September 2003 arXiv papers — page 18

Maciej Blaszak

Liouville integrable separable systems with quadratic in momenta first integrals are considered. Particular attention is paid to the systems generated by the so-called special conformal Killing tensors, i.e. Benenti systems. Then, infinitely many new classes of separable systems are constructed by appropriate deformations of Benenti class systems.

A. Atoyan, J. Patera

A versatile method is described for the practical computation of the discrete Fourier transforms (DFT) of a continuous function $g(t)$ given by its values $g_{j}$ at the points of a uniform grid $F_{N}$ generated by conjugacy classes of elements of finite adjoint order $N$ in the fundamental region $F$ of compact semisimple Lie groups. The present implementa

E. H. El Kinani

A realization of various algebraic structures in terms of the $C_λ$-extended oscillator algebras is introduced. In particular, the $C_λ$-extended oscillator algebras realization of Fairlie-Fletcher-Zachos (FFZ)algebra is given. This latter lead easily to the realization of the quantum $U_t(sl(2))$ algebra. The new deformed Virasoro algebra is also presented.

Maxim Raginsky

Given a completely positive (CP) map $T$, there is a theorem of the Radon-Nikodym type [W.B. Arveson, Acta Math. {\bf 123}, 141 (1969); V.P. Belavkin and P. Staszewski, Rep. Math. Phys. {\bf 24}, 49 (1986)] that completely characterizes all CP maps $S$ such that $T-S$ is also a CP map. This theorem is reviewed, and several alternative formulations are given

Ian M. Aberbach

Let (R,m,k) be an excellent local ring of positive prime characteristic. We show that if Tor_1^R(R^+,k) = 0 then R is regular. This improves a result of Schoutens, in which the additional hypothesis that R was an isolated singularity was required for the proof.

Astrid Reifegerste

We show how the sign of a permutation can be deduced from the tableaux induced by the permutation under the Robinson-Schensted-Knuth correspondence. The result yields a simple proof of a conjecture on the squares of imbalances raised by Stanley.

R. Fioresi

In this paper is constructed an algebraic deformation quantization of the coadjoint orbits of the group G semidirect product of the symmetric n by n matrices and GL(n). This group is linked to the dynamics of the self gravitating ellipsoid.

Juan-Pablo Ortega, Victor Planas-Bielsa

This paper shows that various relevant dynamical systems can be described as vector fields associated to smooth functions via a bracket that defines what we call a Leibniz structure. We show that gradient flows, some dissipative systems, and nonholonomically constrained simple mechanical systems, among other dynamical behaviors, can be described using this m

Dan Volok

We generalize some classical results for the Schlesinger system of partial differential equations and give the explicit form of its solution, associated with rational matrix functions in general position.

Allen Knutson, Ezra Miller

Let (Π,Σ) be a Coxeter system. An ordered list of elements in Σand an element in Πdetermine a {\em subword complex}, as introduced in our paper on Gröbner geometry of Schubert polynomials (math.AG/0110058). Subword complexes are demonstrated here to be homeomorphic to balls or spheres, and their Hilbert series are shown to reflect combinatorial properties of

Renyi Ma

We give an proof on the Weinstein conjecture on the cotangent bundles of open manifolds. Its proof is based on Gromov's nonlinear Fredholm alternative.

Lajos Molnar

In this paper we describe the structure of all sequential isomorphisms between the sets of von Neumann algebra effects. It turns out that if the underlying algebras have no commutative direct summands, then every sequential isomorphism between the sets of their effects extends to the direct sum of a *-isomorphism and a *-antiisomorphism between the underlyin

David Helm, Ezra Miller

Let Q be an affine semigroup generating Z^d, and fix a finitely generated Z^d-graded module M over the semigroup algebra k[Q] for a field k. We provide an algorithm to compute a minimal Z^d-graded injective resolution of M up to any desired cohomological degree. As an application, we derive an algorithm computing the local cohomology modules H^i_I(M) support

Daniel Jupiter, Krastio Lilov

We examine invariant nonrecurrent Fatou components of automorphisms of $\mathbb{C}^2$ in the case where all limit maps are constant. We show that except in special cases there cannot be more than one such limit map. We also briefly examine such Fatou components where the limit maps may be nonconstant. Lastly we present a few examples of such Fatou components

Paolo Rocchi, Leonida Gianfagna

This contribution derives from a rather extensive study on the foundations of probability. We start by discussing critically the two main models of the random event in Probability Theroy and cast light over a number of incongruities. We conclude that the argument of probability is the critical knot of the probability foundations and put forward the structure

C. P. Hughes, Z. Rudnick

We show that the number of lattice points lying in a thin annulus has a Gaussian value distribution if the width of the annulus tends to zero sufficiently slowly as we increase the inner radius.

Weiqiang Wang

We study the structure constants of the class algebra $R_Z(G_n)$ of the wreath products $G_n$ associated to an arbitrary finite group G with respect to the basis of conjugacy classes. We show that a suitable filtration on $R_Z(G_n)$ gives rise to the graded ring $\mathcal G_G(n)$ with non-negative integer structure constants independent of n (some of which a

Meng Chen

If $X$ is a smooth complex projective 3-fold with ample canonical divisor $K$, then the inequality $K^3\ge {2/3}(2p_g-7)$ holds, where $p_g$ denotes the geometric genus. This inequality is nearly sharp. We also give similar, but more complicated, inequalities for general minimal 3-folds of general type. (A noether type of inequality lies, by all means, on th

Stefano Giusto, Camillo Imbimbo

We illustrate a method for computing the number of physical states of open string theory at the stable tachyonic vacuum in level truncation approximation. The method is based on the analysis of the gauge-fixed open string field theory quadratic action that includes Fadeev-Popov ghost string fields. Computations up to level 9 in the scalar sector are consiste

W. Bietenholz, A. Gfeller, U. -J. Wiese

We study the dimensional reduction of fermions, both in the symmetric and in the broken phase of the 3-d Gross-Neveu model at large N. In particular, in the broken phase we construct an exact solution for a stable brane world consisting of a domain wall and an anti-wall. A left-handed 2-d fermion localized on the domain wall and a right-handed fermion locali

A. Fabbri, S. Farese, J. Navarro-Salas

We derive the anomalous transformation law of the quantum stress tensor for a 2D massless scalar field coupled to an external dilaton. This provides a generalization of the Virasoro anomaly which turns out to be consistent with the trace anomaly. We apply it together with the equivalence principle to compute the expectation values of the covariant quantum st

Gabriele Honecker

Intersecting D-brane worlds provide phenomenologically appealing constructions of four dimensional low energy string vacua. In this talk, a Z_4 x Z_2 orbifold background is taken into account. It is possible to obtain supersymmetric and stable chiral models. In particular, a three generation model with Pati-Salam gauge group and no exotic chiral matter is pr

Paul Sutcliffe

The study of Skyrmions predicts that there is an icosahedrally symmetric charge seventeen SU(2) Yang-Mills instanton in which the topological charge density, for fixed Euclidean time, is localized on the edges of the truncated icosahedron of the buckyball. In this paper the existence of such an instanton is proved by explicit construction of the associated A

Keiichi Nagao

We discuss that the Ginsparg-Wilson relation, which has the key role in the recent development of constructing lattice chiral gauge theory, can play an important role to define chiral structures in finite matrix models and noncommutative geometries.

Kei-ichi Maeda, Takashi Torii

We present the covariant gravitational equations to describe a four-dimensional brane world in the case with the Gauss-Bonnet term in a bulk spacetime, assuming that gravity is confined on the $Z_2$ symmetric brane. It contains some components of five-dimensional Weyl curvature ($E_{μν}$) which describes all effects from the bulk spacetime just as in the cas

Marc Soussa

Recently, we proposed a non-local relativistic formulation of MOND (Modified Newtonian Dynamics). The equations of motion were not derived, rather they were inferred from the result one would obtain by using the Schwinger-Keldysh formalism. The formalism simultaneously ensures causality of the field equations and the reality of in-out operator amplitudes. Th

W. Siegel

Analysis of string interactions indicates a weakening of gravity at the string length scale, thus avoiding black holes and their singularities.

Mary Alberg, Ernest M. Henley

We use detailed balance for a hadron composed of quark and gluon Fock states to obtain parton distributions in the proton and pion on the basis of a simple statistical model.

Alberto Sirlin

We review the radiative corrections to superallowed Fermi transitions and neutron beta decay in the Standard Model, and their relevance for the universality of the Weak Interactions.

S. G. Rubin

The concept of a random Lagrangian is proposed. It is considered as a basis for a new view of the old problems such as renormalization, nonzero vacuum energy and the anthropic principle. It gives rise to nontrivial consequences both in cosmology and in particle physics. It is shown that some of them could be checked in the nearest future. Scalar-tensor model

Ph. Brax, C. van de Bruck, A. -C. Davis, C. S. Rhodes

The evolution of moduli fields, which naturally appear in higher dimensional models such as brane worlds, and their effects on the anisotropies of the cosmological microwave background radiation is discussed.

Ph. Brax, C. van de Bruck, A. -C. Davis, C. S. Rhodes

Brane models at low energy are described by an effective action involving gravity and two moduli fields associated with the brane positions. The scalar-tensor nature of the effective theory and the coupling to matter are explicitly spelt out. We discuss the post-Newtonian gravitational constraints on the models, some applications to quintessence and the vari

V. I. Zakharov

The paper is motivated by observation of a kind of branes in the vacuum state of the lattice SU(2) gluodynamics. The branes represent two-dimensional vortices whose total area scales in physical units while the non-Abelian action diverges in the ultraviolet. We consider the question whether effects of the branes can be accommodated into the continuum theory.

The MILC Collaboration, C. Bernard, T. Burch, C. E. DeTar

We report on progress in our study of high temperature QCD with three flavors of improved staggered quarks. Simulations are being carried out with three degenerate quarks with masses less than or equal to the strange quark mass, $m_s$, and with degenerate up and down quarks with masses in the range $0.1 m_s \leq m_{u,d}\leq 0.6 m_s$, and the strange quark ma

MILC Collaboration, C. Bernard, T. Burch, C. DeTar

We report on preliminary results from multi-particle fits to meson propagators with three flavors of light dynamical quarks. We are able to measure excited states in propagators with pion quantum numbers, which we interpret as the pion 2S state, and is evidence of locality of the action. In the a_0 (0^{++}) propagators we find evidence for excited states whi

Oliver Jahn, Philippe de Forcrand

The subleading term of the heavy quark potential (the analogue of the Luscher term) is computed in a string model for the case of three quarks. It turns out to be positive in 2+1 dimensions, making the potential non-concave as a function of the scale for fixed geometry. The results are compared to numerical simulations of the lattice gauge theory.

Shigemi Ohta, Kostas Orginos

We report the current status of RBCK calculations on nucleon structure with both quenched and unquenched lattice QCD. The combination of domain wall fermions and DBW2 gauge action works well for isovector vector and axial charges, and moments of structure functions <x>_q, d_1, and <1>_{δq}.

Y. Schroder

Perturbative calculations of corrections to the behavior of an ideal gas of quarks and gluons, the limit that is formally realized at infinite temperature, are obstructed by severe infrared divergences. The limits to computability that the infrared problem poses can be overcome in the framework of dimensionally reduced effective theories. Here, we give detai

F. Di Renzo, A. Mantovi, V. Miccio, Y. Schroder

Dimensional reduction is a key issue in finite temperature field theory. For example, when following the QCD Free Energy from low to high scales across the critical temperature, ultrasoft degrees of freedom can be captured by a 3d SU(3) pure gauge theory. For such a theory a complete perturbative matching requires four loop computations, which we undertook b

M. -P. Lombardo, M. L. Paciello, S. Petrarca, B. Taglienti

We present preliminary results from a high statistics study of 2-color QCD at low temperature and non-zero baryon density. The simulations are carried out on a 6^3*12 lattice and use a standard hybrid molecular dynamics algorithm for staggered fermions for two values of quark mass. Observables include glueball correlators evaluated via a multi-step smearing

Ph. de Forcrand, O. Philipsen

We demonstrate how to locate the critical endpoint of the QCD phase transition by means of simulations at imaginary μ. For the three flavor theory, we present numerical results for the pseudo-critical line as a function of chemical potential and bare quark mass, as well as the bare quark mass dependence of the endpoint.

F. Di Renzo, A. Mantovi, V. Miccio, L. Scorzato

Introducing fermionic loops contributions in Numerical Stochastic Perturbation Theory was mainly motivated by the proposal to compute 2-3 loops for renormalization constants (and improvement coefficients). This is feasible because the computational overhead of unquenching NSPT is by far lower than for non perturbative simulations. We report on first, prelimi

Masataka Okamoto, Massimo di Pierro, Aida X. El-Khadra, Steven Gottlieb

We present our preliminary results for semileptonic form factors of $D$ mesons in unquenched lattice QCD. Simulations are carried out with $n_f=2+1$ dynamical quarks using gauge configurations generated by the MILC collaboration. For the valence quarks, we adopt an improved staggered light quark action and the clover heavy quark action. Our results for $D \t

Christof Gattringer, Ernst-Michael Ilgenfritz, Boris V. Martemyanov, Michael Müller-Preussker

We discuss Kraan - van Baal - Lee - Lu (KvBLL) solutions of the classical Yang-Mills equations with temperature in the context of SU(3) lattice gauge theory. We present discretized lattice versions of KvBLL solutions and other dyonic structures, obtained by cooling in order to understand their variety and signature. An analysis of the zero modes of the latti

Deog Ki Hong, Stephen D. H. Hsu

Euclidean dense matter generically suffers from the fermion sign problem. However, we argue that the sign problem is absent if one considers only low-energy degrees of freedom. Specifically, the low energy effective theory of dense QCD has positive Euclidean path integral measure, which allows one to establish rigorous inequalities showing that the color-fla

Noriyoshi Ishii, Hideo Suganuma

Maximum Entropy Method (MEM) is applied to glueball correlators at finite temperature constructed by using 5,500-9,900 gauge field configurations generated in SU(3) quenched lattice QCD with the lattice parameter beta = 2N_c/g^2 = 6.25 and the renormalized anisotropy a_s/a_t = 4. The results support the thermal width broadening of the 0++ glueball near the c

Maarten Golterman, Santi Peris

When we embed the strong penguin operator Q_6 in the quenched theory, it does not remain a singlet under right-handed chiral transformations. As a consequence, more low-energy constants associated with this operator appear than in the unquenched theory. We give analytic estimates of the leading constants. The results suggest that the effects of quenching on

P. Boyle

A formulation of the fermion action is discussed which includes an explicit four momentum boost on the field prior to discretisation. This is used to shift the zero of lattice momentum to lie near one of the on-shell quark poles. The positive pole is selected if we wish to describe a valence quark, and negative pole for a valence anti-quark. Like NRQCD, the

S. Chandrasekharan, M. Pepe, F. D. Steffen, U. -J. Wiese

We present the lattice formulation of effective Lagrangians in which chiral symmetry is realized nonlinearly on the fermion fields. In this framework both the Wilson term removing unphysical doubler fermions and the fermion mass term do not break chiral symmetry. Our lattice formulation allows us to address non-perturbative questions in effective theories of

S. Laplace

The search for rare B decays and direct CP violation at BABAR is described. The following measurements (based on integrated luminosities ranging from 56.4 to 81.9fb-1) are summarized: the inclusive branching fractions and direct CP asymmetries of B+ to h+h-h+ (h=pi, K), the exclusive branching fractions of B+ to K+pi-pi+ (where significant signals are observ

Jurgen Ehlers, Robert Geroch

There is proven a theorem, to the effect that a material body in general relativity, in a certain limit of sufficiently small size and mass, moves along a geodesic.

M. J. Pareja

For general relativistic equilibrium stellar models (stationary axisymmetric asymptotically flat and convection-free) with differential rotation, it is shown that for a wide class of rotation laws the distribution of angular velocity of the fluid has a sign, say &#34;positive&#34;, and then both the dragging rate and the angular momentum density are positive

Wei Zhou, Jian-Yang Zhu

To find what influence the charge of the black hole $Q$ will bring to the evolution of the quasinormal modes, we calculate the quasinormal frequencies of the neutrino field (charge $e=0$) perturbations and those of the massless Dirac field ($e\neq 0$) perturbations in the RN metric. The influences of $Q$, $e$, the momentum quantum number $l$, and the mode nu

J. Maebe, K. De Bosschere

Adding small code snippets at key points to existing code fragments is called instrumentation. It is an established technique to debug certain otherwise hard to solve faults, such as memory management issues and data races. Dynamic instrumentation can already be used to analyse code which is loaded or even generated at run time.With the advent of environment

Fred Mesnard, Roberto Bagnara

We present cTI, the first system for universal left-termination inference of logic programs. Termination inference generalizes termination analysis and checking. Traditionally, a termination analyzer tries to prove that a given class of queries terminates. This class must be provided to the system, for instance by means of user annotations. Moreover, the ana

Philip B. Allen

The dipole-dipole interaction influences nanoscopic matter by fixing the patterns of permanent, displacive, and induced dipole moments, subject to constraints of molecular size and other short range interactions. Prediction of these arrangements is a challenging problem. The eigenvector of maximum eigenvalue of the dipole-dipole interaction matrix can provid

Wayne M. Saslow

We consider slow, steady transport for the normal state of the superconductor La$_2$CuO$_{4+δ}$ in a one-dimensional geometry, with surface fluxes sufficiently general to permit oxygen to be driven into the sample (``loaded&#39;&#39;) either by electrochemical means or by high oxygen partial pressure. We include the bulk reaction O$\to$O$^{2-}+2h$, where neu

S. N. Shevchenko, Yu. V. Pershin, I. D. Vagner

Properties of a Nuclear-Spin-Polarization-Induced Quantum Ring (NSPI QR) are studied theoretically. In the proposed system a local nuclear spin polarization creates an effective hyperfine field which confines the electrons with the spins opposite to the hyperfine field to the regions of maximal nuclear spin polarization. We investigate the electron energy sp

V. Hardy, S. Majumdar, S. Crowe, M. R. Lees

Field-induced magnetization jumps with similar characteristics are observed at low temperature for the intermetallic germanide Gd5Ge4and the mixed-valent manganite Pr0.6Ca0.4Mn0.96Ga0.04O3. We report that the field location -and even the existence- of these jumps depends critically on the magnetic field sweep rate used to record the data. It is proposed that

Jesús Casado-Pascual, José Pablo Baltanás

We study the overdamped motion of a particle in a bistable potential subject to the action of a bichromatic force and additive noise, within the context of the vibrational resonance phenomenon. Under appropriate conditions, we obtain analytical expressions for the relevant observables which quantifies this phenomenon. The theoretical results are compared wit

Maria R. D&#39;Orsogna, Marc Suchard, Tom Chou

Motivated by observations of the dynamics of {\it Myxococcus xanthus}, we present a self-interacting random walk model that describes the competition between chemokinesis and chemotaxis. Cells are constrained to move in one dimension, but release a chemical chemoattractant at a steady state. The bacteria senses the chemical that it produces. The probability

K. Vakili, Y. P. Shkolnikov, E. Tutuc, E. P. De Poortere

By using different widths for two AlAs quantum wells comprising a bilayer system, we force the X-point conduction-band electrons in the two layers to occupy valleys with different Fermi contours, electron effective masses, and g-factors. Since the occupied valleys are at different X-points of the Brillouin zone, the interlayer tunneling is negligibly small d

J. F. Fernandez, J. J. Alonso

We show that correlations established before quenching to very low temperatures, later drive the magnetization process of systems of single molecule magnets, after a magnetic field is applied at t=0. We also show that in SC lattices, m \propto sqrt(t), as observed in Fe_8, but only for 1+2*log_10(h_d/h_w) time decades, where h_d is a nearest neighbor dipolar

Yaniv Dover

We use the formalism of &#39;Maximum Principle of Shannon&#39;s Entropy&#39; to derive the general power law distribution function, using what seems to be a reasonable physical assumption, namely, the demand of a constant mean &#34;internal order&#34; (Boltzmann Entropy) of a complex, self interacting, self organized system. Since the Shannon entropy is equi

S. E. Skipetrov, B. A. van Tiggelen

We develop a transport theory to describe the dynamics of (weakly) localized waves in a quasi-1D tube geometry both in reflection and in transmission. We compare our results to recent experiments with microwaves, and to other theories such as random matrix theory and supersymmetric theory.

Z. B. Huang, W. Hanke, E. Arrigoni

Using the Quantum Monte Carlo (QMC) technique within frozen-phonon, we studied the effects of the half-breathing O$(π,0)$ phonon mode on the ground-state properties of the three-band Peierls-Hubbard model. Our simulations are performed for both ionic and covalent electron-phonon couplings. The effects of lattice displacements on the ground-state energies and

H. Kleinert, J. Zaanen

Assuming that at small distances space-time is equivalent to an elastic medium which is isotropic in space and time directions, we demonstrate that the quantum nematic liquid arising from this crystal by spontaneous proliferation of dislocations corresponds with a medium which is merely carrying curvature rigidity. This medium is at large distances indisting

G. Fath, O. Legeza, J. Solyom

Two-leg spin ladders have a rich phase diagram if rung, diagonal and plaquette couplings are allowed for. Among the possible phases there are two Haldane-type spin liquid phases without local order parameter, which differ, however, in the topology of the short range valence bonds. We show that these phases can be distinguished numerically by two different st

Lorenzo Sabatelli, Peter Richmond

Ising or Potts models of ferromagnetism have been widely used to describe locally interacting social or economic systems. We consider a related model, introduced by Sznajd to describe the evolution of consensus in a society. In this model, the opinion or state of any spins can only be changed through the influence of neighbouring pairs of similarly aligned s

Carsten Honerkamp, Walter Hofstetter

We investigate the fermionic SU(N) Hubbard model on the two-dimensional square lattice for weak to moderate interaction strengths using one-loop renormalization group and mean-field methods. For the repulsive case U>0 at half filling and small N the dominant tendency is towards breaking of the SU(N) symmetry. For N>6 staggered flux order takes over as the do

S. Tanaka, S. U. Egelhaaf, W. C. K. Poon

We studied the crystallization of a globular protein, lysozyme, in the cubic phase of the lipid monoolein. The solubility of lysozyme in salt solution decreased by a factor of $\sim 4$ when confined in cubic phase. Calculations and Monte Carlo simulations show that this can be explained by the {\it confinement} of lysozyme molecules to the narrow water cells

M. E. Zhitomirsky, V. -H. Dao

The Ginzburg-Landau functional for a two-gap superconductor is derived within the weak-coupling BCS model. The two-gap Ginzburg-Landau theory is, then, applied to investigate various magnetic properties of MgB2 including an upturn temperature dependence of the transverse upper critical field and a core structure of an isolated vortex. Orientation of vortex l

A. M. Povolotsky

The eigenfunctions and eigenvalues of the master-equation for zero range process on a ring are found exactly via the Bethe ansatz. The rates of particle exit from a site providing the Bethe ansatz applicability are shown to be expressed in terms of single parameter. Continuous variation of this parameter leads to the transition of driving diffusive system fr

L. Craco, M. S. Laad, S. Leoni, E. Müller-Hartmann

The doping induced insulator-metal transition in $La_{1-x}Sr_{x}TiO_{3}$ is studied using the ab-initio LDA+DMFT method. Combining the LDA bandstructure for the actual, distorted structure found recently with multi-orbital DMFT to treat electronic correlations, we find: $(i)$ ferro-orbital order in the Mott insulating state without orbital degeneracy, $(ii)$

K. K. Rajagopal, P. Vignolo, M. P. Tosi

We study a Bose-condensed gas at finite temperature, in which the particles of the condensate and of the thermal cloud are constrained to move in a plane under radial harmonic confinement and interact via strictly two-dimensional collisions. The coupling parameters are obtained from a calculation of the many-body T-matrix and decreases as temperature increas

T. C. Kim, C. -M. Ghim, H. J. Kim, D. H. Kim

We investigate the kinetic roughening of Ar$^+$ ion-sputtered Pd(001) surface both experimentally and theoretically. \textit{In situ} real-time x-ray reflectivity and \textit{in situ} scanning tunneling microscopy show that nanoscale adatom islands form and grow with increasing sputter time $t$. Surface roughness, $W(t)$, and lateral correlation length, $ξ(t

Andrey Shiryayev, James D. Gunton

A continuum model of globular proteins proposed by Talanquer and Oxtoby (J. Chem. Phys. vol. 109, p. 223 (1998)) is investigated numerically, with particular emphasis on the region near the metastable fluid-fluid coexistence curve. Classical nucleation theory is shown to be invalid not only in the vicinity of the metastable critical point but also close to t

Stanislav V. Dobrov

Jordan-Wigner-type transformations connecting the spin-3/2 operators and two kinds of fermions are derived. A general condition of fermionizability of spins is obtained and a theorem establishing connection between half integer spins and fermions is proved. The fallibility of a previous attempt to generalize the Jordan-Wigner transformation for all spins (C.

Hyun-Tak Kim, B. G. Chae, D. H. Youn, S. L. Maeng

For a strongly correlated material, VO2, near a critical on-site Coulomb energy U/Uc=1, the abrupt Mott metal-insulator transition (MIT) rather than the continuous Hubbard MIT is observed by inducing internal optical phonon-coupled holes (hole inducing of 0.018%) into conduction band, with a gate field of fabricated transistors. Observed gate effects, change

Sandy Shaw

Temporal gene expression data (Wen, et. al.) was analyzed using the recently introduced inverse modeling technique of Embedded Complex Logistic Maps (ECLM). Preliminary results indicate scale-free structure in the gene regulatory network topology as well as in the network&#39;s energy dissipation characteristics. General agreement was found with other recent

J. W. Sulentic, S. Zamfir, P. Marziani, R. Bachev

We consider the properties of radio-loud (RL) AGN in the context of the Eigenvector 1 (E1) parameter space. RL sources show a restricted E1 parameter space occupation relative to the radio-quiet (RQ) majority. The Fanaroff-Riley II ``parent population&#39;&#39; of relatively un-boosted RL sources (median radio/optical flux ratio ~490) shows the most restrict

Daniel Stern, Patrick B. Hall, L. Felipe Barrientos, Andrew J. Bunker

We report an infrared 1-1.8 micron (J+H-bands), low-resolution (R=450) spectrogram of the highest-redshift radio-loud quasar currently known, SDSS J083643.85+005453.3, obtained during the spectroscopic commissioning run of the FLAMINGOS multi-object, near-infrared spectrograph at the 8m Gemini-South Observatory. These data show broad emission from both CIV 1

D. Weedman, V. Charmandaris, A. Zezas

Tracking the star formation rate to high redshifts requires knowledge of the contribution from both optically visible and obscured sources. The dusty, optically-obscured galaxies can be located by X-ray and infrared surveys. To establish criteria for selecting such sources based only on X-ray and infrared surveys, we determine the ratio of infrared to X-ray

Oleg Y. Gnedin

Numerical simulations of a Milky Way-size galaxy demonstrate that globular clusters with the properties similar to observed can form naturally at z > 3 in the concordance Lambda-CDM cosmology. The clusters in our model form in the strongly baryon-dominated cores of supergiant molecular clouds. The first clusters form at z = 12, while the peak formation appea

D. Q. Lamb, T. Q. Donaghy, C. Graziani

HETE-2 has confirmed the connection between GRBs and Type Ic supernovae. Thus we now know that the progenitors of long GRBs are massive stars. HETE-2 has also provided strong evidence that the properties of X-Ray Flashes (XRFs) and GRBs form a continuum, and therefore that these two types of bursts are the same phenomenon. We show that both the structured je

Kim-Vy Tran, Marijn Franx, Garth Illingworth, Daniel Kelson

[Abridged] Combining HST/WFPC2 mosaics with extensive ground-based spectroscopy, we study the nature of E+A galaxies in three intermediate redshift clusters (z=0.33, 0.58, & 0.83). From a sample of ~500 confirmed cluster members, we isolate 46 E+A candidates to determine the E+A fraction and study their physical properties. We find E+A&#39;s comprise a non-n

Wouter Vlemmings, Huib Jan van Langevelde, Phil Diamond

The OH main line masers in circumstellar shells were observed with astrometric VLBI in order to accurately determine the position of the star, as well as its motion, including the parallax. Results are presented on 4 Mira stars monitored for 2 - 8 years with the VLBA. The data show that in some stars the VLBI detection is dominated by blue-shifted emission t

Jeremy D. Schnittman, Edmund Bertschinger

Observations from the Rossi X-Ray Timing Explorer have shown the existence of high frequency quasi-periodic oscillations (HFQPOs) in the X-ray flux from accreting black hole binary systems. In at least two systems, these HFQPOs come in pairs with a 2:3 frequency commensurability. We propose a simple ``hot spot&#39;&#39; model to explain the position and ampl

Stanimir A. Metchev, Lynne A. Hillenbrand, Michael R. Meyer

(abridged) We present new 10-micron photometry of 21 nearby young stars obtained at the Palomar 5-meter and at the Keck I 10-meter telescopes as part of a program to search for dust in the habitable zone of young stars. Thirteen of the stars are in the F-K spectral type range (&#34;solar analogs&#34;), 4 have B or A spectral types, and 4 have spectral type M

W. Lewandowski, A. Wolszczan, G. Feiler, M. Konacki

We present new results of timing and single pulse measurements for 18 radio pulsars discovered in 1993 - 1997 by the Penn State/NRL declination-strip survey conducted with the 305-m Arecibo telescope at 430 MHz. Long-term timing measurements have led to significant improvements of the rotational and the astrometric parameters of these sources, including the

Jordi Jose, Margarita Hernanz, Enrique Garcia-Berro, Pilar Gil-Pons

We analyse the impact of the initial abundances of the underlying white dwarf core on the nucleosynthesis accompanying classical nova outbursts, in the framework of hydrodynamic models of the explosion. Specifically, we take into account the chemical stratification of the white dwarf. It turns out that the presence of a thick CO-buffer on top of the ONe-rich

B. M. Poggianti, T. J. Bridges, Y. Komiyama, M. Yagi

The spectroscopic properties of galaxies in the Coma cluster are compared with those of galaxies in rich clusters at $z \sim 0.5$, to investigate the evolution of the star formation history in clusters. Luminous galaxies with $M_V \leq -20$ and post-starburst/post-starforming (k+a) spectra which constitute a significant fraction of galaxies in distant cluste

M. Kutschera

Einstein&#39;s general relativity predicts that pressure, in general stresses, play a similar role to energy density in generating gravity. The source of gravitational field, the active gravitational mass density, sometimes referred to as Whittaker&#39;s mass density, is not conserved, hence its changes can propagate as monopole gravitational waves. Such wav

A. Tarchi, A. Greve, A. B. Peck, N. Neininger

We present 1.4 GHz HI absorption line observations towards the starburst in NGC2146, made with the VLA and MERLIN. The HI absorption has a regular spatial and regular velocity distribution, and does not reveal any anomaly as a sign of an encounter with another galaxy or of a far-evolved merger.

A. Tarchi, C. Henkel, A. B. Peck, N. Nagar

We report the results of a search for 22 GHz water maser emission in IRAS-bright galaxies, using the 100-m Effelsberg telescope. In particular, we present the details of four new maser detections (IC342, NGC2146, NGC3556, and Arp299) and follow-up interferometric studies. A comparison between water maser detection rates derived in the present study and those

Katherine E. McGowan, Silvia Zane, Mark Cropper, Jamie A. Kennea

We report on the XMM-Newton observations of the young, 102 ms pulsar PSR B1706-44. We have found that both a blackbody plus power-law and a magnetized atmospheric model plus power-law provide an excellent fit to the EPIC spectra. The two scenarios are therefore indistinguishable on a statistical basis, although we are inclined to prefer the latter on physica

V. M. Bogod, G. B. Gelfreikh, F. Ch. Drago, V. P. Maximov

The results of the microwave observations of the Sun made with the RATAN-600 have shown the existence of many types of spectral peculiarities in polarized emission of active regions, which produce powerful flares. These phenomena happen at microwaves and reflect inhomogeneous structure of magnetic field in magnetospheres of flaring active regions in wide ran

Henric Krawczynski

Since the first TeV blazar Markarian (Mrk) 421 was detected in 1992, the number of established TeV gamma-ray emitting BL Lac objects has grown to 6, with redshifts ranging from 0.031 (Mrk 421) to 0.129 (H 1426+428). The intensive study of these sources has had a major impact on our understanding of the blazar phenomenon. The most notable observational result

J. Knodlseder, V. Lonjou, P. Jean, M. Allain

We provide first constraints on the morphology of the 511 keV line emission from the galactic centre region on basis of data taken with the spectrometer SPI on the INTEGRAL gamma-ray observatory. The data suggest an azimuthally symmetric galactic bulge component with FWHM of ~9 deg with a 2 sigma uncertainty range covering 6-18 deg. The 511 keV line flux in

Corina Vogt, Torsten A. Ensslin

We apply a novel technique of Faraday Rotation measure (RM) map analysis to three galaxy clusters, Abell 400, Abell 2634 and Hydra A, in order to estimate cluster magnetic field strengths, length scales and power spectra. This analysis is based on the assumption that the magnetic fields are statistically isotropically distributed across the Faraday screen. W