June 2002 arXiv papers — page 21

Shilong Ma, Yuefei Sui, Ke Xu

The limit behavior of inductive logic programs has not been explored, but when considering incremental or online inductive learning algorithms which usually run ongoingly, such behavior of the programs should be taken into account. An example is given to show that some inductive learning algorithm may not be correct in the long run if the limit behavior is n

W. Chen

Part III of the reports consists of various unconventional distance function wavelets (DFW). The dimension and the order of partial differential equation (PDE) are first used as a substitute of the scale parameter in the DFW transforms and series, especially with the space and time-space potential problems. It is noted that the recursive multiple reciprocity

Kirill Katsov, John D. Weeks

We have developed a new and general theory of nonuniform fluids that naturally incorporates molecular scale information into the classical van der Waals theory of slowly varying interfaces. Here the theory is applied to the liquid-vapor interface of a Lennard-Jones fluid. The method combines a molecular field treatment of the effects of unbalanced attractive

A. Gukasov, M. Braden, R. J. Papoular, S. Nakatsuji

By means of polarized neutron diffraction in a magnetic field of 7.0 T at 1.6 K an anomalously large magnetization density is observed on the in-plane oxygen in Ca$_{1.5}$Sr$_{0.5}$RuO$_4$. Field-induced moments of different ions are determined by refinement on the flipping ratios, yielding $μ$$_{Ru}$ = 0.346(11) $μ$$_B$, $μ_{O1}$ = 0.076(6) $μ$$_B$ and $μ_{

A. Puglisi, A. Baldassarri, V. Loreto

We study the dynamics of a 2d driven inelastic gas, by means of Direct Simulation Monte Carlo (DSMC) techniques, i.e. under the assumption of Molecular Chaos. Under the effect of a uniform stochastic driving in the form of a white noise plus a friction term, the gas is kept in a non-equilibrium Steady State characterized by fractal density correlations and n

Zbigniew Koza

We study long-time properties of reversible reaction-diffusion systems of type A + B <-> C by means of perturbation expansion in powers of 1/t (inverse of time). For the case of equal diffusion coefficients we present exact formulas for the asymptotic forms of reactant concentrations and a complete, recursive expression for an arbitrary term of the expansion

R. Hayn, V. A. Pashchenko, A. Stepanov, T. Masuda

Antiferromagnetic resonance (AFMR) of BaCu2Si2O7 and a microscopic theory of the magnetic anisotropy of spin 1/2 chain compounds with folded CuO3 geometry being in good agreement with the available data are presented. The AFMR studies at 4.2 K show the existence of two gaps (40 and 76 GHz) at zero magnetic field and of two spin re-orientation transitions for

M. Bauer, D. Bernard

Using a maximum entropy principle to assign a statistical weight to any graph, we introduce a model of random graphs with arbitrary degree distribution in the framework of standard statistical mechanics. We compute the free energy and the distribution of connected components. We determine the size of the percolation cluster above the percolation threshold. T

L. Donetti

In this paper we show that all infinite trees which have bounded coordination and whose surface is negligible with respect to the volume in the limit of large distances (so that they can be embedded in a finite-dimensional euclidean space) are recurrent on the average; this has important consequences about the spontaneous symmetry breaking of statistical mod

Jae Dong Noh, Heiko Rieger

We investigate the roughening phase transition of a $(3+1)$-dimensional elastic manifold driven by the completion between a periodic pinning potential and a randomly distributed impurities. The elastic manifold is modeled by a solid-on-solid type interface model, and universal features of the transition from a flat phase (for strong periodic potential) to a

J. Androulakis, N. Katsarakis, J. Giapintzakis

Single-phase polycrystalline La2MnVO6 samples were synthesized by arc melting and characterized by X-ray diffraction, magnetization and resistivity measurements. We find that the compound has cubic (space group), partly ordered double perovskite structure. The sample exhibits ferrimagnetic behavior and variable-range hopping conductivity. We conclude based o

Y. Kafri, E. Levine, D. Mukamel, J. Torok

Models of one-dimensional driven diffusive systems sometimes exhibit an abrupt increase of the correlation length to an anomalously large but finite value as the parameters of the model are varied. This behavior may be misinterpreted as a genuine phase transition. A simple mechanism for this sharp increase is presented. The mechanism is introduced within the

I. V. Zozoulenko, T. Blomquist

We perform numerical studies of the wave packet propagation through open quantum billiards whose classical counterparts exhibit regular and chaotic dynamics. We show that for t less or similar to tau (tau being the Heisenberg time), the features in the transmitted and reflected currents are directly related to specific classical trajectories connecting the b

S. Krompiewski, J. Martinek, J. Barnas

In a recent paper Liang {\it et al.} [Nature {\bf 411}, 665 (2001)] showed experimentally, that metallic nanotubes, strongly coupled to external electrodes, may act as coherent molecular waveguides for electronic transport. The experimental results were supported by theoretical analysis based on the scattering matrix approach. In this paper we analyze theore

H. Schiessel, G. Oshanin, A. M. Cazabat, M. Moreau

We study long-range morphological changes in atomic monolayers on solid substrates induced by different types of defects; e.g., by monoatomic steps in the surface, or by the tip of an atomic force microscope (AFM), placed at some distance above the substrate. Representing the monolayer in terms of a suitably extended Frenkel-Kontorova-type model, we calculat

E. K. O. Hellen, P. E. Salmi, M. J. Alava

The persistence probability, $P_C(t)$, of a cluster to remain unaggregated is studied in cluster-cluster aggregation, when the diffusion coefficient of a cluster depends on its size $s$ as $D(s) \sim s^γ$. In the mean-field the problem maps to the survival of three annihilating random walkers with time-dependent noise correlations. For $γ\ge 0$ the motion of

S. Y. Savrasov, G. Kotliar

We introduce a new linear response method to study the lattice dynamics of materials with strong correlations. It is based on a combination of dynamical mean field theory of strongly correlated electrons and the local density functional theory of electronic structure of solids. We apply the method to study the phonon dispersions of a prototype Mott insulator

Markus Deserno, Axel Arnold, Christian Holm

We use Molecular Dynamics simulations to study attractive interactions and the underlying ionic correlations between parallel like-charged rods in the absence of additional salt. For a generic bulk system of rods we identify a reduction of short range repulsions as the origin of a negative osmotic coefficient. The counterions show signs of a weak three-dimen

Gaspar Galaz, Julianne Dalcanton, Leopoldo Infante, Ezequiel Treister

(Abridged) We present results for J and Ks near-IR imaging data on a large sample of 88 galaxies drawn from the catalogue of Impey et al. (1996). The near-IR data unveils many features of LSBGs not seen before in the optical. First, a high fraction of the observed LSBGs are very luminous in the near-IR, indicating that they have a well developed old stellar

U. Heiter, F. Kupka, C. van &#39;t Veer-Menneret, C. Barban

We present several new sets of grids of model stellar atmospheres computed with modified versions of the ATLAS9 code. Each individual set consists of several grids of models with different metallicities ranging from [M/H] = -2.0 to +1.0 dex. The grids range from 4000 to 10000 K in T_eff and from 2.0 to 5.0 dex in logg. The individual sets differ from each ot

Stuart Wyithe, Abraham Loeb

We provide a simple theoretical model for the quasar luminosity function at high redshifts that naturally reproduces the statistical properties of the luminous SDSS quasar sample at redshifts z~4.3 and z>5.7. Our model is based on the assumptions that quasar emission is triggered by galaxy mergers, and that the black hole mass is proportional to a power-law

Brad Hansen

I examine the hypothesis that many of the high velocity white dwarfs observed by Oppenheimer et al. (2001) are the remnants of donor stars from binaries that produced type Ia supernovae via the `single degenerate&#39; channel. If this channel is a significant contributor to the Galactic SN Ia supernova rate, then the local density of such remnants with V>100

V. Charmandaris, O. Laurent, E. Le Floc&#39;h, I. F. Mirabel

We present a study of the three ultraluminous infrared galaxies IRAS14348-1447, IRAS19254-7245, and IRAS23128-5919, based on mid-infrared (MIR) spectro-imaging (5-18microns) observations performed with ISOCAM. We find that the MIR emission from each system, which consists of a pair of interacting late type galaxies, is principally confined to the nuclear reg

Juri Poutanen, Marek Gierlinski

The pulse profiles of the accreting X-ray millisecond pulsar SAX J1808.4-3658 at different energies are studied. The two main emission component, a black body and a power-law tail, clearly identified in the time-averaged spectrum, do not vary in phase. We show that the observed variability can be easily explained if the emission patterns of the black body an

S. M. Molnar, J. P. Hughes, M. Donahue, M. Joy

We have searched for unresolved X-ray sources in the vicinity of two rich clusters of galaxies: Abell 1995 (A1995) and MS 0451.6-0305 (MS0451), using the Chandra X-ray observatory. We detected significantly more unresolved sources around A1995 than expected based on the number of X-ray sources to the same flux limit detected in deep \CHANDRA observations of

Thomas H. Puzia, Stephen E. Zepf, Markus Kissler-Patig, Michael Hilker

We combine near-infrared photometry obtained with the VLT/ISAAC instrument and archival HST/WFPC2 optical images to determine VIK magnitudes and colours of globular clusters in two early-type galaxies, NGC 3115 and NGC 4365. The combination of near-IR and optical photometry provides a way to lift the age-metallicity degeneracy. For NGC 3115, the globular clu

F. R. Ferraro, M. Bellazzini, E. Pancino

Recent wide-field photometric surveys (Lee et al.; Pancino et al.) have shown the existence of a previously unknown metal-rich ([Fe/H] -0.6) stellar population in the galactic globular cluster omega Centauri. The discovery of this new component, which comprises only a small percentage (~5%) of the entire cluster population, has added a new piece to the alrea

Rosemary F. G. Wyse, Gerard Gilmore, Mark L. Houdashelt, Sofia Feltzing

The stellar initial mass function at high redshift is an important defining property of the first stellar systems to form and may also play a role in various dark matter problems. We here determine the faint stellar luminosity function in an apparently dark-matter-dominated external galaxy in which the stars formed at high redshift. The Ursa Minor dwarf sphe

I. F. Bikmaev, T. A. Ryabchikova, H. Bruntt, F. A. Musaev

We have performed abundance analysis of two slowly rotating, late A-type stars, HD 32115 (HR 1613) and HD 37594 (HR 1940), based on obtained echelle spectra covering the spectral range 4000-9850 AAngstrom. These spectra allowed us to identify an extensive line list for 31 chemical elements, the most complete to date for A-type stars. Two approaches to abunda

G. Miniutti, J. A. Pons, E. Berti, L. Gualtieri

A phase transition occurring in the inner core of a neutron star could be associated to a density discontinuity that would affect the frequency spectrum of the non-radial oscillation modes in two ways. Firstly, it would produce a softening of the equation of state, leading to more compact equilibrium configurations and changing the frequency of the fundament

Janusz Gil, George I. Melikidze

The problem of formation of the Ruderman-Sutherland type inner vacuum gap in neutron stars with ${\bfΩ}\cdot{\bf B}<0$ is considered. It is argued by means of the condition $T_i/T_s>1$ (where $T_i$ is the critical temperature above which $^{56}_{26}$Fe ions will not be bound at the surface and $T_s$ is the actual temperature of the polar cap surface heated b

Markus Kissler-Patig, Jean P. Brodie, Dante Minniti

We compare optical and near infrared colours of globular clusters in M87, the central giant elliptical in Virgo, and NGC 4478, an intermediate luminosity galaxy in Virgo, close in projection to M87. Combining V and I photometry obtained with the WFPC2 on HST and Ks photometry obtained with the NIRC on Keck 1, we find the broad range in colour and previously

G. Muratorio, N. Markova, M. Friedjung, G. Israelian

We have used the optical lines of N II and Fe III to study the wind of the luminous blue variable P Cyg. This was performed by applying a version of the Self Absorption Curve (SAC) method, involving few assumptions, to lines whose flux can be measured. A rather surprising result was obtained; the lines of more excited multiplets without blue shifted absorpti

V. Joergens, Matilde Fernandéz, Ralph Neuhäuser, Eike Guenther

A photometric monitoring campaign of brown dwarfs in the ChaI star forming region in the i and R band revealed significant periodic variations of the three M6.5-M7 type brown dwarf candidates ChaHa2, 3 and 6 (Joergens et al. 2002). These are the first rotational periods for very young (1-5 Myr) brown dwarfs and among the first rotational periods for brown dw

V. Buat, D. Burgarella, J. M. Deharveng, D. Kunth

We present the 970-1175 A spectral energy distributions (SEDs) of 12 starburst galaxies observed with the Far Ultraviolet Spectroscopic Explorer FUSE. We take benefit of the high spectral resolution of FUSE to estimate a continuum as much as possible unaffected by the interstellar lines. The continuum is rather flat with, in few cases, a decrease at lambda <

D. Rigopoulou, D. Kunze, D. Lutz, R. Genzel

We present results from a survey of molecular hydrogen emission from a sample of Starburst and Seyfert galaxies carried out with the Infrared Space Observatory (ISO). Pure rotational H_2 emission has been detected in a number of extragalactic objects and a variety of environments. A number of transitions from S(7) to S(0) are detected in both Starbursts and

N. S. Singh, S. Naik, B. Paul, P. C. Agrawal

A nonlinear nature of the binary ephemeris of Cygnus X-3 indicates either a change in the orbital period or an apsidal motion of the orbit. We have made extended observations of Cygnus X-3 with the Pointed Proportional Counters (PPCs) of the Indian X-ray Astronomy Experiment (IXAE) during 1999 July 3-13 and October 11-14. Using the data from these observatio

Shinya Wanajo, Naoki Itoh, Yuhri Ishimaru, Satoshi Nozawa

The discovery of the second highly $r$-process-enhanced, extremely metal-poor star, CS 31082-001 ([Fe/H] $= -2.9$) has provided a powerful new tool for age determination, by virtue of the detection and measurement of the radioactive species uranium and thorium. One of the serious limitations of this approach, however, is that predictions of the production ra

Frederik Denef

Two pictures of BPS bound states in Calabi-Yau compactifications of type II string theory exist, one as a set of particles at equilibrium separations from each other, the other as a fusion of D-branes at a single point of space. We show how quiver quantum mechanics smoothly interpolates between the two, and use this, together with recent mathematical results

John G. Miller

Let M be a complete orientable manifold of bounded geometry. Suppose that M has finitely many ends, each having a neighborhood quasi-isometric to a neighborhood of an end of an infinite cyclic covering of a compact manifold. We consider a class of exponentially weighted inner products (\cdot ,\cdot)_k on forms, indexed by k>0. Let δ_k be the formal adjoint o

Howard J. Schnitzer, Niclas Wyllard

We study the N=1 Sp(2N+2M)xSp(2N) gauge theory on a stack of N physical and M fractional D3-branes in the background of an orientifolded conifold. The gravity dual is a type IIB orientifold of adS_5xT^11 (with certain background fluxes turned on) containing an O7-plane and 8 D7-branes. In the conformal case (M=0), we argue that the alpha&#39;^2-corrections l

Tommy Ohlsson, Gerhart Seidl

We present a model for leptonic mixing and the lepton masses based on flavor symmetries and higher-dimensional mass operators. The model predicts bilarge leptonic mixing (i.e., the mixing angles theta_{12} and theta_{23} are large and the mixing angle theta_{13} is small) and an inverted hierarchical neutrino mass spectrum. Furthermore, it approximately yiel

Thomas Dent, Joaquim Silva-Marcos

CP violation in the SM is naturally implemented as a small imaginary perturbation to real Yukawa couplings. For example, a large CP asymmetry in B_d decays can arise if the imaginary parts of quark mass matrices are of order 10^(-3)m_t,b or smaller. Applying the same principle of ``additive CP violation&#39;&#39; to soft SUSY-breaking terms, the electric dip

Katsuyuki Sugiyama, Kentaroh Yoshida

We study the closed and open supermembranes on the maximally supersymmetric pp-wave background. In the framework of the membrane theory, the superalgebra is calculated by using the Dirac bracket and we obtain its central extension by surface terms. The result supports the existence of the extended objects in the membrane theory in the pp-wave limit. When the

Vasily Pestun

In this paper the partition function of N=4 D=0 super Yang-Mills matrix theory with arbitrary simple gauge group is discussed. We explicitly computed its value for all classical groups of rank up to 11 and for the exceptional groups G_2, F_4 and E_6. In the case of classical groups of arbitrary rank we conjecture general formulas for the B_r, C_r and D_r ser

Erzsebet Ravasz, Albert-Laszlo Barabasi

Many real networks in nature and society share two generic properties: they are scale-free and they display a high degree of clustering. We show that these two features are the consequence of a hierarchical organization, implying that small groups of nodes organize in a hierarchical manner into increasingly large groups, while maintaining a scale-free topolo

Igor Frenkel, Anton Malkin, Maxim Vybornov

We suggest a (conjectural) construction of a basis in the plus part of the affine Lie algebra of type ADE indexed by irreducible components of certain quiver varieties. This construction is closely related to a string-theoretic construction of a Lie algebra of BPS states. We then study the new combinatorial questions about the (classical) root systems natura

F. Alberto Grunbaum, Plamen Iliev

In the case of the heat equation $u_t=u_{xx}+Vu$ on the real line there are some remarkable potentials $V$ for which the asymptotic expansion of the fundamental solution becomes a finite sum and gives an exact formula. We show that a similar phenomenon holds when one replaces the real line by the integers. In this case the second derivative is replaced by th

I. Binder, L. DeMarco

Let $F$ be a polynomial endomorphism of $\C^n$ which extends holomorphically to $¶^n$. We prove that the dimension of $μ_F$, the pluriharmonic measure on the boundary of the filled Julia set of $F$, is bounded above by $2n-1$.

Tsuyoshi Kobayashi, Yo&#39;av Rieck

We study the way a strongly irreducible Heegaard surface $Σ$ intersects a knot exterior $X$ embedded in a 3-manifold, and show that if $Σ\cap \partial X$ consists of simple closed curves which are essential in both $Σ$ and $\partial X$, then the intersection $X \cap Σ$ consists of meridional annuli only. As an application we show that when considering two He

Amilcar Pacheco

Let C be a smooth irreducible projective curve defined over a finite field $\mathbb{F}_{q}$ of q elements of characteristic p>3 and $K=\mathbb{F}_{q}(C)$ its function field and $ϕ_{\mathcal{E}}:\mathcal{E}\to C$ the minimal regular model of $\mathbf{E}/K$. For each $P\in C$ denote $\mathcal{E}_P=ϕ^{-1}_{\mathcal{E}}(P)$. The elliptic curve $E/K$ has good red

Jaroslaw Piskorski

The influence of a hypothetical CP violating $|ΔS|=2$ interaction on the time evolution of the $K^{0} - \bar{K^{0}}$ system is investigated. It is shown, that if we were to assume the existence of the superweak-like interaction then this would lead to the conclusion, that there might be observable effects in the masses of the neutral kaons. We address the po

Fabio Scardigli

The formulae for Planck length, Hawking temperature and Unruh-Davies temperature are derived by using only laws of classical physics together with the Heisenberg principle. Besides, it is shown how the Hawking relation can be deduced from the Unruh relation by means of the principle of equivalence; the deep link between Hawking effect and Unruh effect is in

Atsushi Fujii, Tetsuya Ishikawa

Cross-language information retrieval (CLIR), where queries and documents are in different languages, has of late become one of the major topics within the information retrieval community. This paper proposes a Japanese/English CLIR system, where we combine a query translation and retrieval modules. We currently target the retrieval of technical documents, an

Atsushi Fujii, Katunobu Itou, Tetsuya Ishikawa

While recent retrieval techniques do not limit the number of index terms, out-of-vocabulary (OOV) words are crucial in speech recognition. Aiming at retrieving information with spoken queries, we fill the gap between speech recognition and text retrieval in terms of the vocabulary size. Given a spoken query, we generate a transcription and detect OOV words t

Guang-Ming Zhang, Hui Hu, Lu Yu

To describe the scattering of superconducting quasiparticles from non-magnetic (Zn) or magnetic (Ni) impurities in optimally doped high T$_c$ cuprates, we propose an effective Anderson model Hamiltonian of a localized electron hybridizing with $d_{x^2-y^2}$-wave BCS type superconducting quasiparticles with an attractive scalar potential at the impurity site.

S. N. Dorogovtsev, J. F. F. Mendes, A. N. Samukhin

We propose a construction procedure which generates a wide class of random evolving networks with fat-tailed degree distributions and an arbitrary clustering. This procedure applies the stochastic transformations of edges, which can be used as the basis of a real space renormalization group for evolving networks.

S. N. Dorogovtsev, J. F. F. Mendes, A. N. Samukhin

(a) We propose a ``static&#39;&#39; construction procedure for random networks with given correlations of the degrees of the nearest-neighbor vertices. This is an equilibrium graph, maximally random under the constraint that its degree-degree distribution is fixed. (b) We generalize the notion of preferential linking and introduce a new category, {\em pair p

T. Padmanabhan

This pedagogical review addresses several issues related to statistical description of gravitating systems in both static and expanding backgrounds, focusing on the latter. After briefly reviewing the results for the static background, I describe the key issues and recent progress in the context of gravitational clustering of collision-less particles in an e

Zhanwen Han, Philipp Podsiadlowski, Pierre L. F. Maxted, Tom R. Marsh

Subdwarf B (sdB) stars (and related sdO/sdOB stars) are believed to be helium core-burning objects with very thin hydrogen-rich envelopes. In recent years it has become increasingly clear from observational surveys that a large fraction of these objects are members of binary systems. To better understand their formation, we here present the results of a deta

A . H. Prestwich, J. A. Irwin, R. E. Kilgard, M. I. Krauss

The X-ray populations of Local group galaxies have been classified in detail by Einstein, ROSAT and ASCA revealing a mix of binaries, supernova remnants and HII regions. However, these observatories were unable to resolve X-ray sources in galaxies beyond the local group. With Chandra&#39;s exquisite spatial resolution we are able to resolve sources in a samp

Emmanuel I. Rashba

Insertion of a resistive contact between a ferromagnetic metal and a semiconductor microstructure is of critical importance for achieving efficient spin injection into a semiconductor. However, the equations of the diffusion theory are rather cumbersome for the junctions including such contacts. A technique based on deriving a system of self-consistent equat

A. Scardicchio, P. Facchi, S. Pascazio

We study the time evolution of a chain of nonlinear oscillators. We focus on the fractal features of the spectral entropy and analyze its characteristic intermediate timescales as a function of the nonlinear coupling. A Brownian motion is recognized, with an analytic power-law dependence of its diffusion coefficient on the coupling.

Luis G. Cabral-Rosetti, Miguel A. Sanchis-Lozano

The scalar three-point function appearing in one-loop Feynman diagrams is compactly expressed in terms of a generalized hypergeometric function of two variables. Use is made of the connection between such Appell function and dilogarithms coming from a previous investigation. Special cases are obtained for particular values of internal masses and external mom

Elena D&#39;Onghia, Andreas Burkert

Self-interacting dark matter was proposed by Spergel & Steinhardt (2000) to alleviate two conflicts between Cold Dark Matter (CDM) models and observations. Firstly, CDM N-body simulations predict dark matter halo density profiles that diverge at the centre in disagreement with the constant density cores observed in late-type dwarf and Low Surface Brightness

Dimitri Kusnezov, Eric Lutz, Kenichiro Aoki

We study the statistical mechanics of classical and quantum systems in non-equilibrium steady states. Emphasis is placed on systems in strong thermal gradients. Various measures and functional forms of observables are presented. The quantum problem is set up using random matrix techniques, which allows for the construction of the master equation. Special sol

Ali Tahzibi

We show stable ergodicity of a class of conservative diffeomorphisms which do not have any hyperbolic invariant subbundle. Moreover the uniqueness of SRB measures for non-conservative $C^1$ perturbations of such diffeomorphisms. This class contains strictly non-partially hyperbolic robustly transitive diffeomorphisms by Bonatti-Viana and so we answer their q

Wladyslaw Marcinek

A proposal of an algebraic model for the relation between a quantum environment and certain classical particle system is given. The quantum environment is described by a category of possible quantum states, the initial particle system is represented by an associative algebra in the category of states. The result of particle interactions with quantum environm

Novica Blazic, Srdjan Vukmirovic

In this paper we construct a family of examples of self-dual Einstain metrics of neutral signature, which are not Ricci flat, nor locally homogenous. Curvature of these manifolds is studied in details. These are obtained by the para-quaternionic reduction. We compare our examples with the orbifolds $\oo$ given by Galicki and Lawson, for which some new proper

J. P. May

We show how the formal Wirthmuller isomorphism theorem proven in &#34;Isomorphisms between left and right adjoints&#34;, by Fausk, Hu, and May, simplifies the proof of the Wirthmuller isomorphism in equivariant stable homotopy theory. Other examples from equivariant stable homotopy theory show that the hypotheses of the formal Wirthmuller and formal Grothend

H. Fausk, P. Hu, J. P. May

There are many contexts in algebraic geometry, algebraic topology, and homological algebra where one encounters a functor that has both a left and right adjoint, with the right adjoint being isomorphic to a shift of the left adjoint specified by an appropriate ``dualizing object&#39;&#39;. Typically the left adjoint is well understood while the right adjoint

Alexander Postnikov

The quantum Bruhat graph, which is an extension of the graph formed by covering relations in the Bruhat order, is naturally related to the quantum cohomology ring of G/B. We enhance a result of Fulton and Woodward by showing that the minimal monomial in the quantum parameters that occurs in the quantum product of two Schubert classes has a simple interpretat

A Shirzad, F Loran

In a recent work we showed that for a Hamiltonian system with constraints, the set of constraints can be investigated in first and second class constraint chains. We show here that using this &#34;chain by chain&#34; method for an arbitrary system one can fix the gauges in the most economical and consistent way. We show that it is enough to assume some gauge

S. M. Barr

There are four puzzling questions about by the magnitudes of neutrino mixings and mass splittings. A brief sketch is given of the various kinds of models of neutrino masses and how they answer these questions. Special attention is given to so-called &#34;lopsided&#34; models.

T. Teshima, T. Asai, Y. Abe

We have analyzed the possibility that the universal Yukawa coupling (democratic mass matrix) with small violations of Dirac and Majorana neutrinos can induce the large mixing of neutrinos through the seesaw mechanism. The possibility can be achieved by the condition that the violation parameters of Majorana neutrinos are sufficiently smaller than the violati

L. G. Cabral-Rosetti, M. Moreno, A. Rosado

We calculate the Dirac neutrino anapole moment (a_{\nu_l}) in the context of the Standard Model (SM) making use of the Dirac form factor F_D(q^2) introduced recently by J. Bernabeu, L. G. Cabral-Rosetti, J. Papavassiliou y J. Vidal by using the Pinch Technique (PT) formalism, working in two different gauge-fixing schemes (R_\xi guage and the electroweak BFM)

Luis G. Cabral-Rosetti, Dario Nunez, Roberto A. Sussman, Tonatiuh Matos

We consider simple hydrodynamical models of galactic dark matter in which the galactic halo is a self-gravitating and self-interacting gas that dominates the dynamics of the galaxy. Modeling this halo as a sphericaly symmetric and static perfect fluid satisfying the field equations of General Relativity, visible barionic matter can be treated as ``test parti

W. Chen

In this study, we presented the high-order fundamental solutions and general solutions of convection-diffusion equation. To demonstrate their efficacy, we applied the high-order general solutions to the boundary particle method (BPM) for the solution of some inhomogeneous convection-diffusion problems, where the BPM is a new truly boundary-only meshfree coll

G. Litak, T. Paiva, R. T. Scalettar, C. Huscroft

We study the effect of random dilution of attraction centers on electron pairing in a generalization of the negative $U$ Hubbard model where the interaction $U_i$, defined on the two dimensional lattice, can be $-|U|$ and 0 with probability $c$ and $1-c$ depending on the lattice site $i$. Using the determinant quantum Monte Carlo approach, we find the critic

Federico Becca, Frederic Mila

We show that the introduction of frustration into the spin-1/2 two-dimensional (2D) antiferromagnetic Heisenberg model on a square lattice via a next-nearest neighbor exchange interaction can lead to a Peierls-like transition, from a tetragonal to an orthorhombic phase, when the spins are coupled to adiabatic phonons. The two different orthorhombic ground st

Hidefumi Akiyama, Loren N. Pfeiffer, Masahiro Yoshita, Aron Pinczuk

A multi-quantum wire laser operating in the 1-D ground state has been achieved in a very high uniformity structure that shows free exciton emission with unprecedented narrow width and low lasing threshold. Under optical pumping the spontaneous emission evolves from a sharp free exciton peak to a red-shifted broad band. The lasing photon energy occurs about 5

Francis W. Starr, Srikanth Sastry, Jack F. Douglas, Sharon C. Glotzer

We examine the local geometry of a simulated glass-forming polymer melt. Using the Voronoi construction, we find that the distributions of Voronoi volume $P(v_V)$ and asphericity $P(a)$ appear to be universal properties of dense liquids, supporting the use of packing approaches to understand liquid properties. We also calculate the average free volume $<v_f>

J. P. Huang, K. W. Yu, G. Q. Gu

When a strong electric field is applied to a colloidal suspension, it may cause an aggregation of the suspended particles in response to the field. In the case of a rotating field, the electrorotation (ER) spectrum can be modified further due to the local field effects arising from the many-particle system. To capture the local field effect, we invoke the Ma

S. A. Stern

The Kuiper Belt (KB) region of the solar system, stretching from 30 to at least 50 AU, contains Pluto-Charon, some ~105 Kuiper Belt Objects (KBOs) larger than 100 km in diameter, and myriad smaller bodies produced by collisions among KBOs (Farinella, Davis, & Stern 2000). The most notable physical attribute of the KBOs discovered to date is their reflectance

D. Cordier, Y. Lebreton, M. -J. Goupil, T. Lejeune

The main scope of this paper is to investigate the possible existence of a metallicity dependence of the overshooting from main sequence stars turbulent cores. We focus on objects with masses in the range ~2.5 Msol - ~25 Msol. Basically, evolutionary time scale ratios are compared with star numbers ratios on the main sequence. Star populations are synthesize

F. Combes

An overview is presented of the main properties of dark matter haloes, as we know them from observations, essentially from rotation curves around spiral and dwarf galaxies. Detailed rotation curves are now known for more than a thousand galaxies, revealing that they are not so flat in the outer parts, but rising for late-types, and falling for early-types. A

R. Palit, J. A. Sheikh, Y. Sun, H. C. Jain

A systematic study of 2-quasiparticle bands of the proton-rich odd-odd nuclei in the mass A ~ 70-80 region is performed using the projected shell model approach. The study includes Br-, Rb-, and Y-isotopes with N = Z+2, and Z+4. We describe the energy spectra and electromagnetic transition strengths in terms of the configuration mixing of the angular-momentu

K. B. Alkalaev, M. A. Vasiliev

We formulate gauge invariant interactions of totally symmetric tensor and tensor-spinor higher spin gauge fields in AdS(5) that properly account for higher-spin-gravitational interactions at the action level in the first nontrivial order.

Motohico Mulase, Andrew Waldron

We present an asymptotic expansion for quaternionic self-adjoint matrix integrals. The Feynman diagrams appearing in the expansion are ordinary ribbon graphs and their non-orientable counterparts. The result exhibits a striking duality between quaternionic self-adjoint and real symmetric matrix integrals. The asymptotic expansions of these integrals are give

C. Adler

The STAR collaboration reports the first observation of exclusive rho^0 photo-production, AuAu->AuAu rho^0, and rho^0 production accompanied by mutual nuclear Coulomb excitation, AuAu->Au*Au*rho^0, in ultra-peripheral heavy-ion collisions. The rho^0 have low transverse momenta, consistent with coherent coupling to both nuclei. The cross sections at sqrt(s_NN

M. Jezabek, P. Urban

The Dirac masses of neutrinos can exhibit a strong hierarchy even if the Majorana masses of the right-handed neutrinos are degenerate and the hierarchy of the mass scales governing the oscillations of solar and atmospheric neutrinos is rather small. This phenomenon results from the see-saw mechanism and the algebraic structure of the effective mass operator

Luis Anchordoqui, Thomas Paul, Stephen Reucroft, John Swain

In this review we discuss the important progress made in recent years towards understanding the experimental data on cosmic rays with energies $\agt 10^{19}$ eV. We begin with a brief survey of the available data, including a description of the energy spectrum, mass composition, and arrival directions. At this point we also give a short overview of experimen

Charles Livingston

An open question asks if every knot of 4-genus g_s can be changed into a slice knot by g_s crossing changes. A counterexample is given.

T. Mishonov, E. Penev

The free energy, non-gradient terms of the Ginzburg-Landau expansion, and the jump of the specific heat of a multiband anisotropic-gap clean BCS superconductor are derived in the framework of a separable-kernel approximation. Results for a two-band superconductor, d-wave superconductor, and some recent models for MgB_2 are derived as special cases.

G. Rigolin, C. O. Escobar

We construct an explicit model where it can be established if a two mode pure Gaussian system is entangled or not by acting only on one of the parts that constitute the system. Measuring the dispersion in momentum and the time evolution of the dispersion in position of one particle we can tell if entanglement is present as well as the degree of entanglement

G. E. Brown, Mannque Rho

The recent developments on the &#34;vector manifestation&#34; of chiral symmetry by Harada and Yamawaki provide a compelling evidence for, and &#34;refine,&#34; the in-medium scaling of hadronic properties in dense/hot matter (call it ``BR scaling&#34;) proposed by the authors in 1991. We reinterpret the Harada-Yamawaki result obtained in a Wilsonian renorma

Eugene F. Chaffin, Daniel S. Banks

Using the exponentially diffuse boundary potential of Green and Lee (1955), we develop a Mathematica notebook to treat alpha decay by using the complex energy approach of Preston (1947), as modified by Pierronne and Marquez (1978). Our approach allows the potential to change slowly from the well depth of the interior of the nucleus to the top of the Coulomb

S. Ettori, S. De Grandi, S. Molendi

We consider a sample of 22 nearby clusters of galaxies observed with the Medium Energy Concentrator Spectrometer (MECS) on board of BeppoSAX. They cover the range in gas temperature between 3 and 10 keV, with bolometric X-ray luminosity between 2e44 erg/s and 6e45 erg/s. Using the de-projected gas temperature and density profiles resolved in a number of bins

Peter Austing, Thordur Jonsson, Larus Thorlacius

We study scalar solitons on the fuzzy sphere at arbitrary radius and noncommutativity. We prove that no solitons exist if the radius is below a certain value. Solitons do exist for radii above a critical value which depends on the noncommutativity parameter. We construct a family of soliton solutions which are stable and which converge to solitons on the Moy

V. S. Fadin, A. Papa

It is shown that the kernel of the BFKL equation for the octet color state of two Reggeized gluons satisfies the strong bootstrap condition in the next-to-leading order. This condition is much more restrictive than the one obtained from the requirement of Reggeized form for the elastic scattering amplitudes in the next-to-leading approximation. It is necessa