December 2002 arXiv papers — page 13

F. Calvo, F. Spiegelman, D. J. Wales

Using approximate partition functions and a master equation approach, we investigate the statistical relaxation toward equilibrium in selected CaAr$_n$ clusters. The Gaussian theory of absorption (previous article) is employed to calculate the average photoabsorption intensity associated with the 4s^2-> 4s^14p^1 transition of calcium as a function of time du

F. Calvo, F. Spiegelman, M. C. Heitz

The photoabsorption spectra of calcium-doped argon clusters CaAr_n are investigated at thermal equilibrium using a variety of theoretical and numerical tools. The influence of temperature on the absorption spectra is estimated using the quantum superposition method for a variety of cluster sizes in the range 6<=n<=146. At the harmonic level of approximation,

Alexander Wurm, Marcus Berg

In quantum field theory, physicists routinely use &#34;normal ordering&#34; of operators, which just amounts to shuffling all creation operators to the left. Potentially confusing, then, is the occurrence in the literature of normal-ordered functions, sometimes called &#34;Wick transforms&#34;. We aim to introduce the reader to some basic results and ideas a

F. Sattin, K. Katsonis

In this paper we present Classical Trajectory Monte Carlo (CTMC) calculations for single and multiple electron ionization of Argon atoms and ions in the threshold region. We are able to recover the Wannier exponents a for the power-law behavior of the cross section s versus excess energy: the exact value of the exponent as well as the existence of its satura

H. Y. Cui

According to the theory of relativity, the relativistic Coulomb&#39;s force between an electron pair is composed of two parts, the main part is repulsive, while the rest part can be attractive in certain situations. Thus the relativistic attraction of an electron pair provides an insight into the mechanism of superconductivity. In superconductor, there are,

E. L. Afraimovich

During strong magnetic storms, the errors of determination of the range, frequency Doppler shift and angles of arrival of transionospheric radio signals exceeds the one for magnetically quiet days by one order of magnitude as a minimum. This can be the cause of performance degradation of current satellite radio engineering navigation, communication and radar

S. J. Puglia, A. Bhattacharyya, R. J. Furnstahl

Effective field theory (EFT) methods are applied to density functional theory (DFT) as part of a program to systematically go beyond mean-field approaches to medium and heavy nuclei. A system of fermions with short-range, natural interactions and an external confining potential (e.g., fermionic atoms in an optical trap) serves as a laboratory for studying DF

M. Asakawa, H. Minakata, B. Muller

We discuss characteristic experimental signatures related to the mechanism of DCC formation triggered by the chiral U(1) anomaly in relativistic heavy ion collisions. We predict an enhancement of the fraction of neutral pions compared with all pions in the direction perpendicular to the scattering plane. To quantify the effect on the angular distribution of

P. E. Falloon, P. C. Abbott, J. B. Wang

In this paper we report on a package, written in the Mathematica computer algebra system, which has been developed to compute the spheroidal wave functions of Meixner [J. Meixner and R.W. Schaefke, Mathieusche Funktionen und Sphaeroidfunktionen, 1954] and is available online (www.physics.uwa.edu.au/~falloon/spheroidal/spheroidal.html). This package represent

Yan V. Fyodorov, Jonathan P. Keating

We calculate the negative integer moments of the (regularized) characteristic polynomials of N x N random matrices taken from the Gaussian Orthogonal Ensemble (GOE) in the limit as $N \to \infty$. The results agree nontrivially with a recent conjecture of Berry & Keating motivated by techniques developed in the theory of singularity-dominated strong fluctuat

Robert Lauter, Sergiu Moroianu

We consider a compact manifold whose boundary is a locally trivial fiber bundle and an associated pseudodifferential algebra that models fibered cusps at infinity. Using trace-like functionals that generate the 0-dimensional Hochschild cohomology groups, we express the index of a fully elliptic fibered cusp operator as the sum of a local contribution from th

Thomas C. Hales

This article shows that under general conditions, p-adic orbital integrals of definable functions are represented by virtual Chow motives. This gives an explicit example of the philosophy of Denef and Loeser, which predicts that all naturally occurring p-adic integrals are motivic.

Tapani Hyttinen, Saharon Shelah, Jouko Väänänen

Let A and B be two first order structures of the same relational vocabulary L. The Ehrenfeucht-Fraisse-game of length gamma of A and B denoted by EFG_gamma(A,B) is defined as follows: There are two players called for all and exists. First for all plays x_0 and then exists plays y_0. After this for all plays x_1, and exists plays y_1, and so on. Eventually a

Saharon Shelah, Juris Stepráns

The maximality of Abelian subgroups play a role in various parts of group theory. For example, Mycielski has extended a classical result of Lie groups and shown that a maximal Abelian subgroup of a compact connected group is connected and, furthermore, all the maximal Abelian subgroups are conjugate. For finite symmetric groups the question of the size of ma

Takuro Mochizuki

Let $E$ be a holomorphic vector bundle. Let $θ$ be a Higgs field, that is a holomorphic section of $End(E)\otimesΩ^{1,0}_X$ satisfying $θ^2=0$. Let $h$ be a pluriharmonic metric of the Higgs bundle $(E,θ)$. The tuple $(E,θ,h)$ is called a harmonic bundle. Let $X$ be a complex manifold, and $D$ be a normal crossing divisor of $X$. In this paper, we study the

Arjen Doelman David Iron Yasumasa Nishiura

In this article, we consider a class of bi-stable reaction-diffusion equations in two components on the real line. We assume that the system is singularly perturbed, i.e. that the ratio of the diffusion coefficients is (asymptotically) small. This class admits front solutions that are asymptotically close to the (stable) front solution of the `trivial&#39; s

Vladimir I. Ovchinnikov

We consider linear operators $T$ mapping a couple of weighted $L_p$ spaces $\{L_{p_0}(U_0), L_{p_1}(U_1)\}$ into $\{L_{q_0}(V_0), L_{q_1}(V_1)\}$ for any $1\le p_0$, $ p_1$, $q_0$, $q_1\le\infty$, and describe the interpolation orbit of any $a\in L_{p_0}(U_0)+ L_{p_1}(U_1)$ that is we describe a space of all $\{Ta\}$, where $T$ runs over all linear bounded m

A. Yu. Olshanskii, M. V. Sapir

For every finitely generated recursively presented group G we construct a finitely presented group H containing G such that G is (Frattini) embedded into H and the group H has solvable conjugacy problem if and only if G has solvable conjugacy problem. Moreover G and H have the same r.e. Turing degrees of the conjugacy problem. This solves a problem by D. Col

Kai Behrend

We construct a 2-category of differential graded schemes. The local affine models in this theory are differential graded algebras, which are graded commutative with unit over a field of characteristic zero, are concentrated in non-positive degrees and have perfect cotangent complex. Quasi-isomorphic differential graded algebras give rise to 2-isomorphic diff

Kai Behrend

We introduce perfect resolving algebras and study their fundamental properties. These algebras are basic for our theory of differential graded schemes, as they give rise to affine differential graded schemes. We also introduce etale morphisms. The purpose for studying these, is that they will be used to glue differential graded schemes from affine ones with

A. M. Moya, V. V. Fernández, W. A. Rodrigues

This paper is an introduction to the theory of multivector functions of a real variable. The notions of limit, continuity and derivative for these objects are given. The theory of multivector functions of a real variable, even being similar to the usual theory of vector functions of a real variable, has some subtle issues which make its presentation worhtwhi

H. Bruin, S. Troubetzkoy

We study the dynamics of a class of interval translation map on three intervals. We show that in this class the typical ITM is of finite type (reduce to an interval exchange transformation) and that the complement contains a Cantor set. We relate our maps to substitution subshifts. Results on Hausdorff dimension of the attractor and on unique ergodicity are

Stephane Baseilhac, Riccardo Benedetti

We give parallel constructions of an invariant R(W,f), based on the classical Rogers dilogarithm, and of quantum hyperbolic invariants (QHI), based on the Faddeev-Kashaev quantum dilogarithms, for flat PSL(2,C)-bundles f over closed oriented 3-manifolds W. All these invariants are explicitely computed as a sum or state sums over the same hyperbolic ideal tet

Atanas Iliev, Kristian Ranestad

The geometry of Sp(3)/U(3) as a subvariety of Gr(3,6) is explored to explain several examples given by Mukai of non-abelian Brill-Noether loci, and to give some new examples. These examples identify Brill-Noether loci of vector bundles on linear sections of the Lagrangian Grassmannian Sp(3)/U(3) with orthogonal linear sections of the dual variety and vice ve

L. Feher, I. Marshall

We derive a generalization of the classical dynamical Yang-Baxter equation (CDYBE) on a self-dual Lie algebra $\cal G$ by replacing the cotangent bundle T^*G in a geometric interpretation of this equation by its Poisson-Lie (PL) analogue associated with a factorizable constant r-matrix on $\cal G$. The resulting PL-CDYBE, with variables in the Lie group G eq

Nir Ailon, Zeev Rudnick

We study the behavior of the greatest common divisor of a^k-1 and b^k-1, where a,b are fixed integers or polynomials, and k varies. In the integer case, we conjecture that when a and b are multiplicatively independent and in addition a-1 and b-1 are coprime, then a^k-1 and b^k-1 are coprime infinitely often. In the polynomial case, we prove a strong version

Kalle Karu

The Hard Lefschetz theorem is known to hold for the intersection cohomology of the toric variety associated to a rational convex polytope. One can construct the intersection cohomology combinatorially from the polytope, hence it is well defined even for nonrational polytopes when there is no variety associated to it. We prove the Hard Lefschetz theorem for t

Richard P. Stanley

We give a new formula for the values of an irreducible character of the symmetric group S_n indexed by a partition of rectangular shape. Some observations and a conjecture are given concerning a generalization to arbitrary shapes.

Oleg Lunin, Juan Maldacena, Liat Maoz

We construct a large family of supergravity solutions that describe BPS excitations on AdS_3 x S^3 with angular momentum on S^3. These solutions take into account the full backreaction on the metric. We find that as we increase the energy of the excitation, the energy gap to the next non-BPS excitation decreases. These solutions can be viewed as Kaluza-Klein

Elcio Abdalla, L. Alejandro Correa-Borbonet

We considered the solutions of the Friedmann equation in several setups, arguing that the Weierstra$ß$ form of the solutions leads to connections with some Conformal Field Theory on a torus. Thus a link with the Cardy entropy formula is obtained in a quite natural way. The argument is shown to be valid in a four dimensional radiation dominated universe with

Thomas Mohaupt

We study the impact of topological phase transitions of the internal Calabi-Yau threefold on the space-time geometry of five-dimensional extremal black holes and black strings. For flop transitions and SU(2) gauge symmetry enhancement we show that solutions can always be continued and that the behaviour of metric, gauge fields and scalars can be characterize

Stefan Forste

In this talk we discuss symmetry preserving D-branes on a line of a marginally deformed SU(2) WZW model. A semiclassical and a quantum theoretical approach are presented.

Marcus Berg

This is a very brief review of some results from hep-th/0112154 and hep-th/0209191. In holographic renormalization, we studied the RG flow of a 2d N=(4,4) CFT perturbed by a relevant operator, flowing to a conformal fixed point in the IR. Here, the supergravity dual is displayed, and the computation of correlators is discussed. The sample stress-energy corre

Paul Bressler, Alexander Chervov

This paper is devoted to studying some properties of the Courant algebroids: we explain the so-called &#34;conducting bundle construction&#34; and use it to attach the Courant algebroid to Dixmier-Douady gerbe (following ideas of P. Severa). We remark that WZNW-Poisson condition of Klimcik and Strobl (math.SG/0104189) is the same as Dirac structure in some p

Chethan N. Gowdigere, Nicholas P. Warner

We consider holographic RG flow solutions with eight supersymmetries and study the geometry transverse to the brane. For both M2-branes and for D3-branes in F-theory this leads to an eight-manifold with only a four-form flux. In both settings there is a natural four-dimensional hyper-Kahler slice that appears on the Coulomb branch. In the IIB theory this hyp

Bo Feng

In this paper, we use the matrix model of pure fundamental flavors (without the adjoint field) to check the Seiberg duality in the case of complete mass deformation. We show that, by explicit integration at both sides of electric and magnetic matrix models, the results agree with the prediction in the field theory.

Yi-Xin Chen

We propose two non-abelian Chern-Simons matrix models as the effective descriptions of 4-dimensional quantum Hall fluids. One of them describes a new type of 4-dimensional quantum Hall fluid on the space of quaternions, the other provides the description of non-commutative field theory for Zhang and Hu&#39;s 4-dimensional quantum Hall fluid of $S^4$. The com

T. Morii, D. Roy, K. Sudoh

We have calculated the cross section of $ψ&#39;$ photoproduction at small-$p_{T}$ regions in polarized $γp$ collisions for testing the color-octet model, which is based on NRQCD factorization formalism. We show that the measurement of the two-spin asymmetry of this process might be effective to constrain the value of NRQCD matrix elements.

B. Borasoy, E. Marco, S. Wetzel

The photo- and electroproduction of eta, eta-prime mesons on nucleons are investigated within a relativistic chiral unitary approach based on coupled channels. The s-wave potentials for electroproduction and meson-baryon scattering are derived from a chiral effective Lagrangian which includes the eta-prime as an explicit degree of freedom and incorporates im

Yu. A. Simonov

Some short history of few-body methods originated from the famous Skornyakov-Ter-Martirosyan equation is given, including latest development of Faddeev formalism and Efimov states. The 3q system is shown to require an alternative, which is provided by the hyperspherical method (K-harmonics) which is highly successful for baryons.

A. E. Dorokhov

Instanton liquid model being effective model of the QCD vacuum describes well the hadrons at low as well at intermediate energies. Thus, contact with perturbative QCD results is possible providing the unique information about the quark-gluon distribution functions in the QCD vacuum and hadrons at low energy normalization point. As an illustrative example we

Cristina Manuel

Transport theory is an efficient approach to derive an effective theory for the soft modes of QCD at high temperature. It is known that the leading order operators of this theory can be obtained from (semi-classical) kinetic equations of quasiparticles carrying classical or quantum color charges. Higher order operators can also be obtained. Discrepancy betwe

Kazutaka Sudoh

Semi-inclusive $D / \Dbar$ meson productions in neutrino deep inelastic scattering are studied including ${\cal O}(α_s)$ corrections. Supposing a future neutrino factory, cross sections and spin asymmetries in polarized processes are calculated by using various parametrization models of polarized parton distribution functions. We suggest that $\Dbar$ product

K. S. Babu, Ilia Gogoladze, Kai Wang

In the minimal supersymmetric Standard Model with seesaw neutrino masses we show how R-parity can emerge naturally as a discrete gauge symmetry. The same discrete symmetry explains the smallness of the μ-term (the Higgsino mass parameter) via the Giudice--Masiero mechanism. The discrete gauge anomalies are cancelled by a discrete version of the Green--Schwar

K. Kampf, M. Knecht, J. Novotny

A calculation of the Dalitz decay in next-to-leading order in chiral perturbation theory of two flavour case extended by virtual photons is presented. The whole kinematic sector is covered and realistic experimental situation is discussed.

Takahiro Miura, Tetsuo Shindou, Eiichi Takasugi

We considered a model where |V_{13}|=0 so that delta=0 at M_R and analyzed mixing angles and CP violation angles at the low energy scale by using the renormalization group in the MSSM model. In this model, parameters at M_R scale are two mixing angles (theta_{12} and theta_{23}), three neutrino masses, and two Majorana phases. We found that (1) sin^2 2 theta

Gyan Bhanot, Dong Chen, Alan Gara, Pavlos Vranas

The architecture of the BlueGene/L massively parallel supercomputer is described. Each computing node consists of a single compute ASIC plus 256 MB of external memory. The compute ASIC integrates two 700 MHz PowerPC 440 integer CPU cores, two 2.8 Gflops floating point units, 4 MB of embedded DRAM as cache, a memory controller for external memory, six 1.4 Gbi

Vladimir K. Petrov

Transition from discrete to continuous Fourier series is studied for the functions becoming singular in the transition. Conditions are specified when summing replacement by integration is inadmissible.

Vladimir Savinov, Romeo Ahohe, CLEO Collaboration

We analyzed 13.8 fb^{-1} of the integrated e+e- luminosity collected at 10.6 GeV center-of-mass energy with the CLEO II and II.V detectors to study exclusive two-photon production of single hadronic resonances. We searched for hadrons decaying into Ks K pi when both leptons remain undetected. In this analysis we studied the detection efficiency and evaluated

Zhiqing Zhang

New structure function results from H1 are presented. The measurements cover a huge kinematical range for Q^2, the four momentum transfer squared, from 0.35, GeV^2 to 30,000, GeV^2, and for Bjorken x between \sim 5\cdot 10^{-6} and 0.65. At Q^2>100, GeV^2, full HERA, I data have been analyzed. The data are compared with a new QCD analysis. The impact of the

R. H. Bernstein

This article studies the potential of combining charged-current disappearance measurements of ν_μ to ν_τ from MINOS and an off-axis beam. I find that the error on Δm^2 from a 100 kt-yr off-axis measurement is a few percent of itself. Further, I find little improvement to an off-axis measurement by combining it with MINOS.

Matthew Dickerson, David Eppstein, Michael T. Goodrich, Jeremy Meng

In this paper, we introduce a new approach for drawing diagrams that have applications in software visualization. Our approach is to use a technique we call confluent drawing for visualizing non-planar diagrams in a planar way. This approach allows us to draw, in a crossing-free manner, graphs--such as software interaction diagrams--that would normally have

J. Wachter, R. Walser, J. Cooper, M. Holland

We present a unified kinetic theory that describes the finite-temperature, non-equilibrium dynamics of a Bose-Einstein condensed gas interacting with a thermal cloud. This theory includes binary interactions to second order in the interaction potential and reduces to a diagonal quantum Boltzmann equation for Bogoliubov quasiparticles. The Hartree-Fock-Bogoli

Tom Chou

We find exact solutions to a new one-dimensional (1D) interacting particle theory and apply the results to the adsorption and wrapping of polymers (such as DNA) around protein particles (such as histones). Each adsorbed protein is represented by a Tonks gas particle. The length of each particle is a degree of freedom that represents the degree of DNA wrappin

D. Bonamy, P. Mills

Considering recent results revealing the existence of multi-scale rigid clusters of grains embedded in granular surface flows, i.e. flows down an erodible bed, we describe here the surface flows rheology through a non-local constitutive law. The predictions of the resulting model are compared quantitatively to experimental results: The model succeeds to acco

Andres Jerez, Mireille Lavagna, Damien Bensimon

We study an extended SU(N) single-impurity Kondo model in which the impurity spin is described by a combination of Abrikosov fermions and Schwinger bosons. Our aim is to describe both the quasiparticle-like excitations and the locally critical modes observed in various physical situations, including non-Fermi liquid behavior in heavy fermion systems in the v

W. C. Barber, F. Ye, D. P. Belanger, J. A. Fernandez-Baca

Neutron scattering experiments at the magnetic vacancy percolation threshold concentration, x_v, using the random-field Ising crystal Fe(0.76)Zn(0.24)F2, show stability of the transition to long-range order up to fields H=6.5 T. The observation of the stable long-range order corroborates the sharp boundary observed in computer simulations at x_v separating e

Z. Jiang, H. Lim, J. Eom, V. Chandrasekhar

In mesoscopic superconductor/normal-metal/superconductor (SNS) heterostructures, it is known that the resistance of the normal metal between the superconductors has a strong temperature dependence. Based on this phenomenon, we have developed a new type of thermometer, which dramatically enhances our ability to measure the local electron temperature Te at low

B. Kramer, N. Magnoli, E. Mariani, M. Merlo

The model of Composite Fermions for describing interacting electrons in two dimensions in the presence of a magnetic field is described. In this model, charged Fermions are combined with an even number of magnetic flux quanta in such a way that the external magnetic field is compensated on the average for half filling of Landau levels and the interaction is

E. Mariani, N. Magnoli, F. Napoli, M. Sassetti

The effect of interactions near the coincidence of two Landau levels with opposite spins at filling factor 1/2 is investigated. By mapping to Composite Fermions it is shown that the fluctuations of the gauge field induces an effective attractive Fermion interaction. This can lead to a spin-singlet ground state that is separated from the excited states by a g

Markus Deserno, Thomas Bickel

We theoretically study the elastic deformation of a fluid membrane induced by an adhering spherical colloidal particle within the framework of a Helfrich energy. Based on a full optimization of the membrane shape we find a continuous binding and a discontinuous envelopment transition, the latter displaying a potentially substantial energy barrier. A small gr

Félicien Schopfer, Christopher Bäuerle, Wilfried Rabaud, Laurent Saminadayar

We present measurements of the magnetoconductance of long and narrow quasi one-dimensional gold wires containing magnetic iron impurities in a temperature range extending from $15 $mK to $4.2 $K. The dephasing rate extracted from the weak antilocalisation shows a pronounced plateau in a temperature region of $300 $mK - $800 $mK, associated with the phase bre

Zhao Z. Z. Wang, Denis Jerome, Jean Christophe Girard, Claude Pasquier

Charge density waves (CDW) have been studied at the surface of a cleaved TTF-TCNQ single crystal using a low temperature scanning tunneling microscope (STM) under ultra high vacuum (UHV) conditions. All CDW phase transitions of TTF-TCNQ have been identified. The measurement of the modulation wave vector along the a direction provides the first evidence for t

A. Recati, P. O. Fedichev, W. Zwerger, J. von Delft

We show that ultracold atoms confined in a quasi-1d trap can be used to study the dissipative spin-boson model with {\it tunable} tunneling splitting and strength of dissipation. It is shown that with realistic parameters this system allows to study the crossover from coherent Rabi dynamics to incoherent tunneling.

Andrei N. Yakunin

The research is important for a molecular theory of liquid and has a wide interest as an example solving the problem when dynamic parameters of systems can be indirectly connected with their equilibrium properties. In frameworks of the reptation model the power law with the 3.5-exponent for the melt viscosity relation to the molecular weight of flexible-chai

L. Turban

The crossing probability in the time direction is defined for an off-equilibrium reaction-diffusion system as the probability that the system of size L is still active at time t, in the finite-size scaling limit. Exact results are obtained for the diffusion-limited coalescence problem in 1+1 dimensions with periodic and free boundary conditions using empty i

Ezio Bruno, Leon Zingales, Antonio Milici

Electronic structure calculations performed on very large supercells have shown that the local charge excesses in metallic alloys are related through simple linear relations to the local electrostatic field resulting from distribution of charges in the whole crystal. By including local external fields in the single site Coherent Potential Approximation theor

D. V. Shantsev, P. E. Goa, F. L. Barkov, T. H. Johansen

Magneto-optical imaging was used to study a zero-field-cooled MgB2 film at 9.6K where in a slowly increasing field the flux penetrates by abrupt formation of large dendritic structures. Simultaneously, a gradual flux penetration takes place, eventually covering the dendrites, and a detailed analysis of this process is reported. We find an anomalously high gr

A. O. Sousa, S. Moss de Oliveira, J. S. Sa Martins

We modify the Penna Model for biological aging, which is based on the mutation-accumulation theory, in order to verify if there would be any evolutionary advantage of triploid over diploid organisms. We show that this is not the case, and that usual sex is always better than that involving three individuals.

S. V. Okatov

The electronic and energy properties of beta-Si3N4 (a), Si{6-x}AlxOxN{8-x} (b) and the hypothetical ordered solid solutions Si{6-x}MgxO{2x}N{8-2x} (c), Si{6-x}MgxOxN{8-2x}Sx (d), Si{6-x}MgxOxN{8-x} (e), Si{6-x}Mg{x/2}Al{x/2}OxN{8-x} (f) are considered by the ab-initio band FP-LMTO method. The calculations show that the stability of the systems decreases in t

A. Pimenov, A. V. Pronin, A. Loidl, A. Tsukada

We performed far-infrared and submillimeter-wave conductivity experiments in the electron-doped cuprate La_{2-x}Ce_xCuO_4 with x = 0.081 (underdoped regime, T_c = 25 K). The onset of the absorption in the superconducting state is gradual in frequency and is inconsistent with the isotropic s-wave gap. Instead, a narrow quasiparticle peak is observed at zero f

B. Sorensen, J. Sadowski, R. Mathieu, P. Svedlindh

We report a clear correspondence between changes in the Curie temperature and carrier density upon annealing in epitaxially grown (Ga,Mn)As layers with thicknesses in the range between 5 nm and 20 nm. The changes are dependent on the layer thickness, indicating that the (Ga,Mn)As - GaAs interface has importance for the physical properties of the (Ga,Mn)As la

Ezio Bruno

Charge Distributions in Metallic Alloys: a Charge Excess Functional theory approach

S. V. Okatov

We propose a microscopic method for modeling atomic ordering effects in multi-component solid solutions, which is based on minimizing the number of unfavorable interatomic bonds in the system. Atomic ordering effects are studied in the solid solutions Si{6-x}AlxOxN{8-x} (beta-SiAlONs) and hypothetical Si{6-x}BexO{2x}N{8-2x} in the beta-Si3N4-Be-O system. It

Wojciech Florek

The group-theoretical classification of states of identical particle pairs is presented. Then obtained states are coupled with those of an antiparticle to construct states of a three-particle system. Investigations are performed using products of irreducible projective representations of the 2D translation group. For a given BvK period N degeneracy of pair s

T. Motohashi, R. Ueda, E. Naujalis, T. Tojo

Here we report an unconventional magnetic and transport phenomenon in a layered cobalt oxide, NaxCoO2. Only for x = 0.75, a magnetic transition of the second order was clearly detected at Tm ~ 22 K where an apparent specific-heat jump, an onset of extremely small spontaneous magnetization, and a kink in resistivity came in. Moreover large positive magnetores

X. Cartoixa, D. Z. -Y. Ting, T. C. McGill

We have developed an 8-band Effective Mass Approximation model that describes the zero field spin splitting in the band structure of zincblende heterostructures due to bulk inversion asymmetry (BIA). We have verified that our finite difference Hamiltonian transforms in almost all situations according to the true $D_{2d}$ or $C_{2v}$ symmetry of [001] heteros

Kyungsik Kim, Seong-Min Yoon

We study the tick dynamical behavior of the bond futures in Korean Futures Exchange(KOFEX) market. Since the survival probability in the continuous-time random walk theory is applied to the bond futures transaction, the form of the decay function in our bond futures model is discussed from two kinds of Korean Treasury Bond(KTB) transacted recently in KOFEX.

S. A. Tretyakov, S. I. Maslovski, I. S. Nefedov, M. K. Kärkkäinen

As was shown by N. Engheta, electromagnetic fields in two adjacent slabs bounded by two metal walls can satisfy the boundary conditions even if the distance between the two walls is much smaller than the wavelength. This is possible if one of the slabs has a negative permeability. Here we show that these subwavelength &#34;resonators&#34; resonate only if th

Koichi Kusakabe, Masanori Maruyama

Hydrogenated nanographite can display spontaneous magnetism. Recently we proposed that hydrogenation of nanographite is able to induce finite magnetization. We have performed theoretical investigation of a graphene ribbon in which each carbon is bonded to two hydrogen atoms at one edge and to a single hydrogen atom at another edge. Application of the local-s

A. I. Olemskoi

On the basis of the assumption that atoms play a role of effective Fermions at lattice distribution, the study of the long-range ordering is shown to be reduced to self-consistent consideration of single and collective excitations being relevant to the space distribution of atoms and Fourier transform of such distribution, respectively. A diagram method adva

T. Fukumura, Y. Yamada, K. Tamura, K. Nakajima

Magneto-optical spectroscopy of a transparent ferromagnetic semiconductor, anatase TiO2 doped with Co, is carried out at room temperature. A large magneto-optical response with ferromagnetic field dependence is observed throughout from ultraviolet to visible range and increases with increasing Co content or carrier concentration. The magnitude of magnetic ci

Jun Wang, D. Y. Xing, H. B. Sun

In order to enhance spin injection efficiency from ferromagnetic (FM) metal into a two-dimensional electron gas (2DEG), we introduce another FM metal and two tunnel barriers (I) between them to investigate the current polarization in such ballistic FM/I/FM/I/2DEG junction. Our treatment is based on the free-electron scattering theory. It is found that due to

J. P. Huang, L. Gao, K. W. Yu

When a sinusoidal (ac) field is applied to a suspension containing nonlinear dielectric particles, the electrical response will generally consist of ac fields at frequencies of the higher-order harmonics. The situation is further complicated by an intrinsic dielectric dispersion which often occurs due to the surface conductivity or inhomogeneous structure of

R. B. Capaz, Belita Koiller, Xuedong Hu, S. Das Sarma

This paper has been withdrawn by the authors. A more complete treatment of the bandstructure effects is forthcoming.

Helmut G. Katzgraber, A. P. Young

We present results from Monte Carlo simulations of the two- and three-dimensional gauge glass at low temperature using the parallel tempering Monte Carlo method. Our results in two dimensions strongly support the transition being at T_c=0. A finite-size scaling analysis, which works well only for the larger sizes and lower temperatures, gives the stiffness e

Paul Martini, Michael W. Regan, John S. Mulchaey, Richard W. Pogge

The detailed morphology of the interstellar medium (ISM) in the central kiloparsec of galaxies is controlled by pressure and gravitation. The combination of these forces shapes both circumnuclear star formation and the growth of the central, supermassive black hole. We present visible and near-infrared Hubble Space Telescope images and color maps of 123 near

Romeel Davé, Neal Katz, David H. Weinberg

Lyman alpha absorber correlations contain information about the underlying density distribution associated with a particular class of absorbers. As such, they provide an opportunity to independently measure the &#34;bias&#34; of the Lyman alpha forest, i.e. the relationship between HI column density and underlying dark matter density. In these proceedings we

Panayiotis Tzanavaris, Robert F. Carswell

A new analysis of Keck/HIRES observations of the broad absorption line QSO APM 0827+5255 indicates that a number of intervening C IV absorbers give rise to absorption lines for which the observed optical depths for 1548, 1550 A doublet components are not in the expected 2:1 ratio. To compensate for the effect, a local adjustment of the zero-level is required

Paul Martini, Michael W. Regan, John S. Mulchaey, Richard W. Pogge

(Abridged) We present a detailed study of the relation between circumnuclear dust morphology, host galaxy properties, and nuclear activity in nearby galaxies. We use our sample of 123 nearby galaxies with visible--near-infrared colormaps from the Hubble Space Telescope to create well-matched, &#34;paired&#34; samples of 28 active and 28 inactive galaxies, as

J. S. Arabadjis, M. W. Bautz, G. Arabadjis

Determining the structure of galaxy clusters is essential for an understanding of large scale structure in the universe, and may hold important clues to the identity and nature of dark matter particles. Moreover, the core dark matter distribution may offer insight into the structure formation process. Unfortunately, cluster cores also tend to be the site of

F. E. Bauer, C. Vignali, D. M. Alexander, W. N. Brandt

We investigate the nature of the faint X-ray source population through X-ray spectroscopy and variability analyses of 136 AGN detected in the 2 Ms Chandra Deep Field-North survey with > 200 background-subtracted 0.5-8.0 keV counts [F(0.5-8.0 keV)=(1.4-200)e-15 erg cm^{-2} s^{-1}]. Our preliminary spectral analyses yield median spectral parameters of Gamma=1.

I. M. Hook, P. A. Shaver, C. A. Jackson, J. V. Wall

We present optical spectra and redshift measurements for 178 flat-spectrum objects from the Parkes quarter-Jansky flat-spectrum sample. These spectra were obtained in order to compile a complete sample of quasars for use in a study of quasar evolution. We present a composite optical spectrum made from the subset of 109 quasars that have flux densities in the

M. A. Reid, R. E. Pudritz, J. Wadsley

We have performed fully 3D simulations of the collapse of molecular cloud cores which obey the logatropic equation of state. By following the collapse of these cores from states of near hydrodynamic equilibrium, we are able to produce accretion histories which closely resemble those of observed cores. The accretion proceeds in four distinct stages: an initia

L. Deharveng, A. Zavagno, L. Salas, A. Porras

The HII regions Sh 217 and Sh 219 are textbook examples of a Stromgren sphere surrounded by an annular photodissociation region (PDR). The annular PDR is observed in both the 21 cm atomic hydrogen emission and the dust (PAH) emission near 8 micron (MSX Survey). An ultracompact radio continuum source is observed in the direction of the annular PDR, in both Sh

S. Johansson, V. S. Letokhov

We propose that a radiative cycle operates in atoms (ions) located in a rarefied gas in the vicinity of a hot star. Besides spontaneous transitions the cycle includes a stimulated transition in one very weak intermediate channel. This radiative &#34;bottle neck&#34; creates a population inversion, which for an appropriate column density results in amplificat

Eric S. Perlman, Andrew S. Wilson

We use Chandra, HST and VLA observations of M87 to investigate the physics of X-ray emission from AGN jets. We find that X-ray hotspots in the M87 jet occur primarily in regions with hard optical-to-X-ray spectra and lower than average polarization. Particle injection appears to be required both continuously in the jet sheath as well as locally at X-ray hots

Matthew R. Bate, Ian A. Bonnell, Volker Bromm

We present results from the largest numerical simulation of star formation to resolve the fragmentation process down to the opacity limit. The simulation follows the collapse and fragmentation of a large-scale turbulent molecular cloud to form a stellar cluster and, simultaneously, the formation of circumstellar discs and binary stars. This large range of sc

Karoline M. Gilbert, Bradley M. Peterson

We investigate the possibility of an intrinsic Baldwin Effect (i.e.,nonlinear emission-line response to continuum variations) in the broad H-beta emission line of the active galaxy NGC 5548 using cross-correlation techniques to remove light travel-time effects from the data. We find a nonlinear relationship between the H-beta emission line and continuum flux

V. S. Beskin

The goal of my lecture is to present the introduction into the hydrodynamical version of the Grad-Shafranov equation. Although not so well-known as the full MHD one, it allows us to clarify the nontrivial structure of the Grad-Shafranov approach as well as to discuss the simplest version of the 3+1-split language -- the most convenient one for the descriptio