January 2006 arXiv papers — page 40

T. Belloni, I. Parolin, M. Del Santo, J. Homan

On 2004 August 15, we observed a fast (shorter than 10 hours) state transition in the bright black-hole transient GX 339-4 simultaneously with RossiXTE and INTEGRAL. This transition was evident both in timing and spectral properties. Combining the data from PCA, HEXTE and IBIS, we obtained good quality broad-band (3-200 keV) energy spectra before and after t

G. R. Meurer

Observations with the ACS Wide Field Camera and G800L grism can produce thousands of spectra within a single WFC field producing a potentially rich treasure trove of information. However, the data are complicated to deal with. Here we describe algorithms to find and characterize spectra of emission line galaxies and supernovae using tools we have developed i

N. Jeremy Kasdin, Isabelle Braems

Current plans call for the first Terrestrial Planet Finder mission, TPF-C, to be a monolithic space telescope with a coronagraph for achieving high contrast. The coronagraph removes the diffracted starlight allowing the nearby planet to be detected. In this paper, we present a model of the planet measurement and noise statistics. We utilize this model to dev

Raffaele Gratton, Angela Bragaglia, Eugenio Carretta, Monica Tosi

We have observed four red clump stars in the very old and metal-rich open cluster NGC 6791 to derive its metallicity, using the high resolution spectrograph SARG mounted on the TNG. Using a spectrum synthesis technique we obtain an average value of [Fe/H] = +0.47 (+/- 0.04, rms=0.08) dex. Our method was tested on mu Leo, a well studied metal-rich field giant

B. Paczynski, D. Szczygiel, B. Pilecki, G. Pojmanski

ASAS is a long term project to monitor bright variable stars over the whole sky. It has discovered 50,122 variables brighter than V < 14 mag south of declination +28 degrees, and among them 11,099 eclipsing binaries. We present a preliminary analysis of 5,384 contact, 2,957 semi-detached, and 2,758 detached systems. The statistics of the distribution provide

Jason Harris, Dennis Zaritsky

We present a spectroscopic survey of 2046 red giant stars, distributed over the central 4x2 kpc of the Small Magellanic Cloud (SMC). After fitting and removing a small velocity gradient across the SMC (7.9 km/s/deg oriented at 10 deg E of N), we measure an rms velocity scatter of 27.5+-0.5 km/s. The line of sight velocity distribution is well-characterized b

N. C Santos, F. Pont, C. Melo, G. Israelian

Context: During the past years photometric surveys, later complemented by follow-up radial-velocity measurements, have revealed the presence of several new extra-solar transiting planets, in very short period orbits. Many of the host stars are extremely faint (V$\sim$16), making high-precision spectroscopic measurements challenging. Aims: We have used the UV

Gijs Verdoes Kleijn, Roeland van der Marel, Jacob Noel-Storr

(abridged) We analyze and model HST /STIS observations of a sample of 27 galaxies; 16 Fanaroff & Riley Type I radio galaxies and 11 (more) normal early-type galaxies. We focus here on what can be learned from the nuclear velocity dispersion (line width) of the gas as a complement to the many studies dealing with gas rotation velocities. We find that the disp

Godfrey Louis, A. Santhosh Kumar

A red rain phenomenon occurred in Kerala, India starting from 25th July 2001, in which the rainwater appeared coloured in various localized places that are spread over a few hundred kilometers in Kerala. Maximum cases were reported during the first 10 days and isolated cases were found to occur for about 2 months. The striking red colouration of the rainwate

A. Crider

To identify extragalactic magnetar flares, we have searched for their periodic tails by generating Lomb periodograms of the emission following short bursts detected by the Burst and Transient Source Experiment (BATSE). Out of 358 short bursts examined, one has a significant tail periodicity (T = 13.8 s, P = 4 x 10^-5). The most probable host galaxy for this

H. A. Weaver, S. A. Stern, M. J. Mutchler, A. J. Steffl

Pluto&#39;s first known moon, Charon, was discovered in 1978 (Christy 1978) and has a diameter about half that of Pluto (Buie 1992,Young 1994, Sicardy 2005), which makes it larger relative to its primary than any other moon in the Solar System. Previous searches for other satellites around Pluto have been unsuccessful (Stern 1991, Stern 1994, Stern 2003), bu

Andrew Gould, Susan Dorsher, B. Scott Gaudi, Andrzej Udalski

We derive the frequencies of hot Jupiters (HJs) with 3--5 day periods and very hot Jupiters (VHJs) with 1-3 day periods by comparing the planets actually detected in the OGLE-III survey with those predicted by our models. The models are constructed following Gould & Morgan (2003) by populating the line of sight with stars drawn from the Hipparcos catalog. Us

Gorazd Cvetic, Igor Kondrashuk, Ivan Schmidt

On the basis of the general considerations such as $R$-operation and Slavnov-Taylor identity we show that the effective action, being understood as Legendre transform of the logarithm of the path integral, possesses particular structure in ${\cal N} = 4$ supersymmetric Yang-Mills theory for kernels of the effective action expressed in terms of the dressed ef

Romulus Godang

We report on new measurements of the Cabibbo-Kobayashi-Maskawa matrix elements |V_{cb}| and |V_{ub}| with inclusive and exclusive semileptonic B decays, highlighting the recent precision measurements with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC.

Alex Buchel

Braneworld inflation on the resolved warped deformed conifold is represented by the dynamics of a D3-brane probe with the world volume of a brane spanning the large dimensions of the observable Universe. This model was recently proposed as a string theory candidate for slow-roll inflationary cosmology in hep-th/0511254. During inflation, the scalar curvature

Roland Diehl, Hubert Halloin, Karsten Kretschmer, Giselher G. Lichti

Gamma-rays from radioactive 26Al (half life ~7.2 10^5 yr) provide a &#39;snapshot&#39; view of ongoing nucleosynthesis in the Galaxy. The Galaxy is relatively transparent to such gamma-rays, and emission has been found concentrated along the plane of the Galaxy. This led to the conclusion1 that massive stars throughout the Galaxy dominate the production of 2

Harald O. Jeschke, L. Andrea Salguero, Roser Valenti, Christian Buchsbaum

The detailed investigation of electronic and magnetic properties of polymeric coordination materials with accurate ab initio quantum mechanical methods is often computationally extremely demanding because of the large number of atoms in the unit cell. Moreover, usually the available structural data are insufficient or poorly determined, especially when the s

Weigang Qiu, Fei Sun, Hongbao Zhang

From the modern viewpoint and by the geometric method, this paper provides a concise foundation for the quantum theory of massless spin-3/2 field in Minkowski spacetime, which includes both the one-particle&#39;s quantum mechanics and the many-particle&#39;s quantum field theory. The explicit result presented here is useful for the investigation of spin-3/2

Steven M. Valone, Susan R. Atlas

The energies of a pair of strongly-interacting subsystems with arbitrary noninteger charges are examined from closed and open system perspectives. An ensemble representation of the charge dependence is derived, valid at all interaction strengths. Transforming from resonance-state ionicity to ensemble charge dependence imposes physical constraints on the occu

Mahmoud Abdel-Aty, Hamada F. Abdel-Hameed, N. Metwally

We present an analytical expression for the response of a transient spectrum to a single-Cooper-pair box biased by a classical voltage and irradiated by a single-mode quantized field. The exact solution of the model is obtained, by means of which we analyze the analytic form of the fluorescence spectrum using the transitions among the dressed states of the s

Erik Andries, Thomas Hagstrom, Susan R. Atlas, Cheryl Willman

Linear discrimination, from the point of view of numerical linear algebra, can be treated as solving an ill-posed system of linear equations. In order to generate a solution that is robust in the presence of noise, these problems require regularization. Here, we examine the ill-posedness involved in the linear discrimination of cancer gene expression data wi

Jerzy Czyz

To test the limits of quantum mechanics, a proposal for an experiment on protons is suggested. The spin component of proton is measured very rapidly in sequential measurements. The reason for this experiment is derived from the genuine fortuitousness principle, (A. Bohr, B. R. Mottelson, and O. Ulfbeck, (2004)).

Alexei Borodin

Periodic Schur process is a generalization of the Schur process introduced in math.CO/0107056. We compute its correlation functions and their bulk scaling limits, and discuss several applications including asymptotic analysis of uniform measures on cylindric partitions, time-dependent extensions of the discrete sine kernel, and bulk limit behavior of certain

A. K. Kwasniewski

The taylor formula pertains historically also to johann or ivan bernoulli. Bernoulli series uiversalisima appeared in acta eruditorum in leipzig when brook taylor was nine years old. As on today one affirms two hundred fifty eight anniversary of death of johann bernoulli this article is proposed also pro memoriam. Very recent extensions of this celebrated fo

Araceli Bonifant, Marius Dabija, John Milnor

A study of rational maps of the real or complex projective plane of degree two or more, concentrating on those which map an elliptic curve onto itself, necessarily by an expanding map. We describe relatively simple examples with a rich variety of exotic dynamical behaviors which are perhaps familiar to the applied dynamics community but not to specialists in

Laurent Decreusefond, Pascal Moyal

In this paper we present the fluid limit of an heavily loaded Earliest Deadline First queue with impatient customers, represented by a measure-valued process keeping track of residual time-credits of lost and waiting customers. This fluid limit is the solution of an integrated transport equation. We then use this fluid limit to derive fluid approximations of

Sema Salur

Asymptotically cylindrical Ricci-flat manifolds play a key role in constructing Topological Quantum Field Theories. It is particularly important to understand their behavior at the cylindrical ends and the natural restrictions on the geometry. In this paper we show that an orientable, connected, asymptotically cylindrical manifold (M,g) with Ricci-flat metri

Gustavo Niz, Neil Turok

One of the simplest time-dependent solutions of M theory consists of nine-dimensional Euclidean space times 1+1-dimensional compactified Milne space-time. With a further modding out by Z_2, the space-time represents two orbifold planes which collide and re-emerge, a process proposed as an explanation of the hot big bang. When the two planes are near, the lig

Tomoki Endo, Toshiki Maruyama, Satoshi Chiba, Toshitaka Tatsumi

We show that the hadron-quark mixed phase is restricted to narrow range of baryon chemical potential by the charge screening effect. Accordingly the mixed phase expected in hadron-quark hybrid stars should be narrow. Although the screening would not have large effect in bulk properties of the star such as mass or radius, it change the internal structure of t

Bogdan Mihaila, Krastan B. Blagoev, Fred Cooper

We study the phase structure of a 4-fermi model with three bare coupling constants, which potentially has three types of bound states. This model is a generalization of the model discussed previously by A. Chodos et al. [Phys. Rev. D 61, 045011 (2000)], which contained both chiral condensates and Cooper pairs. For this generalization we find that there are t

S. M. Troshin, N. E. Tyurin

We note that the new unitarity regime when scattering amplitude goes beyond the black disc limit (antishadowing) could help in the explanation of the regularities such as knee in the energy spectrum, existence of penetrating and long-flying particles and other features observed in the measurements of the extensive air showers which originate from cosmic part

Nicole F. Bell, V. Cirigliano, M. J. Ramsey-Musolf, P. Vogel

The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent &#34;naturalness&#34; upper bounds on the magnetic moments of Dirac neutrinos, generated by physics above the electroweak scale. The neutrino mass receives a contribution from higher order operators, which are renormal

Wei Zhu, Zhenqi Shen, Jifeng Yang, Jianhong Ruan

The DGLAP, BFKL, modified DGLAP and modified BFKL equations are constructed in a unified partonic framework. The antishadowing effect in the recombination process is emphasized, which leads to two different small $x$ behaviors of gluon distribution. In the meantime, the BFKL equation and modified DGLAP equation are viewed as the corrections of the initial gl

N. Ishii, T. Doi, H. Iida, M. Oka

Anisotropic lattice QCD studies of penta-quarks(5Q) with J^P=1/2^\pm and 3/2^{\pm} are presented at the quenched level together with tetra-quarks(4Q). The standard gauge action at β=5.75 and O(a) improved quark (clover) action with κ=0.1410(0.010)0.1440 are employed on the anisotropic lattice with the renormalized anisotropy a_s/a_t = 4. The ``hybrid boundar

CDF Collaboration

We present the first observation of the baryon decay $Λ_b\toΛ_cπ^-$ followed by $Λ_c\to p K^-π^+$ in 106 pb-1 of $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV in the CDF experiment. In order to reduce systematic error, the measured rate for $Λ_b$ decay is normalized to the kinematically similar meson decay $B^0\to D^+π^-$ followed by $D^+\toπ^+K^-π^+$. We r

Tomas Ortin

In the recent times a lot of effort has been devoted to improve our knowledge about the space of string theory vacua (``the landscape&#39;&#39;) to find statistical grounds to justify how and why the theory selects its vacuum. Particularly interesting are those vacua that preserve some supersymmetry, which are always supersymmetric solutions of some supergra

Leonardo E. Silbert, Andrea J. Liu, Sidney R. Nagel

We study the pair correlation function $g(r)$ for zero-temperature, disordered, soft-sphere packings just above the onset of jamming. We find distinct signatures of the transition in both the first and split second peaks of this function. As the transition is approached from the jammed side (at higher packing fraction) the first peak diverges and narrows on

Bogdan Mihaila, Scott A. Crooker, Krastan B. Blagoev, Dwight G. Rickel

Ultracold alkali atoms provide experimentally accessible model systems for probing quantum states that manifest themselves at the macroscopic scale. Recent experimental realizations of superfluidity in dilute gases of ultracold fermionic (half-integer spin) atoms offer exciting opportunities to directly test theoretical models of related many-body fermion sy

Qimiao Si

We address the global magnetic phase diagram of Kondo lattice systems. Through the distinct Fermi surface properties of the various phases at zero temperature, we argue that the phase diagram supports two classes of quantum critical point. One of these describes a direct transition from a magnetic metal phase with localized f-electrons to a paramagnetic one

Tomoki Endo, Toshiki Maruyama, Satoshi Chiba, Toshitaka Tatsumi

We study the charge screening effect in the hadron-quark mixed phase. By including the charge screening effect, rearrangement of charged particles occurs and some part becomes locally charge-neutral. As a result the equation of state for the mixed phase becomes close to that given by the Maxwell construction, which means that the Maxwell construction would e

S. Argiro, S. L. C Barroso, J. Gonzalez, L. Nellen

The Pierre Auger Observatory is designed to unveil the nature and the origins of the highest energy cosmic rays. The large and geographically dispersed collaboration of physicists and the wide-ranging collection of simulation and reconstruction tasks pose some special challenges for the offline analysis software. We have designed and implemented a general pu

Hideko Nomura, Yoshitsugu Nakagawa

We have studied dust evolution in a quiescent or turbulent protoplanetary disk by numerically solving coagulation equation for settling dust particles, using the minimum mass solar nebular model. As a result, if we assume an ideally quiescent disk, the dust particles settle toward the disk midplane to form a gravitationally unstable layer within 2x10^3 - 4x1

S. Kaviraj, I. Ferreras, S. -J. Yoon, S. K. Yi

We deduce the globular cluster formation history of the nearby elliptical NGC 5128 by using a phenomenological chemical enrichment model to reproduce its observed metallicity distribution function (MDF). We derive the observed MDF using recently obtained U and B photometry of the NGC 5128 GC system, with (U-B) used as the metallicity indicator. We test wheth