June 2006 arXiv papers — page 22
Showing 2,101–2,200 of 4,372 papers
Y. Mambrini
We analyse the effect of the compression of the dark matter due to the infall of baryons to the galactic center on the gamma-ray flux. In addition, we also consider the effect of non-universal supersymmetric soft terms. This analysis shows that neutralino dark matter annihilation can give rise to signals largely reachable by future experiments like GLAST. Th
Branching Ratio and CP Asymmetry of $B_s \to π^0 η^{(\prime)}$ Decays in the perturbative QCD Approach
hep-phZhen-jun Xiao, Xin Liu, Hui-sheng Wang
We calculate the branching ratios and CP-violating asymmetries for $B_s^0 \to π^0 η^{(\prime)}$ decays in the perturbative QCD (pQCD) factorization approach here. We not only calculate the usual factorizable contributions, but also evaluate the non-factorizable and annihilation type contributions. The pQCD predictions for the CP-averaged branching ratios are
F. Gonzalez-Canales, A. Mondragon
Recent measurements of the neutrino solar mixing angle and the Cabibbo angle satisfy the empirical relation theta_{sol} + theta_{C} ~ 45^{o}. This relation suggests the existence of a correlation between the mixing matrices of leptons and quarks, the so called quark-lepton complementarity. Here, we examine the possibility that this correlation originates in
The BABAR Collaboration, B. Aubert
A measurement of the spin of the Omega^- hyperon produced through the exclusive process Xi_c^0 --> Omega^- K^+ is presented using a total integrated luminosity of 116 fb^-1 recorded with the BABAR detector at the e^+ e^- asymmetric-energy B-Factory at SLAC. Under the assumption that the Xi_c^0 has spin 1/2, the angular distribution of the Lambda from Omega^-
S. Cecchini, D. Centomo, G. Giacomelli, R. Giacomelli
Total solar eclipses (TSEs) offer a good opportunity to look for photons produced in possible radiative decays of solar neutrinos. In this paper we briefly review the physics bases of such searches as well as the existing limits on the neutrino proper lifetimes obtained by such experiments. We the report on the observations performed in occasion of the 29 Ma
László Á. Gergely
We discuss the status of both cosmological and black hole type singularities in the framework of the brane-world model of gravity. We point out that the Big Bang is not properly understood yet. We also show new features of the gravitational collapse on the brane, the most important being the production of dark energy during the collapse.
Alok Laddha
We present a polymer(loop) quantization of a two dimensional theory of dilatonic gravity known as the CGHS model. We recast the theory as a parametrized free field theory on a flat 2-dimensional spacetime and quantize the resulting phase space using techniques of loop quantization. The resulting (kinematical) Hilbert space admits a unitary representation of
Kamal K. Nandi, Yuan-Zhong Zhang, Nail G. Migranov
The present article lies at the interface between gravity, a highly nonlinear phenomenon, and quantum field theory. The nonlinear field equations of Einstein permit the theoretical existence of classical wormholes. One of the fundamental questions relates to the practical viability of such wormholes. One way to answer this question is to assess if the total
Daniil Ryabko, Marcus Hutter
Suppose we are given two probability measures on the set of one-way infinite finite-alphabet sequences and consider the question when one of the measures predicts the other, that is, when conditional probabilities converge (in a certain sense) when one of the measures is chosen to generate the sequence. This question may be considered a refinement of the pro
Bin Bin Chen, Pascale Primet
In grid networks, distributed resources are interconnected by wide area network to support compute and data-intensive applications, which require reliable and efficient transfer of gigabits (even terabits) of data. Different from best-effort traffic in Internet, bulk data transfer in grid requires bandwidth reservation as a fundamental service. Existing rese
Z. Wei, A. Sharma, A. S. Nunez, P. M. Haney
An electrical current can transfer spin angular momentum to a ferromagnet. This novel physical phenomenon, called spin transfer, offers unprecedented spatial and temporal control over the magnetic state of a ferromagnet and has tremendous potential in a broad range of technologies, including magnetic memory and recording. Recently, it has been predicted that
N. Harrison, R. D. McDonald, J. Singleton
We consider the effect that a change in the magnetic induction B has in causing an orbitally quantized field-induced spin- or charge density wave (FISDW or FICDW) state to depart from thermodynamic equilibrium. The competition between elastic forces of the density wave (DW) and pinning leads to the realization of a critical state that is in many ways analogo
On the Use of Local Diffusion Models for Path Ensemble Averaging in Potential of Mean Force Computations
cond-mat.stat-mechChristopher P. Calderon
We use a constant velocity steered molecular dynamics (SMD) simulation of the stretching of deca-alanine in vacuum to demonstrate a technique that can be used to create surrogate stochastic processes using the time series that come out of SMD simulations. The surrogate processes are constructed by first estimating a sequence of local parametric models along
Przemyslaw Gawronski, Krzysztof Kulakowski
New results are reported of the computer simulations on the magnetic behaviour of magnetic arrays of nanoscopic dots, placed in cells of the square lattice. We show that the remanence magnetization $M_r$ decreases with the array size. For arrays 50x50, we investigate also the stability of the magnetic structure of an array in an oscillating magnetic field. T
J. C. Kimball, H. L. Frisch
Bernoulli random walks, a simple avalanche model, and a special branching process are essesntially identical. The identity gives alternative insights into the properties of these basic model sytems.
H. C. Yao, J. J. Wang, Y. S. Ma, O. Waldmann
This communication reports the first example of cyclic ferric clusters with an odd number of iron atoms capped by phosphonate ligands, namely, [Fe9(m-OH)7(m-O)2(O3PC6H9)8-(py)12]. The magnetic studies support a S = 1/2 ground state with an exchange coupling constant of about J = -30 K.
A. Helzel, I. Kokanovic, D. Babic, L. V. Litvin
We study nonlocal vortex transport in mesoscopic amorphous Nb0.7Ge0.3 samples. A dc current I is passed through a wire connected via a perpendicular channel, of a length L= 2-5 um, with a pair of voltage probes where a nonlocal response Vnl ~ I is measured. The maximum of Rnl=Vnl/I for a given temperature occurs at an L-independent magnetic field and is prop
Generating functional analysis of batch minority games with arbitrary strategy numbers
cond-mat.dis-nnN. Shayeghi, A. C. C. Coolen
Both the phenomenology and the theory of minority games (MG) with more than two strategies per agent are different from those of the conventional and extensively studied case S=2. MGs with $S>2$ exhibit nontrivial statistics of the frequencies with which the agents select from their available decision making strategies, with far-reaching implications. In the
On the surface critical behaviour in Ising strips: density-matrix renormalization-group study
cond-mat.stat-mechA. Drzewinski, A. Maciolek, K. Szota
Using the density-matrix renormalization-group method we study the surface critical behaviour of the magnetization in Ising strips in the subcritical region. Our results support the prediction that the surface magnetization in the two phases along the pseudo-coexistence curve also behaves as for the ordinary transition below the wetting temperature for the f
Martin Gajek, Manuel Bibes, Stephane Fusil, Karim Bouzehouane
Multiferroics are singular materials that can display simultaneously electric and magnetic orders. Some of them can be ferroelectric and ferromagnetic and, for example, provide the unique opportunity of encoding information independently in electric polarization and magnetization to obtain four different logic states. However, schemes allowing a simple elect
Andrzej Drzewinski, J. M. J. van Leeuwen
A simple one-dimensional model is constructed for polymer motion. It exhibits the crossover from reptation to Rouse dynamics through gradually allowing hernia creation and annihilation. The model is treated by the density matrix technique which permits an accurate finite-size-scaling analysis of the behavior of long polymers.
M. Ausloos, F. Petroni
The shape and tails of partial distribution functions (PDF) for a climatological signal, i.e. the El Nino SOI and the turbulent nature of the ocean-atmosphere variability are linked through a model encompassing Tsallis nonextensive statistics and leading to evolution equations of the Langevin and Fokker-Planck type. A model originally proposed to describe th
Unravelling the origin of the controversial magnetic properties of BiFeO3 thin films
cond-mat.mtrl-sciHelene Bea, Manuel Bibes, Eric Jacquet, Karsten Rode
Single phase (001)-oriented BiFeO3 (BFO) thin films grown by pulsed laser deposition can only be obtained in a narrow window of deposition pressure and temperature and have a low magnetic moment. Out of the stability window Fe- or Bi-rich impurity phases form, which has a strong impact on the physical and structural properties of the films, even for impurity
Effect of Ga doping on magnetotransport properties in collosal magnetoresistive La0.7Ca0.3Mn1-xGaxO3 (0 < x < 0.1)
cond-mat.str-elMarek Pekala, Jan Mucha, Benedicte Vertruyen, Rudi Cloots
Samples of La0.7Ca0.3Mn1-xGaxO3 with x = 0, 0.025, 0.05 and 0.10 were prepared by standard solid-state reaction. They were first characterized chemically, including the microstructure. The magnetic properties and various transport properties, i.e. the electrical resistivity, magnetoresistivity (for a field below 8T), thermoelectric power and thermal conducti
Anthony Scemama, Tony Lelièvre, Gabriel Stoltz, Eric Cancès
We propose a new algorithm for sampling the $N$-body density $|Ψ({\bf R})|^2/\int_{\mathbb{R}^{3N}} |Ψ|^2$ in the Variational Monte Carlo (VMC) framework. This algorithm is based upon a modified Ricci-Ciccotti discretization of the Langevin dynamics in the phase space $({\bf R},{\bf P})$ improved by a Metropolis acceptation/rejection step. We show through so
J. Planelles, F. Rajadell, J. I. Climente, M. Royo
The conduction band electron states of laterally-coupled semiconductor quantum rings are studied within the frame of the effective mass envelope function theory. We consider the effect of axial and in-plane magnetic fields for several inter-ring distances, and find strong changes in the energy spectrum depending on the coupling regime. Our results indicate t
R. I. Shekhter, L. Y. Gorelik, L. I. Glazman, M. Jonson
Mechanical displacements of a nanoelectromechanical system (NEMS) shift the electron trajectories and hence perturb phase coherent charge transport through the device. We show theoretically that in the presence of a magnetic feld such quantum-coherent displacements may give rise to an Aharonov-Bohm-type of effect. In particular, we demonstrate that quantum v
About the relation between the quasiparticle Green's function in cuprates obtained from ARPES data and the magnetic susceptibility
cond-mat.supr-conD. S. Inosov, S. V. Borisenko, I. Eremin, A. A. Kordyuk
Angle resolved photoemission spectroscopy (ARPES) provides a detailed view of the renormalized band structure in cuprates and, consequently, is a key to the self-energy and the quasiparticle Green's function. Such information gives a clue to the comparison of ARPES with scanning tunneling microscopy, inelastic neutron scattering (INS), and Raman scatteri
June Seo Kim, Jung Hoon Han
The effects of the ring-exchange Hamiltonian H_3 = J_3 sum_{<ijk>} (S_i * S_j) (S_i * S_k) on the triangular lattice are studied using classical Monte Carlo simulations. Each spin $S_i$ is treated as a classical XY spin taking on Q equally spaced angles (Q-states clock model). For Q=6, a first-order transition into a stripe-ordered phase preempts the macrosc
A weak lensing estimate from GEMS of the virial to stellar mass ratio in massive galaxies to z~0.8
astro-phCatherine Heymans, Eric F. Bell, Hans-Walter Rix, Marco Barden
We present constraints on the evolution of the virial to stellar mass ratio of galaxies with high stellar masses in the redshift range 0.2<z<0.8, by comparing weak lensing measurements of virial mass M_vir to estimates of stellar mass M_star from COMBO-17. For a complete sample of galaxies with log(M_star/ M_\odot) > 10.5, where the majority show an early-ty
Patrick B. Hall, S. C. Gallagher, G. T. Richards, D. M. Alexander
We present short \chandra observations of twelve bright (i<18) z_em~1.5 quasars from the Sloan Digital Sky Survey chosen to have significantly redder optical colors than most quasars at the same redshift. Of the five quasars with optical properties most consistent with dust reddening at the quasar redshift, four show indirect evidence of moderate X-ray absor
Q. Daniel Wang
About 2 million seconds of Chandra observing time have been devoted to the Galactic center (GC), including large-scale surveys and deep pointings. These observations have led to the detection of about 4000 discrete X-ray sources and the mapping of diffuse X-ray emission in various energy bands. In this review, I first summarize general results from recent st
Kenneth G. Carpenter, Carolus J. Schrijver, Margarita Karovska, SI Vision Mission Team
The Stellar Imager (SI) is a UV-Optical, Space-Based Interferometer designed to enable 0.1 milli-arcsecond (mas) spectral imaging of stellar surfaces and of the Universe in general and asteroseismic imaging of stellar interiors. SI is identified as a "Flagship and Landmark Discovery Mission" in the 2005 Sun Solar System Connection (SSSC) Roadmap and
L. M. Young, E. Rosolowsky, J. H. van Gorkom, S. A. Lamb
We present matched-resolution maps of HI and CO emission in the Virgo Cluster spiral NGC 4647. The galaxy shows a mild kinematic disturbance in which one side of the rotation curve flattens but the other side continues to rise. This kinematic asymmetry is coupled with a dramatic asymmetry in the molecular gas distribution but not in the atomic gas. An analys
The VLT-FLAMES Survey of Massive Stars: Stellar parameters and rotational velocities in NGC3293, NGC4755 and NGC6611
astro-phP. L. Dufton, S. J. Smartt, J. K. Lee, R. S. I. Ryans
An analysis is presented of VLT-FLAMES spectroscopy for three Galactic clusters, NGC3293, NGC4755 and NGC6611. Non-LTE model atmosphere calculations have been used to estimate effective temperatures (from either the helium spectrum or the silicon ionization equilibrium) and gravities (from the hydrogen spectrum). Projected rotational velocities have been ded
Masaru Kajisawa, Tadayuki Kodama, Ichi Tanaka, Toru Yamada
We report a discovery of proto-cluster candidates around high redshift radio galaxies at z~2.5 on the basis of clear statistical excess of colour-selected galaxies around them seen in the deep near-infrared imaging data obtained with CISCO on Subaru Telescope. We have observed six targets, all at similar redshifts at z~2.5, and our data reach to J=23.5, H=22
First direct detection of a Keplerian rotating disk around the Be star $α$ Arae using the VLTI/AMBER instrument
astro-phAnthony Meilland, Philippe Stee, Martin Vannier, Florentin Millour
Aims. We aim to study the geometry and kinematics of the disk around the Be star $α$ Arae as a function of wavelength, especially across the Br$γ$ emission line. The main purpose of this paper is to answer the question about the nature of the disk rotation around Be stars. Methods. We use the VLTI/AMBER instrument operating in the K band which provides a gai
The VLT-FLAMES survey of massive stars: Mass loss and rotation of early-type stars in the SMC
astro-phM. R. Mokiem, A. de Koter, C. J. Evans, J. Puls
We have studied the optical spectra of a sample of 31 O- and early B-type stars in the Small Magellanic Cloud, 21 of which are associated with the young massive cluster NGC 346. Stellar parameters are determined using an automated fitting method. Comparison with predictions of stellar evolution that account for stellar rotation does not result in a unique ag
T. Kaminski, M. Miller, R. Szczerba, R. Tylenda
We present observations of V838 Mon and its close vicinity in the three lowest rotational transitions of CO. The J = 2-1 and 3-2 data were obtained using the 3 m KOSMA telescope. They include on-the-fly maps covering a large area (~3.4 sq. deg.) around V838 Mon and long integrations on the star position. Complementary observations in the CO J = 1-0 transitio
Adaptive Optics Correction of the Wavefront Distortions Induced by Segments Misalignment in Extremely Large Telescope
astro-phNatalia Yaitskova, Christophe Verinaud
The capability of the adaptive optics to correct for the segmentation error is analyzed in terms of the residual wavefront RMS and the power spectral density of the phase. The analytical model and the end-to-end simulation give qualitatively equal results justifying the significance of the geometrical matching between segmentation geometry and the actuators/
M. D'onofrio, T. Valentinuzzi, L. Secco, R. Caimmi
We present a panoramic review of several observational and theoretical aspects of the modern astrophysical research about the origin of the Fundamental Plane (FP) relation for Early-Type Galaxies (ETGs). The discussion is focused on the problem of the tilt and the tightness of the FP, and on the attempts to derive the luminosity evolution of ETGs with redshi
M. R. Meyer, D. E. Backman, A. J. Weinberger, M. C. Wyatt
Over the past 10 years abundant evidence has emerged that many (if not all) stars are born with circumstellar disks. Understanding the evolution of post-accretion disks can provide strong constraints on theories of planet formation and evolution. In this review, we focus on developments in understanding: a) the evolution of the gas and dust content of circum
Y. Xu, M. J. Reid, K. M. Menten, X. W. Zheng
We have used the Very Large Array to search for compact milliarcsecond-size radio sources near methanol masers in high-mass star-forming regions. Such sources are required for Very Long Baseline Interferometry phase-referencing observations. We conducted pointed observations of 234 compact sources found in the NVSS survey and find 92 sources with unresolved
Telescope to Observe Planetary Systems (TOPS): a high throughput 1.2-m visible telescope with a small inner working angle
astro-phOlivier Guyon, James R. P. Angel, Charles Bowers, James Burge
The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image in the visible (0.4-0.9 micron) planetary systems of nearby stars simultaneously in 16 spectral bands (resolution R~20). For the ~10 most favorable stars, it will have the sensitivity to discover 2 R_E rocky planets within habitable zones and characterize their surfaces or
Chemical Abundance Study of One Red Giant Star in NGC 5694 : A Globular Cluster with Dwarf Spheroidals' Chemical Signature?
astro-phJae-Woo Lee, Mercedes Lopez-Morales, Bruce W. Carney
We report the abundance analysis of one red giant branch star in the metal-poor outer halo globular cluster NGC 5694. We obtain [Fe/H] = -1.93, based on the ionized lines, and our metallicity measurement is in good agreement with previous estimates. We find that [Ca+Ti/2Fe] and [Cu/Fe] of NGC 5694 are about 0.3 -- 0.4 dex lower than other globular clusters w
High accuracy transit photometry of the planet OGLE-TR-113b with a new deconvolution-based method
astro-phM. Gillon, F. Pont, C. Moutou, F. Bouchy
A high accuracy photometry algorithm is needed to take full advantage of the potential of the transit method for the characterization of exoplanets, especially in deep crowded fields. It has to reduce to the lowest possible level the negative influence of systematic effects on the photometric accuracy. It should also be able to cope with a high level of crow
Davor Palle
We study gravitational lensing by quadrupole potentials within the linearized gravity approximation and the integration over the unperturbed photon trajectory. It is well known that the quadrupole potential contribution to the deviation angle is much smaller than that of the monopole one. We show, however, that quadrupole potentials can change the photon pol
David Bachman, Ryan Derby-Talbot
We survey known (and unknown) results about the behavior of Heegaard genus of 3-manifolds constructed via various gluings. The constructions we consider are (1) gluing together two 3-manifolds with incompressible boundary, (2) gluing together the boundary components of surface times I, and (3) gluing a handlebody to the boundary of a 3-manifold. We detail th
Satoshi X. Nakamura, Shung-ichi Ando
A Wilsonian renormalization group (WRG) equation for nuclear current operators in two-nucleon systems is derived. Nuclear current operators relevant to low-energy Gamow-Teller transitions are analyzed using the WRG equation. We employ the axial two-body current operators from phenomenological models and heavy-baryon chiral perturbation theory, which are quit
T. Fiedler, V. Kurlin
To an oriented link in a solid torus we associate a trace graph in a thickened torus in such a way that links are isotopic if and only if their trace graphs can be related by moves of finitely many standard types. The key ingredient is a study of codimension~2 singularities of link diagrams. For closed braids with a fixed number of strands, trace graphs can
Angela Kopp, Amit Ghosal, Sudip Chakravarty
The extreme variability of observables across the phase diagram of the cuprate high temperature superconductors has remained a profound mystery, with no convincing explanation of the superconducting dome. While much attention has been paid to the underdoped regime of the hole-doped cuprates because of its proximity to a complex Mott insulating phase, little
M. Passera
Improved values for the two- and three-loop mass-dependent QED contributions to the anomalous magnetic moments of the electron, muon, and tau lepton are presented. The Standard Model prediction for the electron (g-2) is compared with its most precise recent measurement, providing a value of the fine-structure constant in agreement with a recently published d
Leonid Rybnikov
We construct a family of maximal commutative subalgebras in the tensor product of n copies of the universal enveloping algebra U(g) of a semisimple Lie algebra g. This family is parameterized by collections μ; z_1,...,z_n, where μ\in g^*, and z_1,...,z_n are pairwise distinct complex numbers. The construction presented here generalizes the famous constructio
Kenneth L. Baker, Jesse E. Johnson, Elizabeth A. Klodginski
We determine the genus one fibered knots in lens spaces that have tunnel number one. We also show that every tunnel number one, once-punctured torus bundle is the result of Dehn filling a component of the Whitehead link in the 3-sphere.
Cornel Pasnicu, Mikael Rordam
We show that a separable purely infinite C*-algebra is of real rank zero if and only if its primitive ideal space has a basis consisting of compact-open sets and the natural map K_0(I) -> K_0(I/J) is surjective for all closed two-sided ideals J contained in I in the C*-algebra. It follows in particular that if A is any separable C*-algebra, then A tensor O_2
Flavor Changing Neutral Currents, an Extended Scalar Sector, and the Higgs Production Rate at the LHC
hep-phAneesh V. Manohar, Mark B. Wise
We study extensions of the standard model with additional colored scalar fields which can couple directly to quarks. Natural suppression of flavor changing neutral currents implies minimal flavor violation, and fixes the scalars to transform as (8,2)_1/2 under the SU(3) X SU(2) X U(1) gauge symmetry. We explore the phenomenology of the standard model with on
Andras Szenes
We give a proof of the periodicity of Zamolodchikov's Y-systems in the AxA case using a novel interpretation of the system as a condition of flatness of a connection on a certain graph.
Zhan Shi, Olivier Zindy
Sinai's walk is a recurrent one-dimensional nearest-neighbor random walk in random environment. It is known for a phenomenon of strong localization, namely, the walk spends almost all time at or near the bottom of deep valleys of the potential. Our main result shows a weakness of this localization phenomenon: with probability one, the zones where the wal
Jennifer Posson-Brown, Vinay L. Kashyap, Deron O. Pease, Jeremy J. Drake
We have analyzed Chandra calibration observations of Betelgeuse (alpha Ori, M2Iab, m_V=0.58, 131 pc) obtained at the aimpoint locations of the HRC-I (8 ks), HRC-S (8 ks), and ACIS-I (5 ks). Betelgeuse is undetected in all the individual observations as well as cumulatively. We derive upper limits to the X-ray count rates and compute the corresponding X-ray f
Field Emission in CEBAF's Superconducting RF Cavities and Implications for Future Accelerators
physics.acc-phJay Benesch
Field emission is one of the key issues in superconducting RF for particle accelerators. When present, it limits operating gradient directly or via induced heat load at 2K. In order to minimize particulate contamination of and thus field emission in the CEBAF SRF cavities during assembly, a cold ceramic RF window was placed very close to the accelerating cav
Eli Glasner, Michael Megrelishvili, Vladimir V. Uspenskij
When a topological group $G$ acts on a compact space $X$, its enveloping semigroup $E(X)$ is the closure of the set of $g$-translations, $g\in G$, in the compact space $X^X$. Assume that $X$ is metrizable. It has recently been shown by the first two authors that the following conditions are equivalent: (1) $X$ is hereditarily almost equicontinuous; (2) $X$ i
Ian Ellwood, Martin Schnabl
We prove Sen's third conjecture that there are no on-shell perturbative excitations of the tachyon vacuum in open bosonic string field theory. The proof relies on the existence of a special state A, which, when acted on by the BRST operator at the tachyon vacuum, gives the identity. While this state was found numerically in Feynman-Siegel gauge, here we
Number counts and clustering properties of bright Distant Red Galaxies in the UKIDSS Ultra Deep Survey Early Data Release
astro-phS. Foucaud, O. Almaini, I. Smail, C. J. Conselice
We describe the number counts and spatial distribution of 239 Distant Red Galaxies (DRGs), selected from the Early Data Release of the UKIDSS Ultra Deep Survey. The DRGs are identified by their very red infrared colours with (J-K)AB>1.3, selected over 0.62 sq degree to a 90% completeness limit of KAB~20.7. This is the first time a large sample of bright DRGs
J. A. Minahan, A. Tirziu, A. A. Tseytlin
Motivated by recent works of Hofman and Maldacena and Dorey we consider a special infinite spin limit of semiclassical spinning string states in AdS5 x S5. We discuss examples of known folded and circular 2-spin string solutions and demonstrate explicitly that the 1-loop superstring correction to the classical expression for the energy vanishes in the limit
Stephen G. Naculich, Howard J. Schnitzer
We analyze the level-rank duality of omega_c-twisted D-branes of SU(N)_K (when N and K>2). When N or K is even, the duality map involves Z_2-cominimal equivalence classes of twisted D-branes. We prove the duality of the spectrum of an open string stretched between omega_c-twisted D-branes, and ascertain the relation between the charges of level-rank-dual ome
Jacqueline Chen, Eduardo Rozo, Neal Dalal, James E. Taylor
In recent years, gravitational lensing has been used as a means to detect substructure in galaxy-sized halos, via anomalous flux ratios in quadruply-imaged lenses. In addition to causing anomalous flux ratios, substructure may also perturb the positions of lensed images at observable levels. In this paper, we numerically investigate the scale of such astrome
G. Sikkema, R. F. Peletier, D. Carter, E. A. Valentijn
Shells in Elliptical Galaxies are faint, sharp-edged features, believed to provide evidence of a recent ($\sim 0.5 - 2 \times 10^9$ years ago) merger event. We analyse the Globular Cluster (GC) systems of six shell elliptical galaxies, to examine the effects of mergers upon the GC formation history. We examine the colour distributions, and investigate differ
R. Lopes de Oliveira, G. B. Lima Neto, C. Mendes de Oliveira, E. Janot-Pacheco
We report the discovery of Cl 2334+48, a rich cluster of galaxies in the Zone of Avoidance, identified in public images from the XMM-Newton archive. We present the main properties of this cluster using the XMM-Newton X-ray data, along with new optical spectroscopic and photometric observations. Cl 2334+48 is located at z = 0.271 +/- 0.001, as derived from th
Steven B. Giddings
Perturbative dynamics of gravity is investigated for high energy scattering and in black hole backgrounds. In the latter case, a straightforward perturbative analysis fails, in a close parallel to the failure of the former when the impact parameter reaches the Schwarzschild radius. This suggests a flaw in a semiclassical description of physics on spatial sli
Karyn Le Hur
We investigate the decoherence of the electron wavepacket in purely ballistic one-dimensional systems described through the Luttinger liquid (LL). At a finite temperature $T$ and long times $t$, we show that the electron Green's function for a fixed wavevector close to one Fermi point decays as $\exp(-t/τ_F)$, as opposed to the power-law behavior occurri
John G. Miller
Consider a complete orientable manifold with countably many components of bounded dimension. Suppose that its rational homology is infinitely generated in some degree. Then there is no choice of weight function for which the natural map from weighted L^2 cohomology to de Rham cohomology is surjective in that degree.
Alon E. Faraggi, Costas Kounnas, John Rizos
Free fermionic construction of four dimensional string vacua, are related to the Z2XZ2 orbifolds at special points in the moduli space, and yielded the most realistic three family string models to date. Using free fermionic construction techniques we are able to classify more than 10^10 string vacua by the net family and anti-family number. Using a montecarl
Ying-Jia Gao, Yu-Jie Zhang, Kuang-Ta Chao
We study radiative decays of $Υ$ to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet $b\bar b$ operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by thes
A. Crisanti, L. Leuzzi
We present a critical analysis of the Sompolinsky theory of equilibrium dynamics. By using the spherical $2+p$ spin glass model we test the asymptotic static limit of the Sompolinsky solution showing that it fails to yield a thermodynamically stable solution. We then present an alternative formulation, based on the Crisanti, Hörner and Sommers [Z. für Physik
Yury Sherkunov
The Casimir-Polder potential for interaction between an excited atom and a ground-state one in the retarded case obtained with the help of perturbation technique drops as R^-2 with the distance between the atoms [E.A. Power, T.Thirunamachandran, Phys. Rev. A, 47, 2539 (1993)]. It results in diverdent integrals for interaction between an excited atom and a di
Neretin Yuri
We construct a canonical embedding of the Schwartz space on $R^n$ to the space of distributions on the adelic product of all the $p$-adic numbers. This map is equivariant with respect to the action of the symplectic group $Sp(2n, Q)$ over rational numbers and with respect to the action of the rational Heisenberg group.
B. Mitrovic, K. V. Samokhin
We calculate the effect of nonmagnetic impurity scattering on the spin-lattice relaxation rate in two-band superconductors with the s-wave pairing symmetry. It is found that for the interaction parameters appropriate for MgB2 the Hebel-Slichter peak is suppressed by disorder in the limit of small interband impurity scattering rate. In the limit of strong imp
Nicolas Brodu
This document is both a synthesis of current notions about complex systems, and a practical approach description. A disambiguation is proposed and exposes possible reasons for controversies related to causation and emergence. Theoretical considerations about simulations are presented. A justification is then given for the development of practical tools and t
F. M. Jiménez-Esteban, P. García-Lario, D. Engels, A. Manchado
We present the results of a near-infrared monitoring programme of a selected sample of stars, initially suspected to be Mira variables and OH/IR stars, covering more than a decade of observations. The objects monitored cover the typical range of IRAS colours shown by O-rich stars on the Asymptotic Giant Branch and show a surprisingly large diversity of varia
Shi-Quan Su, Jun-Liang Song, Shi-Jian Gu
In this paper, we study the entanglement between two-neighboring sites and the rest of the system in a simple quantum phase transition of 1D transverse field Ising model. We find that the entanglement shows interesting scaling and singular behavior around the critical point, and then can be use as a convenient marker for the transition point.
Yemon Choi
Let $Γ$ be a discrete group and let $f \in \ell^1(Γ)$. We observe that if the natural convolution operator $ρ_f:\ell^{\infty}(Γ)\to \ell^{\inf ty}(Γ)$ is injective, then f is invertible in $\ell^1(Γ)$. Our proof simplifies and generalizes calculations in a preprint of Deninger and Schmidt, by appealing to the direct finiteness of the algebra $\ell^1(Γ)$. We
On O-X mode conversion in a cold magnetized 2D inhomogeneous plasma in the electron cyclotron frequency range
physics.plasm-phA. Popov
In this paper a reduced set of the partial differential wave equations valid in the conversion layer close to O-mode cutoff surface and accounting for the magnetic field 2D inhomogeneity with no restriction to an angle between the toroidal direction and the magnetic field direction is derived. An integral representation of a solution to the derived set of eq
Ph. Brax, C. van de Bruck, A. C. Davis, Stephen C. Davis
Hybrid inflation can be realised in low-energy effective string theory, as described using supergravity. We find that the coupling of moduli to F-term hybrid inflation in supergravity leads to a slope and a curvature for the inflaton potential. The epsilon and eta parameters receive contributions at tree and one loop level which are not compatible with slow
Jesper Fevre Bertelsen, Henrik Kjaer Andersen, Sune Mai, Michael Budde
We demonstrate a method to make mixtures of ultracold atoms that does not make use of a two-species magneto-optical trap. We prepare two clouds of 87Rb atoms in distinct magnetic quadrupole traps and mix the two clouds by merging the traps. For correctly chosen parameters the mixing can be done essentially without loss of atoms and with only minor heating. T
Yemon Choi
Building on an old result of Duncan and Namioka, we show that the ${\ell}^1$-convolution algebra of a semilattice $S$ is biflat precisely when $S$ is uniformly locally finite. The proof shows in passing that for such $S$ the convolution algebra is isomorphic to ${\ell}^1(S)$ with pointwise multiplication. At the end we sketch how these techniques may be exte
A. V. Smilga
We show that the recently constructed higher-derivative 6D SYM theory involves an internal chiral anomaly breaking gauge invariance. The anomaly is cancelled when adding to the theory an adjoint matter hypermultiplet.
Y. S. Lim, K. J. Yee, J. H. Kim, J. Shaver
We have generated and detected the radial-breathing mode of coherent lattice vibrations in single-walled carbon nanotubes using ultrashort laser pulses. Because the band gap is a function of diameter, these diameter oscillations cause ultrafast band gap oscillations, modulating interband excitonic resonances at the phonon frequencies (3-9 THz). Excitation sp
Feng-Li Lin, Toshihiro Matsuo
We calculate the jet quenching parameter in medium with chemical potential from AdS/CFT correspondence. Our result is summarized in a plot. Moreover, we extract the explicit form of the jet quenching parameter of medium with small chemical potential for phases of dual SYM corresponding to large and small black holes. For the former phase, the jet quenching i
Vittorio Giovannetti, Diego Frustaglia, Fabio Taddei, Rosario Fazio
We show that multi-mode entanglement of electrons in a mesoscopic conductor can be detected by a measurement of the zero-frequency current correlations in an electronic Hong-Ou-Mandel interferometer. By this mean, one can further establish a lower bound to the entanglement of formation of two-electron input states. Our results extend the work of Burkard and
Lorenzo Magnea
I discuss soft-gluon resummation and power corrections for event shape distributions, mostly in e+ e- annihilation. I consider specifically the thrust, the C parameter, and the class of angularities, and show how factorization techniques and dressed gluon exponentiation lead to predictive models of power corrections that are firmly grounded in perturbative Q
A. Efimov
A new short clear proof of the asymptotics for the number $c_n$ of real roots of the Bernoulli polynomials $B_n(x)$, as well as for the maximal root $y_n$: $$y_n=\frac{n}{2\pi e}+\frac{\ln(n)}{4\pi e}+O(1)\quad\text{and}\quad c_n=\frac{2n}{\pi e}+\frac{\ln(n)}{\pi e}+O(1).$$
P. Singha Deo
At a Fano resonance in a quantum wire there is strong quantum mechanical back-scattering. When identical wave packets are incident along all possible modes of incidence, each wave packet is strongly scattered. The scattered wave packets compensate each other in such a way that the outgoing wave packets are similar to the incoming wave packets. This is as if
Jorma Louko, Alejandro Satz
We analyse within first-order perturbation theory the instantaneous transition rate of an accelerated Unruh-DeWitt particle detector whose coupling to a massless scalar field on four-dimensional Minkowski space is regularised by a spatial profile. For the Lorentzian profile introduced by Schlicht, the zero size limit is computed explicitly and expressed as a
Julius Borcea, Petter Brändén
A multivariate polynomial is {\em stable} if it is nonvanishing whenever all variables have positive imaginary parts. We classify all linear partial differential operators in the Weyl algebra $\A_n$ that preserve stability. An important tool that we develop in the process is the higher dimensional generalization of Pólya-Schur's notion of multiplier sequ
Rayleigh-Taylor turbulence is nothing like Kolmogorov turbulence in the self similar regime
physics.plasm-phOlivier Poujade
An increasing number of numerical simulations and experiments describing the turbulent spectrum of Rayleigh-Taylor (RT) mixing layers came to light over the past few years. Results reported in recent studies allow to rule out a turbulence {\it à la Kolmogorov} as a mechanism acting on a self similar RT turbulent mixing layer. A different mechanism is present
Effects of Disorder and Momentum Relaxation on the Intertube Transport of Incommensurate Carbon Nanotube Ropes and Multiwall Nanotubes
cond-mat.mes-hallM. A. Tunney, N. R. Cooper
We study theoretically the electrical transport between aligned carbon nanotubes in nanotube ropes, and between shells in multiwall carbon nanotubes. We focus on transport between two metallic nanotubes (or shells) of different chiralities with mismatched Fermi momenta and incommensurate periodicities. We perform numerical calculations of the transport prope
The train/embankment thought experiment, Einstein's second postulate of special relativity and relativity of simultaneity
physics.gen-phJ. H. Field
The relativistic time dilatation effect and Einstein's second postulate of special relativity are used to analyse train/embankment thought expriments, both Einstein's original one, and an extension where observers on two trains moving at different speeds, as well as on the embankment, are considered. Whereas the relativistic analysis of Einstein'
A. Adelmann, K. Kirch, C. J. G. Onderwater, T. Schietinger
We present the concept of a compact storage ring of less than 0.5 m orbit radius to search for the electric dipole moment of the muon ($d_μ$) by adapting the "frozen spin" method. At existing muon facilities a statistics limited sensitivity of $d_μ\sim 5 \times 10^{-23} \ecm$ can be achieved within one year of data taking. Reaching this precision wou
The Unitarity Triangle Fit in the Standard Model and Hadronic Parameters from Lattice QCD: A Reappraisal after the Measurements of Delta m_s and BR(B to tau nu)
hep-phUTfit Collaboration, M. Bona, M. Ciuchini, E. Franco
The recent measurements of the B_s meson mixing amplitude by CDF and of the leptonic branching fraction BR(B to tau nu) by Belle call for an upgraded analysis of the Unitarity Triangle in the Standard Model. Besides improving the previous constraints on the parameters of the CKM matrix, these new measurements, combined with the recent determinations of the a
S. S. Komissarov, M. Barkov, M. Lyutikov
Many astrophysical sources of high energy emission, such as black hole magnetospheres, superstrongly magnetized neutron stars (magnetars), and probably relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts involve relativistically magnetically dominated plasma. In such plasma the energy density of magnetic field greatly exceeds the thermal and the