July 2002 arXiv papers — page 26

S. Zibetti, G. Gavazzi, M. Scodeggio, P. Franzetti

We analyse the structural and dynamical properties of a sample of 324 nearby elliptical and dwarf elliptical galaxies observed during an extensive NIR survey in H-band (1.65 micron). The Fundamental Plane (FP) is determined and a significant tilt is assessed. The origins of such a tilt are investigated by means of a spherically symmetric, isotropic pressure

Patricia Whitelock

The prevailing evidence suggests that most large-amplitude AGB variables follow the period luminosity (PL) relation that has been established for Miras in the LMC and galactic globular clusters. Hipparcos observations indicate that most Miras in the solar neighbourhood are consistent with such a relation. There are two groups of stars with luminosities that

V. Mainieri, J. Bergeron, G. Hasinger, I. Lehmann

We present the results of the X-ray spectral analysis of the first deep X-ray survey with the XMM-Newton observatory during Performance Verification. We restrict the analysis to the sample of 98 sources with more than 70 net counts (flux limit in the [0.5-7] keV band of 1.6 10^{-15} erg cm^{-2} s^{-1}) of which 61 have redshift identification. We find no cor

W. Forman, C. Jones, M. Markevitch, A. Vikhlinin

We discuss Chandra results related to 1) cluster mergers and cold fronts and 2) interactions between relativistic plasma and hot cluster atmospheres. We describe the properties of cold fronts using NGC1404 in the Fornax cluster and A3667 as examples. We discuss multiple surface brightness discontinuities in the cooling flow cluster ZW3146. We review the supe

Andreea Munteanu, Enrique Garcia-Berro, Jordi Jose, Emilia Petrisor

When intermediate mass stars reach their last stages of evolution they show pronounced oscillations. This phenomenon happens when these stars reach the so-called Asymptotic Giant Branch (AGB), which is a region of the Hertzsprung-Russell diagram located at about the same region of effective temperatures but at larger luminosities than those of regular giant

P. E. Nissen, Y. Q. Chen, M. Asplund, M. Pettini

From equivalent widths of the SI lines at 8694 A, Israelian & Rebolo (2001) and Takada-Hidai et al. (2002) have derived a surprisingly high sulphur-to-iron ratio ([S/Fe] = 0.5 to 0.7) in six halo stars with [Fe/H] ~ -2.0 suggesting perhaps that hypernovae made a significant contribution to the formation of elements in the early Galaxy. To investigate this pr

C. M. Bridge, Mark Cropper, Gavin Ramsay, M. A. C. Perryman

We apply an eclipse mapping technique to observations of the eclipsing magnetic cataclysmic variable HU Aqr. The observations were made with the S-Cam2 Superconducting Tunnel Junction detector at the WHT in October 2000, providing high signal-to-noise observations with simultaneous spectral and temporal resolution. HU Aqr was in a bright (high accretion) sta

T. Bloecker

The structure and evolution of central stars of planetary nebulae (CSPNe) is reviewed. CSPNe represent the rapid transitional stage between the Asymptotic Giant Branch (AGB) and the white-dwarf domain. It is shown that the whole evolution off the AGB through the central-star regime depends on the evolutionary history. The detailed evolution into a white dwar

M. Ostrowski, L. Stawarz

We consider radiation of relativistic electrons accelerated within the jet extended boundary layer. Due to velocity shear across the boundary the observed jet/counterjet brightness ratio is diminished as compared to the one derived for the jet spine. Thus the jet Lorentz factor evaluated from the observed jet asymmetry can be an underestimated value influenc

M. Ostrowski, L. Stawarz

We discuss processes accelerating cosmic ray electrons at boundaries of relativistic jets. The resulting spectrum is expected to posses two characteristic components: a power-law distribution at lower energies and a harder high energy component preceding the high energy cut-off. An example of high energy spectrum from such electron distribution is presented,

A. R. McDonald, T. W. B. Muxlow, K. A. Wills, A. Pedlar

Observations of the starburst galaxy, M82, have been made with the VLA in its A-configuration at 15 GHz and MERLIN at 5 GHz enabling a spectral analysis of the compact radio structure on a scale of < 0.1&#39;&#39; (1.6 pc). Crucial to these observations was the inclusion of the Pie Town VLBA antenna, which increased the resolution of the VLA observations by

F. Tavecchio, L. Maraschi, G. Ghisellini, A. Celotti

We report the BeppoSAX observations of 6 Flat Spectrum Radio Quasars. Three of them have a clear detection up to 100 keV with the PDS instrument. For 4 objects the X-ray spectrum is satisfactorily fitted by a power-law continuum with Galactic absorption. 2251+158 show the presence of absorption higher than the galactic value, while the spectrum of the source

M. A. Beasley, C. M. Baugh, D. A. Forbes, R. M. Sharples

We describe a scheme for the formation of globular cluster systems in early-type galaxies using a semi-analytic model of galaxy formation. Operating within a Lambda CDM cosmology, we assume that metal-poor globular clusters are formed at high-redshift in pre-galactic fragments, and that the subsequent gas-rich merging of these fragments leads to the formatio

Heon-Young Chang, Chul-Sung Choi, Insu Yi

Optically thin and geometrically thick accretion flows are known to be responsible for the observed radio/X-ray luminosity relation of the X-ray bright galactic nuclei. It has also been suggested that supermassive black hole masses can be estimated from measurements of the core radio luminosity and the X-ray luminosity by using the advection-dominated accret

Enrique Vazquez-Semadeni, Adriana Gazol, Thierry Passot, Javier Sanchez-Salcedo

We review recent results on the nonlinear development of thermal instability in the context of the turbulent atomic interstellar medium (ISM). First, we pre- sent a brief summary of the linear theory, remarking that, in the atomic ISM, the wave mode is stable at small scales. Next, we revisit the growth of isolated entropy perturbations in initially unstable

J. W. van Holten

We present a time-dependent solution to the coupled Einstein-Higgs equations for general Higgs-type potentials in the context of flat FRW cosmological models. Possible implications are discussed.

E. Kiritsis, G. Kofinas, N. Tetradis, T. N. Tomaras

The consequences for the brane cosmological evolution of energy exchange between the brane and the bulk are analysed in detail, in the context of a non-factorizable background geometry with vanishing effective cosmological constant on the brane. A rich variety of brane cosmologies is obtained, depending on the precise mechanism of energy transfer, the equati

I. T. Habibullin

The problem of searching boundary value problems for soliton equations consistent with the integrability property is discussed. A method of describing integrals of motion for the integrable initial boundary value problems for the Kadomtsev-Petviashvili equation is suggested via Green identity.

P. Calabrese, E. V. Orlov, P. Parruccini, A. I. Sokolov

We analyse the critical behavior of two-dimensional N-vector spin systems with noncollinear order within the five-loop renormalization-group approximation. The structure of the RG flow is studied for different N leading to the conclusion that the chiral fixed point governing the critical behavior of physical systems with N = 2 and N = 3 does not coincide wit

Shi-Liang Zhu, Z. D. Wang

We propose an experimentally feasible scheme to achieve quantum computation based on nonadiabatic geometric phase shifts, in which a cyclic geometric phase is used to realize a set of universal quantum gates. Physical implementation of this set of gates is designed for Josephson junctions and for NMR systems. Interestingly, we find that the nonadiabatic phas

Andrzej J. Buras, Fabrizio Parodi, Achille Stocchi

The unitarity triangle can be determined by means of two measurements of its sides or angles. Assuming the same relative errors on the angles $(α,β,γ)$ and the sides $(R_b,R_t)$, we find that the pairs $(γ,β)$ and $(γ,R_b)$ are most efficient in determining $(\bar\varrho,\barη)$ that describe the apex of the unitarity triangle. They are followed by $(α,β)$,

K. Urbanowski

We show that the real parts of diagonal matrix elements of the exact effective Hamiltonian governing the time evolution in the subspace of states of neutral kaons and similar particles can not be equal for $t > t_{0}$ ($t_{0}$ is the instant of creation of the pair $K_{0}, {\bar{K}}_{0}$) when the total system under consideration is CPT invariant but CP noni

Hui Zhao, Sebastian Moehl, Heinz Kalt

We report on the first experimental determination of the coherence length of excitons in semiconductors using the combination of spatially resolved photoluminescence with phonon sideband spectroscopy. The coherence length of excitons in ZnSe quantum wells is determined to be 300 ~ 400 nm, about 25 ~ 30 times the exciton de Broglie wavelength. With increasing

T. Wong, A. Melatos

A new astronomical window into the southern skies has been opened with the high-frequency upgrade to the Australia Telescope Compact Array (ATCA), which allows radio-interferometric mapping of sources at wavelengths as short as 3mm. In anticipation of the upgrade&#39;s completion, a two-day workshop was held at the University of Melbourne in November 2001. T

Daniel Arndt, Patrick J. Fox

We study the possibility of emission of the saxion, a superpartner of the axion, from SN1987A. The fact that the observed neutrino pulse from SN1987A is in excellent agreement with the current theory of supernovae places a strong bound on the energy loss into any non-standard model channel, therefore enabling bounds to be placed on the decay constant, f_a, o

P. K. Aravind

A proof of Bell&#39;s theorem without inequalities and involving only two observers is given by suitably extending a proof of the Bell-Kochen-Specker theorem due to Mermin. This proof is generalized to obtain an inequality-free proof of Bell&#39;s theorem for a set of n Bell states (with n odd) shared between two distant observers. A generalized CHSH inequal

Peter B. Kahn, Yair Zarmi

In the Method of Multiple-Time-Scales (MMTS), the introduction of independent time scales and the elimination of secular terms in the fast time variable, T0 = t, lead to the well-known solvability conditions. Starting from first order, free terms (solutions of the unperturbed equations) emerge in every order in the expansion of the approximate solution. In o

Shigeki Matsutani, Yoshihiro Ônishi

Berry and Klein (J. Mod. Opt. (1997) 43 2139-2164) showed that the Talbot effects in classical optics are naturally explained by Gauss sums studied in number theory. Their result was based on Helmholtz equation. In this article, we explain the effect based on Fresnel integral also by Gauss sums. These two explanations are shown to agree with by the reciproci

David Savitt, Kristin Lauter

This paper proves that the maximum number of rational points on a smooth, absolutely irreducible genus 4 curve over the field of 8 elements is 25. The body of the paper shows that 27 points is not possible using techniques from algebraic geometry. The appendix shows that 26 points is not possible by examining the zeta functions.

Jnanadeva Maharana

The symmetry structure of axion-dilaton quantum string cosmology is investigated. The invariance of the string effective action under S-duality group, SU(1,1), facilitates solution of Wheeler-De Witt equation from group theoretic considerations; revealing existence of a new class of wave functions. We discover the an underlying ${W}$-infinity algebra in this

Thomas Curtright

New features are described for models with multi-particle area-dependent potentials, in any number of dimensions. The corresponding many-body field theories are investigated for classical configurations. Some explicit solutions are given, and some conjectures are made about chaos in such field theories.

A. Ahmedov, E. N. Antonov, E. Bartos, E. A. Kuraev

Single-spin asymmetry appears due to the interference of single and double gluon exchange between protons. A heavy fermion model is used to describe the jet production in the interaction of gluon with the proton implying the further averaging over its mass. As usually in one-spin correlations, the imaginary part of the double gluon exchange amplitude play th

Beverly K. Berger

A systematic asymptotic expansion is developed for the gravitational wave degrees of freedom of a class of expanding, vacuum Gowdy cosmological spacetimes. In the wave map description of these models, the evolution of the gravitational wave amplitudes defines an orbit in the target space. The circumference of this orbit decays to zero indicating that the asy

Mehdi Dastani, Leendert van der Torre

In this paper we introduce a qualitative decision and game theory based on belief (B) and desire (D) rules. We show that a group of agents acts as if it is maximizing achieved joint goals.

Piero A. Bonatti

Open logic programs and open entailment have been recently proposed as an abstract framework for the verification of incomplete specifications based upon normal logic programs and the stable model semantics. There are obvious analogies between open predicates and abducible predicates. However, despite superficial similarities, there are features of open prog

J. Ranninger, A. Romano

Strongly interacting systems are characterized by heavily dressed entities with internal degrees of freedom, which, on a local level, can be described in terms of coherent quantum states. We examine the modification of these local coherent quantum states when such entities condense into a macroscopic coherent quantum state, such as superfluidity. As an examp

Dibyendu Das, Jané Kondev, Bulbul Chakraborty

We consider dynamics of classical dimer models undergoing a phase transition to an ordered, frozen state. Relaxation processes are dominated by traps which are entropic in origin and can be traced to the locally jammed nature of the dimer states. Depending on the nature of the phase transition, critical dynamics are characterized either by an exponential, or

N. Bulut

The numerical studies of d_{x^2-y^2}-wave pairing in the two-dimensional (2D) and the 2-leg Hubbard models are reviewed. For this purpose, the results obtained from the determinantal Quantum Monte Carlo and the density-matrix renormalization-group calculations are presented. These are calculations which were motivated by the discovery of the high-T_c cuprate

H. Kfir, I. Kanter

sequential updating scheme (SUS) for the belief propagation algorithm is proposed, and is compared with the parallel (regular) updating scheme (PUS). Simulation results on various codes indicate that the number of iterations of the belief algorithm for the SUS is about one half of the required iterations for the PUS, where both decoding algorithms have the s

Noah Brosch

I review the status of knowledge about the dwarf galaxies in the Virgo Cluster (VC) concentrating on work published after 1995. I explain the present ideas about the nature and history of the dwarf elliptical galaxies and emphasize the major increments in understanding achieved in the study of the dwarf irregular population. Special attention is given to the

A. O. Govorov, S. E. Ulloa, K. Karrai, R. J. Warburton

The quantum nature of matter lies in the wave function phases that accumulate while particles move along their trajectories. A prominent example is the Aharonov-Bohm phase, which has been studied in connection with the conductance of nanostructures. However, optical response in solids is determined by neutral excitations, for which no sensitivity to magnetic

Sadhan K. Adhikari

Using the explicit numerical solution of the axially-symmetric Gross-Pitaevskii equation we study the dynamics of interaction among vortex solitons in a rotating matter-wave bright soliton train in a radially trapped and axially free Bose-Einstein condensate to understand certain features of the experiment by Strecker et al.[2002 Nature 417 150]. In a solito

R. Gonzalez Felipe, H. J. Mosquera Cuesta, A. Perez Martinez, H. Perez Rojas

The equations of state for degenerate electron and neutron gases are studied in the presence of magnetic fields. After including quantum effects to study the structural properties of these systems, it is found that some hypermagnetized stars can be unstable based on the criterium of stability of pressures. Highly magnetized white dwarfs should collapse produ

K. G. Geojo, S. Sree Ranjani, A. K. Kapoor

A few quasi-exactly solvable models are studied within the quantum Hamilton-Jacobi formalism. By assuming a simple singularity structure of the quantum momentum function, we show that the exact quantization condition leads to the condition for quasi-exact solvability.

Amir Aghamohammadi, Masoud Alimohammadi, Mohammad Khorrami

Multi-species reaction-diffusion systems, with nearest-neighbor 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 of

Davoud Kamani

We study the action of the $SL(2;R)$ group on the noncommutative DBI Lagrangian. The symmetry conditions of this theory under the above group will be obtained. These conditions determine the extra U(1) gauge field. By introducing some consistent relations we observe that the noncommutative (or ordinary) DBI Lagrangian and its $SL(2;R)$ dual theory are dual o

C. Giunti, M. Tanimoto

We have studied how observables of the neutrino mixing matrix can link up with the ones in the quark sector. The deviation from the bi-maximal flavor mixing is parameterized using a 3 x 3 unitary matrix. The neutrino mixings are investigated supposing this unitary matrix to be hierarchical like the quark mixing matrix. We obtain the remarkable prediction |U_

Yoshiharu Kawamura

We propose a generalization of cubic matrix mechanics by introducing a canonical triplet and study its relation to Nambu mechanics. The generalized cubic matrix mechanics we consider can be interpreted as a &#39;quantum&#39; generalization of Nambu mechanics.

Rong-Gen Cai

We construct a positive constant curvature space by identifying some points along a Killing vector in a de Sitter Space. This space is the counterpart of the three-dimensional Schwarzschild-de Sitter solution in higher dimensions. This space has a cosmological event horizon, and is of the topology ${\cal M}_{D-1}\times S^1$, where ${\cal M}_{D-1}$ denotes a

Philippe Elbaz-Vincent, Herbert Gangl, Christophe Soule

For N=5 and N=6, we compute the Voronoi cell complex attached to real N-dimensional quadratic forms, and we obtain the homology of GL_N(Z) with trivial coefficients, up to small primes. We also prove that K_5(Z) = Z and K_6(Z) has only 3-torsion.

Raul E. Curto, Sang Soo Park

We characterize $k$-hyponormality and quadratic hyponormality of powers of weighted shifts using Schur product techniques.

Raul E. Curto, Lawrence A. Fialkow

Tchakaloff&#39;s Theorem establishes the existence of a quadrature rule of prescribed degree relative to a positive, compactly supported measure that is absolutely continuous with respect to Lebesgue measure on $\mathbb{R}^{d}$. Subsequent extensions were obtained by Mysovskikh and by Putinar. We provide new proofs and partial extensions of these results, ba

Raul E. Curto, Young Min Han

We give necessary and sufficient conditions for a Banach space operator with the single valued extension property (SVEP) to satisfy Weyl&#39;s theorem and $a$-Weyl&#39;s theorem. We show that if $T$ or $T^{\ast}$ has SVEP and $T$ is transaloid, then Weyl&#39;s theorem holds for $f(T)$ for every $f\in H(σ(T))$. When $T^{\ast}$ has SVEP, $T$ is transaloid and

A. Tsemo

A Sim(n-1,1) affine manifold is an affine manifold whose linear holonomy is contained in the similarity lorentzian group but not in the lorentzian group. The class of similarity lorentzian affine manifolds is a small part in the nice class of conformally lorentzian flat manifolds. In this paper we show that a compact Sim(n-1,1) affine manifold is incomplete.

Jean-Claude Hausmann, Susan Tolman

We study the poset of Hamiltonian tori for polygon spaces. We determine some maximal elements and give examples where maximal Hamiltonian tori are not all of the same dimension.

Fayez A. Alhargan

A simpler proof of the four color theorem is presented. The proof was reached using a series of equivalent theorems. First the maximum number of edges of a planar graph is obatined as well as the minimum number of edges for a complete graph. Then it is shown that for the theorem to be false there must exist a complete planar graph of $h$ edges such that $h>4

Frederick M. Goodman

We generalize results of Mingo and Nica on graded independence from the context of $\mathbb Z_2$--graded (Fermionic) noncommutative probability spaces to that of $\mathbb Z_n$--graded noncommutative probability spaces. We show that for $q$ a primitive $n$-th root of unity, the $q$-cumulants defined by Nica linearize the addition of homogeneous $\mathbb Z_n$-

Wadim Zudilin

A motivated q-extension of the values of the Riemann zeta function at positive integers is presented. Several irrationality and transcendence results as well as new general problems for these q-zeta values are stated.

Wadim Zudilin

In 1978, Apery has given sequences of rational approximations to $ζ(2)$ and $ζ(3)$ yielding the irrationality of each of these numbers. One of the key ingredient of Apery&#39;s proof are second-order difference equations with polynomial coefficients satisfied by numerators and denominators of the above approximations. Recently, a similar second-order differe

Detlev Buchholz, Jens Mund, Stephen J. Summers

We propose a canonical description of the dynamics of quantum systems on a class of Robertson-Walker space-times. We show that the worldline of an observer in such space-times determines a unique orbit in the local conformal group SO(4,1) of the space-time and that this orbit determines a unique transport on the space-time. For a quantum system on the space-

David J. Toms

We look at vacuum solutions for fields confined in cavities where the boundary conditions can rule out constant field configurations, other than the zero field. If the zero field is unstable, symmetry breaking can occur to a field configuration of lower energy which is not constant. The stability of the zero field is determined by the size of the length scal

J. Syska

Non-homogeneous gauge ground state solutions in a six-dimensional gauge model in the presence of non-zero extended fermionic charge density fluctuations are reviewed and fully reinterpreted.

N. B. Skachkov

In present note the arguments in favour of future high statistical measurements of the formfactors that describe pi-meson decays into lepton-antilepton pair and photon are presented. It is shown that these formfactors Q^2 dependence contains the important information on the dynamics of quark motion inside a hadron.

Roger Barlow

The treatment of systematic errors is often mishandled. This is due to lack of understanding and education, based on a fundamental ambiguity as to what is meant by the term. This note addresses the problems and offers guidance to good practice.

O. Lalakulich, Yu. Novoseltsev, R. Novoseltseva, G. Vereshkov

The results of measurements of gamma-N total cross section, obtained by the method of photoproduction processes registration at the Baksan Underground Scintillation Telescope, are presented. These data at energies sqrt(s)=40-130 GeV confirm the effect of more rapid photon-hadron cross-section rise as compared to the hadron-hadron ones. It is shown, the incre

S. Avdonin, N. Bagraev, A. Mikhailova, B. Pavlov

Simplest models of two- and three-terminal Quantum Quantum Gates are suggested in form of a quantum ring with few one-dimensional quantum wires attached to it and several point-wise govering electrodes inside the ring which are charged by a single hole. In resonance case, when the Fermi level in the wires coincides with the resonance energy level on the ring

Christian Schulze

The traditional Sznajd model, as well as its Ochrombel simplification for opinion spreading, are applied to marketing with the help of advertising. The larger the lattice is the smaller is the amount of advertising needed to convince the whole market

B. P. Dolan, D. A. Johnston, R. Kenna

In various statistical-mechanical models the introduction of a metric onto the space of parameters (e.g. the temperature variable, $β$, and the external field variable, $h$, in the case of spin models) gives an alternative perspective on the phase structure. For the one-dimensional Ising model the scalar curvature, ${\cal R}$, of this metric can be calculate

Oleg Derzhko, Taras Verkholyak, Reimar Schmidt, Johannes Richter

Using the 2D Jordan-Wigner transformation we reformulate the square-lattice s=1/2 XY (XZ) model in terms of noninteracting spinless fermions and examine the ground-state and thermodynamic properties of this spin system. We consider the model with two types of anisotropy: the spatial anisotropy interpolating between 2D and 1D lattices and the anisotropy of th

S. H. Chun, S. J. Potashnik, K. C. Ku, P. Schiffer

We demonstrate efficient spin-polarized tunneling between a ferromagnetic metal and a ferromagnetic semiconductor with highly mismatched conductivities. This is indicated by a large tunneling magnetoresistance (up to 30%) at low temperatures in epitaxial magnetic tunnel junctions composed of a ferromagnetic metal (MnAs) and a ferromagnetic semiconductor (GaM

K. Totsuka, H-J. Mikeska

We investigate low-lying singlet and triplet excitations and the magnetization process of quasi-1D spin systems composed of tetrahedral spin clusters. For a class of such models, we found various exact low-lying excitations; some of them are responsible for the first-order transition between two different ground states formed by local singlets. Moreover, we

Avik W. Ghosh, Ferdows Zahid, Supriyo Datta, Robert R. Birge

We discuss the nature of charge transfer in molecular conductors upon connecting to two metallic contacts and imposing a voltage bias across them. The sign of the charge transfer (oxidation vs. reduction) depends on the position of the metal Fermi energy with respect to the molecular levels. In addition, the charge transfer depends on the strength of the cou

A. Smerzi, A. Trombettoni, P. G. Kevrekidis, A. R. Bishop

We predict a dynammical classical superfluid-insulator transition (CSIT) in a Bose-Einstein condensate (BEC) trapped in an optical and a magnetic potential. In the tight-binding limit, this system realizes an array of weakly-coupled condensates driven by an external harmonic field. For small displacements of the parabolic trap about the equilibrium position,

A. A. Schekochihin, S. C. Cowley, G. W. Hammett, J. L. Maron

This is a brief review of the main results of our recent studies of the nonlinear evolution of the small-scale MHD dynamo in the high-Prandtl-number regime and of the structure of the resulting saturated state of the isotropic homogeneous MHD turbulence. It is emphasized that the MHD regime without a uniform mean field (as is the case in our studies) is fund

R. Atkins, W. Benbow, D. Berley, M. L. Chen

Evidence of TeV emission from GRB970417a has been previously reported using data from the Milagrito detector. Constraints on the TeV fluence and the energy spectrum are now derived using additional data from a scaler system that recorded the rate of signals from the Milagrito photomultipliers. This analysis shows that if emission from GRB970417a has been obs

J. Patrick Henry

The amount and nature of the evolution of the X-ray properties of clusters of galaxies provides information on the formation of structure in the universe and on the properties of the universe itself. The cluster luminosity - temperature relation does not evolve strongly, suggesting that the hot X-ray gas had a more complicated thermodynamic history than simp

S. S. Mizrahi, V. V. Dodonov

An asymmetric nature of the boson `destruction&#39; operator $\hat{a}$ and its `creation&#39; partner $\hat{a}^{\dagger}$ is made apparent by applying them to a quantum state $|ψ>$ different from the Fock state $|n>$. We show that it is possible to {\em increase} (by many times or by any quantity) the mean number of quanta in the new `photon-subtracted&#39;

L. I. Deych, M. V. Erementchouk, A. A. Lisyansky

We numerically study the distribution function of the conductivity (transmission) in the one-dimensional tight-binding Anderson model in the region of fluctuation states. We show that while single parameter scaling in this region is not valid, the distribution can still be described within a scaling approach based upon the ratio of two fundamental quantities

Keshav Dasgupta, Mohammad M. Sheikh-Jabbari, Mark Van Raamsdonk

We show that the symmetry algebra governing the interacting part of the matrix model for M-theory on the maximally supersymmetric pp-wave is the basic classical Lie superalgebra SU(4|2). We determine the SU(4|2) multiplets present in the exact spectrum in the limit where μ(the mass parameter) becomes infinite, and find that these include infinitely many BPS

Joerg Jaeckel, Christof Wetterich

We compare different methods used for non-perturbative calculations in strongly interacting fermionic systems. Mean field theory often shows a basic ambiguity related to the possibility to perform Fierz transformations. The results may then depend strongly on an unphysical parameter which reflects the choice of the mean field, thus limiting the reliability.

Jai Sukhatme, Raymond T. Pierrehumbert

We examine the decay of passive scalars with small, but non zero, diffusivity in bounded 2D domains. The velocity fields responsible for advection are smooth (i.e., they have bounded gradients) and of a single large scale. Moreover, the scale of the velocity field is taken to be similar to the size of the entire domain. The importance of the initial scale of

D. Duerr, P. Pickl

We consider the asymptotic evolution of a relativistic spin-1/2-particle. i.e. a particle whose wavefunction satisfies the Dirac equation with external static potential. We prove that the probability for the particle crossing a (detector) surface converges to the probability, that the direction of the momentum of the particle lies within the solid angle defi

F. Wiekhorst, E. Shevchenko, H. Weller, J. Kötzler

Based on the high-temperature organometallic route (Sun et al. Science 287, 1989 (2000)), we have synthesized powders containing CoPt_3 single crystals with mean diameters of 3.3(2) nm and 6.0(2) nm and small log-normal widths sigma=0.15(1). In the entire temperature range from 5 K to 400 K, the zero-field cooled susceptibility chi(T) displays significant de

S. Kutter, E. M. Terentjev

Biological molecules can form hydrogen bonds between nearby residues, leading to helical secondary structures. The associated reduction of configurational entropy leads to a temperature dependence of this effect: the &#34;helix-coil transition&#34;. Since the formation of helices implies a dramatic shortening of the polymer dimensions, an externally imposed

Ozgur Ceyhan

We introduce the moduli space $R \bar{M}_{2k,l}$ of pointed real curves of genus zero and give its natural stratification. The strata of $R \bar{M}_{2k,l}$ correspond to real curves of genus zero with different degeneration types and are encoded by their dual trees with certain decorations. By using this stratification, we calculate the first Stiefel-Whitney

The MACRO Collaboration

We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles in the penetrating cosmic radiation, for the range $4\times 10^{-5}< β< 1$. Several searches with all the MACRO sub-detectors (i.e. scintillation counters, limited streamer tubes and nuclear track detectors) were performed, both in stand alone and combined

Elvio Di Salvo

We show that the transverse momentum dependent transversity function is proportional to the longitudinal polarization of a quark in a transversely polarized proton. This result suggests an alternative, convenient method for determining transversity, without knowing unusual fragmentation functions. The method consists of measuring the double spin azimuthal as

Gerald V. Dunne, Alex Kovner, Shinsuke M. Nishigaki

We analyze the effect of heavy fundamentally charged particles on the finite temperature deconfining phase transition in the 2+1 dimensional Georgi-Glashow model. We show that in the presence of fundamental matter the transition turns into a crossover. The near critical theory is mapped onto the 2 dimensional Ising model in an external magnetic field. Using

I. M. Sokolov

We discuss a problem of cyclization of a polymer molecule, which is an important example of reaction in a system showing strongly non-Markovian behavior on the timescales of interest. We show that the knowledge of the joint three-time probability distribution of the end-to-end distance is sufficient for the full description of the cyclization kinetics, so th

Belle Collaboration, T. Tomura

The oscillation frequency of B0-B0bar mixing (Delta-m_d) has been measured using 29.1 fb^{-1} of datacollected with the Belle detector at KEKB. This measurement is made through the distributions of the proper decay time difference of B pairs in events tagged as same- and opposite-flavor decays. In each event, one $B$ is fully reconstructed in a flavor-specif

Victor S. L&#39;vov, Itamar Procaccia, Vasil Tiberkevich

In anisotropic turbulence the correlation functions are decomposed in the irreducible representations of the SO(3) symmetry group (with different &#34;angular momenta&#34; $\ell$). For different values of $\ell$ the second order correlation function is characterized by different scaling exponents $ζ_2(\ell)$. In this paper we compute these scaling exponents

L. Bonora, D. Mamone, M. Salizzoni

We define a sequence of VSFT D-branes whose low energy limit leads exactly to a corresponding sequence of GMS solitons. The D-branes are defined by acting on a fixed VSFT lump with operators defined by means of Laguerre polynomials whose argument is quadratic in the string creation operators. The states obtained in this way form an algebra under the SFT star

E. O. Iltan, I. Turan

We study the flavor changing t-> c l_1^- l_2^+ decay in the framework of the general two Higgs doublet model, the so called model III. We predict the branching ratio for l_1=τ, l_2=μat the order of magnitude of BR \sim 10^{-8}.

F. K. Sutaria, P. Chandra, S. Bhatnagar, A. Ray

We report on the combined X-ray and radio observations of the type Ic SN 2002ap, using XMM-Newton ToO observation of M74 and the Giant Metrewave Radio Telescope (GMRT). We account for the presence of a nearby source in the pre-supernova Chandra field of view in our measurements of the X-ray flux (0.3 - 10 KeV) 5.2 days after the explosion. The X-ray spectrum

Aleksander Filip Zarnecki

A simple model, based on the analytical formula for the Compton scattering, is proposed to describe the realistic photon-energy spectra for the Photon Collider at TESLA. Parameters of the model are obtained from the full simulation of the beam by V.Telnov, which includes nonlinear corrections and contributions of higher order processes. Photon energy distrib

M. Demiański, A. Doroshkevich, V. Turchaninov

Properties of $\sim$ 5000 observed Ly-$α$ absorbers are investigated using the model of formation and evolution of DM structure elements based on the Zel&#39;dovich theory. This model is generally consistent with simulations of absorbers formation, accurately describes the Large Scale Structure observed in the galaxy distribution at small redshifts and empha

R. -S. Lu

We report the first observation of the charmless two-body mode $B^{\pm} \to ωK^{\pm}$ decay, and a new measurement of the branching fraction for the $B^{\pm} \to ωπ^{\pm}$ decay. The measured branching fractions are ${\cal B} (B^{\pm} \to ωK^{\pm}) = (9.2{}^{+2.6}_{-2.3}\pm 1.0) \times 10^{-6}$ and ${\cal B} (B^{\pm} \to ωπ^{\pm}) = (4.2{}^{+2.0}_{-1.8}\pm 0

Naoki Itoh, Nami Tomizawa, Masaya Tamamura, Shinya Wanajo

We calculate the screening corrections to the electron capture rates in dense stars by the relativistically degenerate electron liquid. In order to calculate the screening corrections we adopt the linear response theory which is widely used in the field of solid state physics and liquid metal physics. In particular, we use the longitudinal dielectric functio

E. B. Postnikov

The purpose of this paper is to present an algorithm for evaluating Hankel transform of the null and the first kind. The result is the exact analytical representation as the series of the Bessel and Struve functions multiplied by the wavelet coefficients of the input function. Numerical evaluation of the test function with known analytical Hankel transform i

Shude Mao, Bohdan Paczynski

We show that the small intrinsic spread in luminosities of red clump giants can be used to constrain the differences in the streaming motions of Galatic bulge stars on the near side and those on the far side. We propose two methods to select two samples with one preferentially on the near side and the other on the far side. In the first method, we divide red