February 2006 arXiv papers — page 4
Showing 301–400 of 3,695 papers
K. Fujiwara
In this paper, congruences between holomorphic Hilbert modular forms are studied. We show the best possible level optimization result outside l for l > 2 by solving the remaining case of Mazur principle when the degree of the totally real field is even.
Hans Lindblad, Avy Soffer
We prove Asymptotic Completeness of one dimensional NLS with long range nonlinearities. We also prove existence and expansion of asymptotic solutions with large data at infinity.
Alina Marian, Dragos Oprea
We show that intersection numbers on the moduli space of stable bundles of coprime rank and degree over a smooth complex curve can be recovered as highest-degree asymptotics in formulas of Vafa-Intriligator type. In particular, we explicitly evaluate all intersection numbers appearing in the Verlinde formula. Our results are in agreement with previous comput
Eugenii Shustin, Emilia Fridman
Stability of linear systems with uncertain bounded time-varying delays is studied under assumption that the nominal delay values are not equal to zero. An input-output approach to stability of such systems is known to be based on the bound of the $L_2$-norm of a certain integral operator. There exists a bound on this operator in two cases: in the case where
Amir Dembo, Yuval Peres, Jay Rosen, Ofer Zeitouni
Let $\mathcal{T}_n(x)$ denote the time of first visit of a point $x$ on the lattice torus $\mathbb {Z}_n^2=\mathbb{Z}^2/n\mathbb{Z}^2$ by the simple random walk. The size of the set of $α$, $n$-late points $\mathcal{L}_n(α)=\{x\in \mathbb {Z}_n^2:\mathcal{T}_n(x)\geq α\frac{4}π(n\log n)^2\}$ is approximately $n^{2(1-α)}$, for $α\in (0,1)$ [$\mathcal{L}_n(α)$
P. Midodashvili
In the article we present explicit expressions for quantum fluctuations of spacetime in the case of $(4+n)$-dimensional spacetimes, and consider their holographic properties and some implications for clocks, black holes and computation. We also consider quantum fluctuations and their holographic properties in ADD model and estimate the typical size and mass
Igor Salom
The duality symmetry of free electromagnetic field is analyzed within an algebraic approach. To this end, the conformal $c(1,3)$ algebra generators are expressed as operators quadratic in some abstract operators $κ^α$ and $π_β$ which satisfy Heisenberg algebra relations. It is then shown that the duality generator can also be expressed in this manner. Standa
L. E. Ibanez
I propose that the primordial baryon asymmetry of the universe was induced by the presence of a non-vanishing antisymmetric field background H_ijk across the three space dimensions. This background creates a dilute (B-L)-number density in the universe cancelling the contribution from baryons and leptons. This situation naturally appears if the U(1)_{B-L} sym
César Gómez, Sergio Montañez, Pedro Resco
The target space of minimal $(2,2m-1)$ strings is embedded into the phase space of an integrable mechanical model. Quantum effects on the target space correspond to quantum corrections on the mechanical model. In particular double scaling is equivalent to standard uniform approximation at the classical turning points ot the mechanical model. After adding ZZ
Liu Yu-Fen
It is proved that there exist a vector representation of Dirac's spinor field and in one sense it is equivalent to biquaternion (i.e. complexified quaternion) representation. This can be considered as a generalization of Cartan's idea of triality to Dirac's spinors. In the vector representation the first order Dirac Lagrangian is dual equivalent
Generic approach to dimensional reduction and selection principle for low-energy limit of M theory
hep-thKonstantin G. Zloshchastiev
We propose the approach to deriving lower-dimensional limit of modern high-energy theory which does not make explicit use of the Kaluza-Klein scheme and predefined compactification manifolds. The approach is based on the selection principle in which a crucial role is played by p-brane solutions and their preservation, in a certain sense, under dimensional re
Rebecca J. Erwin, Jennifer Kile, Michael J. Ramsey-Musolf, Peng Wang
We use the scale of neutrino mass to derive model-independent naturalness constraints on possible contributions to muon decay Michel parameters from new physics above the electroweak symmetry-breaking scale. Focusing on Dirac neutrinos, we obtain a complete basis of effective dimension four and dimension six operators that are invariant under the gauge symme
X. Jiang, G. A. Navarro, R. Sassot
We investigate the potential impact of forthcoming Jefferson Lab semi-inclusive polarized deep inelastic scattering proton measurements in the determination of the sea quark polarization in the nucleon by means of a next to leading order global QCD analysis. Specifically, we estimate the resulting improvement in the constraints on polarized parton densities
Juerg Gasser, Mikhail A. Ivanov, Mikko E. Sainio
We complete the recalculation of the available two-loop expressions for the reaction γγ->ππin the framework of chiral perturbation theory. Here, we present the results for charged pions. The cross section and the values of the dipole polarizabilities agree very well with the earlier calculation, provided the same set of low-energy constants (LECs) is used. W
Shao-Hsuan Chiu, T. K. Kuo
We investigate the feasibility of probing the neutrino mass hierarchy and the mixing angle $ϕ_{13}$ with the neutrino burst from a future supernova. An inverse power-law density $ρ\sim r^{n} $ with varying $n$ is adopted in the analysis as the density profile of a typical core-collapse supernova. The survival probabilities of $ν_{e}$ and $\barν_{e}$ are show
P. H. Damgaard, U. M. Heller, K. Splittorff, B. Svetitsky
We calculate the response of the microscopic Dirac spectrum to an imaginary isospin chemical potential for QCD with two dynamical flavors in the chiral limit. This extends our previous calculation from the quenched to the unquenched theory. The resulting spectral correlation function in the $ε$-regime provides here, too, a new and efficient way to measure $F
John R. Klauder, J. Scott Little
Motivated by a recent paper of Louko and Molgado, we consider a simple system with a single classical constraint R(q)=0. If q_l denotes a generic solution to R(q)=0, our examples include cases where R'(q_l)\ne 0 (regular constraint) and R'(q_l)=0 (irregular constraint) of varying order as well as the case where R(q)=0 for an interval, such as a \leq
Particles Under Extreme Conditions: Part I Quantum Modified Null Trajectories in Schwarzschild Spacetime. Part II Superfluid Behaviour of the 2+1d NJL Model at High Density
gr-qcAvtar Singh Sehra
In part I we study quantum modified photon trajectories in a Schwarzschild blackhole spacetime. The photon vacuum polarization effect in curved spacetime leads to birefringence, i.e. the photon velocity becomes c+/-dc depending on its polarization. This velocity shift then results in modified photon trajectories. In this work we give an introduction to this
Subenoy Chakraborty, Asit Banerjee, Ujjal Debnath
A dynamical symmetry for spherical collapse has been studied using a linear transformation of the initial data set (mass and kinetic energy function) and the area radius. With proper choice of the initial area radius, the evolution as well as the physical parameters namely energy density and shear remain invariant both initially and at any time instant. Fina
H. Dehnen, V. D. Ivashchuk, S. A. Kononogov, V. N. Melnikov
Expressions for G-dot are considered in a multidimensional model with an Einstein internal space and a multicomponent perfect fluid. In the case of two non-zero curvatures without matter, a mechanism for prediction of small G-dot is suggested. The result is compared with exact (1+3+6)-dimensional solutions. A two-component example with two matter sources (du
Abhilash Ponnath
This paper reviews various engineering hurdles facing the field of quantum computing. Specifically, problems related to decoherence, state preparation, error correction, and implementability of gates are considered.
François Denis, Yann Esposito
The goal of the present paper is to provide a systematic and comprehensive study of rational stochastic languages over a semiring K \in {Q, Q +, R, R+}. A rational stochastic language is a probability distribution over a free monoid Σ^* which is rational over K, that is which can be generated by a multiplicity automata with parameters in K. We study the rela
Inconsistent parameter estimation in Markov random fields: Benefits in the computation-limited setting
cs.LGMartin J. Wainwright
Consider the problem of joint parameter estimation and prediction in a Markov random field: i.e., the model parameters are estimated on the basis of an initial set of data, and then the fitted model is used to perform prediction (e.g., smoothing, denoising, interpolation) on a new noisy observation. Working under the restriction of limited computation, we an
Impurities, Quantum Interference and Quantum Phase Transitions in s-wave superconductors
cond-mat.supr-conDirk K. Morr, Jaesung Yoon
We study the effects of quantum interference in impurity structures consisting of two or three magnetic impurities that are located on the surface of an s-wave superconductor. By using a self-consistent Bogoliubov-de Gennes formalism, we show that quantum interference leads to characteristic signatures not only in the local density of states (LDOS), but also
B. Schmittmann, Gunnar Pruessner, H. K. Janssen
Using renormalized field theory, we examine the dynamics of a growing surface, driven by an obliquely incident particle beam. Its projection on the reference (substrate) plane selects a ``parallel'' direction, so that the evolution equation for the surface height becomes anisotropic. The phase diagram of the model is controlled by the properties of a
Free energy landscapes, dynamics and the edge of chaos in mean-field models of spin glasses
cond-mat.dis-nnT. Aspelmeier, R. A. Blythe, A. J. Bray, M. A. Moore
Metastable states in Ising spin-glass models are studied by finding iterative solutions of mean-field equations for the local magnetizations. Two different equations are studied: the TAP equations which are exact for the SK model, and the simpler `naive-mean-field' (NMF) equations. The free-energy landscapes that emerge are very different. For the TAP eq
P. Verrocchio
The vibrational spectra of glass formers follow different laws with respect to crystals. A rationale for their anomalous behaviour is provided by the euclidean random matrix theory. Experiments on glass formers at different densities might be a suitable route to test the prediction of the theory.
Allan D. Boardman, Yuriy G. Rapoport, V. V. Grimalsky, B. A. Ivanov
It is shown that stationary vortex structures can be excited in a ferrite film. This is the first proposal for creating vortex structures in the important cm and mm wavelength ranges. It is shown that both linear and nonlinear structures can be excited using a three-beam interaction created with circular antennae. These give rise to a special phase distribut
F. Simon, H. Kuzmany, J. Bernardi, F. Hauke
Filling of single-wall carbon nanotubes with C59N azafullerene derivatives is reported from toluene solvent at ambient temperature. The filling is characterized by high resolution transmission electron microscopy and Raman spectroscopy. The filling efficiency is the same as for C60 fullerenes and the tube-azafullerene interaction is similar to the tube-C60 i
Eytan Grosfeld, Steven H. Simon, Ady Stern
We propose an experiment to probe the unconventional quantum statistics of quasi-particles in fractional quantum Hall states by measurement of current noise. The geometry we consider is that of a Hall bar where two quantum point contacts introduce two interfering amplitudes for back-scattering. Thermal fluctuations of the number of quasi-particles enclosed b
Thermal and mechanical equilibrium among weakly interacting systems in generalized thermostatistics framework
cond-mat.stat-mechA. M. Scarfone
We consider two statistically independent systems described by the same entropy belonging to the two-parameter family of Sharma-Mittal. Assuming a weak interaction among the systems, allowing in this way an exchange of heat and work, we analyze, both in the entropy representation and in the energy representation, the evolution toward the equilibrium. The the
Relation between the thermodynamic Casimir effect in Bose-gas slabs and critical Casimir forces
cond-mat.stat-mechA. Gambassi, S. Dietrich
In a recent letter, Martin and Zagrebnov [Europhys. Lett., 73 (2006) 1] discussed the thermodynamic Casimir effect for the ideal Bose gas confined in a thin film. We point out that their findings can be expressed in terms of previous general results for the Casimir effect induced by confined critical fluctuations. This highlights the links between the Casimi
Influence of water intercalation on the electronic structure of the hydrated Na0.3CoO2.yH2O using a local spin density approximation
cond-mat.supr-conR. J. Xiao, H. X. Yang, J. Q. Li
The electronic band structures of the parent compound Na0.3CoO2 and the hydrated superconductor Na0.3CoO2.1.3H2O were evaluated using the local spin density approximation (LSDA). Systematic analysis on the bands near the Fermi surface (FS) revealed that the hydration-induced modifications appear, notably in the valence charge density and the orbital hybridiz
Pierre Lugan Davide Sarchi Vincenzo Savona
We consider the system of a quantum well embedded in a planar semiconductor microcavity with a shallow circular mesa patterned on top of the cavity spacer. For this system we develop the linear coupling theory of polaritons. We then compute polariton eigenstates and the corresponding optical spectrum. The theory predicts the existence of laterally confined p
Relating supercooling and glass-like arrest of kinetics for phase separated systems: studies on doped CeFe$_2$ and (La,Pr,Ca)MnO$_3$
cond-mat.str-elKranti Kumar, A. K. Pramanik, A. Banerjee, P. Chaddah
Coexisting ferromagnetic and antiferromagnetic phases over a range of temperature as well as magnetic field have been reported in many materials of current interest, showing disorder-broadened 1st order transitions. Anomalous history effects observed in magnetization and resistivity are being explained invoking the concepts of kinetic arrest akin to glass tr
Ayumu Sugita
We propose a new approach to justify the use of the microcanonical ensemble for isolated macroscopic quantum systems. Since there are huge number of independent observables in a macroscopic system, we cannot see all of them. Actually what we observe can be written in a rather simple combination of local observables. Considering this limitation, we show that
Molecular Transport Junctions: Propensity Rules for Inelastic Electron Tunneling Spectra
cond-mat.mtrl-sciAlessandro Troisi, Mark A. Ratner
We develop a series of propensity rules for interpreting Inelastic Electron Tunneling (IET) spectra of single-molecule transport junctions. IETS has no selection rules, such as those seen in optical, infrared and Raman spectra, because IETS features arise not from the field-dipole interaction characterizing these other spectroscopies, but from vibronic modif
Keiji Saito
The characteristics of heat flow in a coupled magnetic system are studied. The coupled system is composed of a gapped chain and a gapless chain. The system size is assumed to be quite small so that the mean free path is comparable to it. When the parameter set of the temperatures of reservoirs is exchanged, the characteristics of heat flow are studied with t
The carrier ''antibinding'' in quantum dots: a charge separation effect
cond-mat.mes-hallMonique Combescot, Marc-André Dupertuis
We show that the carrier ''antibinding'' observed recently in semiconductor quantum dots, i.e., the fact that the ground state energy of two electron-hole pairs goes above twice the ground-state energy of one pair, can entirely be assigned to a charge separation effect, whatever its origin. In the absence of external electric field, this char
Origin of the large thermoelectric power in oxygen-variable RBaCo_{2}O_{5+x} (R=Gd, Nd)
cond-mat.str-elA. A. Taskin, A. N. Lavrov, Yoichi Ando
Thermoelectric properties of GdBaCo_{2}O_{5+x} and NdBaCo_{2}O_{5+x} single crystals have been studied upon continuous doping of CoO_2 planes with either electrons or holes. The thermoelectric response and the resistivity behavior reveal a hopping character of the transport in both compounds, providing the basis for understanding the recently found remarkabl
D. A. W. Hutchinson, P. B. Blakie
We briefly review the theory of Bose-Einstein condensation in the two-dimensional trapped Bose gas and, in particular the relationship to the theory of the homogeneous two-dimensional gas and the Berezinskii-Kosterlitz-Thouless phase. We obtain a phase diagram for the trapped two-dimensional gas, finding a critical temperature above which the free energy of
Wang-Kong Tse, S. Das Sarma
Intrinsic and extrinsic spin Hall effects are considered together on an equal theoretical footing for the Rashba spin-orbit coupling in two-dimensional (2D) electron and hole systems, using the diagrammatic method for calculating the spin Hall conductivity. Our analytic theory for the 2D holes shows the expected lowest-order additive result for the spin Hall
Chunhua Li, Sen Zhou, Ziqiang Wang
We study inhomogeneous states in the t-J model using an unrestricted Gutzwiller approximation. We find that $pa\times pa$ checkerboard order, where $p$ is a doping dependent number, emerges from Fermi surface instabilities of both the staggered flux phase and the Fermi liquid state with realistic band parameters. In both cases, the checkerboard order develop
Congjun Wu, B. Andrei Bernevig, Shou-Cheng Zhang
The edge states of the recently proposed quantum spin Hall systems constitute a new symmetry class of one-dimensional liquids dubbed the ``helical liquid'', where the spin orientation is determined by the direction of electron motion. We prove a no-go theorem which states that a helical liquid with an odd number of components cannot be constructed in
Junren Shi, Ping Zhang, Di Xiao, Qian Niu
The conventional definition of spin current is incomplete and unphysical in describing spin transport in systems with spin-orbit coupling. A proper and measurable spin current is established in this study, which fits well into the standard framework of near-equilibrium transport theory and has the desirable property to vanish in insulators with localized orb
Spectrum of Cosmic Microwave Fluctuations and the Formation of Galaxies in a Modified Gravity Theory
astro-phJ. W. Moffat
A modified gravity (MOG) possesses a light, neutral vector particle called a ``phion'' associated with a vector field $ϕ^μ$, which forms a cold fluid of Bose-Einstein condensates before recombination with zero pressure and zero shear viscosity. The energy density associated with this Bose-Einstein condensate fluid dominates the energy density before
Stellar abundances and molecular hydrogen in high-redshift galaxies -the far-ultraviolet view
astro-phWilliam C. Keel
FUSE spectra of star-forming regions in nearby galaxies are compared to composite spectra of Lyman-break galaxies (LBGs), binned by strength of Lyman alpha emission and by mid-UV luminosity. Several far-UV spectral features, including lines dominated by stellar wind and by photospheric components, are very sensitive to stellar abundances. Their measurement i
Can the unresolved X-ray background be explained by emission from the optically-detected faint galaxies of the GOODS project?
astro-phM. A. Worsley, A. C. Fabian, F. E. Bauer, D. M. Alexander
The emission from individual X-ray sources in the Chandra Deep Fields and XMM-Newton Lockman Hole shows that almost half of the hard X-ray background above 6 keV is unresolved and implies the existence of a missing population of heavily obscured active galactic nuclei (AGN). We have stacked the 0.5-8 keV X-ray emission from optical sources in the Great Obser
Eric Feigelson, Leisa Townsley, Manuel Gudel, Keivan Stassun
Although the environments of star and planet formation are thermodynamically cold, substantial X-ray emission from 10-100 MK plasmas is present. In low mass pre-main sequence stars, X-rays are produced by violent magnetic reconnection flares. In high mass O stars, they are produced by wind shocks on both stellar and parsec scales. The recent Chandra Orion Ul
C. J. Grillmair, R. Johnson
We report on the detection in Sloan Digital Sky Survey data of a 45 degree tidal stream of stars, extending from Bootes to Ursa Major, which we associate with the halo globular cluster NGC 5466. Using an optimal contrast, matched filter technique, we find a long, almost linear stellar stream with an average width of 1.4 degrees. The stream is an order of mag
Jean P. Brodie, Jay Strader
Globular cluster (GC) systems have now been studied in galaxies ranging from dwarfs to giants and spanning the full Hubble sequence of morphological types. Imaging and spectroscopy with the Hubble Space Telescope and large ground-based telescopes have together established that most galaxies have bimodal color distributions that reflect two subpopulations of
Leo Blitz, Yasuo Fukui, Akiko Kawamura, Adam Leroy
We present the first comparative study of extragalactic GMCs using complete data sets for entire galaxies and a uniform set of reduction and analysis techniques. We present results based on CO observations for the LMC, SMC, M33, M31, IC10 and the nucleus of M64, and make comparisons with archival Milky Way observations. Our sample includes large spirals and
Torgny Karlsson
The apparent absence of stars in the Milky Way halo with -5 ~< [Fe/H] ~< -4 suggests that the gas out of which the halo stars were born experienced a period of low or delayed star formation after the local universe was lit up by the first, metal-free generation of stars (Pop III). Negative feedback owed to the Pop III stars could initially have prevented the
Star Formation and Extinction in Redshift z~2 Galaxies: Inferences from Spitzer MIPS Observations
astro-phNaveen A. Reddy, Charles C. Steidel, Dario Fadda, Lin Yan
Using very deep Spitzer/MIPS 24 micron observations, we present an analysis of the bolometric luminosities (L[bol]) and UV extinction properties of more than 200 spectroscopically identified, optically selected (UGR) z~2 galaxies in the GOODS-N field. The large spectroscopic sample is supplemented with near-IR selected (BzK/DRG) galaxies and submm sources at
Jesper Sommer-Larsen
Based on 19 high-resolution N-body/gas-dynamical galaxy formation simulations in the LCDM cosmology it is shown, that for a galaxy like the Milky Way, in addition to the baryonic mass of the galaxy itself, about 70% extra baryonic mass should reside around the galaxy (inside of the virial radius), chiefly in the form of hot gas. Averaging over the entire fie
Extrasolar planets and brown dwarfs around A-F type stars. IV. A candidate brown dwarf around the A9V pulsating star HD180777
astro-phF. Galland, A. M. Lagrange, S. Udry, J. L. Beuzit
We present here the detection of a brown dwarf orbiting the A9V star HD180777. The radial velocity measurements, obtained with the ELODIE echelle spectrograph at the Haute-Provence Observatory, show a main variation with a period of 28.4 days. Assuming a primary mass of 1.7 Mo, the best Keplerian fit to the data leads to a minimum mass of 25 MJup for the com
Ruth Lazkoz, Genly León
In this paper we investigate the evolution of a class of cosmologies fuelled by quintom dark energy and dark matter. Quintom dark energy is a hybrid of quintessence and phantom which involves the participation of two reals scalar fields playing the roles of those two types of dark energy. In that framework we examine from a dynamical systems perspective the
Robert Williams, Elena Mason
High resolution spectra of novae after outburst reveal distinctive characteristics in the line profiles and intensities. The higher Balmer lines are often broader than the lower members of the series, and the relative profiles and intensities of the [O I] λ\lambda6300, 6364 doublet differ from normal values. We suggest these features may be caused by the Qua
Claudio Macculi, Mario Zannoni, Oscar Antonio Peverini, Ettore Carretti
The instrumental polarization induced by a flat isotropic dielectric slab in microwave frequencies is faced. We find that, in spite of its isotropic nature, such a dielectric can produce spurious polarization either by transmitting incoming anisotropic diffuse radiation or emitting when it is thermally inhomogeneous. We present evaluations of instrumental po
The scaling relation of early-type galaxies in clusters. II: Spectroscopic data for galaxies in eight nearby clusters
astro-phD. Bettoni, M. Moles, P. Kjaergaard, G. Fasano
AIMS: We present in this work low and intermediate resolution spectroscopic data collected for 152 early type galaxies in 8 nearby clusters with z $\leq$ 0.10. METHODS: We use low resolution data to produce the redshift and the K-correction for every individual galaxy, as well as to give their overall spectral energy distribution, and some spectral indicator
Cecilia Ceccarelli, Carsten Dominik
It has been suggested that the dark halos of galaxies are constituted by cloudlets of cold (< 10 K) H_2 and dense (> 10^7$ cm^{-3}) molecular gas. Such gas is extremely difficult to detect, because the classical tracers of molecular gas, CO and/or dust grains, have very low abundances and their emission is exceedingly weak. For this reason, the cloudlet hypo
P. Tzanavaris, I. Georgantopoulos, A. Georgakakis
We cross-correlated the Chandra XASSIST and XMM-Newton Serendipitous Source Catalogues with the 2 degree Field Galaxy Redshift Survey (2dfGRS) database. Our aim was to identify the most X-ray luminous (L_X > 10^42 erg s^-1) examples of galaxies in the local Universe whose X-ray emission is dominated by stellar processes rather than AGN activity ('normal&
M. P. Leubner
Pronounced core-halo patterns of dark matter and gas density profiles, observed in relaxed galaxies and clusters, were hitherto fitted by empirical power-laws. On the other hand, similar features are well known from astrophysical plasma environments, subject to long-range interactions, modeled in the context of nonextensive entropy generalization. We link no
Luigina Feretti, Doris M. Neumann
Using XMM Newton data, we investigate the nature of the X-ray emission in the radio relic 1253+275 in the Coma cluster. We determine the conditions of the cluster gas to check current models of relic formation, and we set constraints on the intracluster magnetic field. Both imaging and spectral analysis are performed, and the X-ray emission is compared with
J. de Plaa, N. Werner, A. M. Bykov, J. S. Kaastra
Using a new long X-ray observation of the cluster of galaxies Sersic 159-03 with XMM-Newton, we derive radial temperature and abundance profiles using single- and multi-temperature models. The fits to the EPIC and RGS spectra prefer multi-temperature models especially in the core. The radial profiles of oxygen and iron measured with EPIC/RGS and the line pro
Astrocladistics: a phylogenetic analysis of galaxy evolution I. Character evolutions and galaxy histories
astro-phDidier Fraix-Burnet, Philippe Choler, Emmanuel J. P. Douzery, Anne Verhamme
This series of papers is intended to present astrocladistics in some detail and evaluate this methodology in reconstructing phylogenies of galaxies. Being based on the evolution of all the characters describing galaxies, it is an objective way of understanding galaxy diversity through evolutionary relationships. In this first paper, we present the basic step
Astrocladistics: a phylogenetic analysis of galaxy evolution II. Formation and diversification of galaxies
astro-phDidier Fraix-Burnet, Emmanuel J. P. Douzery, Philippe Choler, Anne Verhamme
This series of papers is intended to evaluate astrocladistics in reconstructing phylogenies of galaxies. The objective of this second paper is to formalize the concept of galaxy formation and to identify the processes of diversification. We show that galaxy diversity can be expected to organize itself in a hierarchy. In order to better understand the role of
A. Karastergiou, R. Neri, M. A. Gurwell
We outline here a simple yet efficient method for finding optimized configurations of the elements of radio-astronomical interferometers with fixed pad locations. The method can be successfully applied, as we demonstrate, to define new configurations when changes to the array take place. This may include the addition of new pads or new antennas, or the loss
The buildup of stellar mass and the 3.6 micron luminosity function in clusters from z=1.25 to z=0.2
astro-phS. Andreon
We have measured the 3.6 micron luminosity evolution of about 1000 galaxies in 32 clusters at 0.2<z<1.25, without any a priori assumption about luminosity evolution, i.e. in a logically rigorous way. We find that the luminosity of our galaxies evolves as an old and passively evolving population formed at high redshift without any need for additional redshift
Yookyung Noh, Jounghun Lee
We analyze the Tully catalog of nearby galaxies to investigate the local pancaking effect on the orientation of disk galaxies. We first select only those edge-on disk galaxies in the catalog whose axis-ratios are less than 0.1 to measure their spin axes unambiguously. A local pancake at the location of each selected galaxy is found as a plane encompassing th
Jin Ozaki, Toshikazu Shigeyama
We propose a method to identify the companion stars of type Ia supernovae (SNe Ia) in young supernova remnants (SNRs) by recognizing distinct features of absorption lines due to Fe I appearing in the spectrum. If a sufficient amount of Fe I remains in the ejecta, Fe I atoms moving toward us absorb photons by transitions from the ground state to imprint broad
Cepheid Distances to SNe Ia Host Galaxies based on a Revised Photometric Zero-Point of the HST-WFPC2 and New P-L Relations and Metallicity Corrections
astro-phA. Saha, F. Thim, G. A. Tammann, B. Reindl
With this paper we continue the preparation for a forthcoming summary report of our experiment with the Hubble Space Telescope (HST) to determine the Hubble constant using type Ia supernovae as standard candles. Two problems are addressed. (1) We examine the need for, and determine the value of, the corrections to the apparent magnitudes of our program Cephe
A. Bouchard, C. Carignan, L. Staveley-Smith
Parkes neutral hydrogen 21 cm line (HI) observations of the surroundings of 9 early-type Local Group dwarfs are presented. We detected numerous HI clouds in the general direction of those dwarfs and these clouds are often offset from the optical center of the galaxies. Although all the observed dwarfs, except Antlia, occupy phase-space regions where the High
M. Ruzzi, M. A. Marchiolli, E. C. Silva, D. Galetti
An approach featuring $s$-parametrized quasiprobability distribution functions is developed for situations where a circular topology is observed. For such an approach, a suitable set of angle-angular momentum coherent states must be constructed in appropriate fashion.
Boris Noyvert
Parafermionic conformal field theories are considered on a purely algebraic basis. The generalized Jacobi type identity is presented. Systems of free fermions coupled to each other by nontrivial parafermionic type relations are studied in detail. A new parafermionic conformal algebra is introduced, it describes the sl(2|1)/u(1)^2 coset system.
k-core (bootstrap) percolation on complex networks: Critical phenomena and nonlocal effects
cond-mat.stat-mechA. V. Goltsev, S. N. Dorogovtsev, J. F. F. Mendes
We develop the theory of the k-core (bootstrap) percolation on uncorrelated random networks with arbitrary degree distributions. We show that the k-core percolation is an unusual, hybrid phase transition with a jump emergence of the k-core as at a first order phase transition but also with a critical singularity as at a continuous transition. We describe the
Dmitry B. Rokhlin
Given a set-valued stochastic process $(V_t)_{t=0}^T$, we say that the martingale selection problem is solvable if there exists an adapted sequence of selectors $ξ_t\in V_t$, admitting an equivalent martingale measure. The aim of this note is to underline the connection between this problem and the problems of asset pricing in general discrete-time market mo
Richard L. Hall, Wolfgang Lucha
We analyze a system of self-gravitating identical bosons by means of a semirelativistic Hamiltonian comprising the relativistic kinetic energies of the involved particles and added (instantaneous) Newtonian gravitational pair potentials. With the help of an improved lower bound to the bottom of the spectrum of this Hamiltonian, we are able to enlarge the kno
Saul Jacka, Abdelkarem Berkaoui
We consider trading in a financial market with proportional transaction costs. In the frictionless case, claims are maximal if and only if they are priced by a consistent price process--the equivalent of an equivalent martingale measure. This result fails in the presence of transaction costs. A properly maximal claim is one which does have this property. We
Controlled Lagrangians and Potential Shaping for Stabilization of Discrete Mechanical Systems
math.OCAnthony M. Bloch, Melvin Leok, Jerrold E. Marsden, Dmitry V. Zenkov
The method of controlled Lagrangians for discrete mechanical systems is extended to include potential shaping in order to achieve complete state-space asymptotic stabilization. New terms in the controlled shape equation that are necessary for matching in the discrete context are introduced. The theory is illustrated with the problem of stabilization of the c
Energy distribution in the dyadosphere of a Reissner-Nordstrom black hole in Moller's prescription
gr-qcElias C. Vagenas
The energy and momentum distributions in the dyadosphere of a Reissner-Nordstrom black hole are evaluated. The Moller's energy-momentum complex is employed for this computation. The spacetime under study is modified due to the effects of vacuum fluctuations in the dyadosphere. Therefore, the corrected Reissner-Nordstrom black hole metric takes into accou
N. Wiese, T. Dimopoulos, M. Rührig, J. Wecker
The temperature dependence of saturation and spin-flop fields for artificial ferrimagnets (AFi) based on antiparallel coupled CoFeB/Ru/CoFeB trilayers has been investigated in a temperature range between 80K and 600K. The results presented in this paper are relevant for magnetic devices using this system, e.g. magnetic-random access memory based on spin-flop
Taeyoung Lee, Amit K. Sanyal, Melvin Leok, N. Harris McClamroch
A deterministic attitude estimation problem for a rigid body in an attitude dependent potential field with bounded measurement errors is studied. An attitude estimation scheme that does not use generalized coordinate representations of the attitude is presented here. Assuming that the initial attitude, angular velocity and measurement noise lie within given
Taeyoung Lee, N. Harris McClamroch, Melvin Leok
Optimal control problems are formulated and efficient computational procedures are proposed for combined orbital and rotational maneuvers of a rigid body in three dimensions. The rigid body is assumed to act under the influence of forces and moments that arise from a potential and from control forces and moments. The key features of this paper are its use of
E. B. Aleksandrov, V. S. Zapasskii
A critical review of experimental studies of the so-called 'slow light' arising due to anomalously high steepness of the refractive index dispersion under conditions of electromagnetically induced transparency or coherent population oscillations is presented. It is shown that a considerable amount of experimental evidence for observation of the '
Izumi Hachisu, Mariko Kato
RS Ophiuchi is one of the well-observed recurrent novae and also a candidate progenitor of Type Ia supernovae. Its sixth recorded outburst was discovered on 12 February 2006. Detection of a supersoft X-ray phase will provide a firm confirmation of hydrogen shell-burning on the white dwarf and its turn-on/turn-off dates strongly constrain a mass range of the
The process $\epem\to J/ ψX(3940)$ at $\sqrt s = 10.6$ GeV in the framework of light cone formalism
hep-phV. V. Braguta, A. K. Likhoded, A. V. Luchinsky
This paper is devoted to the study of the process $\epem\to J/ψX(3940)$ in the framework of light cone formalism. In our calculation two hypotheses about the structure of X(3940) meson are considered: X(3940) is $3^1$S$_0$ state and X(3940) is one of $2^3$P states. The former hypothesis leads to a good agreements with the cross section measured at the experi
S Satheesh, E Sandhya
The structure of stationary first order max-autoregressive schemes with max-semi-stable marginals is studied. A connection between semi-selfsimilar extremal processes and this max-autoregressive scheme is discussed resulting in their characterizations. Corresponding cases of max-stable and selfsimilar extremal processes are also discussed.
Andreas Karch, Emanuel Katz, Dam T. Son, Mikhail A. Stephanov
In a theory with linear confinement, such as QCD, the masses squared m^2 of mesons with high spin S or high radial excitation number n are expected, from semiclassical arguments, to grow linearly with S and n. We show that this behavior can be reproduced within a putative 5-dimensional theory holographically dual to QCD (AdS/QCD). With the assumption that su
Scott Taylor
A Heegaard splitting of an open 3-manifold is the partition of the manifold into two non-compact handlebodies which intersect on their common boundary. This paper proves several non-compact analogues of theorems about compact Heegaard splittings. The main theorem is: if N is a compact, connected, orientable 3-manifold with non-empty boundary, containing no S
Mun Dae Kim
We propose a scheme for tunable coupling of phase-coupled flux qubits. The phase-coupling scheme can provide a strong coupling strength of the order of Josephson coupling energy of Josephson junctions in the connecting loop, while the previously studied inductive coupling scheme cannot provide due to small mutual inductance and induced currents. We show that
Three-Way Entanglement and Three-Qubit Phase Gate Based on a Coherent Six-Level Atomic System
quant-phChao Hang, Yun Li, Lei Ma, Guoxiang Huang
We analyze the nonlinear optical response of a six-level atomic system under a configuration of electromagnetically induced transparency. The giant fifth-order nonlinearity generated in such a system with a relatively large cross-phase modulation effect can produce efficient three-way entanglement and may be used for realizing a three-qubit quantum phase gat
Exploring Harmony between Theory and Computation - Toward a unified electronic structure theory
physics.chem-phLiqiang Wei
The physical aspect of a general perturbation theory is explored. Its role as a physical principle for understanding the interaction among matter with different levels of hierarchy is appreciated. It is shown that the generic perturbation theory can not only be used for understanding various electronic phenomena including the nature of chemical bonds but als
The Reasons of Line Broadening of Lattice Oscillations in Spectrum Small Frequencies of P-Chloronitrobenzene
physics.opticsM. A. Korshunov
Raman spectroscopies are carried out by the Method polarizable examinations of the lattice oscillations of p-chloronitrobenzene at temperature 293 K. The led matching of spectrums of p-chloronitrobenzene with p-bromochlorobenzene and p-dibromobenzene has shown that the significant line broadening in p-chloronitrobenzene is caused not only clutter in allocati
P. J. Kellogg, S. D. Bale, F. S. Mozer, T. S. Horbury
Measurements of fluctuations of electric fields in the frequency range from a fraction of one Hz to 12.5 Hz are presented, and corrected for the Lorentz transformation of magnetic fluctuations to give the electric fields in the plasma frame. The electric fields are large enough to provide the dominant force on the ions of the solar wind in the region near th
Andre Gsponer
The paper begins with a general introduction and update to Fourth Generation Nuclear Weapons (FGNW), and then addresses some particularly important military aspects on which there has been only limited public discussion so far. These aspects concern the unique military characteristics of FGNWs which make them radically different from both nuclear weapons bas
Two-color discrete localized modes and resonant scattering in arrays of nonlinear quadratic optical waveguides
nlin.PSM. I. Molina, R. A. Vicencio, Y. S. Kivshar
We analyze the properties and stability of two-color discrete localized modes in arrays of channel waveguides where tunable quadratic nonlinearity is introduced as a nonlinear defect by periodic poling of a single waveguide in the array. We show that, depending on the value of the phase mismatch and the input power, such two-color defect modes can be realize
M. I. Molina, R. A. Vicencio, Y. S. Kivshar
We discuss the formation of self-trapped localized states near the edge of a semi-infinite array of nonlinear waveguides. We study a crossover from nonlinear surface states to discrete solitons by analyzing the families of odd and even modes centered at different distances from the surface, and reveal the physical mechanism of the nonlinearity-induced stabil
Turbulent Drag Reduction by Flexible and Rodlike Polymers: Crossover Effects at Small Concentrations
nlin.CDEmily S. C. Ching, T. S. Lo, Itamar Procaccia
Drag reduction by polymers is bounded between two universal asymptotes, the von-Kármán log-law of the law and the Maximum Drag Reduction (MDR) asymptote. It is theoretically understood why the MDR asymptote is universal, independent of whether the polymers are flexible or rodlike. The cross-over behavior from the Newtonian von-Kármán log-law to the MDR is ho
Cristian Predescu
We present an integral transformation capable of extracting moments of arbitrary Paley-Wiener entire functions against a given spectral distribution based solely on short-time values of the correlation function in a small open disk about the origin. The integral is proven to converge absolutely to the expected result for those correlation functions that can