August 2004 arXiv papers — page 4

Christopher R. Ashman, Clemens J. Foerst, Karlheinz Schwarz, Peter E. Bloechl

This paper reports state-of-the-art electronic structure calculations of La adsorption on the Si(001) surface. We predict La chains in the low coverage limit, which condense in a stable phase at a coverage of 1/5 monolayer. At 1/3 monolayer we predict a chemically rather inert, stable phase. La changes its oxidation state from La(3+) at lower coverages to La

Ernesto P. Borges, Constantino Tsallis, Jose G. V. Miranda, Roberto F. S. Andrade

We generalize some widely used mother wavelets by means of the q-exponential function $e_q^x \equiv [1+(1-q)x]^{1/(1-q)}$ ($q \in {\mathbb R}$, $e_1^x=e^x$) that emerges from nonextensive statistical mechanics. Particularly, we define extended versions of the mexican hat and the Morlet wavelets. We also introduce new wavelets that are $q$-generalizations of

F. J. Cao, L. Dinis, J. M. R. Parrondo

An ensemble of Brownian particles in a feedback controlled flashing ratchet is studied. The ratchet potential is switched on and off depending on the position of the particles, with the aim of maximizing the current. We study in detail a protocol which maximizes the instant velocity of the center of mass of the ensemble at any time. This protocol is optimal

K. Malarz, K. Kulakowski

In a graph, nodes can be characterized locally (with their degree $k$) or globally (e.g. with their average length path $ξ$ to other nodes). Here we investigate how $ξ$ depends on $k$. Our earlier algorithm of the construction of the distance matrix is applied to the random graphs. Numerical calculations are performed for the random graphs and the growing ne

I. F. Mirabel, I. Rodrigues, Q. Z. Liu

We show that the microquasar LSI+61303 is running away from its birth place in a young complex of massive stars. The supernova explosion that formed the compact object shot out the x-ray binary with a linear momentum of 430 +/- 140 Msun km/s, which is comparable to the linear momenta found in solitary runaway neutron stars and millisecond pulsars. The proper

D. L. DePoy, J. Pepper, Richard W. Pogge, Amelia Stutz

We report measurements of the light curve of the variable Galactic Center source IRS16SW. The light curve is not consistent with an eclipsing binary or any other obvious variable star. The source may be an example of a high mass variable predicted theoretically but not observed previously.

Yen-Ting Lin, Joseph J Mohr

We investigate the near-infrared K-band properties of the brightest cluster galaxies (BCGs) in a sample of 93 galaxy clusters and groups, using data from the Two Micron All Sky Survey. Our cluster sample spans a factor of 70 in mass, making it sensitive to cluster mass related trends. We study the correlations between the BCG luminosity L_b and the mass or l

Shinae Q. Park, Jon M. Miller, Jeffrey E. McClintock, Stephen S. Murray

We present an analysis of a Chandra observation of the field surrounding the low-mass X-ray binary 4U 1755-33, which has been in quiescence since 1996. In 2003, Angelini and White reported the appearance of a narrow 7 arcmin long jetlike feature centered on the position of 4U 1755-33 using the XMM-Newton telescope. Though the source and jet are not visibly a

C. Zanni, G. Murante, G. Bodo, S. Massaglia

X-Ray observations of groups and clusters of galaxies show that the Intra-Cluster Medium (ICM) in their cores is hotter than expected from cosmological numerical simulations of cluster formation which include star formation, radiative cooling and SN feedback. We investigate the effect of the injection of supersonic AGN jets into the ICM using axisymmetric hy

Trevor A. Miles, Somak Raychaudhury, Duncan A. Forbes, Paul Goudfrooij

We present B and R-band luminosity functions (LF) for a sample of 25 nearby groups of galaxies. We find that the LFs of the groups with low X-ray luminosity (L_X < 10^{41.7} erg/s) are significantly different from those of the X-ray brighter groups, showing a prominent dip around M_b = -18. While both categories show lack of late-type galaxies in their centr

Alon Retter

It is commonly accepted that jets have not been observed in CVs so far. This absence was recently explained by their low mass transfer rates compared with objects with jets. A mass accretion limit for jets in CVs was proposed to be about 1e-7-1e-6 Mo/yr. There was, however, a report of evidence for jets in V1494 Aql=Nova Aql 1999/2. We estimate the mass tran

K. Bajan, M. Biernacka, P. Flin, W. Godlowski

We review the previous studies of galaxies and quasar redshifts discretisation. We present also the investigations of the large scale periodicity, detected by pencil--beam observations, which revealed 128 (1/h) Mpc period, afterwards confirmed with supercluster studies. We present the theoretical possibility of obtaining such a periodicity using a toy-model.

J. Wiersma, A. Achterberg

We discuss magnetic field generation by the proton Weibel instability in relativistic shocks, a situation that applies to the external shocks in the fireball model for Gamma-ray Bursts, and possibly also to internal shocks. Our analytical estimates show that the linear phase of the instability ends well before it has converted a significant fraction of the e

Tzu-Ching Chang, Alexandre Refregier, David J. Helfand

We present the first measurement of weak lensing by large-scale structure on 1-4 degree scales based on the FIRST Radio Survey, a quarter-sky, 20-cm survey produced with the NRAO Very Large Array (VLA). The large angular scales provide an unique measurement in the linear regime of the matter power spectrum. We use the shapelet method to estimate the shear of

Yi-Ping Qin, Hong-Tao Liu, En-Wei Liang, Yun-Ming Dong

We make an analysis of the distribution of the extensive Doppler redshift defined as $\widetilde{z}_{Dopp}=(z_{abs}-z_{em})/(1+z_{em})$ with a sample of 1317 absorption redshifts available from 401 quasars. The analysis reveals a bi-peak structure in the distribution, with one component located at $\widetilde{z}_{Dopp}\simeq 0.00$ and the other at $\widetild

Cui-hua Du, Xu Zhou, Jun Ma, Jian-rong Shi

Based on synthetic flux spectra calculated from theoretical atmospheric models, a calibration of temperature and metallicity for the dwarfs observed in the Beijing-Arizona-Taiwan-Connecticut (BATC) multicolor photometric system is presented in this paper. According to this calibration, stellar effective temperatures can be obtained from some temperature-sens

J. C. Berengut, V. A. Dzuba, V. V. Flambaum, M. V. Marchenko

We calculate the dependence of atomic transition frequencies on the fine structure constant, $α= e^2/\hbar c$, for some ions of Ti, Mn, Na, C, and O. The results of these calculations will be used in the search for variation of alpha in quasar absorption spectra.

Richard Wigmans

Paper withdrawn by author. New treatment is in preparation.

Gábor Elek, Endre Szabó

We prove that Connes&#39; Embedding Conjecture holds for the von Neumann algebras of sofic groups, that is sofic groups are hyperlinear. Hence we provide some new examples of hyperlinearity. We also show that the Determinant Conjecture holds for sofic groups as well. We introduce the notion of essentially free actions and amenable actions and study their pro

Sean Sather-Wagstaff

Among the finitely generated modules over a Noetherian ring R, the semidualizing modules have been singled out due to their particularly nice duality properties. When R is a normal domain, we exhibit a natural inclusion of the set of isomorphism classes of semidualizing R-modules into the divisor class group of R. After a description of the basic properties

Mei Huang, Igor A. Shovkovy

Recent results on the gapless 2SC phase are reviewed. These include: the thermal stability under the constraint of the local charge neutrality condition, the properties at zero and nonzero temperatures, and the color screening properties.

L. P. Grishchuk, V. V. Kulagin, V. N. Rudenko, A. Serdobolski

The existing high technology laser-beam detectors of gravitational waves may find very useful applications in an unexpected area - geophysics. To make possible the detection of weak gravitational waves in the region of high frequencies of astrophysical interest, ~ 30 - 10^3 Hz, control systems of laser interferometers must permanently monitor, record and com

M. -C. Chang

We report results of a search for the charmless two-body baryonic decays B^0 \to p \bar{p}, B^0 \to Λ\barΛ, and B^+\to p \barΛ based on the analysis of a 140 fb^{-1} data sample. We set 90% confidence level upper limits on their branching fractions: B(B^0 \to p \bar{p}) < 4.1 x 10^{-7}, B(B^0 \to Λ\barΛ) < 6.9 x 10^{-7}$, and B(B^+ \to p \barΛ) < 4.9 x 10^{-

Jiliang Jing

The late-time evolution of the charged massive Dirac fields in the background of a Reissner-Norström (RN) black hole is studied. It is found that the intermediate late-time behavior is dominated by an inverse power-law decaying tail without any oscillation in which the dumping exponent depends not only on the multiple number of the wave mode but also on the

Sumedha, Deepak Dhar

We study the efficiency of the incomplete enumeration algorithm for linear and branched polymers. There is a qualitative difference in the efficiency in these two cases. The average time to generate an independent sample of $n$ sites for large $n$ varies as $n^2$ for linear polymers, but as $exp(c n^α)$ for branched (undirected and directed) polymers, where

S. W. Ham, S. K. Oh

The possibility of a strongly first-order electroweak phase transition by means of a dimension-six Higgs operator in the Higgs potential of the standard model is studied at finite temperature at the one-loop level. Exact calculation of the one-loop effective Higgs potential at finite temperature suggests that for the Higgs boson with its mass between 115 and

Alan Hammond, Fraydoun Rezakhanlou

We consider a random model of diffusion and coagulation. A large number of small particles are randomly scattered at an initial time. Each particle has some integer mass and moves in a Brownian motion whose diffusion rate is determined by that mass. When any two particles are close, they are liable to combine into a single particle that bears the mass of eac

Zhide Chen, Tianming Bu, Hong Zhu

This paper has been withdrawn.

Zhide Chen, Tianming Bu, Hong Zhu

This paper has been withdrawn.

T J Beams, G Peach, I B Whittingham

Collisions between tightly confined atoms can lead to ionization and hence to loss of atoms from the trap. We develop second-order perturbation theory for a tensorial perturbation of a spherically symmetric system and the theory is then applied to processes mediated by the spin-dipole interaction. Redistribution and loss mechanisms are studied for the case o

Y. Kanada-En&#39;yo

Systematic analysis of the deformations of proton and neutron densities in even-even C isotopes was done based on the method of antisymmetrized molecular dynamics. The $E2$ transition strength was discussed in relation to the deformation. We analyze the $B(E2;2^+_1\to 0^+_1)$ in $^{16}$C, which has been recently measured to be abnormally small. The results s

J. D. Bondurant, S. A. Fulling

A simple transformation converts a solution of a partial differential equation with a Dirichlet boundary condition to a function satisfying a Robin (generalized Neumann) condition. In the simplest cases this observation enables the exact construction of the Green functions for the wave, heat, and Schrodinger problems with a Robin boundary condition. The resu

Olivier Schiffmann

This paper is a sequel (and contains a better treatment) of math.QA/0404032; We construct some canonical bases for quantum toroidal algebras of types D_4, E_6, E_7, E_8 using perverse sheaves on quot schemes parametrizing equivariant coherent sheaves on elliptic curves. We also study some compatibility properties of these bases with some natural filtrations

J. Cooper, J. Solymosi

Consider the following problem: how many collinear triples of points must a transversal of (Z/nZ)^2 have? This question is connected with venerable issues in discrete geometry. We show that the answer, for n prime, is between (n-1)/4 and (n-1)/2, and consider an analogous question for collinear quadruples. We conjecture that the upper bound is the truth and

K. Koyama, D. Langlois, R. Maartens, D. Wands

We investigate the scalar metric perturbations about a de Sitter brane universe in a 5-dimensional anti de Sitter bulk. We compare the master-variable formalism, describing metric perturbations in a 5-dimensional longitudinal gauge, with results in a Gaussian normal gauge. For a vacuum brane (with constant brane tension) there is a continuum of normalizable

M. Alimohammadi, M. Khorrami

The large-N limit of the two-dimensional U$(N)$ Yang-Mills theory on an arbitrary orientable compact surface with boundaries is studied. It is shown that if the holonomies of the gauge field on boundaries are near the identity, then the critical behavior of the system is the same as that of an orientable surface without boundaries with the same genus but wit

T. Matsuki, K. Mawatari, T. Morii, K. Sudoh

In heavy quark effective theory, heavy mesons which contain a heavy quark (or antiquark) are classified by $s_l^{pi_l}$, i.e., the total angular momentum $s_l$ and the parity $pi_l$ of the light quark degrees of freedom around a static heavy quark. In this case, however, one needs to separately estimate the parity other than the angular momentum of a light q

Y. Itoh, M. A. Papa, B. Krishnan, X. Siemens

In a blind search for continuous gravitational wave signals scanning a wide frequency band one looks for candidate events with significantly large values of the detection statistic. Unfortunately, a noise line in the data may also produce a moderately large detection statistic. In this paper, we describe how we can distinguish between noise line events and a

Alessandra Buonanno

These lectures discuss how the direct detection of gravitational waves can be used to probe the very early Universe. We review the main cosmological mechanisms which could have produced relic gravitational waves, and compare theoretical predictions with capabilities and time scales of current and upcoming experiments.

Per Hyldgaard, T. L. Einstein

Since metallic surface states on (111) noble metals are free-electron like, their propagators can be evaluated analytically. Since they are well-screened, one can use simple tight-binding formalism to study their effects. The needed phase shifts can be extracted from experiment. Hence, one can now make quantitative predictions of these slowly-decaying, oscil

G. M. Jones, M. J. Yang, Y. B. Lyanda-Geller, C. H. Yang

We report experiments on gated Y-branch switches made from InAs ballistic electron wave guides. We demonstrate that gating modifies the electron wave functions as well as their interference pattern, causing the anti-correlated, oscillatory transconductances. Such previously unexpected phenomenon provides evidence of steering the electron wave function in a m

Masafumi Udagawa, Youichi Yanase, Masao Ogata

We have studied the field-orientational dependence of zero-energy density of states (FODOS) for a series of systems with different Fermi surface and superconducting gap structures. Instead of phenomenological Doppler-shift method, we use an approximate analytical solution of Eilenberger equation together with self-consistent determination of order parameter

V. M. Apalkov, M. E. Raikh

We demonstrate that the tail of transmission distribution through 1D disordered Anderson chain is a strong function of the correlation radius of the random potential, $a$, even when this radius is much shorter than the de Broglie wavelength, $k_F^{-1}$. The reason is that the correlation radius defines the phase volume of the trapping configurations of the r

Er&#39;el Granot

It is well known that in 1D the cross section of a point scatterer increases along with the scatterer&#39;s strength (potential). In this paper we show that this is an exceptional case, and in all the other cases, where a point defect has a physical meaning, i.e., 0<d<1 and 1<d<=2 (d is the dimensions number), the cross section does not increase monotonicall

D. N. Sheng, Leon Balents

Based on exact numerical calculations, we show that the generalized Kagome spin model in the easy axis limit exhibits a spin liquid, topologically degenerate ground state over a broad range of phase space. We present an (to our knowledge the first) explicit calculation of the gap (and dispersion) of ``vison&#39;&#39; excitations, and exponentially decaying s

E. Smorgrav, J. Smiseth, A. Sudbo, F. S. Nogueira

We study the effect of a Chern-Simons (CS) term in the phase structure of two different Abelian gauge theories. For the compact Maxwell-Chern-Simons theory, we obtain that for values $g=n/2π$ of the CS coupling with $n=\pm 1,\pm 2$, the theory is equivalent to a gas of closed loops with contact interaction, exhibiting a phase transition in the $3dXY$ univers

Amir Aghamohammadi, Mohammad Khorrami

Multi-species reaction-diffusion systems, with more-than-two-site interaction on a one-dimensional lattice are considered. Necessary and sufficient constraints on the interaction rates are obtained, that guarantee the closedness of the time evolution equation for $E^{\mathbf a}_n(t)$&#39;s, the expectation value of the product of certain linear combination o

M. J. Ireland, M. Scholz, P. G. Tuthill, P. R. Wood

Models of M-type Miras with masses of 1 $M_\odot$ and 1.2 $M_\odot$, i.e. with envelope masses of about 0.4 $M_\odot$ and 0.6 $M_\odot$, have been constructed, and a comparison has been made of their observable properties. Geometric pulsation of continuum-forming layers is found to be little affected by the mass difference. The influence of molecular contami

J. Marvin Herndon

Recently, I showed that the &#34;standard model&#34; of solar system formation is wrong,yielding the contradiction of terrestrial planets having insufficiently massive cores, and showed instead the consistency of Eucken&#39;s 1944 concept of planets raining out in the central regions of hot, gaseous protoplanets. Planets generally consist of concentric shell

Gaku Kiuchi, Kouji Ohta, Marcin Sawicki, Michael Allen

Results of submillimeter (450 micron and 850 micron) observations of a nearby dwarf irregular galaxy NGC 4214 with SCUBA on JCMT are presented. We aimed at examining the far-infrared to submillimeter spectral energy distribution (SED) and properties of dust thermal emission in a low metallicity environment by choosing NGC 4214 of which gas metallicity (log O

Chris Blake, Michael Pracy, Warrick Couch, Kenji Bekki

We select a sample of low-redshift (z ~ 0.1) E+A galaxies from the 2dF Galaxy Redshift Survey (2dFGRS). The spectra of these objects are defined by strong hydrogen Balmer absorption lines (H-delta, H-gamma, H-beta) combined with a lack of [OII] 3727A emission, together implying a recently-truncated burst of star formation. The E+A spectrum is thus a signpost

Hung-Jen Chiang-Hsieh, Joseph Lipman

We investigate conditions for &#34;simultaneous normalizability&#34; of a family of reduced schemes, i.e., the normalization of the total space normalizes, fiber by fiber, each member of the family. The main result (under more general conditions) is that a flat family of reduced equidimensional projective complex varieties X_y with parameter y ranging over a

Itay Asulin, Amos Sharoni, Ofer Yulli, Gad Koren

Scanning tunneling spectroscopy of (110) $YBa_2Cu_3O_{7-δ}/Au$ bi-layers reveal a proximity effect markedly different from the conventional one. While proximity-induced mini-gaps rarely appear in the Au layer, the Andreev bound states clearly penetrate into the metal. Zero bias conductance peaks are measured on Au layers thinner than 7 nm with magnitude simi

Lisa M H Hall, Ian G Moss

This paper discusses models of inflation based on global supersymmetry. It is shown that there are parameter ranges, consisent with observational constraints, for which warm inflation occurs and supergravity effects can be neglected. There is no need for any fine tuning of parameters. The thermal corrections to the inflaton potential are calculated and found

J. Kinast, A. Turlapov, J. E. Thomas

We measure the magnetic field dependence of the frequency and damping time for the radial breathing mode of an optically trapped, Fermi gas of $^6$Li atoms near a Feshbach resonance. The measurements address the apparent discrepancy between the results of Kinast et al., [Phys. Rev. Lett. {\bf 92}, 150402 (2004)] and those of Bartenstein et al., [Phys. Rev. L

J. G. Russo, P. K. Townsend

Cosmology can be viewed as geodesic motion in an appropriate metric on an `augmented&#39; target space; here we obtain these geodesics from an effective relativistic particle action. As an application, we find some exact (flat and curved) cosmologies for models with N scalar fields taking values in a hyperbolic target space for which the augmented target spa

J. -P. Onnela, J. Saramäki, J. Kertész, K. Kaski

The local structure of unweighted networks can be characterized by the number of times a subgraph appears in the network. The clustering coefficient, reflecting the local configuration of triangles, can be seen as a special case of this approach. In this Letter we generalize this method for weighted networks. We introduce subgraph intensity as the geometric

V. K. Chandrasekar, M. Senthilvelan, M. Lakshmanan

A method of finding general solutions of second-order nonlinear ordinary differential equations by extending the Prelle-Singer (PS) method is briefly discussed. We explore integrating factors, integrals of motion and the general solution associated with several dynamical systems discussed in the current literature by employing our modifications and extension

Florentin Smarandache, Jean Dezert

In this paper we propose five versions of a Proportional Conflict Redistribution rule (PCR) for information fusion together with several examples. From PCR1 to PCR2, PCR3, PCR4, PCR5 one increases the complexity of the rules and also the exactitude of the redistribution of conflicting masses. PCR1 restricted from the hyper-power set to the power set and with

Kenji Fukushima, Chris Kouvaris, Krishna Rajagopal

We explore the phase diagram of neutral quark matter at high baryon density as a function of the temperature T and the strange quark mass Ms. At T=0, there is a sharp distinction between the insulating color-flavor locked (CFL) phase, which occurs where Ms^2/mu < 2 Delta, and the metallic gapless CFL phase, which occurs at larger Ms^2/mu. Here, mu is the che

Alexey K. Mazur

Dynamics of the polymorphic A<->B transitions in DNA is compared for two polypurine sequences, poly(dA).poly(dT) and poly(dG).poly(dC), long known to exhibit contrasting properties in experiments. In free molecular dynamics simulations reversible transitions are induced by changing the size of a water drop around DNA neutralized by Na ions. In poly(dG).poly(

T. Mayteevarunyoo, Boris A. Malomed, P. L. Chu, A. Roeksabutr

We report results of a systematic study of one-dimensional four-wave moving solitons in a recently proposed model of the Bragg cross-grating in planar optical waveguides with the Kerr nonlinearity; the same model applies to a fiber Bragg grating (BG) carrying two polarizations of light. We concentrate on the case when the system&#39;s spectrum contains no tr

E. A. Ivanova

It is proved that for any prime $p$ a finitely generated nilpotent group is conjugacy separable in the class of finite $p$-groups if and only if the torsion subgroup of it is a finite $p$-group and the quotient group by the torsion subgroup is abelian.

Masha Vlasenko

Construction of the diagrammatic version of the affine Temperley-Lieb algebra of type $\widetilde{A_N}$ as a subring of matrices over the Laurent polynomials is given. We move towards geometrical understanding of cellular structure of the Temperley-Lieb algebra. We represent its center as a coordinate ring of the certain affine algebraic variety and describe

Marcelo Gleiser

Extremely long-lived, time-dependent, spatially-bound scalar field configurations are shown to exist in $d$ spatial dimensions for a wide class of polynomial interactions parameterized as $V(ϕ) = \sum_{n=1}^h\frac{g_n}{n!}ϕ^n$. Assuming spherical symmetry and if $V&#39;&#39;<0$ for a range of values of $ϕ(t,r)$, such configurations exist if: i) spatial dimen

Inyong Cho

We investigate the localization of 4D topological global defects on the brane embedded in 5D. The defects are induced by 5D scalar fields with a symmetry-breaking potential. Taking an ansatz which separates the scalar field into the 4D and the extra-D part, we find that the static-hedgehog configuration is accomplished and the defects are formed only in the

W. Smilga

Inspired by Bohr&#39;s dictum that &#34;physical phenomena are observed relative to different experimental setups&#34;, this article investigates the notion of relativity in Bohr&#39;s sense, starting from a set of binary elements. The most general form of information coding within such sets requires a description by four-component states. By using Bohr&#39;

T. Hattori, M. Hayashi, T. Inagaki, Y. Kitadono

We calculate the explicit expression of the effective potential in a $λϕ^4$ theory at finite temperature in a static universe for arbitrary spacetime dimensions (2\leq D < 5). To study the combined effects of the temperature and scale factor to the spontaneous symmetry breaking we evaluate the effective potential at finite temperature in $R\otimes S^{D-1}$ a

George Redlinger

I briefly review recent progress in rare kaon decays, where I take &#34;rare&#34; to mean those with B < O(10^{-7}).

M. N. Huda, A. K. Ray

Oxygen molecule adsorptions on a Pu (100) surface have been studied in detail, using the generalized gradient approximation to density functional theory. Dissociative adsorption with a layer by layer alternate spin arrangement of the plutonium layer is found to be energetically more favorable compared to molecular adsorption. Hor2 approach on a bridge site w

H. Kurt, R. Loloee, W. P. Pratt, J. Bass

We compare magnetoresistances (MR) and switching currents (I_s) at room temperature (295K) and 4.2K for Permalloy/N/Permalloy nanopillars undergoing current-induced magnetization switching (CIMS), with non-magnetic metals N = Cu, Ag, and Au. The N-metal thickness is held fixed at 10 nm. Any systematic differences in MR and I_s for the different N-metals are

Gang Yan, Tao Zhou, Ying-Di Jin, Zhong-Qian Fu

What is the underlying mechanism leading to power-law degree distributions of many natural and artificial networks is still at issue. We consider that scale-free networks emerges from self-organizing process, and such a evolving model is introduced in this letter. At each time step, a new node is added to the network and connect to some existing nodes random

Chul Koo Kim, A. Rakhimov, Jae Hyung Yee

The post Gaussian effective potential in $D=2+2\veps$ dimensions is evaluated for the Ginzburg-Landau theory of superconductivity. Two and three loop integrals for the post Gaussian correction terms in $D=2+2\veps$ dimensions are calculated and $\veps$-expansion for these integrals are constructed. In $D=2+2\veps$ fractal dimensions Ginzburg Landau parameter

K. Kudo, S. Kurogi, Y. Koike, T. Nishizaki

We have succeeded in growing large-size single-crystals of Ca$_{2+x}$Y$_{2-x}$Cu$_5$O$_{10}$ with $0 \le x \le 1.67$ and measured the magnetic susceptibility, specific heat and magnetization curve, in order to study the magnetic ground state in the edge-sharing CuO$_2$ chain as a function of hole concentration and magnetic field. In $0 \le x \le 1.3$, it has

Seiki Komiya, Yoichi Ando

The normal-state in-plane resistivity (ρ_{ab}) is measured in lightly Zn-doped La_{2-x}Sr_xCuO_4 (LSCO) crystals with 0.06 \leq x \leq 0.17 to systematically study the localization behavior. It is found that the localization temperature, T_{loc}, where ρ_{ab}(T) turns from metallic (dρ_{ab}/dT>0) to insulating (dρ_{ab}/dT<0), shows an anomalous enhancement a

Zeina S. Khan, Stephen W. Morris

Granular mixtures rapidly segregate radially by size when tumbled in a partially filled horizontal drum. The smaller component moves toward the axis of rotation and forms a buried core, which then splits into axial bands. Models have generally assumed that the axial segregation is opposed by diffusion. Using narrow pulses of the smaller component as initial

Kyungsik Kim, Seong-Min Yoon

We study the phase transition of dynamical herd behaviors for the yen-dollar exchange rate in the Japanese financial market. It is obtained that the probability distribution of returns satisfies the power-law behavior with three different values of the scaling exponent 3.11 (one time lag $τ$ = 1 minute), 2.81 (30 minutes), and 2.29 (1 hour). The crash regime

M. Simon, L. Prato

We report detection of the low-mass secondary in the spectroscopic binary Haro 1-14c in the Ophiuchus star forming region. The secondary/primary mass ratio is $0.310\pm 0.014$. With an estimated photometric primary mass of 1.2 $M_{\odot}$, the secondary mass is $\sim 0.4 M_{\odot}$ and the projected semi-major axis is $\sim 1.5$ AU. The system is well-suited

C. Konar, D. J. Saikia, C. H. Ishwara-Chandra, V. K. Kulkarni

We present multifrequency observations with the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA) of a sample of seventeen largely giant radio sources (GRSs). These observations have either helped clarify the radio structures or provided new information at a different frequency. The broad line radio galaxy, J0313+413, has an asymmetric, c

Dennis Zaritsky

I explore the hypothesis that many of the unusual aspects of the apparent stellar bar of the Large Magellanic Cloud are the result of viewing a triaxial stellar bulge that is embedded in a highly obscuring thin disk. Specifically, this hypothesis explains the observed off-center position of the bar within the disk, the differing apparent distances of the bar

Fabio Bresolin

The question of the variation of the upper IMF at high metallicity is briefly reviewed. I show recent results suggesting a revision in the definition of `high metallicity&#39; in extragalactic H II regions. I present preliminary results concerning constraints on the upper mass limit in metal-rich spiral galaxies derived from the detection of Wolf-Rayet stars

O. Schuetz, H. Boehnhardt, E. Pantin, M. Sterzik

We present results of a coronographic imaging search for circumstellar dust disks with the Adaptive Optics Near Infrared System (ADONIS) at the ESO 3.6m telescope in La Silla (Chile). 22 candidate stars, known to be orbited by a planet or to show infrared excess radiation, were examined for circumstellar material. In the PSF-subtracted images no clear disk w

Robert J. Finkelstein

We attempt to go beyond the standard electroweak theory by replacing SU(2) with its q-deformation: SU_q(2). This step introduces new degrees of freedom that we interpret as indicative of non-locality and as a possible basis for a solitonic model of the elementary particles. The solitons are conjectured to be knotted flux tubes labelled by the irreducible rep

Masahiro Nagashima, Cedric G. Lacey, Carlton M. Baugh, Carlos S. Frenk

We investigate the metal enrichment of the intracluster medium (ICM) in the framework of hierarchical models of galaxy formation. We calculate the formation and evolution of galaxies and clusters using a semi-analytical model which includes the effects of flows of gas and metals both into and out of galaxies. For the first time in a semi-analytical model, we

Misha Verbitsky

Let $A$ be a diagonal linear operator on $\C^n$, with all eigenvalues satisfying $0<|α_i|<1$, and $M = (\C^n\backslash 0)/<A>$ the corresponding Hopf manifold. We show that any stable holomorphic bundle on $M$ can be lifted to a $G$-equivariant coherent sheaf on $\C^n$, where $G=(\C^*)^l$ is a Lie group acting on $\C^n$ and containing $A$. This is used to sh

Paul Terwilliger

Let $K$ denote a field, and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V\to V$ and $A^*:V\to V$ that satisfy the following two conditions: There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is di

Ziqiang Wang

The physics of vortices, instantons and deconfinement is studied for layered superfluids in connection to bilayer quantum Hall systems at filling fraction nu=1. We develop an effective gauge theory taking into account both vortices and instantons induced by interlayer tunneling. The renormalization group flow of the gauge charge and the instanton fugacity sh

M. G. Santos, A. Cooray, L. Knox

We study the prospects for extracting detailed statistical properties of the neutral Hydrogen distribution during the era of reionization using the brightness temperature fluctuations from redshifted 21 cm line emission. Detection of this signal is complicated by contamination from foreground sources such as diffuse Galactic synchrotron and free-free emissio

Igor Mencattini, Dirk Kreimer

We continue our investigation into the insertion-elimination Lie algebra of Feynman graphs in the ladder case, emphasizing the structure of this Lie algebra relevant for future applications in the study of Dyson-Schwinger equations. We work out the relation of this Lie algebra to some classical infinite dimensional Lie algebra and we determine its cohomology

Stefano Giusto, Camillo Imbimbo

We point out that insertions of matrix fields in (connected amputated) amplitudes of (generalized) Kontsevich models are given by covariant derivatives with respect to the Kontsevich moduli. This implies that correlators are sections of symmetric products of the (holomorphic) tangent bundle on the (complexified) moduli space of FZZT Liouville branes. We disc

M. B. Voloshin

The properties of the resonance X(3872) are discussed under the assumption that this resonance is dominantly a `molecular&#39; $J^{PC}=1^{++}$ state of neutral $D$ and $D^*$ mesons. It is argued that in these properties should dominate the states with the total spin of the charmed quark-antiquark pair equal to one. As a practical application of this observat

J. David Brown, Lisa L. Lowe

We solve for single distorted black hole initial data using the puncture method, where the Hamiltonian constraint is written as an elliptic equation in R^3 for the nonsingular part of the metric conformal factor. With this approach we can generate isometric and non--isometric black hole data. For the isometric case, our data are directly comparable to those

Christopher D. Matzner, Yuri Levin

We argue that gravitational instability of typical protostellar disks is not a viable mechanism for the fragmentation into multiple systems -- binary stars, brown dwarf companions, or gas giant planets -- except at periods above roughly 20,000 years. Our conclusion is based on a comparison between prior numerical work on disk self-gravity by Gammie (2001) wi

Gian F. Giudice, Tilman Plehn, Alessandro Strumia

Astrophysical bounds severely limit the possibility of observing collider signals of gravity with less than 3 flat extra dimensions. However, small distortions of the compactified space can lift the masses of the lightest graviton excitations, evading astrophysical bounds without affecting collider signals of quantum gravity. Following this procedure we reco

Daniel Arean, David E. Crooks, Alfonso V. Ramallo

We study the supersymmetric embeddings of different D-brane probes in the AdS_5 x T^{1,1} geometry. The main tool employed is kappa symmetry and the cases studied include D3-, D5- and D7-branes. We find a family of three-cycles of the T^{1,1} space over which a D3-brane can be wrapped supersymmetrically and we determine the field content of the corresponding

Volker Runde

Let $G$ be a locally compact group, and let ${\cal R}(G)$ denote the ring of subsets of $G$ generated by the left cosets of open subsets of $G$. The Cohen--Host idempotent theorem asserts that a set lies in ${\cal R}(G)$ if and only if its indicator function is a coefficient function of a unitary representation of $G$ on some Hilbert space. We prove related

David P. Chassin, Christian Posse

The reliability of electric transmission systems is examined using a scale-free model of network structure and failure propagation. The topologies of the North American eastern and western electric networks are analyzed to estimate their reliability based on the Barabasi-Albert network model. A commonly used power system reliability index is computed using a

S. D. H. Hsu, F. Sannino

We exhibit a solution to the strong CP problem in which ultraviolet physics renders the QCD theta angle physically unobservable. Our models involve new strong interactions beyond QCD and particles charged under both the new interactions and ordinary color.

Stephen M. West

In the context of supersymmetric theories, a weakly broken gauged SO(3) flavour symmetry is used to produce two highly degenerate right handed (RH) neutrinos. It is then shown that this SO(3) flavour symmetry is compatible with all fermion masses and mixings if it is supplemented with a further SU(3) flavour symmetry. A specific Susy breaking model is used t

R. M. L. Evans

When modelling driven steady states of matter, it is common practice either to choose transition rates arbitrarily, or to assume that the principle of detailed balance remains valid away from equilibrium. Neither of those practices is theoretically well founded. Hypothesising ergodicity constrains the transition rates in driven steady states to respect relat