January 2003 arXiv papers — page 21

Rui-Hua Xie, Garnett W. Bryant, Vedene H. Smith

We carry out large scale {\sl ab initio} calculations of Raman scattering activities and Raman-active frequencies (RAFs) in ${\rm C}_{48}{\rm N}_{12}$ aza-fullerene. The results are compared with those of ${\rm C}_{60}$. Twenty-nine non-degenerate polarized and 29 doubly-degenerate unpolarized RAFs are predicted for ${\rm C}_{48}{\rm N}_{12}$. The RAF of the

Rui-Hua Xie, Garnett W. Bryant, Lasse Jensen, Jijun Zhao

In this work, we perform first-principles calculations of the structural, electronic, vibrational and magnetic properties of a novel ${\rm C}_{48}{\rm N}_{12}$ azafullerene. Full geometrical optimization shows that ${\rm C}_{48}{\rm N}_{12}$ is characterized by several distinguishing features: only one nitrogen atom per pentagon, two nitrogen atoms preferent

J. K. Freericks, V. Zlatic

The Falicov-Kimball model was introduced in 1969 as a statistical model for metal-insulator transitions; it includes itinerant and localized electrons that mutually interact with a local Coulomb interaction and is the simplest model of electron correlations. It can be solved exactly with dynamical mean-field theory in the limit of large spatial dimensions wh

A. A. Shashkin, Maryam Rahimi, S. Anissimova, S. V. Kravchenko

We have accurately measured the effective mass in a dilute two-dimensional electron system in silicon by analyzing temperature dependence of the Shubnikov-de Haas oscillations in the low-temperature limit. A sharp increase of the effective mass with decreasing electron density has been observed. Using tilted magnetic fields, we have found that the enhanced e

L. L. Bonilla, R. Escobedo, F. J. Higuera

An asymptotic analysis of the Gunn effect in two-dimensional samples of bulk n-GaAs with circular contacts is presented. A moving pulse far from contacts is approximated by a moving free boundary separating regions where the electric potential solves a Laplace equation with subsidiary boundary conditions. The dynamical condition for the motion of the free bo

Raimundo R. dos Santos, J. d'Albuquerque e Castro, L. E. Oliveira

We have studied the magnetic-field and concentration dependences of the magnetizations of the hole and Mn subsystems in diluted ferromagnetic semiconductor Ga_{1-x}Mn_xAs. A mean-field approximation to the hole-mediated interaction is used, in which the hole concentration p(x) is parametrized in terms of a fitting (of the hole effective mass and hole/local m

E. A. Masalitin, V. D. Fil, K. R. Zhekov, A. N. Zholobenko

A new version of the phase method of determining the sound velocity is proposed and implemented. It utilizes the ``Nonius'' measurement technique and can give acceptable accuracy (~1%) in samples of submillimeter size. Measurements of the sound velocity are made in single-crystal samples of the borocarbides RNi2B2C (R = Y,Lu,Ho). The elastic constant

Hui Hu, Xia-Ji Liu, Michele Modugno

We study the expansion of an ultracold boson-fermion mixture released from an elongated magnetic trap, in the context of a recent experiment at LENS (G. Roati et al., Phys. Rev. Lett. 89, 150403 (2002)). We discuss in some details the role of the boson-fermion interaction on the evolution of the radial-to-axial aspect ratio of the condensate, and show that i

J. M. Deutsch, Onuttom Narayan

We study numerically the thermal conductivity coefficient $κ$ as a function of system length $L$ for several different quasi one dimensional models: classical gases of hard spheres with both longitudinal and transverse degrees of freedom. We introduce a model that is ergodic and highly chaotic but also conserves energy and momentum, and is very useful becaus

D. Rosenberg, P. Nalbach, D. D. Osheroff

At temperatures below 1 K, the capacitance of a glass sample changes due to the application of a DC field in accordance with A. Burins dipole gap theory. However, we now report that below 20 mK, during the first sweep cycle of the DC electric field the capacitance is smaller by about $10^{-5}$ compared to any subsequent sweep. Despite this overall shift the

Robin C. Ball, Thomas M. A. Fink, Neill E. Bowler

We demonstrate that is it possible to simulate a system in thermal equilibrium even when the energy cannot be evaluated exactly, provided the error distribution is known. This leads to an effective optimisation strategy for problems where the evaluation of each design can only be sampled statistically.

A. I. Coldea, S. J. Blundell, C. A. Steer, J. F. Mitchell

We have performed a muon spin rotation study on polycrystalline samples of electron-doped layered manganites, La$_{2-2x}$Sr$_{1+2x}$Mn$_2$O$_7$ (0.4< x<1), in order to investigate the local magnetic structure and spin dynamics. Our results provide evidence for phase separation into A-type antiferromagnetic and charge-ordered phases for x=0.52 and spin freezi

Hong Jiang, Harold U. Baranger, Weitao Yang

Kohn-Sham spin-density functional theory provides an efficient and accurate model to study electron-electron interaction effects in quantum dots, but its application to large systems is a challenge. An efficient algorithm for the density-functional theory simulation of quantum dots is developed, which includes the particle-in-the-box representation of the Ko

John A. Skint, Mun-Seog Kim, Thomas R. Lemberger, T. Greibe

From measurements of the magnetic penetration depth, $λ(T)$, from 1.6 K to $T_c$ in films of electron-doped cuprates La$_{2-x}$Ce$_x$CuO$_{4-y}$ and Pr$_{2-x}$Ce$_x$CuO$_{4-y}$ we obtain the normalized density of states, $N_s(E)$ at T=0 by using a simple model. In this framework, the flat behavior of $λ^{-2}(T)$ at low $T$ implies $N_s(E)$ is small, possibly

Volodymyr Krasnoholovets, Bohdan Lev

We investigate the behaviour of a system of particles with the different character of interaction. The approach makes it possible to describe systems of interacting particles by statistical methods taking into account a spatial nonhomogeneous distribution of particles, i.e. cluster formation. For these clusters are evaluated: their size, the number of partic

A. J. Barger, L. L. Cowie, P. Capak, D. M. Alexander

Deep Chandra X-ray exposures provide an efficient route for locating optically faint active galactic nuclei (AGN) at high redshifts. We use deep multicolor optical data to search for z>5 AGN in the 2 Ms X-ray exposure of the Chandra Deep Field-North. Of the 423 X-ray sources bright enough (z&#39;<25.2) for a color-color analysis, at most one lies at z=5-6 an

L. L. Cowie, A. J. Barger, M. W. Bautz, W. N. Brandt

The high angular resolution and sensitivity of the Chandra X-ray Observatory has yielded large numbers of faint X-ray sources with measured redshifts in the soft (0.5-2 keV) and hard (2-8 keV) energy bands. Many of these sources show few obvious optical signatures of active galactic nuclei (AGN). We use Chandra observations of the Hubble Deep Field North reg

A. E. Shapley, C. C. Steidel, M. Pettini, K. L. Adelberger

We present the results of a systematic study of the rest-frame UV spectroscopic properties of Lyman Break Galaxies (LBGs). The database of almost 1000 LBG spectra proves useful for constructing high S/N composite spectra. The composite spectrum of the entire sample reveals a wealth of features attributable to hot stars, HII regions, dust, and outflowing neut

S. Mitra, R. Foot

A new and inexpensive technique for detecting self interacting dark matter in the form of small grains in bulk matter is proposed. Depending on the interactions with ordinary matter, dark matter grains in bulk matter may be isolated by using a centrifuge and using ordinary matter as a filter. The case of mirror matter interacting with ordinary matter via pho

J. S. Gallagher, G. J. Madsen, R. J. Reynolds, E. K. Grebel

The Wisconsin H Alpha Mapper has been used to set the first deep upper limits on the intensity of diffuse H alpha emission from warm ionized gas in the Local Group dwarf spheroidal galaxies (dSphs) Draco and Ursa Minor. Assuming a velocity dispersion of 15 km/s for the ionized gas, we set limits for the H alpha intensity of less or equal to 0.024 Rayleighs a

P. Padovani, E. Perlman, H. Landt, P. Giommi

We use statistical results from a large sample of about 500 blazars, based on two surveys, the Deep X-ray Radio Blazar Survey (DXRBS), nearly complete, and the RASS-Green Bank survey (RGB), to provide new constraints on the spectral energy distribution of blazars, particularly flat-spectrum radio quasars (FSRQ). This reassessment is prompted by the discovery

Boris Dirsch, Tom Richtler, Doug Geisler, Juan Carlos Forte

We present a photometric investigation of the globular cluster population of NGC 1399, the central galaxy in the Fornax cluster, in Washington C and Kron R filters within a field of 36&#39;x36&#39;. This is the largest area around this galaxy ever studied with CCD photometry. The cluster system of NGC 1399 is found to extend further than 100 kpc away from th

C. M. Dutra, E. Bica, J. Soares, B. Barbuy

We carried out a 2MASS J, H and K_s survey of infrared star clusters in the Milky Way sector 230$^{\circ}$ $< \ell <$ 350$^{\circ}$. This zone was the least studied in the literature, previously including only 12 infrared clusters or stellar groups with $|b|<$ 10$^{\circ}$, according to the recent catalogue by Bica et al. (2003). We concentrated efforts on e

N. Aghanim, M. Kunz, P. G. Castro, O. Forni

In the context of the present and future Cosmic Microwave Background (CMB) experiments, going beyond the information provided by the power spectrum has become necessary in order to tightly constrain the cosmological model. The non-Gaussian signatures in the CMB represent a very promising tool to probe the early universe and the structure formation epoch. We

Susan M. Percival, Maurizio Salaris, David Kilkenny

We present new BVRI photometry for a sample of 54 local G and K stars with accurate Hipparcos parallaxes in the metallicity range -0.4 < [Fe/H] < +0.3. We use this sample to develop a completely model-independent main sequence (MS) fitting method which we apply to 4 open clusters - the Hyades, Praesepe, the Pleiades and NGC 2516 - which all have direct Hippa

Terry Jay Jones, Hassib Amini

We present broadband imaging polarimetry of DR21 at 2.2$μ$m. Background stars shining through the lobes of the bipolar outflow show polarization aligned with the long axis of the outflow, indicating a magnetic field geometry oriented along the flow axis. There is no indication of a spiral or turbulent magnetic field geometry in the lobes. The polarization of

Phil Uttley, Rick Edelson, Ian McHardy, Bradley M. Peterson

We combine the long-term optical light curve of the Seyfert 1 galaxy NGC5548 with the X-ray light curve measured by the Rossi X-ray Timing Explorer over 6 years, to determine the relationship between the optical and X-ray continua. The X-ray light curve is strongly correlated with the optical light curve on long (~year) time-scales. The amplitude of the long

T. A. Lozinskaya, A. V. Moiseev, N. Yu. Podorvanyuk

We carried out detailed kinematic studies of the complex of multiple HI and HII shells that represent the only region of ongoing star formation in the dwarf irregular galaxy IC 1613. We investigated the ionized-gas kinematics by using Fabry--Perot H-alpha observations with the 6-m Special Astrophysical Observatory telescope and the neutral-gas kinematics by

Tomaz Zwitter

GAIA observations of eclipsing binary stars will have a large impact on stellar astrophysics. Accurate parameters, including absolute masses and sizes will be derived for $\sim 10^4$ systems, orders of magnitude more than what has ever been done from the ground. Observations of 18 real systems in the GAIA-like mode as well as with devoted ground-based campai

Tomaz Zwitter, Ulisse Munari, Fiorella Castelli

Two sets of grids of Kurucz ATLAS~9 model spectra are presented. The first one covers the GAIA spectral interval, while the second one which is still being computed covers the whole range from 2500 -- 10500 Å. Both grids include parameters needed for realistic spectral simulation, e.g. stellar rotation and are computed at R=20000 and lower spectral resolutio

L. Costamante, F. Aharonian, G. Ghisellini, D. Horns

The recent HEGRA detection and spectrum of 1ES 1426+428 at TeV energies, once corrected for absorption using present estimates of the diffuse extragalactic IR background, suggest that the high energy peak of the Spectral Energy Distribution (SED) could be much higher than the synchrotron one ($L_c/L_s>10$), and lie at energies above 8-10 TeV. To see if such

A. Udalski, O. Szewczyk, K. Zebrun, G. Pietrzynski

We present results of the second planetary and low-luminosity object transit campaign conducted by the OGLE-III survey. Three fields (35'x35' each) located in the Carina regions of the Galactic disk (l~290) were monitored continuously in February-May 2002. About 1150 epochs were collected for each field. The search for low depth transits was conducted on abo

Tomaz Zwitter

The RVS instrument aboard GAIA is a slitless spectrograph, so some spectral tracing overlap is inevitable. We show that this background can be accurately modeled and subtracted. Radial velocity accuracy is not degraded significantly unless the star density is higher than the value typical for the Galactic plane.

S. Naik, B. Paul

We present spectral variations of the binary X-ray pulsar LMC X-4 using the RXTE/PCA observations at different phases of its 30.5 day long super-orbital period. Only out of eclipse data were used for this study. During the high state of the super-orbital period of LMC X-4, the spectrum is well described by a high energy cut-off power-law with a photon index

Tomaz Zwitter, Arne Henden

Superpositions of stellar tracings are present in every slitless spectrograph. The probability for such overlaps in the GAIA RVS spectrograph focal plane is estimated using photometric observations of 66 stellar fields, mostly close to the Galactic plane. It is shown that overlaps of bright stars (V<17) are common near the Galactic plane, and no spectrum is

M. Bacchi, L. Feretti, G. Giovannini, F. Govoni

New radio data are presented for the clusters A401, A545, A754, A1914, A2219 and A2390, where the presence of diffuse radio emission was suggested from the images of the NRAO VLA Sky Survey. Sensitive images of these clusters, obtained with the Very Large Array (VLA)at 20 cm confirm the existence of the diffuse sources and allow us to derive their fluxes and

N. P. Bannister, M. A. Barstow, J. B. Holberg, F. C. Bruhweiler

We present a phenomenological study of highly ionised, non-photospheric absorption features in high spectral resolution vacuum ultraviolet spectra of 23 hot DA white dwarfs. Prior to this study, four of the survey objects (Feige 24, REJ 0457-281, G191-B2B and REJ 1614-085) were known to possess these features. We find four new objects with multiple component

Sylvie Theado, Sylvie Vauclair

In the two previous papers of this series, we have discussed the importance of t he $μ$-gradients due to helium settling on rotation-induced mixing, first in a n approximate analytical way, second in a 2D numerical simulation. We have found that, for slowly rotating low mass stars, a process of ``creeping paralysis&#34; in which the circulation and the diffu

Sylvie Vauclair, Sylvie Theado

In the presence of rotation-induced mixing, element diffusion still occurs in stellar radiative zones, although at a slower rate than in the case of a complete stability of the stellar gas. As a consequence, helium settling leads to vertical $\displaystyle μ$-gradients which, due to the meridional circulation, turn into horizontal fluctuations. Up to now, th

Aprajita Verma, Dieter Lutz, Eckhard Sturm, Amiel Sternberg

We present spectroscopy of MIR emission lines in twelve starburst regions, located in eleven starburst galaxies, for which a significant number of lines between 2.38 and 45micron were observed with the ISO Short Wavelength Spectrometer, with the intention of providing a reference resource for MIR spectra of starburst galaxies. The observation apertures were

M. Landgraf, R. Jehn, W. Flury

In the effort to obtain low cost routine space debris observations in low Earth orbit, ESA plans to utilise the radar facilities of the European Incoherent Scatter Scientific Association. First demonstration measurements were performed from 11 to 23 February 2001. In total $16{\rm hours}$ of radar signals were collected. Here we compare these initial measure

Alan H. Guth

While there is no consensus about the history of time since the beginning, in this paper I will discuss some possibilities. We have a pretty clear picture of cosmic history from the electroweak phase transition through the time of recombination, a period which includes the QCD phase transition and big bang nucleosynthesis. This paper includes a quantitative

J. P. U. Fynbo, P. Moller, B. Thomsen, J. Hjorth

Ly-alpha emission is indicative of on-going star formation in a dust-poor environment. Ly-alpha imaging is therefore a probe of the star formation rate and of the dust-content of Gamma-Ray Burst host galaxies. Both of these parameters are central to our understanding of GRB progenitors and of how the environments affect the propagation of afterglow emission

C. Jin, M. A. Garrett, S. Nair, R. W. Porcas

We present eight epochs of 43 GHz, dual-polarisation VLBA observations of the gravitational lens system PKS 1830-211, made over fourteen weeks. A bright, compact ``core&#39;&#39; and a faint extended ``jet&#39;&#39; are clearly seen in maps of both lensed images at all eight epochs. The relative separation of the radio centroid of the cores (as measured on t

T. M. Aliev, A. Ozpineci, M. Savci

We study the effects of sequential fourth quark generation in rare &#34;B -> K(K*) l^+ l^-&#34; decays induced by &#34;b -> s&#34; transition and in &#34;B_s^0 - bar{B}_s^0&#34; mixing. Using the experimental values on branching ratios of the &#34;B -> X_s gamma&#34; and &#34;B -> K(K*) l^+ l^-&#34; decays, the allowed regions for $\vel V_{tb} V_{ts}^\ast\ve

Edward A. Spiegel, Jean-Luc Thiffeault

The Hilbert-Chapman-Enskog expansion of the kinetic equations in mean flight times is believed to be asymptotic rather than convergent. It is therefore inadvisable to use lower order results to simplify the current approximation as is done in the traditional Chapman-Enskog procedure, since that is an iterative method. By avoiding such recycling of lower orde

Ramandeep S. Johal

We consider the meta-equilibrium state of a composite system made up of independent subsystems satisfying the additive form of external constraints, as recently discussed by Abe [Phys. Rev. E {\bf 63}, 061105 (2001)]. We derive the additive entropy $S$ underlying a composable entropy $\tilde{S}$ by identifying the common intensive variable. The simplest form

Bin Wang, Li-Hui Xue, Xinmin Zhang, W-Y. P. Hwang

We compute the cosmological perturbations generated in the brane world inflation driven by the bulk inflaton. Different from the model that the inflation is a brane effect, we exhibit the modification of the power spectrum of scalar perturbations due to the existence of the fifth dimension. With the change of the initial vacuum, we investigate the dependence

Tetsufumi Hirano, Yasushi Nara

We investigate the suppression factor and the azimuthal correlation function for high $p_T$ hadrons in central Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV by using a dynamical model in which hydrodynamics is combined with explicitly traveling jets. We study the effects of parton energy loss in a hot medium, intrinsic $k_T$ of partons in a nucleus, and $p_{\p

S. Deser, A. Waldron

We present a simple group representation analysis of massive, and particularly ``partially massless&#39;&#39;, fields of arbitrary spin in de Sitter spaces of any dimension. The method uses bulk to boundary propagators to relate these fields to Euclidean conformal ones at one dimension lower. These results are then used to revisit an old question: can a cons

O. Oron, L. P. Horwitz

We solve the problem of formulating Brownian motion in a relativistically covariant framework in 1+1 and 3+1 dimensions. We obtain covariant Fokker-Planck equations with (for the isotropic case) a differential operator of invariant d&#39;Alembert form. Treating the spacelike and timelike fluctuations separately, we show that it is essential to take into acco

L. Chekhov, A. Marshakov, A. Mironov, D. Vasiliev

We prove that the quasiclassical tau-function of the multi-support solutions to matrix models, proposed recently by Dijkgraaf and Vafa to be related to the Cachazo-Intrilligator-Vafa superpotentials of the N=1 supersymmetric Yang-Mills theories, satisfies the Witten-Dijkgraaf-Verlinde-Verlinde equations.

L. Frankfurt, L. Gerland, M. Strikman, M. Zhalov

We demonstrate how the elementary amplitudes $γN\to ΨN$, the amplitude of the nondiagonal $J/ψN\Leftrightarrow ψ&#39; N$ transition, and the total $J/ψN$ and $ψ&#39; N$ cross sections can be determined from measurements of the coherent $J/ψ$ and $ψ&#39;$ photoproduction off light nuclei at moderate energies. For this purpose we provide a detailed numerical a

A. A. Pivovarov

The determination of the numerical value for the strong coupling constant from tau decays in perturbative QCD is briefly described. Main emphasis is made on the use of the renormalization scheme invariance of the theory for reducing uncertainties related to truncation of the series in the strong coupling constant. The analysis of the convergence of the serie

Eckhard von Toerne

The CLEO detector is located at the CESR e+e- collider in Ithaca, NY. CLEO&#39;s wide range of experimental measurements in b-hadron decays is represented by improved measurements of Vcb and Vub, rare B decays, and bb-bar spectroscopy. New experimental results in exclusive hadronic transitions will aid theorists in developing a theory of hadronic B decays. S

S. Yi, Ö. E. Müstecaplıoğlu, L. You

We discuss the quantum phases and their diffusion in a spinor-1 atomic Bose-Einstein condensate. For ferromagnetic interactions, we obtain the exact ground state distribution of the phase fluctuations corresponding to the total atom number ($N$), the magnetization (${\cal M}$), and the alignment (or hypercharge) ($Y$) of the system. The mean field ground sta

A. Bandrivskyy, S. Beri, D. G. Luchinsky

We analyse the non-equilibrium distribution in dissipative dynamical systems at finite noise intensities. The effect of finite noise is described in terms of topological changes in the pattern of optimal paths. Theoretical predictions are in good agreement with the results of numerical solution of the Fokker-Planck equation and Monte Carlo simulations.

G. Gallavotti

Twentyseven comments (.) on the Second Law and nonequilibrium systems

Paolo Lipari

Research in cosmic rays is now nearly a century old, but most of the fundamental questions in this field remain unanswered, on the other hand the perspectives of future studies in the next decade are very bright. New detectors will provide higher quality data in the entire energy range from 10^8 to 10^{20} eV (or more if particles of higher energy have non n

J. de Plaa, L. Kuiper, W. Hermsen

We report the hard X-ray properties of the young Crab-like LMC pulsar PSR B0540-69, using archival RXTE PCA (2 - 60 keV) and RXTE HEXTE (15 - 250 keV) data. Making use of the very long effective exposure of 684 ks, we derived a very detailed master pulse profile for energies 2 - 20 keV. We confirm the broad single-pulse shape with a dip in the middle and wit

Ayesha Begum, Jayaram N. Chengalur, Ulrich Hopp

We present deep, high velocity resolution (1.6 km/s) GMRT HI as well as optical data for the faint (M_B ~ -10.9) galaxy Camelopardalis B. We find that the HI in the galaxy has a regular velocity field, consistent with rotational motion. The implied kinematical major axis is well aligned with the major axis of both the HI and optical images. Cam B is the fain

S. E. Parkhomenko

The construction of D-branes in N=2 superconformal minimal models, based on free field realization of N=2 super-Virasoro algebra unitary modules is represented.

C. E. Creffield

Calculation of the Floquet quasi-energies of a system driven by a time-periodic field is an efficient way to understand its dynamics. In particular, the phenomenon of dynamical localization can be related to the presence of close approaches between quasi-energies (either crossings or avoided crossings). We consider here a driven two-level system, and study h

M. A. Cazalilla

We study the limit of large onsite repulsion of the one-dimensional Bose-Hubbard model at low densities, and derive a strong-coupling effective Hamiltonian. By taking the lattice parameter to zero, the Hamiltonian becomes a continuum model of fermions with attractive interactions. The leading corrections to the internal energy of a hard-core-boson (Tonks) ga

A. Balbi, C. Baccigalupi, F. Perrotta, S. Matarrese

We investigate the accuracy attainable by forthcoming space-based observations of the cosmic microwave background (CMB) temperature and polarization anisotropy in constraining the dark energy density parameter $\Oq$ and equation of state $\wq=p_{\rm Q}/ρ_{\rm Q}$. Despite degeneracies among parameters, it is possible for high precision observations such as t

Olivier Guyon

In this paper, an alternative to the classical pupil apodization techniques (use of an amplitude pupil mask) is proposed. It is shown that an apodized pupil suitable for imaging of Extrasolar planets can be obtained by reflection of an unapodized flat wavefront on 2 mirrors. By carefully choosing the shape of these 2 mirrors, it is possible to obtain a contr

Tapas Kumar Das, Jayant K. Pendharkar, Sanjit Mitra

In this work we would like to address the issue of shock formation in black hole accretion discs. We provide a {\it generalized two parameter solution scheme} for multi-transonic, accretion and wind around Schwarzschild black holes, by mainly concentrating on accretion solutions which may contain steady, standing isothermal shocks. Such shocks conserve flow

Michal Rokni, Premala Chandra

We present a dynamical study of the disordered quantum p=2 spherical model at long times. Its phase behavior as a function of spin-bath coupling, strength of quantum fluctuations and temperature is characterized, and we identify different paramagnetic and coarsened regions. A quantum critical point at zero temperature in the limit of vanishing dissipation is

Ivone F. M. Albuquerque, Laura Baudis

The dark matter in the Universe might be composed of superheavy particles (mass >~ 10^10 GeV). These particles can be detected via nuclear recoils produced in elastic scatterings from nuclei. We estimate the observable rate of strongly interacting supermassive particles (simpzillas) in direct dark matter search experiments. The simpzilla energy loss in the E

Mikio Fujii

We give a description of balanced homodyne detection (BHD) using a conventional laser as a local oscillator (LO), where the laser field outside the cavity is a mixed state whose phase is completely unknown. Our description is based on the standard interpretation of the quantum theory for measurement, and accords with the experimental result in the squeezed s

Jiangfeng Du, Xiaodong Xu, Hui Li, Xianyi Zhou

Quantum game theory is a recently developing field of physical research. In this paper, we investigate quantum games in a systematic way. With the famous instance of the Prisoner&#39;s Dilemma, we present the fascinating properties of quantum games in different conditions, i.e. different number of the players, different strategic space of the players and dif

Alexander Yu. Vlasov

Here is considered a specific detection loophole, that is relevant not only to testing of quantum nonlocality, but also to some other applications of quantum computations and communications. It is described by a simple affine relation between different quantum &#34;data structures&#34; like pure and mixed state, separable and inseparable one. It is shown als

Gerald A. Miller

A relativistic interpretation for why the proton&#39;s $G_E/G_M$ falls and $QF_2/F_1$ is approximately constant is presented. Reproducing the observed $G_E^n$ mandates the inclusion of the effects of the pion cloud. The full relativistic model with a pion cloud provides a good reproduction of all of the nucleon electromagnetic form factors.

Mike Lisa

The STAR Collaboration has measured two-pion correlation functions versus emission angle with respect to the event plane in non-central Au+Au collisions at \sqrt{s_{NN}}=130, 200 GeV. In the context of a parameterized freezeout scenario, the data suggest an out-of-plane freezeout geometry, and a rapid system evolution to freezeout.

Daniel Smania

We show the hyperbolicity of the Feigenbaum fixed point using the inflexibility of the Feigenbaum tower, the Mane-Sad-Sullivan $λ$-Lemma and the existence of parabolic domains (petals) for semi-attractive fixed points.

Delfim F. M. Torres

We extend the second Noether theorem to optimal control problems which are invariant under symmetries depending upon k arbitrary functions of the independent variable and their derivatives up to some order m. As far as we consider a semi-invariance notion, and the transformation group may also depend on the control variables, the result is new even in the cl

Ehud Moshe Baruch, Zhengyu Mao

We prove a generalization to the totally real field case of the Waldspurger&#39;s formula relating the Fourier coefficient of a half integral weight form and the central value of the L-function of an integral weight form. Our proof is based on a new interpretation of Waldspurger&#39;s formula in terms of equality between global distributions. As applications

Roberto Frigerio, Bruno Martelli, Carlo Petronio

We define for each g>=2 and k>=0 a set M_{g,k} of orientable hyperbolic 3-manifolds with $k$ toric cusps and a connected totally geodesic boundary of genus g. Manifolds in M_{g,k} have Matveev complexity g+k and Heegaard genus g+1, and their homology, volume, and Turaev-Viro invariants depend only on g and k. In addition, they do not contain closed essential

R. A. Vitale

Intrinsic $L_p$ metrics are defined and shown to satisfy a dimension--free bound with respect to the Hausdorff metric.

Ken Dykema, Uffe Haagerup

We previously introduced the class of DT--operators, which are modeled by certain upper triangular random matrices, and showed that if the spectrum of a DT-operator is not reduced to a single point, then it has a nontrivial, closed, hyperinvariant subspace. In this paper, we prove that also every DT-operator whose spectrum is concentrated on a single point h

Z. Zakirova

In this paper, we continue studying the 6-dimensional pseudo-Riemannian space V^6(g_{ij}) with signature [++--], which admits projective motions, i. e. continuous transformation groups preserving geodesics. In particular, we determine a necessary and sufficient condition that the 6-dimensional rigid h-spaces have constant curvature.

D. V. Gal&#39;tsov, V. V. Dyadichev

We investigate dynamics of the homogeneous time-dependent SU(2) Yang-Mills fields governed by the non-Abelian Born-Infeld lagrangian which arises in superstring theory as a result of summation of all orders in the string slope parameter $α&#39;$. It is shown that generically the Born-Infeld dynamics is less chaotic than that in the ordinary Yang-Mills theory

Ralf Hofmann, Maxim Pospelov

Warped backgrounds in five dimensional models can provide solutions to various hierarchy problems in particle physics if the standard model matter is associated with the zero modes of bulk fields with nontrivial profiles along the extra dimension. We investigate the case of a {\sl conformally} coupled massless scalar. This field possesses a zero mode whose a

John Womersley

These lectures form a personal, and not necessarily comprehensive, survey of physics at the Fermilab Tevatron proton-antiproton collider. They cover detectors, analysis issues, and physics prospects for the current Tevatron run. (Version 2 has typographic corrections).

John L. Bell

The immensely fruitful concept of Grothendieck topology or covering issued from the efforts of algebraic geometers to study &#34;sheaf-like&#34; objects defined on categories more general than the lattice of open sets on a topological space. In the present paper the covering concept - here called a cover scheme -is presented and developed in the simple case

Olaf Mandel, Markus Greiner, Artur Widera, Tim Rom

We demonstrate the controlled coherent transport and splitting of atomic wave packets in spin-dependent optical lattice potentials. Such experiments open intriguing possibilities for quantum state engineering of many body states. After first preparing localized atomic wave functions in an optical lattice through a Mott insulating phase, we place each atom in

J. Zhu, H. L. Stormer, L. N. Pfeiffer, K. W. Baldwin

We determine the spin susceptibility in a two dimensional electron system in GaAs/AlGaAs over a wide range of low densities from 2$\times10^{9}$cm$^{-2}$ to 4$\times10^{10}$cm$^{-2}$. Our data can be fitted to an equation that describes the density dependence as well as the polarization dependence of the spin susceptibility. It can account for the anomalous

Dmitry V. Khmelev, William J. Teahan

We describe general approach to classification of character sequences (texts, DNA) using relative entropy estimated by off-the-shelf compression and Markov Chains and find them precise enough. We also notice that the method for estimating relative entropy described in the paper cond-mat/0108530 &#34;Language Trees...&#34; by D. Benedetto et al. was considere

Marjorie Gonzalez, Samar Safi-Harb

We present spatially resolved spectroscopy of the supernova remnant (SNR) G292.0+1.8 with the Chandra X-ray observatory. This SNR contains the 135 ms pulsar, J1124-5916. We apply non-equilibrium ionization (NEI) models to the data. By comparing the derived abundances with those predicted from nucleosynthesis models, we estimate a progenitor mass of 30-40 sol

Paul C. Hewett, Craig B. Foltz

A sample of 67 Broad Absorption Line quasars (BALQSOs) from the Large Bright Quasar Survey (LBQS) is used to estimate the observed and intrinsic fraction of BAL quasars in optically--selected samples at intermediate (B_J \simeq 18.5) magnitudes. The observed BALQSO fraction in the redshift range 1.5 < z < 3.0 is 15\pm3%. A well--determined, empirical, k--cor

D. I. Kosenko, S. I. Blinnikov, K. A. Postnov, P. Lundqvist

Time-dependent thermal X-ray spectra are calculated from physically plausible conditions around GRB. It is shown that account for time-dependent ionization processes strongly affects the observed spectra of hot rarefied plasma. These calculations may provide an alternative explanation to the observed X-ray lines of early GRBs afterglows (such as GRB 011211).

C. Hess, B. Büchner, U. Ammerahl, L. Colonescu

We present results of the thermal conductivity of $\rm La_2CuO_4$ and $\rm La_{1.8}Eu_{0.2}CuO_4$ single-crystals which represent model systems for the two-dimensional spin-1/2 Heisenberg antiferromagnet on a square lattice. We find large anisotropies of the thermal conductivity, which are explained in terms of two-dimensional heat conduction by magnons with

Mikhail Plyushchay, Dmitri Sorokin, Mirian Tsulaia

It is shown that the quantization of a superparticle propagating in an N=1, D=4 superspace extended with tensorial coordinates results in an infinite tower of massless spin states satisfying the Vasiliev unfolded equations for free higher spin fields in flat and AdS_4 N=1 superspace. The tensorial extension of the AdS_4 superspace is proved to be a supergrou

Onofre Rojas, F. C. Alcaraz

The phase diagram of a coupled tetrahedral Heisenberg model is obtained. The quantum chain has a local gauge symmetry and its eigenspectrum is obtained by the composition of the eigenspectra of spin-1/2 XXZ chains with arbitrary distribution of spin-3/2 impurities. The phase diagram is quite rich with an infinite number of phases with ferromagnetic, antiferr

M. Mazars

Using the specific model of a bilayer of classical charged particles (bilayer Wigner crystal), we compare the predictions for energies and pair distribution functions obtained by Monte Carlo simulations using three different methods available to treat the long range Coulomb interactions in systems periodic in two directions but bound in the third one. The th

Richard Lieu, Lloyd W. Hillman

We present a method of directly testing whether time continues to have its usual meaning on scales of <= t_P = sqrt(hbar G/c^5) ~ 5.4E-44 s, the Planck time. According to quantum gravity, the time t of an event cannot be determined more accurately than a standard deviation of the form sigma_t/t = a_o (t_P/t)^a, where a_o and a are positive constants ~1; like

Andrew Rasmussen, Steven M. Kahn, Frits Paerels

Recent observations with the dispersive X-ray spectrometers aboard Chandra and Newton Observatory have begun to probe the properties of the X-ray intergalactic medium (IGM) at small redshifts. Using large quantities (~950 ksec) of spectroscopic data acquired using the RGS aboard Newton Observatory, we investigated the intervening material toward three low re

A. B. Balantekin, H. Yuksel

A global analysis of the data from all the solar neutrino experiments combined with the recent KamLAND data is presented. A formula frequently used in the literature gives survival probability for three active solar neutrino flavors in terms of a suitably-modified two-flavor survival probability. Corrections to this formula, which depend on $θ_{13}$ and $δm_

Supratim Sengupta, F. C. Khanna, Sang Pyo Kim

We study nonequilibrium evolution in a self-interacting quantum field theory invariant under space translation only by using a canonical approach based on the recently developed Liouville-von Neumann formalism. The method is first used to obtain the correlation functions both in and beyond the Hartree approximation, for the quantum mechanical analog of the $

Rahul Malhotra, Duane A. Dicus

The light gluino (12 - 16 GeV) and light sbottom (2 - 6 GeV) scenario has been used to explain the apparent overproduction of b-quarks at the Tevatron. This scenario also predicts the decay Z -> b b-bar ~g ~g where the gluinos subsequently decay into b-quarks and sbottoms. We show that this can contribute to the width Gamma_4b = Gamma(Z -> b b-bar b b-bar) s