagram of water and ice and the folding of proteins. The behaviour of alkanes adsorbed in zeolites, the formation of liquid crystal phases and the process of nucleation. Compu
H. Saarikoski, W. Wetzels, G. E. W. Bauer
We investigate effects of spin-orbit splitting on electronic transport in a spin valve consisting of a large quantum dot defined on a two-dimensional electron gas with two ferromagnetic contacts. In the presence of both structure inversion asymmetry (SIA) and bulk inversion asymmetry (BIA) a giant anisotropy in the spin-relaxation times has been predicted. W
Magnetoelastic coupling across the metamagnetic transition in Ca$_{2-x}$Sr$_x$RuO$_4$ (0.2 < x < 0.5)
cond-mat.str-elJ. Baier, P. Steffens, O. Schumann, M. Kriener
The magnetoelastic coupling in Ca$_{1.8}$Sr$_{0.2}$RuO$_4$ and in Ca$_{1.5}$Sr$_{0.5}$RuO$_4$ has been studied combining high-resolution dilatometer and diffraction techniques. Both compounds exhibit strong anomalies in the thermal-expansion coefficient at zero and at high magnetic field as well as an exceptionally large magnetostriction. All these structura
Ireneusz Weymann
The spin-polarized transport through two-level quantum dots weakly coupled to ferromagnetic leads is considered theoretically in the Coulomb blockade regime. It is assumed that the dot is doubly occupied, so that the current flows due to cotunneling through singlet and triplet states of the dot. It is shown that transport characteristics strongly depend on t
J. Ahokas, J. Jarvinen, S. Vasiliev
We report a measurement of the cold collision frequency shift in atomic hydrogen gas adsorbed on the surface of superfluid 4He at T<=90 mK. Using two-photon electron and nuclear magnetic resonance in 4.6 T field we separate the resonance line shifts due to the dipolar and exchange interactions, both proportional to surface density sigma. We find the clock sh
Screened non-bonded interactions in native proteins manipulate optimal paths for robust residue communication
cond-mat.softAli Rana Atilgan, Deniz Turgut, Canan Atilgan
A protein structure is represented as a network of residues whereby edges are determined by intra-molecular contacts. We introduce inhomogeneity into these networks by assigning each edge a weight that is determined by amino-acid pair potentials. Two methodologies are utilized to calculate the average path lengths (APLs) between pairs: To minimize (i) the ma
Anna N. Morozovska, Sergei V. Svechnikov, Eugene A. Eliseev, Stephen Jesse
Piezoresponse Force Spectroscopy (PFS) has emerged as a powerful technique for probing highly localized switching behavior and the role of microstructure and defects on switching. The application of a dc bias to a scanning probe microscope tip in contact with a ferroelectric surface results in the nucleation and growth of a ferroelectric domain below the tip
Optical response of high-$T_c$ cuprates: possible role of scattering rate saturation and in-plane anisotropy
cond-mat.supr-conN. E. Hussey, J. C. Alexander, R. A. Cooper
We present a generalized Drude analysis of the in-plane optical conductivity $σ_{ab}$($T$,$ω$) in cuprates taking into account the effects of in-plane anisotropy. A simple ansatz for the scattering rate $Γ$($T$,$ω$), that includes anisotropy, a quadratic frequency dependence and saturation at the Mott-Ioffe-Regel limit, is able to reproduce recent normal sta
E. V. Charnaya, A. L. Pirozerski, Cheng Tien, M. K. Lee
The influence of the pore network geometry and interparticle long-distance electric coupling on the ferroelectric phase transition in small particles embedded into mesoporous matrices is considered. It was shown that the temperature of the ferroelectric phase transition in a system of electrically linked particles can be well different from that in isolated
Thomas Bickel
The translational motion of a solid sphere near a deformable fluid interface is studied in the low Reynolds number regime. In this problem, the fluid flow driven by the sphere is dynamically coupled the instantaneous conformation of the interface. Using a two-dimensional Fourier transform technique, we are able to account for the multiple backflows scattered
Low-Energy Electronic Structure of the High-Tc Cuprates La2-xSrxCuO4 Studied by Angle-resolved Photoemission Spectroscopy
cond-mat.str-elT. Yoshida, X. J. Zhou, D. H. Lu, Seiki Komiya
We have performed a systematic angle-resolved photoemission spectroscopy (ARPES) study of the high-Tc cuprates La2-xSrxCuO4, ranging from the underdoped insulator to the superconductor to the overdoped metal. We have revealed a systematic doping evolution of the band dispersions and (underlying) Fermi surfaces, pseudogap and quasi-particle features under the
Takahiro Harada, Shin-ichi Sasa
A novel equality relating the rate of energy dissipation to a degree of violation of the fluctuation-response relation (FRR) in nonequilibrium Langevin systems is described. The FRR is a relation between the correlation function of the fluctuations and the response function of macroscopic variables. Although it has been established that the FRR holds in equi
Carolina Brito, Matthieu Wyart
We study theoretically and numerically the microscopic cause of the mechanical stability of hard sphere glasses near their maximum packing. We show that, after coarse-graining over time, the hard sphere interaction can be described by an effective potential which is exactly logarithmic at the random close packing $ϕ_c$. This allows to define normal modes, an
An Min Wang
We investigate the exact solution of BCS pairing model using direct diagonalization of Fock space. By the data analysis and numerical calculation, we verify the symmetry between energy spectrum of Fock subspaces, obtain the common structure features of energy gaps and energy bands in Hamiltonian spectrum of reduced model, propose the formula to estimate the
F. Galliano
I summarize the results of two recent studies, based on ISO and Spitzer mid-IR spectra of galaxies and Galactic regions, aimed at understanding the origins of the variations of the aromatic features among and inside galaxies. I show that the ratios between the most intense bands (6.2, 7.7, 8.6 and 11.3 microns) are principally sensitive to the charge of the
Eric J. Hallman, Brian W. O'Shea, Michael L. Norman, Rick Wagner
We present preliminary results from simulated large sky coverage (~100 square degrees) Sunyaev-Zeldovich effect (SZE) cluster surveys using the cosmological adaptive mesh refinement N-body/hydro code Enzo. We have generated simulated light cones to match the resolution and sensitivity of current and future SZE instruments. These simulations are the most adva
Jack O. Burns, Eric J. Hallman, Brennan Gantner, Patrick M. Motl
Why do some clusters have cool cores while others do not? In this paper, cosmological simulations, including radiative cooling and heating, are used to examine the formation and evolution of cool core (CC) and non-cool core (NCC) clusters. Numerical CC clusters at z=0 accreted mass more slowly over time and grew enhanced cool cores via hierarchical mergers;
The Spitzer c2d survey of Large, Nearby, Interstellar Clouds. V. Chamaeleon II Observed with IRAC
astro-phAlicia Porras, Jes K. Jørgensen, Lori E. Allen, Neal J. Evans
We present IRAC (3.6, 4.5, 5.8, and 8.0 micron) observations of the Chamaeleon II molecular cloud. The observed area covers about 1 square degree defined by $A_V >2$. Analysis of the data in the 2005 c2d catalogs reveals a small number of sources (40) with properties similar to those of young stellaror substellar objects (YSOs). The surface density of these
The flux ratio of the [OIII] 5007,4959 lines in AGN: Comparison with theoretical calculations
astro-phM. S. Dimitrijevic, L. C. Popovic, J. Kovacevic, M. Dacic
By taking into account relativistic corrections to the magnetic dipole operator, the theoretical [OIII] 5006.843/4958.511 line intensity ratio of 2.98 is obtained. In order to check this new value using AGN spectra we present the measurements of the flux ratio of the [OIII] 4959,5007 emission lines for a sample of 62 AGN, obtained from the Sloan Digital Sky
Quasar X-ray jets: Gamma-ray diagnostics of the synchrotron and inverse Compton hypotheses, the case of 3C 273
astro-phMarkos Georganopoulos, Eric S. Perlman, Demosthenes Kazanas, Julie McEnery
The process responsible for the Chandra-detected X-ray emission from the large scale jets of powerful quasars is a matter of ongoing debate. The two main contenders are external Compton (EC) scattering off the cosmic microwave background (CMB) photons (EC/CMB) and synchrotron emission from a population of electrons separate from those producing the radio - I
The Luminosity Function and Star Formation Rate between Redshifts of 0.07 and 1.47 for Narrow-band Emitters in the Subaru Deep Field
astro-phChun Ly, Matt A. Malkan, Nobunari Kashikawa, Kazuhiro Shimasaku
Abridged: Subaru Deep Field line-emitting galaxies in four narrow-band filters at low and intermediate redshifts are presented. Broad-band colors, follow-up optical spectroscopy, and multiple NB filters are used to distinguish Ha, [O II], and [O III] emitters between redshifts of 0.07 and 1.47 to construct their luminosity functions (LFs). These LFs are deri
M. Capalbi, D. Malesani, M. Perri, P. Giommi
We present observations of the X-ray afterglow of GRB 050408, a gamma-ray burst discovered by HETE-II. Swift began observing the field 42 min after the burst, performing follow-up over a period of 38 d (thus spanning three decades in time).The X-ray light curve showed a steepening with time, similar to many other afterglows. However, the steepening was unusu
Adam G. Jensen, Brian L. Rachford, Theodore P. Snow
We report on the abundance of interstellar neutral nitrogen (NI) for 30 sightlines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope (HST). NI column densities are derived by measuring the equivalent widths of several ultraviolet absorption lines and subsequently fitting those to a curve of growth. We find a me
Benjamin J. Weiner, Casey Papovich, K. Bundy, C. J. Conselice
Strong nebular emission lines are a sensitive probe of star formation and extinction in galaxies, and the [O II] line detects star forming populations out to z>1. However, star formation rates from emission lines depend on calibration of extinction and the [O II]/H-alpha line ratio, and separating star formation from AGN emission. We use calibrated line lumi
Magnetorotational collapse of massive stellar cores to neutron stars: Simulations in full general relativity
astro-phMasaru Shibata, Yuk Tung Liu, Stuart L. Shapiro, Branson C. Stephens
We study magnetohydrodynamic (MHD) effects arising in the collapse of magnetized, rotating, massive stellar cores to proto-neutron stars (PNSs). We perform axisymmetric numerical simulations in full general relativity with a hybrid equation of state. The formation and early evolution of a PNS are followed with a grid of 2500 x 2500 zones, which provides bett
Michael L. Balogh, Dave Wilman, Robert D. E. Henderson, Richard G. Bower
We have obtained near-infrared imaging of 58 galaxy groups, in the redshift range 0.1<z<0.6, from the William Herschel Telescope and from the Spitzer IRAC data archive. The groups are selected from the CNOC2 redshift survey, with additional spectroscopy from the Baade telescope (Magellan). Our group samples are statistically complete to K(Vega}=17.7 (INGRID)
Nolan R. Walborn
The systematics of OB spectra are reviewed in the optical domain, dominated by photospheric lines, and in the far ultraviolet (both IUE and FUSE ranges), in which the stellar-wind profiles dominate. First, the two-dimensional (temperature, luminosity) trends in normal spectra are surveyed. Then, the normal reference frame having been established, various cat
Wilfried Buchmuller, Joerg Jaeckel
We revisit the conjecture of a generalized second law of thermodynamics which states that the combined entropy of matter and horizons must grow. In an expanding universe a generalized second law restricts the equation of state. In particular, it conflicts with long phases of a phantom, w<-1, equation of state.
Eric Emsellem
The link between nuclear activity and the host galaxy remains elusive. It seems now clear that the galactic environment is not the key, and that there is no significant apparent difference in terms of the presence of bars/spirals between active and non-active galaxies. Nuclear activity nevertheless requires a small central gas reservoir (10^4-10^7 Msun) whic
Francesca Matteucci
We review some of the models of chemical evolution of ellipticals and bulges of spirals. In particular, we focuse on the star formationn histories of ellipticals and their influence on chemical properties such as the [alpha/Fe] versus [Fe/H], galactic mass and visual magnitudes. By comparing models with observational properties, we can constrain the timescal
Antonio Pipino, Francesca Matteucci
Elliptical galaxies probably host the most metal rich stellar populations in the Universe. The processes leading to both the formation and the evolution of such stars are discussed by means of a new multi-zone photo-chemical evolution model, taking into account detailed nucleosynthetic yields, feedback from supernovae, Pop III stars and an initial infall epi
G. Congedo, F. De Paolis, P. Longo, A. A. Nucita
The diffraction effects on gravitational waves propagating through a stellar cluster are analyzed in the relevant approximation of Fresnel diffraction limit. We find that a gravitational wave scintillation effect - similar to the radio source scintillation effect - comes out naturally, implying that the gravitational wave intensity changes in a characteristi
I. Georgantopoulos, A. Georgakakis, A. Akylas
We present Chandra and Spitzer data of the 186, extragalactic, hard 2-10 keV X-ray selected sources, which lie in the central part of the Chandra Deep Field South (CDFS). For the vast majority of sources (99.5%) there is a spectroscopic or photometric redshift available. We classify 17 sources as X-ray obscured QSOs, according to strictly X-ray criteria, i.e
Thomas Preibisch, Hans Zinnecker
We discuss observational evidence for sequential and triggered star formation in OB associations. We first review the star formation process in the Scorpius-Centaurus OB association, the nearest OB association to the Sun, where several recent extensive studies have allowed us to reconstruct the star formation history in a rather detailed way. We then compare
M. Rengel, K. Hodapp, J. Eisloeffel
According to a triggered star formation scenario (e.g. Martin-Pintado & Cernicharo 1987) outflows powered by young stellar objects shape the molecular clouds, can dig cavities, and trigger new star formation. NGC 1333 is an active site of low- and intermediate star formation in Perseus and is a suggested site of self-regulated star formation Norman & Silk 19
Elizabeth J. Barton, Liese van Zee, Matthew A. Bershady
As the most extreme members of the rapidly evolving faint blue galaxy population at intermediate redshift, the compact narrow emission line galaxies (CNELGs) are intrinsically luminous (-22 < M_B < -18) with narrow emission linewidths (30 < σ< 125 km/s). Their nature is heavily debated: they may be low-mass starbursting galaxies that will fade to present-day
G. Kovacs, G. Kupi
Due to the importance of accurate Fourier parameters, we devise a method that is more appropriate for deriving these parameters on low-quality data than the traditional Fourier fitting. Based on the accurate light curves of 248 fundamental mode RR Lyrae stars, we test the power of a full-fetched implementation of the template method in the computation of the
C. Cameron, J. M. Matthews, J. F. Rowe, R. Kuschnig
We present 10.27$ \rm{hrs}$ of photometry of the roAp star HD 134214 obtained by the MOST satellite. The star is shown to be monoperiodic and oscillating at a frequency of 2948.97$ \pm 0.55 μ\rm{Hz}$. This is consistent with earlier ground based photometric campaigns (e.g. Kreidl et al. 1994). We do not detect any of the additional frequencies identified in
Hiroyuki Nakanishi, Nario Kuno, Yoshiaki Sofue, Naoko Sato
We found high molecular fractions ($f_{\rm mol}$; ratio of the molecular to total gas surface densities) in three of five Virgo spiral galaxies in spite of their low total gas column density, based on $^{12}$CO$(J=1-0)$ observations with the Nobeyama 45 m telescope equipped with a multi-beam receiver, BEARS. We interpret this as a result of environmental eff
Gary D. Schmidt, Paula Szkody, Arne Henden, Scott F. Anderson
Two new magnetic white dwarf accretion binaries with extremely low mass-transfer rates have been discovered in the course of the Sloan Digital Sky Survey. Measured magnetic fields are 42 MG and 57 MG, and one system orbits with a period of just 82 min. The new systems therefore significantly expand the range in properties exhibited by the small class. The me
Ramesh Narayan, Jonathan C. McKinney, Alison J. Farmer
We consider a self-similar force-free wind flowing out of an infinitely thin disk located in the equatorial plane. On the disk plane, we assume that the magnetic stream function $P$ scales as $P\propto R^ν$, where $R$ is the cylindrical radius. We also assume that the azimuthal velocity in the disk is constant: $v_ϕ= Mc$, where $M<1$ is a constant. For each
Noriyuki Matsunaga, the IRSF/SIRIUS team
We report a result of our near-infrared repeated observations of Mira variables in the globular clusters NGC 6388 and 6441. These two clusters are known as peculiar clusters with blue horizontal branch stars and RR Lyr variables which are unexpected for their relatively high metallicities. We derive their distance moduli by fitting the Mira variables in the
R. Cid Fernandes, N. V. Asari, L. Sodre, G. Stasinska
We explore the mass-assembly and chemical enrichment histories of star forming galaxies by applying a population synthesis method to a sample of 84828 galaxies from the Sloan Digital Sky Survey Data Release 5. Our method decomposes the entire observed spectrum in terms of a sum of simple stellar populations spanning a wide range of ages and metallicities, th
Ing-Guey Jiang, G. Laughlin, D. N. C. Lin
The observational properties of brown dwarfs pose challenges to the theory of star formation. Because their mass is much smaller than the typical Jeans mass of interstellar clouds, brown dwarfs are most likely formed through secondary fragmentation processes, rather than through the direct collapse of a molecular cloud core. In order to prevent substantial p
Sean M. Andrews, Jonathan P. Williams
We present a high spatial resolution submillimeter continuum survey of 24 circumstellar disks in the Tau-Aur and Oph-Sco star formation regions using the SMA. In the context of a simple model, we use broadband SEDs and submillimeter visibilities to derive constraints on some basic parameters that describe the structure of these disks. For the typical disk in
W. B. Hubbard, M. F. Hattori, A. Burrows, I. Hubeny
We present calculations for the evolution and surviving mass of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using a generalized scaled theory for mass loss, together with new surface-condition grids for hot EGPs and a consistent treatment of tidal truncation. Theoretical estimates for the rate of
Alessandro Nagar, Olindo Zanotti, Jose A. Font, Luciano Rezzolla
By combining the numerical solution of the nonlinear hydrodynamics equations with the solution of the linear inhomogeneous Zerilli-Moncrief and Regge-Wheeler equations we investigate the properties of the gravitational radiation emitted during the axisymmetric accretion of matter onto a Schwarzschild black hole. The matter models considered include quadrupol
Alexey Cheskidov, Susan Friedlander, Natasa Pavlović
Properties of an infinite system of nonlinearly coupled ordinary differential equations are discussed. This system models some properties present in the equations of motion for an inviscid fluid such as the skew symmetry and the 3-dimensional scaling of the quadratic nonlinearity. It is proved that the system with forcing has a unique equilibrium and that ev
John D Barrow, Andrew R Liddle, Cédric Pahud
The three-year observations from the Wilkinson Microwave Anisotropy Probe have been hailed as giving the first clear indication of a spectral index n_s<1. We point out that the data are equally well explained by retaining the assumption n_s=1 and allowing the tensor-to-scalar ratio r to be non-zero. The combination n_s=1 and r>0 is given (within the slow-rol
Consequences of dark matter-dark energy interaction on cosmological parameters derived from SNIa data
astro-phL. Amendola, G. C. Campos, R. Rosenfeld
Models where the dark matter component of the universe interacts with the dark energy field have been proposed as a solution to the cosmic coincidence problem, since in the attractor regime both dark energy and dark matter scale in the same way. In these models the mass of the cold dark matter particles is a function of the dark energy field responsible for
Pierluigi Monaco, Fabio Fontanot, Giuliano Taffoni
We present the MOdel for the Rise of GAlaxies aNd Active nuclei (MORGANA). Starting from the merger trees of dark matter halos and a model for the evolution of substructure within the halos, the complex physics of baryons is modeled with a set of state-of-the-art models that describe the mass, metal and energy flows between the various components and phases
Peter Eichelsbacher, Michael Stolz
In his seminal 1962 paper on the ``threefold way'', Freeman Dyson classified the spaces of matrices that support the random matrix ensembles deemed relevant from the point of view of classical quantum mechanics. Recently, Heinzner, Huckleberry and Zirnbauer have obtained a similar classification based on less restrictive assumptions, thus taking care
N. Rea, M. Kramer, L. Stella, P. Jonker
PSR B1931+24 is the first intermittent radio pulsar discovered to date, characterized by a 0.8 s pulsation which turns on and off quasi-periodically every ~35 days, with a duty cycle of ~10%. We present here X-ray and optical observations of PSR B1931+24 performed with the Chandra X-ray Observatory and Isaac Newton Telescope, respectively. Simultaneous monit
Rudolf Baier, Paul Romatschke
We study causal viscous hydrodynamics in the context of central relativistic heavy-ion collisions and provide details of a straightforward numerical algorithm to solve the hydrodynamic equations. It is shown that correlation functions of fluctuations provide stringent test cases for any such numerical algorithm. Passing these tests, we study the effects of v
D. M. Walsh
Standard methods in non-linear analysis are used to show that there exists a parabolic branching of solutions of the Lichnerowicz-York equation with an unscaled source. We also apply these methods to the extended conformal thin sandwich formulation and show that if the linearised system develops a kernel solution for sufficiently large initial data then we o
Rafael Diaz, Eddy Pariguan
We review the construction of a q-analogue of the Gaussian measure. We apply that construction to obtain a q-analogue of Feynman integrals and to compute explicitly an example of such integrals.
Magnetic vortices instead of stripes: another interpretation of magnetic neutron scattering in lanthanum cuprates
cond-mat.str-elBoris V. Fine
It is proposed, that a two-dimensional magnetic superstructure closely related to the one mentioned recently by Christensen et al. [cond-mat/0608204] constitutes a viable interpretation of the four-fold splitting of the magnetic (π, π) peak in lanthanum cuprates. (This splitting is usually interpreted as the evidence for stripes.) The superstructure in quest
Caroline Klivans, Victor Reiner
We study, in three parts, degree sequences of k-families (or k-uniform hypergraphs) and shifted k-families. The first part collects for the first time in one place, various implications such as: Threshold implies Uniquely Realizable implies Degree-Maximal implies Shifted, which are equivalent concepts for 2-families (=simple graphs), but strict implications
Squeezing the Local Oscillator Does Not Improve Signal-to-Noise Ratio in Heterodyne Laser Radar
quant-phMark A. Rubin, Sumanth Kaushik
The signal-to-noise ratio for heterodyne laser radar with a coherent target-return beam and a squeezed local-oscillator beam is lower than that obtained using a coherent local oscillator, regardless of the method employed to combine the beams at the detector.
A new approach to transport equations associated to a regular field: trace results and well-posedness
math.APLuisa Arlotti, Jacek Banasiak, Bertrand Lods
We generalize known results on transport equations associated to a Lipschitz field $\mathbf{F}$ on some subspace of $\mathbb{R}^N$ endowed with some general space measure $μ$. We provide a new definition of both the transport operator and the trace measures over the incoming and outgoing parts of $\partial Ω$ generalizing known results from the literature. W
Mehdi Lejmi
We show that the almost complex structure underlying a non-Kahler, nearly Kahler 6-manifold (in particular, the standard almost complex structure of S^6) cannot be compatible with any symplectic form, even locally.
Bas Janssens
In classical coding, a single quantum state is encoded into classical information. Decoding this classical information in order to regain the original quantum state is known to be impossible. However, one can attempt to construct a state which comes as close as possible. We give bounds on the smallest possible trace distance between the original and the deco
Origin of the Break and Mass-Dependence in the Wide-Binary Projected-Separation Distribution
astro-phAndrew Gould, Jason Eastman
The distribution of Galactic-disk wide binaries shows a clear break in slope at projected separations of about r_\perp ~ 2500 AU in two basically independent surveys by Chaname & Gould and Lepine & Bongiorno. The latter also showed that the frequency of wide-binary companions to G-star primaries declines monotonically as a function of companion mass. We show
Classical central extension for asymptotic symmetries at null infinity in three spacetime dimensions
gr-qcGlenn Barnich, Geoffrey Compere
The symmetry algebra of asymptotically flat spacetimes at null infinity in three dimensions is the semi-direct sum of the infinitesimal diffeomorphisms on the circle with an abelian ideal of supertranslations. The associated charge algebra is shown to admit a non trivial classical central extension of Virasoro type closely related to that of the anti-de Sitt
Relation Between Chiral Susceptibility and Solutions of Gap Equation in Nambu--Jona-Lasinio Model
hep-phYue Zhao, Lei Chang, Wei Yuan, Yu-xin Liu
We study the solutions of the gap equation, the thermodynamic potential and the chiral susceptibility in and beyond the chiral limit at finite chemical potential in the Nambu--Jona-Lasinio (NJL) model. We give an explicit relation between the chiral susceptibility and the thermodynamic potential in the NJL model. We find that the chiral susceptibility is a q
David Futer, François Guéritaud
This paper describes a way to subdivide a 3-manifold into angled blocks, namely polyhedral pieces that need not be simply connected. When the individual blocks carry dihedral angles that fit together in a consistent fashion, we prove that a manifold constructed from these blocks must be hyperbolic. The main application is a new proof of a classical, unpublis
Itai Benjamini, Alain-Sol Sznitman
We consider random walk on a discrete torus E of side-length N, in sufficiently high dimension d. We investigate the percolative properties of the vacant set corresponding to the collection of sites which have not been visited by the walk up to time uN^d. We show that when u is chosen small, as N tends to infinity, there is with overwhelming probability a un
Z. Nussinov, A. V. Balatsky, M. J. Graf, S. A. Trugman
A decrease in the rotational period observed in torsional oscillator measurements was recently taken as a possible indication of a supersolid state of helium. We reexamine this interpretation and note that the decrease in the rotation period is also consistent with a solidification of a small liquid-like component into a low-temperature glass. Such a solidif
S. Bernhart, T. P. Krichbaum, L. Fuhrmann, A. Kraus
For more than a decade from the late 1980s to the late 1990s, the intraday variable (IDV) quasar 0917+624 was known to be strongly variable with amplitude variations of 10-20% within 0.8 to 1.6 days. During that period it showed faster variability in the polarized flux and the polarization angle than in total intensity. However, since 2000 the IDV of this so
José M. M. Senovilla
Inspired by Raychaudhuri's work, and using the equation named after him as a basic ingredient, a new singularity theorem is proved. Open non-rotating everywhere expanding universes with non-vanishing spatial average of the matter variables are severely geodesically incomplete to the past. Another way of stating the result is that, under the same conditions,
Cristian S. Calude, Michael A. Stay
Since many real-world problems arising in the fields of compiler optimisation, automated software engineering, formal proof systems, and so forth are equivalent to the Halting Problem--the most notorious undecidable problem--there is a growing interest, not only academically, in understanding the problem better and in providing alternative solutions. Halting
Keisuke Izumi, Kazuya Koyama, Takahiro Tanaka
The braneworld model of Dvali-Gabadadze-Porrati realizes the self-accelerating universe. However, it is known that this cosmological solution contains a spin-2 ghost. We study the possibility of avoiding the appearance of the ghost by slightly modifying the model, introducing the second brane. First we consider a simple model without stabilization of the sep
M. Branchesi, I. M. Gioia, C. Fanti, R. Fanti
With the superb angular resolution of the Chandra Observatory, it is now possible to detect X-ray point sources, either embedded in galaxy clusters or along the cluster line of sight, which could not be resolved by previous instruments. This now allows studies of source counts in distant cluster fields. A sample of 18 distant (0.25 < z < 1.01) galaxy cluster
Benjamin I. Zwiebel
We present the perturbative Yangian symmetry at next-to-leading order in the su(2|1) sector of planar N=4 SYM. Just like the ordinary symmetry generators, the bi-local Yangian charges receive corrections acting on several neighboring sites. We confirm that the bi-local Yangian charges satisfy the necessary conditions: they transform in the adjoint of su(2|1)
Programmable unknown quantum-state discriminators with multiple copies of program and data: A Jordan basis approach
quant-phBing He, János A. Bergou
The discrimination of any pair of unknown quantum states is performed by devices processing three parts of inputs: copies of the pair of unknown states we want to discriminate are respectively stored in two program systems and copies of data, which is guaranteed to be one of the unknown states, in a third system. We study the efficiency of such programmable
Patrick Guidotti
A general class of singular abstract Cauchy problems is considered which naturally arises in applications to certain Free Boundary Problems. Existence of an associated evolution operator characterizing its solutions is established and is subsequently used to derive optimal regularity results. The latter are well known to be important basic tools needed to de
Chris Van Den Broeck, Anand S. Sengupta
We study parameter estimation with post-Newtonian (PN) gravitational waveforms for the quasi-circular, adiabatic inspiral of spinning binary compact objects. The performance of amplitude-corrected waveforms is compared with that of the more commonly used restricted waveforms, in Advanced LIGO and EGO. With restricted waveforms, the properties of the source c
Taparati Gangopadhyay, Manjari Bagchi, Mira Dey, Jishnu Dey
Parity doubling is observed in hadron states around 1.5 GeV - and the estimated energy density is found to be high. When a large excitation energy is available and the pions decouple from the quarks, the QCD interaction is still not perturbative. And signature of such a system can exist in the form of small ratio of the shear viscosity to entropy density. Th
Ioannis Bakas, Domenico Orlando, P. Marios Petropoulos
We study renormalization-group flows by deforming a class of conformal sigma-models. We consider overall scale factor perturbation of Einstein spaces as well as more general anisotropic deformations of three-spheres. At leading order in alpha, renormalization-group equations turn out to be Ricci flows. In the three-sphere background, the latter is the Halphe
Baojiu Li, K. C. Chan, M. -C. Chu
In this work we derive the covariant and gauge invariant perturbation equations in general theories of $f(R)$ gravity in the Palatini formalism to linear order and calculate the cosmic microwave background (CMB) and matter power spectra for an extensively discussed model, $f(R) = R + α(-R)^β$, which is a possible candidate for the late-time cosmic accelerati
The BES Collaboration, M. Ablikim
With a sample of 14 million psi(2S) events collected by the BESII detector at the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their branching ratios are determined to be (3.36+-0.09+-0.24)*10E-4, (3.39+-0.20+-0.32)*10E-4, (2.35+-0.36+-0.32)*10E-4, (3.03+-0.4
Filling-dependence of the zigzag Hubbard ladder for a quasi-one-dimensional superconductor Pr_2Ba_4Cu_7O_{15-delta}
cond-mat.str-elKouichi Okunishi
We investigate filling dependence of the zigzag Hubbard ladder, using density matrix renormalization group method. We illustrate the chemical-potential vs. electron-density and spin gap vs. electron density curves, which reflect characteristic properties of the electron state.On the basis of the obtained phase diagram, we discuss the connection to a novel qu
Taras Banakh, Wieslaw Kubis
We show that for every Dugundji compact $K$ of weight aleph one the Banach space $C(K)$ is 1-Plichko and the space $P(K)$ of probability measures on $K$ is Valdivia compact. Combining this result with the existence of a non-Valdivia compact group, we answer a question of Kalenda.
R. Peschanski, S. Sapeta
We derive the asymptotic traveling-wave solutions of the nonlinear 1-dimensional Balitsky-Kovchegov QCD equation for rapidity evolution in momentum-space, with 1-loop running coupling constant and equipped with the Balitsky-Kovchegov-Kuraev-Lipatov kernel at next-to-leading logarithmic accuracy, conveniently regularized by different resummation schemes. Trav
Daewoong Cheong
We verify in an elementary way a result of Peterson for the maximal orthogonal and Lagrangian Grassmannians, and then find Vafa-Intriligator type formulas which compute their 3-point, genus zero Gromov-Witten invariants. Finally we study total positivity of the related Peterson varieties and show that Rietsch's conjecture about the total positivity holds
F. Myhrer
The electromagnetic decay processes of excited hyperon states are a very sensitive probe of the structure of hyperons. We will argue that the recent measurements of electromagnetic decay rates indicate that the wave functions of the hyperon ground states should contain sizeable components of excited quark states (configuration mixing). Flavor-SU(3) is a brok
Arindam Mitra
It has been found that an algorithm can generate true random numbers on classical computer. The algorithm can be used to generate unbreakable message PIN (personal identification number) and password.
Séverine Fiedler-Le Touzé
The first part of Hilbert's sixteenth problem deals with the classification of the isotopy types realizable by real plane algebraic curves of given degree $m$. For $m \geq 8$, one restricts the study to the case of the $M$-curves. For $m=9$, the classification is still wide open. We say that an $M$-curve of degree 9 has a deep nest if it has a nest of de
P. Zhang, L. You
A magnetically trapped atom experiences an adiabatic geometric (Berry's) phase due to changing field direction. We investigate theoretically such an Aharonov-Bohm-like geometric phase for atoms adiabatically moving inside a storage ring as demonstrated in several recent experiments. Our result shows that this phase shift is easily observable in a closed
Orders and dimensions for sl(2) or sl(3) module categories and Boundary Conformal Field Theories on a torus
math-phRobert Coquereaux, Gil Schieber
After giving a short description, in terms of action of categories, of some of the structures associated with sl(2) and sl(3) boundary conformal field theories on a torus, we provide tables of dimensions describing the semisimple and co-semisimple blocks of the corresponding weak bialgebras (quantum groupoids), tables of quantum dimensions and orders, and ta
J. -P. Allouche, G. Skordev
We revisit the relation between the von Koch curve and the Thue-Morse sequence given in a recent paper of Ma and Goldener by relating their study to papers written by Coquet and Dekking at the beginning of the 80s. We also emphasize that more general links between fractal objects and automatic sequences can be found in the literature.