October 2006 arXiv papers — page 34
Showing 3,301–3,400 of 5,236 papers
Ronald Babich, Nicolas Garron, Christian Hoelbling, Joseph Howard
We present results for B_K and selected matrix elements for beyond the standard model interactions obtained in quenched QCD with overlap fermions. We also illustrate results on baryon wave-functions and diquark correlations within baryons in the Coulomb and Landau gauge.
ALPHA Collaboration, P. Dimopoulos, G. Herdoiza, F. Palombi
We apply finite-size recursion techniques based on the Schrodinger functional formalism to determine the renormalization group running of four-fermion operators which appear in the Delta S=2 effective weak Hamiltonian of the Standard Model. Our calculations are done using O(a) improved Wilson fermions with N_f=2 dynamical flavours. Preliminary results are pr
M. Pepe, U. -J. Wiese
The Z(N) center symmetry plays an important role in the deconfinement phase transition of SU(N) Yang-Mills theory at finite temperature. The exceptional group G(2) is the smallest simply connected gauge group with a trivial center. Hence, there is no symmetry reason why the low- and high-temperature regimes in G(2) Yang-Mills theory should be separated by a
PACS Collaboration, Y. Nakamura, S. Aoki, M. Fukugita
We present a study of $B$-parameters for generic $ΔS=2$ four-quark operators in domain wall QCD. Our calculation covers all the $B$-parameters required to study the neutral kaon mixing in the standard model (SM) and beyond it. We evaluate one-loop renormalization factors of the operators employing the plaquette and Iwasaki gauge actions. Numerical simulation
Salvatore Mele
The study of Bhabha scattering at e^+e^- colliders probes the running of the electromagnetic coupling. After early measurements by the VENUS collaboration at TRISTAN and the by L3 collaboration at LEP, two recent analyses have been performed by the OPAL and L3 collaborations. The OPAL collaboration studied high-statistics low-angle Bhabha scattering at LEP,
G. S. Huang, CLEO Collaboration
Knowledge of the Bs decay fraction of the Y(5S) resonance, fs, is important for Bs meson studies at the Y(5S) energy. Using a data sample collected by the CLEO III detector at CESR consisting of 0.423/fb on the Y(5S) resonance, 6.34/fb on the Y(4S) and 2.32/fb in the continuum below the Y(4S), we measure B(Y(5S) -> phi X)=(13.8 +/- 0.7 {+2.3}{-1.5})% and B(Y
Determination of CP and CPT violation parameters in the neutral kaon system using the Bell-Steinberger relation and data from the KLOE experiment
hep-exThe KLOE Collaboration, G. D'Ambrosio, G. Isidori
We present an improved determination of the CP and CPT violation parameters Re(epsilon) and Im(delta) based on the unitarity condition (Bell-Steinberger relation) and on recent results from the KLOE experiment. We find Re(epsilon) = (159.6 \pm 1.3)10^-5 and Im(delta) = (0.4 \pm 2.1)10^-5, consistent with no CPT violation.
A two-point boundary value problem on a Lorentz manifold arising in A. Poltorak's concept of reference frame
gr-qcYu. E. Gliklikh, P. S. Zykov
In A. Poltorak's concept, the reference frame in General Relativity is a certain manifold equipped with a connection. The question under consideration here is whether it is possible to join two events in the space-time by a time-like geodesic if they are joined by a geodesic of the reference frame connection that has a time-like initial vector. This ques
Zsolt Horváth, Zoltán Kovács
We briefly discuss the Hamiltonian formalism of Kantowski-Sachs space-times with vacuum, anisotropic fluid and two cross-streaming radiation field sources. For these models a cosmological time is introduced. New constraints are found in which the fluid momenta are separated from the rest of the variables. In consequence their Poisson brackets give an Abelian
Raymond Burston, Anthony Lun
We present a method that yields three decoupled covariant equations for three complex scalars, which completely govern electromagnetic perturbations of non-vacuum, locally rotationally symmetric class II spacetimes. One of these equations is equivalent to the previously established generalized Regge-Wheeler equation for electromagnetic fields. The remaining
Niranjay Ravindran, Nihar Jindal
Block diagonalization is a linear precoding technique for the multiple antenna broadcast (downlink) channel that involves transmission of multiple data streams to each receiver such that no multi-user interference is experienced at any of the receivers. This low-complexity scheme operates only a few dB away from capacity but does require very accurate channe
Georg Schmidt, Vladimir R. Sidorenko, Martin Bossert
Interleaved Reed-Solomon codes are applied in numerous data processing, data transmission, and data storage systems. They are generated by interleaving several codewords of ordinary Reed-Solomon codes. Usually, these codewords are decoded independently by classical algebraic decoding methods. However, by collaborative algebraic decoding approaches, such inte
Frédéric Blanqui
In a previous work, we proved that an important part of the Calculus of Inductive Constructions (CIC), the basis of the Coq proof assistant, can be seen as a Calculus of Algebraic Constructions (CAC), an extension of the Calculus of Constructions with functions and predicates defined by higher-order rewrite rules. In this paper, we prove that almost all CIC
Frédéric Blanqui
This paper presents general syntactic conditions ensuring the strong normalization and the logical consistency of the Calculus of Algebraic Constructions, an extension of the Calculus of Constructions with functions and predicates defined by higher-order rewrite rules. On the one hand, the Calculus of Constructions is a powerful type system in which one can
C. R. dela Cruz, B. Lorenz, Y. Y. Sun, C. W. Chu
The magnetoelastic coupling in multiferroic $DyMn_2O_5$ is investigated by magnetostriction measurements along the three crystallographic orientations. Strong lattice anomalies as a function of the magnetic field are detected at the low temperature magnetic and ferroelectric phase transitions. The sign and magnitude of the magnetostrictive coefficient as wel
Elbert E. M. Chia, Jian-Xin Zhu, H. J. Lee, Namjung Hur
Time-resolved photoinduced reflectivity is measured in the spin-density-wave (SDW) phase using itinerant antiferromagnets UMGa$_{5}$ (M=Ni, Pt). For UNiGa$_{5}$ [$T_{N}$=85 K, $Q$=($π$,$π$,$π$)], the relaxation time $τ$ shows a sharp increase at $T_{N}$ consistent with the opening of a SDW gap. For UPtGa$_{5}$ [$T_{N}$=26 K, $Q$=(0,0,$π$)], no change in $τ$
Optical Metamaterials at Near and Mid IR Range Fabricated by Nanoimprint Lithography
cond-mat.mtrl-sciW. Wu, E. Kim, E. Ponizovskaya, Y. Liu
Two types of optical metamaterials operating at near-IR and mid-IR frequencies, respectively, have been designed, fabricated by nanoimprint lithography (NIL), and characterized by laser spectroscopic ellipsometry. The structure for the near-IR range was a metal/dielectric/metal stack "fishnet" structure that demonstrated negative permittivity and per
Static and dynamic properties of a particle-based algorithm for non-ideal fluids and binary mixtures
cond-mat.softThomas Ihle, Erkan Tuzel
A recently introduced particle-based model for fluid dynamics with effective excluded volume interactions is analyzed in detail. The interactions are modeled by means of stochastic multiparticle collisions which are biased and depend on local velocities and densities. Momentum and energy are exactly conserved locally. The isotropy and relaxation to equilibri
Damage Spreading at the Corner Filling Transition in the two-dimensional Ising Model
cond-mat.stat-mechM. Leticia Rubio Puzzo, Ezequiel V. Albano
The propagation of damage on the square Ising lattice with a corner geometry is studied by means of Monte Carlo simulations. It is found that, just at $T=T_f (h)$ (critical temperature of the filling transition) the damage initially propagates along the interface of the competing domains, according to a power law given by $D(t) \propto t^η$. The value obtain
On the Evolution of Quasicrystalline and Crystalline Phases in Rapidly Quenched Al-Co-Cu-Ni Alloy
cond-mat.mtrl-sciT. P. Yadav, N. K. Mukhopadhyay, R. S. Tiwari, O. N. Srivastava
The occurrence of stable decagonal quasicrystalline phase in Al-Co-Ni and Al-Cu-Co alloys through conventional solidification is well established. Earlier, we have studied the effect of Cu substitution in place of Co in the Al70 Co15Ni15 alloy. Here we report the structural/micro-structural changes with substitution of Cu for Ni in rapidly solidified Al-Co-N
Unconventional motional narrowing in the optical spectrum of a semiconductor quantum dot
cond-mat.otherAlice Berthelot, Ivan Favero, Guillaume Cassabois, Christophe Voisin
Motional narrowing refers to the striking phenomenon where the resonance line of a system coupled to a reservoir becomes narrower when increasing the reservoir fluctuation. A textbook example is found in nuclear magnetic resonance, where the fluctuating local magnetic fields created by randomly oriented nuclear spins are averaged when the motion of the nucle
Angel J. Moreno, Juan Colmenero
Recent computational investigations in polymeric and non-polymeric binary mixtures have reported anomalous relaxation features when both components exhibit very different mobilities. Anomalous relaxation is characterized by sublinear power law behaviour for mean squared displacements, logarithmic decay in dynamic correlators, and a striking concave-to-convex
Leonardo Angelini, Daniele Marinazzo, Mario Pellicoro, Sebastiano Stramaglia
We introduce a semi-supervised learning estimator which tends to the first kernel principal component as the number of labelled points vanishes. Our approach is based on the notion of optimal target vector, which is defined as follows. Given an input data-set of ${\bf x}$ values, the optimal target vector $\mathbf{y}$ is such that treating it as the target a
Time-dependent density-functional theory beyond the adiabatic approximation: insights from a two-electron model system
cond-mat.mes-hallC. A. Ullrich
Most applications of time-dependent density-functional theory (TDDFT) use the adiabatic local-density approximation (ALDA) for the dynamical exchange-correlation potential Vxc(r,t). An exact (i.e., nonadiabatic) extension of the ground-state LDA into the dynamical regime leads to a Vxc(r,t) with a memory, which causes the electron dynamics to become dissipat
T. P. Yadav, Durgesh K. Rai, V. S. Subrahmanyam, O. N. Srivastava
Shape memory Ti-Ni alloys attracted much attention in the recent years, since they are shape memory, intelligent as well as functional materials. In the present investigation Ti51Ni49 and Ti51Ni45Fe4 alloys were synthesized through radio frequency (RF) induction melting. The alloy was characterized through x-ray diffraction (XRD), scanning electron microscop
Properties of grain boundaries in high-Tc superconductors -- notes on a recent presentation --
cond-mat.supr-conJ. Mannhart
The purpose of this article is to discuss a view concerning key datasets of the properties of grain boundaries in high-Tc superconductors that was recently expressed in Ref. 1. The reference also criticizes our research. Using examples I disprove this criticism.
T. Arnal, A. V. Khvalokvskii, M. Bibes, Ph. Lecoeur
We have measured the contribution of magnetic domain walls (DWs) to the electric resistance in epitaxial manganite films patterned by electron-beam lithography into a track containing a set of notches. We find a DW resistance-area (RA) product of ~2.5 10^(-13) Ohm/m^2 at low temperature and bias, which is several orders of magnitude larger than the values re
Andre M. C. Souza
A new lattice model of interacting electrons is presented. It can be viewed as a classical Hubbard model in which the energy associated to electron itinerance is proportional to the total number of possible electron jumps. Symmetry properties of the Hubbard model are preserved. In the half-filled band with strong interaction the model becomes the Ising model
Josephson-vortex-flow terahertz emission in layered high-$T_c$ superconducting single crystals
cond-mat.supr-conMyung-Ho Bae, Hu-Jong Lee, Jae-Hyun Choi
We report on the successful terahertz emission (0.6$\sim$1 THz) that is continuous and tunable in its frequency and power, by driving Josephson vortices in resonance with the collective standing Josephson plasma modes excited in stacked Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ intrinsic Josephson junctions. Shapiro-step detection was employed to confirm the terahertz-w
Collective Josephson vortex dynamics in a finite number of intrinsic Josephson junctions
cond-mat.supr-conMyung-Ho Bae, Jae-Hyun Choi, Hu-Jong Lee
We report the experimental confirmation of the collective transverse plasma modes excited by the Josephson vortex lattice in stacks of intrinsic Josephson junctions in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+x}$ single crystals. The excitation was confirmed by analyzing the temperature ($T$) and magnetic field ($H$) dependencies of the multiple sub-branches in the J
B. Dybiec E. Gudowska-Nowak P. Hänggi
We explore the archetype problem of an escape dynamics occurring in a symmetric double well potential when the Brownian particle is driven by {\it white Lévy noise} in a dynamical regime where inertial effects can safely be neglected. The behavior of escaping trajectories from one well to another is investigated by pointing to the special character that unde
P. Keim, G. Maret, H. H. von Gruenberg
Using video-microscopy data of a two-dimensional colloidal system the bond-order correlation function G6 is calculated and used to determine the temperature-dependence of both the orientational correlation length xi6 in the isotropic liquid phase and the Frank constant F_A in the hexatic phase. F_A takes the value 72/pi at the hexatic to isotropic liquid pha
Masatomo Iwasa, Kazuhiro Nozaki
A renormalization group method with the Lie symmetry is presented for the singular perturbation problems. Asymptotic solutions are obtained as group-invariant solutions under approximate Lie group admitted by perturbed differential equations.
Adrian Stan, Nils Erik Dahlen, Robert van Leeuwen
We solve the Dyson equation for atoms and diatomic molecules within the GW approximation, in order to elucidate the effects of self-consistency on the total energies and ionization potentials. We find GW to produce accurate energy differences although the self-consistent total energies differ significantly from the exact values. Total energies obtained from
Satya N. Majumdar, Michael J. Kearney
We study analytically the dynamics of a ball bouncing inelastically on a randomly vibrating platform, as a simple toy model of inelastic collapse. Of principal interest are the distributions of the number of flights n_f till the collapse and the total time τ_c elapsed before the collapse. In the strictly elastic case, both distributions have power law tails
A. Bussmann-Holder, R. Khasanov, A. Shengelaya, A. Maisuradze
The recent observation of an inflection point in the temperature dependence of the in-plane magnetic field dependence (lambda_ab) is investigated within a two-band model with coupled order parameters of different symmetries. While the dominant order parameter has d-wave symmetry, the smaller one is of s-wave symmetry. Superconductivity is robust in the d-wav
V. P. S. Awana, Rahul Tripaathi, V. K. Sharma, H. Kishan
We report synthesis and magnetization of Sr2RuREO6 (RE/Ru-211O6) with RE = Gd and Eu. Both Gd,Eu/Ru-211O6 are formed in distorted perovskite-type single phase with monoclinic P21/n space group. Magnetization (M/T) measurements exhibited antiferromagnetic ordering of Ru moments for both Gd and Eu compounds at TN of around 30 K due to super-exchange Ru-O-O-Ru
Universal Scaling Behavior of Anomalous Hall Effect and Anomalous Nernst Effect in Itinerant Ferromagnets
cond-mat.mtrl-sciT. Miyasato, N. Abe, T. Fujii, A. Asamitsu
Anomalous Hall effect (AHE) and anomalous Nernst effect (ANE) in a variety of ferromagnetic metals including pure metals, oxides, and chalcogenides, are studied to obtain unified understandings of their origins. We show a universal scaling behavior of anomalous Hall conductivity $σ_{xy}$ as a function of longitudinal conductivity $σ_{xx}$ over five orders of
Simon Pesant, Paul Boulanger, Michel Côté, Matthias Ernzerhof
This article presents an \textit{ab initio} study of four polymers, polythiophene, polypyrrole, ladder-type polythiophene, and ladder-type polypyrrole. Upon an analysis of the variation of the band gap when comparing the unconstrained and the ladder-type polymers, a discrepancy was found between the thiophene and the pyrrole polymer families. For polythiophe
Chiung-Yuan Lin, A. H. Castro Neto, B. A. Jones
We have performed first-principles calculation of the surface and bulk wavefunctions of the Cu(111) surface and their hybridization energies to a Co adatom, including the potential scattering from the Co. By analyzing the calculated hybridization energies, we found the bulk states dominate the contribution to the Kondo temperature, in agreement with recent e
Snezana Stanimirovic, Carl Heiles, Nissim Kanekar
We have obtained deep HI observations in the direction of 22 continuum sources without previously detected cold neutral medium (CNM). 18 CNM clouds were detected with the typical HI column density of $3\times10^{18}$ cm$^{-2}$. Our surprisingly high detection rate suggests that clouds with low HI column densities are quite common in the interstellar medium.
Snezana Stanimirovic
The Magellanic System harbors >800 expanding shells of neutral hydrogen, providing a unique opportunity for statistical investigations. Most of these shells are surprisingly young, 2--10 Myr old, and correlate poorly with young stellar populations. I summarize what we have learned about shell properties and particularly focus on the puzzling correlation betw
Benjamin F. Williams, Robin Ciardullo, Patrick R. Durrell, Matt Vinciguerra
We have used the Hubble Space Telescope's Advanced Camera for Surveys (ACS) to detect and measure ~5300 stars in a single intracluster field in the Virgo Cluster. By performing F606W and F814W photometry on these stars, we have determined their metallicity distribution function, and constrained the types of stars present in this portion of Virgo's in
Modeling Spitzer observations of VV Ser. II. an extended quantum heated nebula and a disk shadow
astro-phKlaus M. Pontoppidan, Cornelis P. Dullemond, Geoffrey A. Blake, Neal J. Evans
We present mid-infrared Spitzer IRAC and MIPS images of the UX Orionis star VV Ser and the surrounding cloud. The 5.6--70 micron images show bright, localized and nebulous emission extended over 4 arcmin centered on VV Ser. We interpret the nebulosity as being due to transiently heated grains excited by UV photons emitted by VV Ser. A companion paper describ
Klaus M. Pontoppidan, Cornelis P. Dullemond, Geoffrey A. Blake, A. C. Adwin Boogert
We present mid-infrared Spitzer-IRS spectra of the well-known UX Orionis star VV Ser. We combine the Spitzer data with interferometric and spectroscopic data from the literature covering UV to submillimeter wavelengths. The full set of data are modeled by a two-dimensional axisymmetric Monte Carlo radiative transfer code. The model is used to test the predic
Dynamics of radiatively inefficient flows accreting onto radiatively efficient black hole objects
astro-phDaniel Proga
I present results from numerical simulations of gas dynamics outside luminous accretion disks in active galactic nuclei. The gas, gravitationally captured by a super massive black hole, can be driven away by the energy and momentum of the radiation emitted during black hole accretion. Assuming axisymmetry, I study how the mass accretion and outflow rates, an
Matthew G. Baring, Alice K. Harding
A significant new development in the study of Anomalous X-ray Pulsars (AXPs) has been the recent discovery by INTEGRAL and RXTE of flat, hard X-ray components in three AXPs. These non-thermal spectral components differ dramatically from the steeper quasi-power-law tails seen in the classic X-ray band in these sources. A prime candidate mechanism for generati
Current Star Formation in the Perseus Molecular Cloud: Constraints from Unbiased Submillimeter and Mid-Infrared Surveys
astro-phJes K. Jorgensen, Doug Johnstone, Helen Kirk, Philip C. Myers
We present a census of the population of deeply embedded young stellar objects (YSOs) in the Perseus molecular cloud complex based on a combination of Spitzer Space Telescope mid-IR data from the c2d legacy team and JCMT/SCUBA submillimeter maps from the COMPLETE team. The mid-IR sources detected at 24 micron and having [3.6]-[4.5] > 1 are located close to t
A Strong Correlation between Circumnuclear Dust and Black Hole Accretion in Early-Type Galaxies
astro-phRamiro D. Simões Lopes, Thaisa Storchi-Bergmann, Maria de Fátima O. Saraiva, Paul Martini
We present a detailed investigation of the incidence of circumnuclear dust structure in a large, well-matched sample of early-type galaxies with and without Active Galactic Nuclei (AGN). All 34 early-type AGN hosts in our sample have circumnuclear dust, while dust is only observed in 26% (nine) of a pair-matched sample of 34 early-type, inactive galaxies. Th
Jonathan Granot
There are several lines of evidence which suggest that the relativistic outflows in gamma-ray bursts (GRBs) are collimated into narrow jets. The jet structure has important implications for the true energy release and the event rate of GRBs, and can constrain the mechanism responsible for the acceleration and collimation of the jet. Nevertheless, the jet str
E. V. Gotthelf
A systematic X-ray survey of the most energetic rotation-powered pulsars known, based on spin-down energy loss rate, $\dot E$ = $Iω\dotω$, shows that all energetic pulsars with $\dot E > \dot E_{c} \approx 3.4 \times\ 10^{36}$ erg s$^{-1}$ are X-ray bright, manifest a distinct pulsar wind nebula (PWN), and are associated with a supernova event, either histor
M. Ruderman
In the core of a canonical spinning magnetized neutron star(NS) a nearly uniform superfluid neutron vortex-array interacts strongly with a twisted array of magnetic flux-tubes threading the core's superconducting protons. One consequence is that changes in NS-spin alter both arrays and also the magnetic field distribution on the surface of the surroundin
Gamma ray signatures of ultra high energy cosmic ray accelerators: electromagnetic cascade versus synchrotron radiation of secondary electrons
astro-phStefano Gabici, Felix A. Aharonian
We discuss the possibility of observing ultra high energy cosmic ray sources inhigh energy gamma rays. Protons propagating away from their accelerators produce secondary electrons during interactions with cosmic microwave background photons. These electrons start an electromagnetic cascade that results in a broad band gamma ray emission. We show that in a ma
F. I. Cooperstock, S. Tieu
We consider the consequences of applying general relativity to the description of the dynamics of a galaxy, given the observed flattened rotation curves. The galaxy is modeled as a stationary axially symmetric pressure-free fluid. In spite of the weak gravitational field and the non-relativistic source velocities, the mathematical system is still seen to be
Elemental Abundances of Nearby Galaxies through High Signal-to-Noise XMM-Newton Observations of ULXs
astro-phLisa M. Winter, Richard F. Mushotzky, Christopher S. Reynolds
(abridged) In this paper, we examined XMM Newton EPIC spectra of 14 ultra-luminous X-ray sources (ULXs)in addition to the XMM RGS spectra of two sources (Holmberg II X-1 and Holmberg IX X-1). We determined oxygen and iron abundances of the host galaxy's interstellar medium (ISM) using K-shell (O) and L-shell (Fe) X-ray photo-ionization edges towards thes
The Transition from Atomic to Molecular Hydrogen in Interstellar Clouds: 21cm Signature of the Evolution of Cold Atomic Hydrogen in Dense Clouds
astro-phPaul F. Goldsmith, Di Li, Marko Krco
We have investigated the time scale for formation of molecular clouds by examining the conversion of HI to H2 using a time-dependent model. H2 formation on dust grains and cosmic ray and photo destruction are included in one-dimensional model slab clouds which incorporate time-independent density and temperature distributions. We calculate 21cm spectral line
G. Lambiase, G. Scarpetta
$f(R)$-theories of gravity are reviewed in the context of the so called gravitational baryogenesis. The latter is a mechanism for generating the baryon asymmetry in the Universe, and relies on the coupling between the Ricci scalar curvature $R$ and the baryon current. Gravity Lagrangians of the form ${\cal L}(R)\sim R^n$, where $n$ differs from 1 (the case o
C. Fechner, D. Reimers
We present a reanalysis of the HeII Lyman alpha absorption towards the quasars HS1700+6416 and HE2347-4342 using new high S/N, optical observations. An alternative analysis method is applied, which fits the high quality, optical HI data directly to the HeII spectrum. The results are compared to those inferred from standard line profile analyses. This new met
A. Reiners, G. Basri
We present the first direct magnetic field measurements on M dwarfs cooler than spectral class M4.5. Utilizing a new method based on the effects of a field on the FeH band near 1 micron, we obtain information on whether the integrated surface magnetic flux (Bf) is low (well under 1 kilogauss), intermediate (between 1 and about 2.5 kG), or strong (greater tha
Luigi Spinoglio, Anna Maria Di Giorgio, Paolo Saraceno
We discuss the potential of high sensitivity mid-IR and far-IR spectroscopy to proof the physical properties of active nuclei and starburst regions of local and distant galaxies. For local galaxies, it will be possible to map the discs and ISM through the low ionization ionic lines and a variety of molecular tracers, such as OH, H2O and high-J CO. At increas
J. A. Stevens, M. J. Page, F. J. Carrera, R. J. Ivison
We discuss preliminary results from our programme to map the fields of high-redshift AGN. In the context of the hierarchical models such fields are predicted to contain an over-density of young, luminous galaxies destined to evolve into the core of a rich cluster by the present epoch. We have thus imaged from submillimetre to X-ray wavelengths the few-arcmin
R. A. Cabanac, C. Alard, M. Dantel-Fort, B. Fort
AIMS: We present data from the CFHTLS Strong Lensing Legacy Survey (SL2S). Due to the unsurpassed combined depth, area and image quality of the Canada-France-Hawaii Legacy Survey it is becoming possible to uncover a large, statistically well-defined sample of strong gravitational lenses which spans the dark halo mass spectrum predicted by the concordance mod
M. Orienti, D. Dallacasa, C. Stanghellini
We constrain the spectral ages for two very asymmetric Compact Symmetric Objects (CSO) from the B3-VLA-CSS sample, and we investigate the role of the ambient medium potentially able to influence the individual source evolution. Multi-frequency VLBA observations have been carried out to study the distribution of the break frequency of the spectra across diffe
R. Landi, A. Malizia, L. Bassani, N. Masetti
In five years of operation, data from INTEGRAL has been used to discover a large number of gamma-ray sources, a substantial fraction of which have turned out to be active galactic nuclei (AGN). Recently Bassani et al. (2006) have presented a sample of around 60 AGNs of which some still lack optical identification or information in the X-ray band. In this wor
G. Ramsay, C. Brocksopp, P. Groot, P. Hakala
We present the results of some recent research on AM CVn systems. We present: X-ray/UV observations made using XMM-Newton; the X-ray grating spectrum of RX J1914+24; preliminary results of a search for radio emission from AM CVn binaries, and discuss the strategy and first results of the RATS project, whose main aim is to discover AM CVn systems.
Kouji Ohta, Kentaro Aoki, Toshihiro Kawaguchi, Gaku Kiuchi
We present optical images of nearby 50 narrow-line Seyfert 1 galaxies (NLS1s) which cover all the NLS1s at z<0.0666 and $δ\ge -25^{\circ}$ known at the time of 2001. Among the 50 NLS1s, 40 images are newly obtained by our observations and 10 images are taken from archive data. Motivated by the hypothesis that NLS1s are in an early phase of a super-massive bl
J. Lopez-Santiago, G. Micela, S. Sciortino, F. Favata
Context: The comparison of observed counts in a given sky direction with predictions by Galactic models yields constraints to the spatial distribution and the stellar birthrate of young stellar populations. In this work we present the results of the analysis of the stellar content of the XMM-Newton Bright Serendipitous Survey (XBSS). This unbiased survey inc
A. Bonanno, M. Kueker, L. Paterno'
The differential rotation of the F5V-IV star Procyon A is computed for a class of models which are consistent with recent astrometric and asteroseismic data. The rotation pattern is determined by solving the Reynolds equation for motion, including the convective energy transport, where the latter is anisotropic owing to the Coriolis force action which produc
J. F. Albacete Colombo, E. Flaccomio, G. Micela, F. Damiani
The aim of this work is to identify the so far unknown low mass stellar population of the ~2Myr old Cygnus OB2 region, and to investigate the X-ray and near-IR stellar properties of its members. We analyzed a 97.7 ksec Chandra ACIS-I observation pointed at the core of the Cygnus OB2 region. X-ray variability ans spectral analysis of sources was characterized
R. J. Simcoe, J. E. Grindlay, E. J. Los, A. Doane
A machine capable of digitizing two 8 inch by 10 inch (203 mm by 254 mm) glass astrophotographic plates or a single 14 inch by 17 inch (356 mm by 432 mm) plate at a resolution of 11 microns per pixel or 2309 dots per inch (dpi) in 92 seconds is described. The purpose of the machine is to digitize the \~500,000 plate collection of the Harvard College Observat
Lyman-Alpha Absorption in the Quasar Triplet Q0107-025A, Q0107-025B, and Q0107-0232: Data Calibration and Line Selection
astro-phC. E. Petry, C. D. Impey, J. L. Fenton, C. B. Foltz
We present spectroscopic observations for quasars Q0107-025A, Q0107-025B, and Q0107-0232. For the first time, all data obtained with the Hubble Space Telescope's GHRS and FOS for these three quasars are combined. Ly-alpha absorbers selected from the spectra can be used to trace the coherence of the intergalactic medium (IGM) on scales of 1-2 h_{70}^{-1}
Masaru Kajisawa, Masahiro Konishi, Ryuji Suzuki, Chihiro Tokoku
We use very deep near-infrared imaging data taken with Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru Telescope to investigate the number counts of Distant Red Galaxies (DRGs). We have observed a 4x7 arcmin^2 field in the Great Observatories Origins Deep Survey North (GOODS-N), and our data reach J=24.6 and K=23.2 (5sigma, Vega magnitud
J. Takata, H. -K. Chang, K. S. Cheng
We investigate polarization of high-energy emissions from the Crab pulsar in the frame work of the outer gap accelerator, following previous works of Cheng and coworkers. The recent version of the outer gap, which extends from inside the null charge surface to the light cylinder, is used for examining the synchrotron radiations from the secondary and the ter
Multiple Regression Analysis of the Variable Component in the Near-Infrared Region for Type 1 AGN MCG+08-11-011
astro-phHiroyuki Tomita, Yuzuru Yoshii, Yukiyasu Kobayashi, Takeo Minezaki
We propose a new method of analysing a variable component for type 1 active galactic nuclei (AGNs) in the near-infrared wavelength region. This analysis uses a multiple regression technique and divides the variable component into two components originating in the accretion disk at the center of AGNs and from the dust torus that far surrounds the disk. Applyi
A. Lecureur, V. Hill, M. Zoccali, B. Barbuy
This paper investigates the peculiar behaviour of the light even (alpha-elements) and odd atomic number elements in red giants in the galactic bulge, both in terms of the chemical evolution of the bulge, and in terms of possible deep-mixing mechanisms in these evolved stars. Using UVES on VLT, we measure the abundances of the four light elements O, Na, Mg an
M. Engelhardt, B. Sperisen
The question whether the center vortex picture of the strongly interacting vacuum can encompass the infrared dynamics of both SU(2) as well as Sp(2) Yang-Mills theory is addressed. These two theories contain the same center vortex degrees of freedom, and yet exhibit deconfinement phase transitions of different order. This is argued to be caused by the effect
E. O. Iltan, B. Korutlu
We predict the branching ratios of lepton flavor violating radion decays r -> e^{\pm} μ^{\pm}, r -> e^{\pm} τ^{\pm} and r -> μ^{\pm} τ^{\pm} in the two Higgs doublet model, in the framework of the Randall Sundurum scenario. We observe that the branching ratios of the processes we study are at most at the order of 10^{-8} for the small values of radion mass a
Andres Anabalon, Steven Willison, Jorge Zanelli
In this paper two things are done. First it is shown how a four dimensional gauged Wess-Zumino-Witten term arises from the five dimensional Einstein-Hilbert plus Gauss-Bonnet lagrangian with a special choice of the coefficients. Second, the way in which the equations of motion of four-dimensional General Relativity arise is exhibited.
Quantum-classical transition for an analog of double-slit experiment in complex collisions: Dynamical decoherence in quantum many-body systems
quant-phL. Benet, L. T. Chadderton, S. Yu. Kun, Wang Qi
We study coherent superpositions of clockwise and anti-clockwise rotating intermediate complexes with overlapping resonances formed in bimolecular chemical reactions. Disintegration of such complexes represents an analog of famous double-slit experiment. The time for disappearance of the interference fringes is estimated from heuristic arguments related to f
J. W. Moffat
A non-singular cosmology is derived in modified gravity (MOG) with a varying gravitational coupling strength $G(t)=G_Nξ(t)$. Assuming that the curvature $k$, the cosmological constant $Λ$ and $ρ$ vanish at $t=0$, we obtain a non-singular universe with a negative pressure, $p_G < 0$. Quantum fluctuations at $t\sim 0$ produce creation of pairs of particles fro
Effect of Chemical Pressure on the Charge Density Wave Transition in Rare-earth Tritellurides RTe_3
cond-mat.str-elN. Ru, C. L. Condron, G. Y. Margulis, K. Y. Shin
The charge density wave transition is investigated in the bi-layer family of rare earth tritelluride RTe_3 compounds (R = Sm, Gd, Tb, Dy, Ho, Er, Tm) via high resolution x-ray diffraction and electrical resistivity. The transition temperature increases monotonically with increasing lattice parameter from 244(3) K for TmTe_3 to 416(3) K for SmTe_3. The heavie
Y. G. Ma, G. L. Ma, S. Zhang, X. Z. Cai
In a framework of a multi-phase transport model with both partonic and hadronic interactions, azimuthal correlations between trigger particles and associated scattering particles in Au + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV/$c$ have been studied by the mixing-event technique. The Mach-like structure has been observed in correlation function for central
Andrew Chamblin, Jeremy Michelson
The Schwarzschild, Schwarzschild-AdS, and Schwarzschild-de Sitter solutions all admit freely acting discrete involutions which commute with the continuous symmetries of the spacetimes. Intuitively, these involutions correspond to the antipodal map of the corresponding spacetimes. In analogy with the ordinary de Sitter example, this allows us to construct new
Giovanni Felder, Alexander P. Veselov
An integral formula for the solutions of Knizhnik-Zamolodchikov (KZ) equation with values in an arbitrary irreducible representation of the symmetric group S_N is presented for integer values of the parameter. The corresponding integrals can be computed effectively as certain iterated residues determined by a given Young diagram and give polynomials with int
Claudio Castelnovo, Claudio Chamon, .
We show that the concept of topological order, introduced to describe ordered quantum systems which cannot be classified by broken symmetries, also applies to classical systems. Starting from a specific example, we show how to use pure state density matrices to construct corresponding thermally mixed ones that retain precisely half the original topological e
Niayesh Afshordi
There has been some recent activity in trying to understand the dark matter clustering properties in the quasilinear regime, through resummation of perturbative terms, otherwise known as the renormalized perturbation theory (astro-ph/0509418), or the renormalization group method (astro-ph/0606028). While it is not always clear why such methods should work so
V. Barzykin, L. P. Gor'kov
We propose that a new state with a fully gapless Fermi surface appears in quasi-2D multiband superconductors in magnetic field applied parallel to the plane. It is characterized by a paramagnetic moment caused by a finite density of states on the open Fermi surface. We calculate thermodynamic and magnetic properties of the gapless state for both s-wave and d
Nero Budur
The space of unitary local systems of rank one on the complement of an arbitrary divisor in a complex projective algebraic variety can be described in terms of parabolic line bundles. We show that multiplier ideals provide natural stratifications of this space. We prove a structure theorem for these stratifications in terms of complex tori and convex rationa
Frederik Witt
We study the geometry of type II supergravity compactifications in terms of an oriented vector bundle $E$, endowed with a bundle metric of split signature and further datum. The geometric structure is associated with a so-called generalised $G$-structure and characterised by an $E$-spinor $ρ$, which we can regard as a differential form of mixed degree. This
Universal waterfalls-like feature in the spectral function of high temperature superconductors
cond-mat.supr-conJ. Graf, G. -H. Gweon, A. Lanzara
By performing high resolution angle resolved photoemission spectroscopy (ARPES) experiments on four different families of p-type cuprates, over an energy range much bigger than investigated before, we report the discovery of a universal high energy anomaly in the spectral function. This anomaly is characterized by the presence of two new high energy scales $
Perturbation Expansion and N-th Order Fermi Golden Rule of the Nonlinear Schrödinger Equations
math.APZhou Gang
In this paper we consider generalized nonlinear Schrödinger equations with external potentials. we compute the forth and the sixed order Fermi Golden Rules (FGR), conjectured in our previous papers, which is used in a study of the asymptotic dynamics of trapped solitons.
Nora Brambilla, Xavier Garcia i Tormo, Joan Soto, Antonio Vairo
Using pNRQCD and known results for the field strength correlator, we calculate the ultrasoft contribution to the QCD static energy of a quark-antiquark pair at short distances at NNNNLO in alpha_s. At the same order, this provides the logarithmic terms of the singlet static potential in pNRQCD and the log alpha_s terms of the static energy.
Severino T. Melo, Marcela I. Merklen
Given a separable unital C*algebra $C$, let $E_n$ denote the Hilbert module equal to the completion of the Schwartz space of rapidly decreasing smooth functions from $R^n$ to $C$ equipped with the $C$-valued inner product given by integration. Let $B$ denote the space of all smooth functions with bounded derivatives from $R^n$ to $C$. For each $a$ in $B$, le
Martin Krause, Paul Alexander
The interaction of optically emitting clouds with warm X-ray gas and hot, tenuous radio plasma in radio jet cocoons is modelled by 2D compressible hydrodynamic simulations. The initial setup is the Kelvin-Helmholtz instability at a contact surface of density contrast 10,000. The denser medium contains clouds of higher density. Optically thin radiation is rea
Johann Kroha, Michael Arnold, Beate Griepernau
We consider the non-equilibrium ferromagnetic transition of a mesoscopic sample of a resistive Stoner ferromagnet coupled to two paramagnetic leads. The transition is controlled by either the lead temperature T or the transport voltage V applied between the leads. We calculate the T and V dependence of the magnetization. For systems with a flat density of st
M. Z. Garaev, C. Y. Yildirim
We prove that for any zero $β'+iγ'$ of $ζ'(s)$ there exists a zero $β+iγ$ of $ζ(s)$ such that $|γ-γ'|\ll \sqrt{|β'-\tfrac{1}{2}|},$ and we provide some other related results.
Gravity Control produced by a Thermoionic Current through the Air at Very Low Pressure
physics.gen-phFran De Aquino
It was observed that samples hung above a thermoionic current exhibit a weight decrease directly proportional to the intensity of the current. The observed phenomenon appears to be absolutely new and unprecedented in the literature and can not be understood in the framework of the general relativity. It is pointed out the possibility that this unexpected eff
T. Varin, J. Welzel, A. Deandrea, D. Davesne
We study one-loop quantum corrections of a compactified Abelian 5d gauge field theory. We use a cut-off regularisation procedure which respects the symmetries of the model, i.e. gauge invariance, exhibits the expected power-like divergences and therefore allows the derivation of power-law behavior of the effective 4d gauge coupling in a coherent manner.
Thorsten Battefeld, Richard Easther
We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including N-flation, where inflation is driven by multiple axion fields arising from shift symmetries in a flux stabilized string vacuum. The non-Gaussianities are associated with
David Heath, Martin Krause, Paul Alexander
We present 2D axisymmetric hydrodynamic simulations investigating the long term effect of FR II radio galaxies on the metal distribution of the surrounding intra-cluster medium (ICM). A light jet is injected into a cooling flow atmosphere for 10-30 Myr. We then follow the subsequent evolution for 3 Gyr on a spherical grid spanning 3 Mpc in radius. A series o