May 2006 arXiv papers — page 13

Pablo G. Perez-Gonzalez, Robert C. Kennicutt, Karl D. Gordon, Karl A. Misselt

The recent star formation (SF) in the early-type spiral galaxy M81 is characterized using imaging observations from the far-ultraviolet (UV) to the far-infrared (IR). We compare these data with models of the stellar, gas, and dust emission for sub-galactic regions. Our results suggest the existence of a diffuse dust emission not directly linked to the recent

Craig S. Rudick, J. Christopher Mihos, Cameron McBride

Using N-body simulations, we have modeled the production and evolution of diffuse, low surface brightness intracluster light (ICL) in three simulated galaxy clusters. Using an observational definition of ICL to be luminosity at a surface brightness mu_V>26.5 mag/sq.arcsec, we have found that the fraction of cluster luminosity contained in ICL generally incre

J. P. Wisniewski, B. L. Babler, K. S. Bjorkman, A. V. Kurchakov

We present the results of long-term spectropolarimetric and spectroscopic monitoring of MWC 314, a candidate Luminous Blue Variable star. We detect the first evidence of H$α$ variability in MWC 314, and find no apparent periodicity in this emission. The total R-band polarization is observed to vary between 2.21% and 3.00% at a position angle consistently aro

Ray Jayawardhana, Jaime Coffey, Alexander Scholz, Alexis Brandeker

We report the findings of a comprehensive study of disk accretion and related phenomena in four of the nearest young stellar associations spanning 6-30 million years in age, an epoch that may coincide with the late stages of planet formation. We have obtained ~650 multi-epoch high-resolution optical spectra of 100 low-mass stars that are likely members of th

Aeree Chung, Baerbel Koribalski, Martin Bureau, J. H. van Gorkom

We present Australia Telescope Compact Array (ATCA) HI imaging of the edge-on galaxy NGC 1596, which was recently found to have counter-rotating ionized gas in its center (<15&#34;). We find a large HI envelope associated with a nearby companion, the dwarf irregular galaxy NGC 1602. The HI covers a region \~11.9&#39;x13.4&#39; (62x70 kpc^2) and the total HI

Jochen Eisloeffel, Artie P. Hatzes, Heike Rauer, Holger Voss

Thueringer Landessternwarte Tautenburg (TLS) has started to operate a small dedicated telescope - the Tautenburg Exoplanet Search Telescope (TEST) - searching for transits of extrasolar planets in photometric time series observations. In a joint effort with the Berlin Exoplanet Search Telescope (BEST) operated by the Institut fuer Planetenforschung of the &#

Tom Ray, Catherine Dougados, Francesca Bacciotti, Jochen Eisloeffel

Jets from young stars represent one of the most striking signposts of star formation. The phenomenon has been researched for over two decades and there is now general agreement that such jets are generated as a by-product of accretion; most likely by the accretion disk itself. Thus they mimic what occurs in more exotic objects such as active galactic nuclei

Manuel Peimbert, Antonio Peimbert

In this review we present a brief discussion on the observational evidence in favor of the presence of temperature variations, and conclude that many planetary nebulae show spatial temperature variations that are larger than those predicted by 1D static chemically homogeneous photoionization models. To determine accurate chemical abundances it is necessary t

Brent A. Buckalew, Henry A. Kobulnicky

(abridged) NGC 1569 is an ideal test environment to understand the impact of &#34;feedback&#34; from massive stars on the surrounding ISM. We present HST WFPC2 narrowband imagery of NGC 1569 in an attempt to understand the underlying ionizing emission mechanisms on a 3 pc scale and to generate a H II region size distribution and luminosity function. We use [

Valery V. Kravtsov

Peak metallicities of metal-rich(MR) populations of GCs belonging to spheroids of different mass fall within the somewhat conservative -0.7<=[Fe/H]<=-0.3 range. Indeed, if possible age effects are taken into account,this metallicity range might become smaller. Irregulars, like the LMC, with longer timescales of their formation and lower star formation (SF) e

B. Stelzer, G. Micela, K. Hamaguchi, J. H. M. M. Schmitt

We performed a systematic search for Chandra archival observations of Herbig Ae/Be stars. These stars are fully radiative and not expected to support dynamo action analogous to their convective lower-mass counterparts, the T Tauri stars. Their X-ray emission has remained unexplained. The superior spatial resolution of Chandra with respect to previous X-ray i

Hideo Matsuhara, Takehiko Wada, Shuji Matsuura, Takao Nakagawa

AKARI (formerly ASTRO-F) is an infrared space telescope designed for an all-sky survey at 10-180 (mu)m, and deep pointed surveys of selected areas at 2-180 (mu)m. The deep pointed surveys with AKARI will significantly advance our understanding of galaxy evolution, the structure formation of the Universe, the nature of the buried AGNs, and the cosmic infrared

A. Aungwerojwit, B. T. Gaensicke, P. Rodriguez-Gil, H. -J. Hagen

We report the discovery of five new dwarf novae from the Hamburg Quasar Survey (HQS), and discuss the properties of the sample of dwarf novae in the HQS. The orbital periods of the new dwarf novae are ~105.1 min or ~109.9 min, 114.3+-2.7 min, 92.66+-0.17 min, 272.317+-0.001 min, 258.02+-0.56 min for HS0417+7445, HS1016+3412, HS1340+1524, HS1857+7127, and HS2

F. L. Schoeier, J. K. Jorgensen, K. M. Pontoppidan, A. A. Lundgren

This paper presents new APEX submillimetre molecular line observations of three low-mass protostars, IRS7A, IRS7B, and IRAS32, in the R Coronae Australis molecular cloud complex. The molecular excitation analysis is performed using a statistical equilibrium radiative transfer code. The derived beam averaged fractional abundances vary by less than a factor of

Kenji Bekki, Hideki Yahagi, Duncan A. Forbes

Using high-resolution numerical simulations, we investigate mass- and luminosity-normalized specific frequencies (T_N and S_N, respectively) of globular cluster systems (GCSs) in order to understand the origin of the observed U-shaped relation between S_N and V-band magnitude (M_V) of their host galaxies. We adopt a biased GC formation scenario in which GC f

Richard J. Stancliffe

A version of the STARS stellar evolution code has been developed that uses a non-simultaneous solution of the equations of stellar structure and evolution. In all other respects it is identical to the normal, fully simultaneous version. It is therefore possible to test the dependence of the solution on how the equations are solved. Two cases are investigated

F. F. S. van der Tak, ; A. Belloche, P. Schilke, R. G&#34;usten

The cosmic-ray ionization rate (zeta) of dense molecular clouds is a key parameter for their dynamics and chemistry. Variations of zeta are well established, but it is unclear if these are related to source column density or to Galactic location. Using the APEX telescope, we have mapped the 364 GHz line of H3O+ in the Sgr B2 region and observed the 307 GHz l

Ata Sarajedini, M. K. Barker, Doug Geisler, Paul Harding

We present observations of RR Lyrae variables in the Local Group late-type spiral galaxy M33. Using the Advanced Camera for Surveys on the Hubble Space Telescope, we have identified 64 ab-type RR Lyraes in M33. We have estimated reddenings for these stars based on their minimum light V-I colors and metallicities based on their periods. From the distributions

Ikuko Matsuyanagi, Yoichi Itoh, Koji Sugitani, Yumiko Oasa

We have carried out a deep near-infrared survey of a bright-rimmed molecular cloud, BRC 14 (IC 1848A). The 10 sigma limiting magnitude of the survey is 17.7 mag at the K-band. Seventy-four sources are classified as young stellar object (YSO) candidates based on the near-infrared color-color diagram. The faintest YSO candidates may have masses of an order of

S. -W. Feng, Z. -Q. Shen, H. -B. Cai, X. Chen

We report on VLBA observations of a gamma-ray bright blazar NRAO 530 at multiple frequencies (5, 8, 15, 22, 39, 43, and 45 GHz) in 1997 and 1999. These multi-epoch multi-frequency high-resolution VLBI images exhibit a consistent core-dominated morphology with a bending jet to the north of the core. The quasi-simultaneous data observed at five frequencies (5,

Ruslan Prozorov, Matthew D. Vannette, German D. Samolyuk, Stephanie A. Law

Shubnikov - de Haas oscillations were measured in single crystals of highly metallic antiferromagnetic SmAgSb$_{2}$ and ferromagnetic CeAgSb$_{2}$ using a tunnel diode resonator. Resistivity oscillations as a function of applied magnetic field were observed via measurements of skin depth variation. The effective resolution of $Δρ\simeq20$ p$Ω$ allows a detai

Artur F. Izmaylov, Ali Ihsan Goker, Peter Nordlander, Barry Friedman

The time-dependent non-crossing approximation is employed for the single-electron transistor to calculate the transient response of the conductance for a variety of temperatures and biases. We consider the case when the dot-lead tunneling constant is suddenly changed such that the Kondo effect is present in the final state. In the fast non-universal timescal

Lars Fromme, Stephan J. Huber, Michael Seniuch

We consider the generation of the baryon asymmetry in the two-Higgs doublet model. Investigating the thermal potential in the presence of CP violation, as relevant for baryogenesis, we find a strong first-order phase transition if the extra Higgs states are heavier than about 300 GeV. The mass of the lightest Higgs can be as large as about 200 GeV. We comput

CDF Collaboration

We present results of a search for anomalous production of events containing a charged lepton (either electron or muon) and a photon, both with high transverse momentum, accompanied by additional signatures, X, including missing transverse energy (MET) and additional leptons and photons. We use the same kinematic selection criteria as in a previous CDF searc

Alexander Gorodnik, Amos Nevo

We prove mean and pointwise ergodic theorems for general families of averages on a semisimple algebraic (or S-algebraic) group G, together with an explicit rate of convergence when the action has a spectral gap. Given any lattice in G, we use the ergodic theorems for G to solve the lattice point counting problem for general domains in G, and prove mean and p

Hongyu He

We study square integrable functions on the metaplectic group and functions on the space of unitary symmetric matrices. We relate them using the oscillator representations.

D Bourilkov, R C Group, M R Whalley

Parton Density Functions (PDFs) and their uncertainties are extremely important topics for both the Tevatron and the LHC. Experiments at the Tevatron can enhance this knowledge not only by constraining the PDF fits, but also by developing and refining the available PDF tools through feed-back from the experiments that are currently analyzing the highest ener

Adolfo De Unánue, Sarira Sahu, Daniel Sudarsky

We consider the possibility that the particles in the Ultra High Energy Cosmic Rays arriving to Earth might be neutrons instead of protons. We stress that in such case the argument for the GZK cutoff is weaker and that it is conceivable that neutrons would not be affected by it. This scenario would require the neutron to start with an energy larger than the

T. Q. Donaghy, D. Q. Lamb, T. Sakamoto, J. P. Norris

Here we report the localizations and properties of four short-duration GRBs localized by the High Energy Transient Explorer 2 satellite (HETE-2): GRBs 010326B, 040802, 051211 and 060121, all of which were detected by the French Gamma Telescope (Fregate) and localized with the Wide-field X-ray Monitor (WXM) and/or Soft X-ray Camera (SXC) instruments. We discu

Carla Farsi

In this paper we prove a relative index theorem for pairs of generalized Dirac operators on orbifolds which are the same at infinity. This generalizes to orbifolds a celebrated theorem of Gromov and Lawson.

Janos Polonyi

A classical field theory is proposed for the electric current and the electromagnetic field interpolating between microscopic and macroscopic domains. It represents a generalization of the density functional for the dynamics of the current and the electromagnetic field in the quantum side of the crossover and reproduces standard classical electrodynamics on

Ron Donagi, Rene Reinbacher, Shing-Tung Yau

We compute the particle spectrum and some of the Yukawa couplings for a family of heterotic compactifications on quintic threefolds X involving bundles that are deformations of TX+O_X. These are then related to the compactifications with torsion found recently by Li and Yau. We compute the spectrum and the Yukawa couplings for generic bundles on generic quin

Yuri G. Zarhin

We construct absolutely simple jacobians of non-hyperelliptic genus 4 curves, using Del Pezzo surfaces of degree 1. This paper is a natural continuation of author's paper math.AG/0405156.

Basudha Misra, Jyoti Prasad Saha, Prasanta Kumar Das

We investigate the ${\bar B_s} \to μ^+ μ^-$ decay in the presence of a light stabilized radion in Randall-Sundrum model. The branching ratio $BR({\bar B_s} \to μ^+ μ^-)$ in the standard model is found to be $3.17 \times 10^{-9}$ (two order smaller than the experimental upper bound) and raises the question whether some new physics can play a crucial role or n

Gabor Etesi

By referring to theorems of Donaldson and Hitchin, we exhibit a rigorous AdS/CFT-type correspondence between classical 2+1 dimensional vacuum general relativity theory on S x R and SO(3) Hitchin theory (regarded as a classical conformal field theory) on the spacelike past boundary S, a compact, oriented Riemann surface of genus greater than one. Within this

Zsolt Horváth, Zoltán Kovács, László Á. Gergely

The spherically symmetric, static spacetime generated by a crossflow of non-interacting radiation streams, treated in the geometrical optics limit (null dust) is equivalent to an anisotropic fluid forming a radiation atmosphere of a star. This reference fluid provides a preferred / internal time, which is employed as a canonical coordinate. Among the advanta

Ismail Zakout, Carsten Greiner, Jurgen Schaffner-Bielich

The order, shape and critical point for the phase transition between the hadronic matter and quark-gluon plasma are considered in a thermodynamical consistent approach. The hadronic phase is taken as Van der Waals gas of all the known hadronic mass spectrum particles $m_H\le 2.0$ GeV as well as Hagedorn bubbles which correspond hadronic states with mass spec

Craig J. Hogan

The mean spectrum and burst statistics of gravitational waves produced by a cosmological population of cosmic string loops are estimated using analytic approximations, calibrated with earlier simulations. Formulas are derived showing the dependence of observables on the string tension, in the regime where newly-formed loops are relatively large, not very muc

Christopher A. Francisco

A tetrahedral curve is a (usually nonreduced) curve in P^3 defined by an unmixed, height two ideal generated by monomials. We characterize when these curves are arithmetically Cohen-Macaulay by associating a graph to each curve and, using results from combinatorial commutative algebra and Alexander duality, relating the structure of the complementary graph t

Nils Greinert, Tiffany Wood, Paul Bartlett

We study the thermal fluctuations of an optically confined probe particle, suspended in an aging colloidal suspension, as the suspension transforms from a viscous liquid into an elastic glass. The micron-sized bead forms a harmonic oscillator. By monitoring the equal-time fluctuations of the tracer, at two different laser powers, we determine the temperature

H. Safari, S. Nasiri, Y. Sobouti

We investigate the standing kink modes of a cylindrical model of coronal loops. The density is stratified along the loop axis and changes discontinuously at the surface of the cylinder. The periods and mode profiles are studies with their deviation from those of the unstratified loops. The aim is to extract information on the density scale heights prevailing

Nan-Kuo Ho, Chiu-Chu Melissa Liu

In &#34;The Yang-Mills equations over Riemann surfaces&#34;, Atiyah and Bott studied Yang-Mills functional over a Riemann surface from the point of view of Morse theory. We generalize their study to all closed, compact, connected, possibly nonorientable surfaces. We introduce the notion of &#34;super central extension&#34; of the fundamental group of a surfa

F. Lechermann, A. Georges, A. Poteryaev, S. Biermann

A versatile method for combining density functional theory (DFT) in the local density approximation (LDA) with dynamical mean-field theory (DMFT) is presented. Starting from a general basis-independent formulation, we use Wannier functions as an interface between the two theories. These functions are used for the physical purpose of identifying the correlate

S. Kajari-Schroeder, G. Morigi, S. Franke-Arnold, G. -L. Oppo

Light propagation in an atomic medium whose coupled electronic levels form a diamond-configuration exhibits a critical dependence on the input conditions. In particular, the relative phase of the input fields gives rise to interference phenomena in the electronic excitation whose interplay with relaxation processes determines the stationary state. We integra

A. Brandenburg, A. Ringwald, A. Utermann

We consider QCD instanton-induced contributions to lepton pair production in hadron-hadron collisions. We relate these contributions to those known from deep inelastic scattering and demonstrate that they can be calculated reliably for sufficiently large momentum transfer. We observe that the instanton contribution to the angular distribution of the lepton p

Cristian D. Gonzalez-Aviles

This paper presents results on both the kernel and cokernel of the S-capitulation map C_{F,S}\ra C_{K,S}^{G} for arbitrary finite Galois extensions K/F (with Galois group G) and arbitrary finite sets of primes S of F (assumed to contain the archimedean primes in the number field case)

T. W. Hijmans, T. N. Huussen, R. J. C. Spreeuw

We present new results on an optical implementation of Grover&#39;s quantum search algorithm. This extends previous work in which the transverse spatial mode of a light beam oscillates between a broad initial input shape and a highly localized spike, which reveals the position of the tagged item. The spike reaches its maximum intensity after $\sim\sqrt N$ ro

Toshihiko Ota, Werner Rodejohann

A supersymmetric see-saw model obeying the flavor symmetry L_mu - L_tau, which naturally predicts quasi-degenerate neutrinos, is investigated. Breaking of the symmetry is introduced in the Dirac mass matrix because it is the most economic choice in the sense that all interesting low and high energy phenomenology is made possible: we analyze the predictions f

Bryan Eastin

I describe a procedure for calculating thresholds for quantum computation as a function of error model given the availability of ancillae prepared in logical states with independent, identically distributed errors. The thresholds are determined via a simple counting argument performed on a single qubit of an infinitely large CSS code. I give concrete example

K. V. Dharmawardane, S. E. Kuhn, P. Bosted, Y. Prok

We report results for the virtual photon asymmetry $A_1$ on the nucleon from new Jefferson Lab measurements. The experiment, which used the CEBAF Large Acceptance Spectrometer and longitudinally polarized proton ($^{15}$NH$_3$) and deuteron ($^{15}$ND$_3$) targets, collected data with a longitudinally polarized electron beam at energies between 1.6 GeV and 5

K. Spekkens, R. Giovanelli

We present I-band photometry, long-slit optical spectroscopy, and new aperture synthesis HI observations for eight late-type spirals with rotation velocities in the range 243 km/s < V_{rot} < 308 km/s. The sample will be used to study the structure and angular momentum of disks at the high-mass end of the spiral galaxy population; here we discuss the basic p

N. N. Lathiotakis, N. Helbig, E. K. U. Gross

The subject of this study is the exchange-correlation-energy functional of reduced density matrix functional theory. Approximations of this functional are tested by applying them to the homogeneous electron gas. We find that two approximations recently proposed by Gritsenko, Pernal, and Baerends, J. Chem. Phys., {\bf 122}, 204102 (2005), yield considerably b

D. Ebert, A. P. Martynenko

On the basis of the perturbative QCD and the relativistic quark model we investigate the relativistic and bound state effects in the production processes of a pair of $S$-wave doubly heavy mesons with opposite charge conjugation consisting of $b$ and $c$ quarks. All possible relativistic corrections in the production amplitude including the terms connected w

A. Tertikas, N. B. Zographopoulos

We consider Hardy-Rellich inequalities and discuss their possible improvement. The procedure is based on decomposition into spherical harmonics, where in addition various new inequalities are obtained (e.g. Rellich-Sobolev inequalities). We discuss also the optimality of these inequalities in the sense that we establish (in most cases) that the constants app

D. Bolle, R. Heylen, N. S. Skantzos

We study the thermodynamic properties of spin systems on small-world hypergraphs, obtained by superimposing sparse Poisson random graphs with p-spin interactions onto a one-dimensional Ising chain with nearest-neighbor interactions. We use replica-symmetric transfer-matrix techniques to derive a set of fixed-point equations describing the relevant order para

Shiro Sakai, Ryotaro Arita, Karsten Held, Hideo Aoki

We propose to combine the Trotter decomposition and a series expansion of the partition function for Hund&#39;s exchange coupling in a quantum Monte Carlo (QMC) algorithm for multiorbital systems that preserves spin and orbital rotational symmetries. This enables us to treat the Hund&#39;s (spin-flip and pair-hopping) terms, which is difficult in the convent

R. Nilsson, H. Uthas, M. Ytre-Eide, J-E. Solheim

The number of discovered non-radially pulsating white dwarfs (WDs) in cataclysmic variables (CVs) is increasing rapidly by the aid of the Sloan Digital Sky Survey (SDSS). We performed photometric observations of two additional objects, SDSS J133941.11+484727.5 (SDSS 1339), independently discovered as a pulsator by Gansicke et al., and SDSS J151413.72+454911.

Persi Diaconis, Silke W. W. Rolles

We introduce a natural conjugate prior for the transition matrix of a reversible Markov chain. This allows estimation and testing. The prior arises from random walk with reinforcement in the same way the Dirichlet prior arises from Pólya&#39;s urn. We give closed form normalizing constants, a simple method of simulation from the posterior and a characterizat

Andreas Hocker, Zoltan Ligeti

Our knowledge of quark-flavor physics and CP violation increased tremendously over the past five years. It is confirmed that the Standard Model correctly describes the dominant parts of the observed CP-violating and flavor-changing phenomena. Not only does CP violation provide some of the most precise constraints on the flavor sector, but several measurement

P. Blythe, B. Varcoe

A quantum computer is a hypothetical device in which the laws of quantum mechanics are used to introduce a degree of parallelism into computations and which could therefore significantly improve on the computational speed of a classical computer at certain tasks. Cluster state quantum computing (recently proposed by Raussendorf and Briegel) is a new paradigm

Andrej Dobrotka, Alon Retter, Alex Liu

A period analysis of CCD unfiltered photometry of V4745 Sgr (Nova Sgr 2003 #1) performed during 23 nights in the years 2003 - 2005 is presented. The photometric data are modulated with a period of 0.20782 +- 0.00003 d ($4.98768 +- 0.00072 h). Following the shape of the phased light curve and the presence of the periodicity in all data sets with no apparent c

Markus Holzmann, Bernard Bernu, D. M. Ceperley

We present new trial wave-functions which include 3-body correlations into the backflow coordinates and a 4-body symmetric potential. We show that our wavefunctions lower the energy enough to stabilize the ground state energies of normal liquid $^3$He in the unpolarized state at all pressures in agreement with experiment; however, quantitative discrepancies

Silvana Botti, Miguel A. L. Marques

Semiconducting nanoparticles are the building blocks of optical nanodevices as their electronic states, and therefore light absorption and emission, can be controlled by modifying their size and shape. CdSe is perhaps the most studied of these nanoparticles, due to the efficiency of its synthesis, the high quality of the resulting samples, and the fact that

Hailu Luo, Zhongzhou Ren, Weixing Shu, Fei Li

We investigate the wave propagation in the anisotropic metamaterial with single-sheeted hyperboloid dispersion relation. Based on boundary conditions and dispersion relations, we find that the opposite amphoteric refraction, such that E- (or H-) polarized waves are positively refracted whereas H- (or E-) polarized waves are negatively refracted, can occur at

Tomohiro Kai, Hiroshi Kozaki, Ken-ichi nakao, Yasusada Nambu

If expanding and contracting regions coexist in the universe, the speed of the cosmic volume expansion can be accelerated. We construct simple inhomogeneous dust-filled universe models in which the speed of the cosmic volume expansion is accelerated for finite periods. These models are constructed by removing spherical domains from the Einstein-de Sitter uni

Y. Hirose, M. Umemura, A. Yonehara, J. Sato

We propose a novel method to extract the imprint of gravitational lensing by Pop III stars in the light curves of Gamma Ray Bursts (GRBs). Significant portions of GRBs can originate in hypernovae of Pop III stars and be gravitationally lensed by foreground Pop III stars or their remnants. If the lens mass is on the order of $10^2-10^3M_\odot$ and the lens re

Kenichiro Konya

We consider a single 3-brane situated between two bulk spacetimes that posses the same cosmological constant, but whose metrics do not posses a $Z_{2}$-symmetry. On each side of the brane, the bulk is a solution to Gauss-Bonnet gravity. This asymmetry modifies junction conditions, and so new terms arise in the Friedmann equation. If these terms become domina

M. Hortacsu, F. Taskin

We show that we can construct a model in 3+1 dimensions where it is necessary that composite vector particles take place in physical processes as incoming and outgoing particles . Cross-section of the processes in which only the constituent spinors take place goes to zero. While the spinor-spinor scattering goes to zero, the scattering of composites gives no

V. P. Neznamov

The paper formulates the Standard Model with massive fermions without introduction of the Yukawa interaction of Higgs bosons with fermions. For invariance to be preserved in the newly stated theory, the covariant derivative should be generalized, as follows. With such approach, Higgs bosons are responsible only for the gauge invariance of the boson sector of

V. P. Neznamov

The paper offers an expression of the general Foldy-Wouthuysen transformation in the chiral representation of Dirac matrices and in the presence of boson fields interacting with fermion field.

Kanan K. Datta, T. Roy Choudhury, Somnath Bharadwaj

Observations of redshifted 21cm radiation from HI at high redshifts is an important future probe of reionization. We consider the Multi-frequency Angular Power Spectrum (MAPS) to quantify the statistics of the HI signal as a joint function of the angular multipole l and frequency separation Δν. The signal at two different frequencies is expected to get decor

Masaru Onoda, Yshai Avishai, Naoto Nagaosa

Localization problem of electronic states in a two-dimensional quantum spin Hall system (QSH - a symplectic model with a non-trivial topological structure) is studied by the transfer matrix method. The phase diagram in the plane of energy and disorder strength is exposed, and demonstrates &#34;levitation&#34; and &#34;pair-annihilation&#34; of the domains of

Indranil Chakrabarty, Satyabrata Adhikari, B. S. Choudhury

In this letter, we show the impossibility of the general operation introduced by Pati [3] using two different but consistent principles (i) no-signalling (ii) non increase of entanglement under LOCC.

Indranil Chakrabarty

In this work we investigate that whether one can construct single and two qubit gates for arbitrary quantum states from the principle of no signalling. We considered the problem for Pauli gates, Hadamard gate, C-Not gate.

Ki-Myeong Lee, Ho-Ung Yee

We study supersymmetric AdS_4 x X_7 solutions of 11-dim supergravity where the tri-Sasakian space X_7 has generically U(1)^2\times SU(2)_R isometry. The compact and regular 7-dim spaces X_7=S(t_1,t_2,t_3) is originated from 8-dim hyperkahler quotient of a 12-dim flat hyperkahler space by U(1) and belongs to the class of the Eschenburg space. We calculate the

Ivana Djuric, Chris P. Search

We examine the spin current and the associated shot noise generated in a quantum dot connected to normal leads with zero bias voltage across the dot. The spin current is generated by spin flip transitions induced by a quantized electromagnetic field inside a cavity with one of the Zeeman states lying below the Fermi level of the leads and the other above. In

Y. J. Jo, L. Balicas, N. Kikugawa, E. S. Choi

We show that the metamagnetic transition in Sr$_4$Ru$_3$O$_{10}$ bifurcates into two transitions as the field is rotated away from the conducting planes. This two-step process comprises partial or total alignment of moments in ferromagnetic bands followed by an itinerant metamagnetic transition whose critical field increases with rotation. Evidence for itine

Henry L. Haselgrove, Peter P. Rohde

In a recent study [Rohde et al., quant-ph/0603130 (2006)] of several quantum error correcting protocols designed for tolerance against qubit loss, it was shown that these protocols have the undesirable effect of magnifying the effects of depolarization noise. This raises the question of which general properties of quantum error-correcting codes might explain

Ying Li, Cai-Dian Lu

With the perturbative QCD approach based on $k_T$ factorization, we study the pure annihilation type radiative decays $B^0 \to ϕγ$ and $B^0\to J/ψγ$. We find that the branching ratio of $B^0 \to ϕγ$ is $(2.7^{+0.3+1.2}_{-0.6-0.6})\times10^{-11}$, which is too small to be measured in the current $B$ factories of BaBar and Belle. The branching ratio of $B^0\to

Cesar J. Niche, Maria E. Schonbek

We address the decay of the norm of weak solutions to the 2D dissipative quasi-geostrophic equation. When the initial data is in $L^2$ only, we prove that the $L^2$ norm tends to zero but with no uniform rate, that is, there are solutions with arbitrarily slow decay. For the initial data in $L^p \cap L^2$, with $1 \leq p < 2$, we are able to obtain a uniform

S. Bianchini, L. V. Spinolo

We study a family of initial boundary value problems associated to mixed hyperbolic-parabolic systems: v^ε _t + A (v^ε, εv^ε_x ) v^ε_x = εB (v^ε ) v^ε_{xx} The conservative case is, in particular, included in the previous formulation. We suppose that the solutions $v^ε$ to these problems converge to a unique limit. Also, it is assumed smallness of the total

Lars Winther Christensen, Oana Veliche

This paper studies infinite acyclic complexes of finitely generated free modules over a commutative noetherian local ring $(R,m)$ with $m^3=0$. Conclusive results are obtained on the growth of the ranks of the modules in acyclic complexes, and new sufficient conditions are given for total acyclicity. Results are also obtained on the structure of rings that a

Juefei Zhou, Mark G. Kuzyk, David S. Watkins

We use numerical optimization to find a one-dimensional potential energy function that yields the largest hyperpolarizability, which we find is within 30% of the fundamental limit. Our results reveal insights into the character of the potential energy functions and wavefunctions that lead to the largest hyperpolarizability. We suggest that donor-acceptor mol

D. Kinzebulatov

The approach to the consideration of the ordinary differential equations with distributions in the classical space $\mathcal D&#39;$ of distributions with continuous test functions has certain insufficiencies: the notations are incorrect from the point of view of distribution theory, the right-hand side has to satisfy the restrictive conditions of equality t

Diego Arbo, Emil Persson, Joachim Burgdoerfer

We show that interference phenomena plays a big role for the electron yield in ionization of atoms by an ultra-short laser pulse. Our theoretical study of single ionization of atoms driven by few-cycles pulses extends the photoelectron spectrum observed in the double-slit experiment by Lindner et al, Phys. Rev. Lett. \textbf{95}, 040401 (2005) to a complete

Biplab Ghosh, A. S. Majumdar, N. Nayak

We consider the coherent state radiation field inside a micromaser cavity and study the entanglement mediated by it on a pair of two level atoms passing though the cavity one after the other. We then investigate the effects of squeezing of the cavity field on the atomic entanglement. We compute the entanglement of formation for the emerging mixed two-atom st

G. Ya. Slepyan, S. A. Maksimenko

Linear media are predicted to exist whose relative permiability is an operator in the space of quantum states of light. Such media are characterized by a photon statistics--dependent refractive index. This indicates a new type of optical dispersion -- the photon statistics dispersion. Interaction of quantum light with such media modifies the photon number di

Minghui Zhang, Qing Wei, Xia Shen, Yongfeng Liu

The Fourier-Transform ghost imaging of both amplitude-only and pure-phase objects was experimentally observed with classical incoherent light at Fresnel distance by a new lensless scheme. The experimental results are in good agreement with the standard Fourier-transform of the corresponding objects. This scheme provides a new route towards aberration-free di

E. Comay

It is proved that density plays a crucial role in the structure of quantum field theory. The Dirac and the Klein-Gordon equations are examined. The results prove that the Dirac equation is consistent with density related requirements whereas the Klein-Gordon equation fails to do that. Experimental data support these conclusions.

Xiao-Yu Chen, Li-zhen Jiang, Liang Han

The state evolution of the initial optical \textit{noon} state is investigated. The residue entanglement of the state is calculated after it is damped by amplitude and phase damping. The relative entropy of entanglement of the damped state is exactly obtained. The performance of direct application of the damped \textit{noon} state is compared with that of fi

Kalin Vetsigian, Carl Woese, Nigel Goldenfeld

A dynamical theory for the evolution of the genetic code is presented, which accounts for its universality and optimality. The central concept is that a variety of collective, but non-Darwinian, mechanisms likely to be present in early communal life generically lead to refinement and selection of innovation-sharing protocols, such as the genetic code. Our pr

M. Hisakado, K. Kitsukawa, S. Mori

We discuss a general method to construct correlated binomial distributions by imposing several consistent relations on the joint probability function. We obtain self-consistency relations for the conditional correlations and conditional probabilities. The beta-binomial distribution is derived by a strong symmetric assumption on the conditional correlations.

Abdolrahman Namdar, Ilya V. Shadrivov, Yuri S. Kivshar

We study the electromagnetic surface waves localized at an interface separating a one-dimensional photonic crystal and left-handed metamaterial, the so-called surface Tamm states. We demonstrate that the metamaterial allows for a flexible control of the dispersion properties of surface states, and can support the Tamm states with a backward energy flow and a

A. I. Mikhailov, A. V. Nefiodov, G. Plunien

The cross section for single K-shell ionization by a high-energy photon is evaluated in the next-to-leading order of the nonrelativistic perturbation theory with respect to the electron-electron interaction. The screening corrections are of particular importance for light helium-like ions. Even in the case of neutral He atom, our analytical predictions turn

A. I. Mikhailov, I. A. Mikhailov, A. V. Nefiodov, G. Plunien

The total cross section for double ionization of lithiumlike ions by a high-energy photon is calculated in leading order of the nonrelativistic perturbation theory. The partial contributions due to simultaneous and sequential emissions of two electrons are taken into account. The cross section under consideration is shown to be related to those for double ph

A. Hofer, P. Moroshkin, D. Nettels, S. Ulzega

We report the observation of emission spectra from Rb*He_n exciplexes in solid 4He. Two different excitation channels were experimentally identified, viz., exciplex formation via laser excitation to the atomic 5P3/2 and to the 5P1/2 levels. While the former channel was observed before in liquid helium, on helium nanodroplets and in helium gas by different gr

Vena Pearl Boñgolan-Walsh, Jinqiao Duan, Paul Fischer, Tamay Özgökmen

Gravity currents have been studied numerically and experimentally both in the laboratory and in the ocean. The question of appropriate boundary conditions is still challenging for most complex flows. Gravity currents make no exception - appropriate, physically and mathematically sound boundary conditions are yet to be found. This task is further complicated

Charles B. Chiu, Rudolph C. Hwa

An approach is proposed to analyze the azimuthal distribution of particles produced on the away side in heavy-ion collisions without background subtraction. Measures in terms of factorial moments are suggested that can suppress the statistical background, while giving clear distinction between one-jet and two-jet event structures on the away side. It is also

B. F. Bayman, F. Zardi

The semiclassical model of relativistic Coulomb excitation is studied in situations in which the impact parameter is small enough so that projectile and target charge distributions overlap. The electromagnetic effects of this overlap are shown to be small. Realistic nucleon-nucleon reaction cross-sections, and realistic nuclear radial charge and matter distr

Giampaolo Co&#39;

The Random Phase Approximation theory is used to calculate the total cross sections of electron neutrinos on $^{12}$C nucleus. The role of the excitation of the discrete spectrum is discussed. A comparison with electron scattering and muon capture data is presented. The cross section of electron neutrinos coming from muon decay at rest is calculated.