January 2002 arXiv papers — page 21

G. D'Agostini

The end of LEP and SLC is a good moment to review the way to summarize search results in order to exploit at best, in future analyses and speculations, the pieces of information coming from all experiments. Some known problems with the usual way of reporting results in terms ``CL limits'' are shortly recalled, and a plea is formulated to publish just

Yosuke Uehara

We argue that future e^{+} e^{-} linear colliders can produce many sneutrinos if lepton-number violating couplings lambda_{1j1} exist and enough beam polarization is obtained. The terms lambda_{ijk} L_{i} L_{j} E_{k}^{c} are allowed in a discrete Z_{3}-symmetry which is used to forbid rapid proton decay, and it is worthwhile to consider the possibility of th

B. Aubert

We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 ${\rm fb}^{-1}$ recorded at the $Υ(4S)$ resonance and 3.9 ${\rm fb}^{-1}$ off-resonance. One of the neutral B meso

A. E. Asratyan, G. V. Davidenko, A. G. Dolgolenko, V. S. Kaftanov

A method for detecting the transition \omutau in long-baseline accelerator experiments, that consists in comparing the far-to-near ratios of the spectra of quasielastic CC events generated by high- and low-energy beams of muon neutrinos, is proposed. The test may be accessible to big water Cherenkov detectors and iron--scintillator calorimeters, and is limit

Salvatore Capozziello

The issues of quintessence and cosmic acceleration can be discussed in the framework of higher order theories of gravity. We can define effective pressure and energy density directly connected to the Ricci scalar of curvature of a generic fourth order theory and then ask for the conditions to get an accelerated expansion. Exact accelerated expanding solution

Bruno Boisseau, Patricio S. Letelier

In order to shed some light in the meaning of the relativistic multipolar expansions we consider different static solutions of the axially symmetric vacuum Einstein equations that in the non relativistic limit have same Newtonian moments. The motion of test particles orbiting around different deformed attraction centers with the same Newtonian limit is studi

Gen Uchida, Misao Sasaki

The quantum fluctuation of the relative location of two (n-1)-dimensional de Sitter branes (i.e., of n spacetime dimensions) embedded in the (n+1)-dimensional anti-de Sitter bulk, which we shall call the quantum radion, is investigated at the linear perturbation level. The quantization of the radion is done by deriving the effective action of the radion. Ass

Chiara Menotti, Sandro Stringari

Starting from the hydrodynamic equations of superfluids, we calculate the frequencies of the collective oscillations of a harmonically trapped Bose gas for various 1D configurations. These include the mean field regime described by Gross-Pitaevskii theory and the beyond mean field regime at small densities described by Lieb-Liniger theory. The relevant combi

V. Rodrigues, J. Bettini, A. R. Rocha, L. G. C. Rego

We have analyzed the atomic arrangements and quantum conductance of silver nanowires generated by mechanical elongation. The surface properties of Ag induce unexpected structural properties, as for example, predominance of high aspect ratio rod-like wires. The structural behavior was used to understand the Ag quantum conductance data and the proposed correla

S. Burger, L. D. Carr, P. Ohberg, K. Sengstock

Generation, interaction and detection of dark solitons in Bose-Einstein condensates is considered. In particular, we focus on the dynamics resulting from phase imprinting and density engineering. The generation of soliton pairs as well as their interaction is also considered. Finally, motivated by the recent experimental results of Cornish et al. (Phys. Rev

D. V. Fil

We investigate the phonon mechanism for the orientational pinning of Wigner crystals and stripes in two-dimensional electron layers in GaAs matrices. We find the orientation of bilayer Wigner crystals on the (001), (111), (0-11) and (311) interfaces versus the interlayer distance and determine the regions of parameters, where polydomain structures can emerge

R. J. Radwanski, Z. Ropka

It has been shown that for the highly-correlated d4 electronic system the spin-orbit interactions produce, even in case of the cubic crystal-field interactions, a singlet ground state. Its magnetic moment grows rapidly with the applied magnetic field approaching 4 uB for the Eg state, but only 3 uB for the T2g state. The applicability of the present results

C. Pennetta, E. Alfinito, L. Reggiani

We investigate the steady state of a two-dimensional random resistor network subjected to two competing biased percolations as a function of the bias strength. The properties of the linear and nonlinear regimes are studied by means of Monte Carlo simulations. In constant current conditions, a scaling relation is found between $<R>/<R>_0$ and $I/I_0$, where $

G. M. Kavoulakis

We investigate the lowest state of a rotating, weakly-interacting Bose-Einstein condensate trapped in a harmonic confining potential that is driven by an infinitesimally asymmetric perturbation. Although in an axially-symmetric confining potential the gas has an axially-symmetric single-particle density distribution, we show that in the presence of the small

Nuno D. Antunes, Luis M. Bettencourt, Martin Kunz

We determine the detailed thermodynamic behavior of vortices in the O(2) scalar model in 2D and of global monopoles in the O(3) model in 3D. We construct new numerical techniques, based on cluster decomposition algorithms, to analyze the point defect configurations. We find that these criteria produce results for the Kosterlitz-Thouless temperature in agreem

A. N. Rubtsov

Modification of the renormalization-group approach, invoking Stratonovich transformation at each step, is proposed to describe phase transitions in 3D Ising-class systems. The proposed method is closely related to the mean-field approximation. The low-order scheme works well for a wide thermal range, is consistent with a scaling hypothesis and predicts very

P. Lunkenheimer, V. Bobnar, A. V. Pronin, A. I. Ritus

Experimental evidence is provided that colossal dielectric constants, epsilon >= 1000, sometimes reported to exist in a broad temperature range, can often be explained by Maxwell-Wagner type contributions of depletion layers at the interface between sample and contacts, or at grain boundaries. We demonstrate this on a variety of different materials. We specu

R. Zitzler, Th. Pruschke, R. Bulla

We discuss the ground state magnetic phase diagram of the Hubbard model off half filling within the dynamical mean-field theory. The effective single-impurity Anderson model is solved by Wilson&#39;s numerical renormalization group calculations, adapted to symmetry broken phases. We find a phase separated, antiferromagnetic state up to a critical doping for

Takuya Arimori, Hikaru Kawamura

Ordering of the geometrically frustrated two-dimensional Heisenberg antiferromagnet on a pyrochlore slab is studied by Monte Carlo simulations. The model is expected to serve as a reference system of SrCrGaO compound studied extensively. In sharp contrast to the kagomé Heisenberg antiferromagnet, the model exhibits locally non-coplanar spin structures at low

L. C. Garcia de Andrade

The stability of de Sitter metric in spacetimes where inflaton fields are non-minimally coupled to propagating torsion is investigated. It is shown that the de Sitter background metric is unstable against small perturbations. Axionic torsion is generated by inflaton fluctuations and the analysis of cosmological perturbations in Einstein-Cartan-Klein-Gordon (

Adrienne M. Cool, Adam S. Bolton

The dense central region of NGC 6397 contains three classes of stars whose origins are likely related to stellar interactions: blue stragglers, cataclysmic variables, and probable helium white dwarfs. We summarize results concerning CVs and HeWD candidates that have been identified in two imaging studies with Hubble Space Telescope, including one CV candidat

Megan Donahue, Beverly J. Smith, John T. Stocke

The NGC4410 group of galaxies provides us a rare opportunity to study a nearby (97 h75^-1 Mpc) example of a radio galaxy (NGC4410A) embedded in an extended X-ray source, with evidence for star formation that can be readily spatially distinguished from regions dominated by the AGN and shocks. We present broadband and narrowband optical images along with optic

R. Lucas, H. S. Liszt

Using data from IRAM&#39;s Plateau de Bure Interferometer and 30 m Telescope, we discuss the mm-wave absorption lines of CS, SO, H2S and HCS+ which arise in diffuse clouds occulting several extragalactic continuum sources. Typical relative abundances are X(CS)/X(HCO+) ~ 2, X(CS)/X(SO) ~ 2, X(CS)/X(H2S) ~ 6 and X(CS)/X(HCS+) ~ 13.

F. J. Clarke, C. G. Tinney, K. R. Covey

We have detected a strong periodicity of 1.80+/-0.05 hours in photometric observations of the brown dwarf Kelu-1. The peak-to-peak amplitude of the variation is ~1.1% (11.9+/-0.8 mmag) in a 41nm wide filter centred on 857nm and including the dust/temperature sensitive TiO & CrH bands. We have identified two plausible causes of variability: surface features r

J. Buckley, T. Burnett, G. Sinnis, P. Coppi

This paper reviews the field of gamma-ray astronomy and describes future experiments and prospects for advances in fundamental physics and high-energy astrophysics through gamma-ray measurements. We concentrate on recent progress in the understanding of active galaxies, and the use of these sources as probes of intergalactic space. We also describe prospects

Y. Momany, E. V. Held, I. Saviane, L. Rizzi

We present deep $BVI$ observations of the dwarf irregular galaxy UKS1927-177 in Sagittarius. Statistically cleaned $V$, $(B-I)$ CMDs clearly display the key evolutionary features in this galaxy. Previously detected C stars are located in the CMDs and shown to be variable, thus confirming the presence of a significant upper-AGB intermediate age population. A

N. M. Nagar, A. S. Wilson, H. Falcke, J. S. Ulvestad

There is now strong evidence that many low-luminosity AGNs (LLAGNs) contain accreting massive black holes and that the nuclear radio emission is dominated by parsec-scale jets launched by these black holes. Here, we present preliminary results on the 1.4 GHz to 667 GHz spectral shape of a well-defined sample of 16 LLAGNs. The LLAGNs have a falling spectrum a

Nail Sibgatullin

We derive a formula for the nodal precession frequency and the Keplerian period of a particle at an arbitrarily inclined orbit (with a minimum latitudinal angle reached at the orbit) in the post-Newtonian approximation in the external field of an oblate rotating neutron star (NS). We also derive formulas for the nodal precession and periastron rotation frequ

R. N Henriksen, M. Le Delliou

The density profiles established in the self-similar dynamical phase of dark matter haloes recollapse are all close to isothermal. This is steeper than the predictions of some n-body simulations for the central regions of the halo, which are in turn steeper than the profiles observed in the centre of some galaxies; particularly dwarfs and low surface brightn

Joseph D. MacMillan, Richard N. Henriksen

In this article we consider the growth of seed black holes immersed in dark matter halos. We first investigate the adiabatic growth in various initial distribution functions (isothermal, power law, and NFW) and find the resulting density, radial velocity, and anisotropy profiles. In addition we estimate the growth rate for a given black hole mass in the corr

E. Kerins, J. Binney, J. Silk

Cold, dense clouds of gas have been proposed as baryonic candidates for the dark matter in Galactic haloes, and have also been invoked in the Galactic disc as an explanation for the excess faint sub-mm sources detected by SCUBA. Even if their dust-to-gas ratio is only a small percentage of that in conventional gas clouds, these dense systems would be opaque

Ramon Toldra

We calculate the spectrum of ultra high energy cosmic rays produced by the decay of a superheavy dark matter population clustered in the galactic halo. To perform this calculation we start with fragmentation functions measured at LEP and evolve them to the cosmic ray energy scale using the QCD DGLAP equations. We consider Standard Model evolution and supersy

A. J. Gomez-Pelaez, F. Moreno-Insertis

A systematic study of the linear thermal stability of a medium subject to cooling, self-gravity and thermal conduction is carried out for the case when the unperturbed state is subject to global cooling and expansion. A general, recursive WKB solution for the perturbation problem is obtained which can be applied to a large variety of situations in which ther

M. R. Bate, G. I. Ogilvie, S. H. Lubow, J. E. Pringle

We analyse the non-linear propagation and dissipation of axisymmetric waves in accretion discs using the ZEUS-2D hydrodynamics code. The waves are numerically resolved in the vertical and radial directions. Both vertically isothermal and thermally stratified accretion discs are considered. The waves are generated by means of resonant forcing and several form

Ignasi Ribas, Frederic Arenou, Edward F. Guinan

We discuss a method to determine orbital properties and masses of low-mass bodies orbiting eclipsing binaries. The analysis combines long-term eclipse timing modulations (light-travel time or LTT effect) with short-term, high-accuracy astrometry. As an illustration of the method, the results of a comprehensive study of Hipparcos astrometry and over a hundred

Y. P. Jing, Yasushi Suto

Understanding of the structure evolution in the Universe has been greatly advanced with a rapid progress in high-resolution cosmological simulations. In this contribution, we report a new set of cosmological simulations with $512^3$ ($\sim 1.4\times 10^8$) particles in a simulation box of $100\mpc$. With this unprecedented resolution, we have successfully ov

Y. P. Jing

Cold Dark Matter (CDM) models of galaxy formation had been remarkably successful to explain a number of observations in the past decade. However, with both the theoretical modeling and the observations being improved, CDM models have been very recently shown to have excessive clustering on the sub-galactic scale. Here I discuss a solution, based on our high-

Y. P. Jing, G. Boerner, Yasushi Suto

We report on the measurement of the two-point correlation function and the pairwise peculiar velocity of galaxies in the IRAS PSCz survey. The real space two-point correlation function can be fitted to a power law $ξ(r) = (r_0/r)^γ$ with $γ=1.69$ and $r_0=3.70 \mpc$. The pairwise peculiar velocity dispersion $σ_{12}(r_p)$ is close to $400 \kms$ at $r_p=3\mpc

Mutsumi Mutoh, Makoto Inoue, Seiji Kameno, Keiichi Asada

We consider the use of polarization properties as a means to discriminate between Synchrotron Self-Absorption (SSA) and Free--Free Absorption (FFA) in GHz-Peaked Spectrum (GPS) sources. The polarization position angle (PA) of synchrotron radiation at high frequencies for the optically thin regime is perpendicular to the magnetic field, whereas it is parallel

R. Y. Chiao, P. G. Kwiat

Heisenberg in 1929 introduced the &#34;collapse of the wavepacket&#34; into quantum theory. We review here an experiment at Berkeley which demonstrated several aspects of this idea. In this experiment, a pair of daughter photons was produced in an entangled state, in which the sum of their two energies was equal to the sharp energy of their parent photon, in

Travis Norsen

We study the transition from npe-type nuclear matter (consisting of neutrons, protons, and electrons) to matter containing strangeness, using a Walecka-type model predicting a first-order kaon-condensate phase transition. We examine the free energy of droplets of K-matter as the density, temperature, and neutrino fraction are varied. Langer nucleation rate t

Gerald A. Miller, Michael R. Frank

A relativistic constituent quark model is found to reproduce the recent data regarding the ratio of proton form factors, $F_2(Q^2)/F_1(Q^2)$. We show that imposing Poincare invariance leads to substantial violation of the helicity conservation rule, as well as an analytic result that the ratio $F_2(Q^2)/F_1(Q^2)\sim 1/Q$ for intermediate values of $Q^2$.

Joan Simón

The existence of supersymmetric D0-branes at an arbitrary distance from a flux 5-brane is proven. The physical picture in type IIA is consistent with the Kaluza-Klein reduction origin of the flux 5-brane. An analysis of the fluctuations around these vacua is performed and the backreaction of the D0-branes computed. Non-threshold D0-D2 bound states and simila

E. A. Barsukova, N. V. Borisov, V. P. Goranskij, V. M. Lyuty

We combined the results of UBVR photometry of CI Cam taken at Sternberg Astronomical Institute in 1998--2001, and moderate resolution spectroscopy taken at Special Astrophysical Observatory during the same time period. Photometry as well as fluxes of Balmer emissions and of some Fe II emission lines of CI Cam in quiet state reveal a cyclic variation with the

Florian Merz, J. T. Chalker

We reexamine the disorder-dominated multicritical point of the two-dimensional +/-J Ising model, known as the Nishimori point (NP). At the NP we investigate numerically and analytically the behavior of the disorder correlator, familiar from the self-dual description of the pure critical point of the two-dimensional Ising model. We consider the logarithmic av

L. Bonora, D. Mamone, M. Salizzoni

We show that squeezed state solutions for solitonic lumps in Vacuum String Field Theory still exist in the presence of a constant B field. We show in particular that, just as in the B=0 case, we can write down a compact explicit form for such solutions.

Sergey Arkhipov, Roman Bezrukavnikov

The geometric Satake isomorphism is an equivalence between the categories of spherical perverse sheaves on affine Grassmanian and the category of representations of the Langlands dual group. We provide a similar description for derived categories of l-adic sheaves on an affine flag variety which are geometric counterparts of a maximal commutative subalgebra

Francois Arleo

A leading-order analysis of E866/NuSea and NA3 Drell-Yan data in nuclei is carried out. At Fermilab energy, the large uncertainties in the amount of sea quark shadowing prohibit clarifying the origin of the nuclear dependence observed experimentally. On the other hand, the small shadowing contribution to the Drell-Yan process in pi- A collisions at SPS allow

Valentin Ferenczi, Christian Rosendal

If a Banach space has an unconditional basis it either contains a continuum of non isomorphic subspaces or is isomorphic to its square and hyperplanes and satisfies other regularity properties. An HI Banach space contains a continuum of non isomorphic subspaces.

G. Polenta, P. A. R. Ade, J. J. Bock, J. R. Bond

We search the BOOMERanG maps of the anisotropy of the Cosmic Microwave Background (CMB) for deviations from gaussianity. In this paper we focus on analysis techniques in pixel-space, and compute skewness, kurtosis and Minkowski functionals for the BOOMERanG maps and for gaussian simulations of the CMB sky. We do not find any significant deviation from gaussi

Gerhard Groessing

The Klein-Gordon equation is shown to be equivalent to coupled partial differential equations for a sub-quantum Brownian movement of a &#39;&#39;particle&#39;&#39;, which is both passively affected by, and actively affecting, a diffusion process of its generally nonlocal environment. This indicates circularly causal, or &#39;&#39;cybernetic&#39;&#39;, relati

Günther Rüdiger, Rainer Arlt

The theory of the solar/stellar activity cycles is presented, based on the mean-field concept in magnetohydrodynamics. A new approach to the formulation of the electromotive force and the theory of differential rotation and meridional circulation is described. Dynamo cycles in the overshoot layer and distributed dynamos are compared, with the latter includin

Claudio Altafini

For the unitary operator, solution of the Schroedinger equation corresponding to a time-varying Hamiltonian, the relation between the Magnus and the product of exponentials expansions can be expressed in terms of a system of first order differential equations in the parameters of the two expansions. A method is proposed to compute such differential equations

Oscar J. C. Dias, Jose&#39; P. S. Lemos

We obtain the magnetic counterpart of the BTZ solution, i.e., the rotating spacetime of a point source generating a magnetic field in three dimensional Einstein gravity with a negative cosmological constant. The static (non-rotating) magnetic solution was found by Clement, by Hirschmann and Welch and by Cataldo and Salgado. This paper is an extension of thei

Rachel Bean, Steen H. Hansen, Alessandro Melchiorri

We combine complementary datasets to constrain dark energy. Using standard Big Bang Nucleosynthesis and the observed abundances of primordial nuclides to put constraints on $Ω_Q$ at temperatures near $T \sim 1MeV$, we find the strong constraint $Ω_Q({MeV}) < 0.045$ at $2σ$ c.l.. Under the assumption of flatness, using results from Cosmic Microwave Background

K. A. Oganessyan, P. J. Mulders, E. De Sanctis

We consider the double-spin cos(phi) asymmetry for pion electroproduction in semi-inclusive deep inelastic scattering of longitudinally polarized leptons off longitudinally polarized protons. We estimate the size of the asymmetry in the approximation where all twist-3 interaction-dependent distribution and fragmentation functions are set to zero. In that app

E. Churazov, R. Sunyaev, W. Forman, H. Boehringer

The assumption that radiative cooling of gas in the centers of galaxy clusters is approximately balanced by energy input from a central supermassive black hole implies that the observed X-ray luminosity of the cooling flow region sets a lower limit on AGN mechanical power. The conversion efficiency of AGN mechanical power into gas heating is uncertain, but w

Xi. Kang, Y. P. Jing, H. J. Mo, G. Borner

We use N-body simulations to test the predictions of the redshift distortion in the power spectrum given by the halo model in which the clustering of dark matter particles is considered as a result both of the clustering of dark halos in space and of the distribution of dark matter particles in individual dark halo. The predicted redshift distortion depends

R. Casalbuoni, R. Gatto, M. Mannarelli, G. Nardulli

In the high density low temperature limit, Quantum Chromodynamics (QCD) exhibits a transition to a phase characterized by color superconductivity and by energy gaps in the fermion spectra. Under specific circumstances the gap parameter has a crystalline pattern, breaking translational and rotational invariance. The corresponding phase is the the crystalline

Yi-shi Duan, Xin Liu, Li-bin Fu

In this paper, the decomposition of SU(2) gauge potential in terms of Pauli spinors is studied. Using this decomposition, the spinor strutures of the Chern-Simons form and the Chern density are obtained. Furthermore, by these spinor structures, the knot quantum number of non-Abelian gauge theory is discussed, and the second Chern number is characterized by t

M. Terraneo, M. Peyrard, G. Casati

We address the problem of heat conduction in 1-D nonlinear chains; we show that, acting on the parameter which controls the strength of the on site potential inside a segment of the chain, we induce a transition from conducting to insulating behavior in the whole system. Quite remarkably, the same transition can be observed by increasing the temperatures of

Witold Skiba, David Smith

We study fermion localization in gauge theory space. We consider four dimensional product gauge groups in which light chiral fermions transform under different gauge factors of the product group. This construction provides a suppression of higher dimensional operators. For example, it can be used to suppress dangerous proton decay operators. The anomalies as

Andrei A. Galiautdinov

Using the recently discovered Clifford statistics we propose a simple model for the grand canonical ensemble of the carriers in the theory of fractional quantum Hall effect. The model leads to a temperature limit associated with the permutational degrees of freedom of such an ensemble. We also relate Schur&#39;s theory of projective representations of the pe

Vasily E. Tarasov

Usually models for quantum computations deal with unitary gates on pure states. In this paper we generalize the usual model. We consider a model of quantum computations in which the state is an operator of density matrix and the gates are quantum operations, not necessarily unitary. A mixed state (operator of density matrix) of n two-level quantum systems is

XuBo Zou, K. Pahlke, W. Mathis

We present a scheme to generate arbitrary superposition of the Fock states in a high-Q cavity. This proposal is based on a sequence of laser pulses, which are tuned appropriately to control transitions on Fock state. It is shown that N laser pulses are needed to generate a pure state with a phonon number limit $N$.

Wang Xiang-bin, Hwang Won Yong, Matsumoto Keiji

The paper is withdrawn.

Carlos C. Rodriguez

The ongoing unprecedented exponential explosion of available computing power, has radically transformed the methods of statistical inference. What used to be a small minority of statisticians advocating for the use of priors and a strict adherence to bayes theorem, it is now becoming the norm across disciplines. The evolutionary direction is now clear. The t

A. Y. Potekhin, G. Chabrier, D. Gilles

The low-frequency electric microfield distribution in a Coulomb plasma is calculated for various plasma parameters, from weak to strong Coulomb coupling and from zero to strong electron screening. Two methods of numerical calculations are employed: the adjustable-parameter exponential approximation and the Monte Carlo simulation. The results are represented

Paul Czarapata, Don Hartill, Steve Myers, Stephen Peggs

In February 2000, the International Committee for Future Accelerators initiated a study of a new model for international collaboration on a future large accelerator project, the Global Accelerator Network. The study is based on a model of a facility, which is remote from most of the collaborating institutions. It is designed, built and operated by a collabor

S. Longhi, P. Laporta, M. Belmone, E. Recami

Tunneling of optical pulses at 1.5 micron wavelength through double-barrier periodic fiber Bragg gratings is experimentally investigated. Tunneling time measurements as a function of barrier distance show that, far from the resonances of the structure, the transit time is paradoxically short, implying Superluminal propagation, and almost independent of the d

Ilya Nemenman, Fariel Shafee, William Bialek

We study properties of popular near-uniform (Dirichlet) priors for learning undersampled probability distributions on discrete nonmetric spaces and show that they lead to disastrous results. However, an Occam-style phase space argument expands the priors into their infinite mixture and resolves most of the observed problems. This leads to a surprisingly good

L. Perrot, A. Billebaud, R. Brissot, A. Giorni

Research on accelerator driven systems (ADS), related new fuels and their ability for nuclear waste incineration has led to a revival of interest in nuclear cross sections of many nuclides over a large energy range. Discrepancies observed between nuclear data bases require new measurements in several cases. A complete measurement of such cross sections inclu

Thomas Peitzmann

A review on experimental results for direct photon production in heavy ion reactions is given. A brief survey of early direct photon limits from SPS experiments is presented. The first measurement of direct photons in heavy ion reactions from the WA98 collaboration is discussed and compared to theoretical calculations. An outlook on the perspective of photon

V. B. Taranenko, F. -J. Ahlers, K. Pierz

We demonstrate switching on and off of spatial solitons in a semiconductor microresonator by injection of light coherent with the background illumination. Evidence results that the formation of the solitons and their switching does not involve thermal processes.

Klaus Hornberger, Uzy Smilansky

Magnetic edge states are responsible for various phenomena of magneto-transport. Their importance is due to the fact that, unlike the bulk of the eigenstates in a magnetic system, they carry electric current along the boundary of a confined domain. Edge states can exist both as interior (quantum dot) and exterior (anti-dot) states. In the present report we d

Hyeonbae Kang, Gen Nakamura

We prove that the linear term and quadratic nonlinear term entering a nonlinear elliptic equation of divergence type can be uniquely identified by the Dirichlet to Neuman map. The unique identifiability is proved using the complex geometrical optics solutions and singular solutions.

Richard L. Hall, Qutaibeh D. Katatbeh

The method of potential envelopes is used to analyse the bound-state spectrum of the Schroedinger Hamiltonian H = -Delta -v/(r+b), where v and b are positive. We established simple formulas yielding upper and lower energy bounds for all the energy eigenvalues.

Pavel Exner, Kazushi Yoshitomi

We investigate the two-dimensional magnetic Schrödinger operator $H_{B,β}=(-i\nabla-A)^2 -βδ(\cdot-Γ)$, where $Γ$ is a smooth loop and the vector potential $A$ corresponds to a homogeneous magnetic field $B$ perpendicular to the plane. The asymptotics of negative eigenvalues of $H_{B,β}$ for $β\to\infty$ is found. It shows, in particular, that for large enou

V. Lakshmibai, Peter Littelmann

We generalize Standard Monomial Theory (SMT) to intersections of Schubert varieties and opposite Schubert varieties; such varieties are called Richardson varieties. The aim of this article is to get closer to a geometric interpretation of the standard monomial theory. Our methods show that in order to develop a SMT for a certain class of subvarieties in G/B

L. El Kaoutit, J. Gomez-Torrecillas, F. J. Lobillo

While semisimple artinian rings and semisimple coalgebras over a field can be described in terms of matrices (either matrix ring over division rings or comatrix coalgebras over the ground field), semisimple corings seem to have a more intrincated structure in general. It turns out that some well-known properties of semisimple rings or coalgebras, which are i

Robert M. Guralnick, Peter Müller, Jan Saxl

In 1923 Schur considered the following problem. Let f(X) be a polynomial with integer coefficients that induces a bijection on the residue fields Z/pZ for infinitely many primes p. His conjecture, that such polynomials are compositions of linear and Dickson polynomials, was proved by M. Fried in 1970. Here we investigate the analogous question for rational f

F. Pakovich

In this note we construct a class of counterexamples to the &#34;composition conjecture&#34; concerning an infinitesimal version of the center problem for the polynomial Abel equation in the complex domain.

Ralf Schindler

We present a simple and purely combinatorial proof of Steel&#39;s result according to which the core model is Σ^1_3 correct under the appropriate hypotheses.

James M Turner

In this paper, we study the André-Quillen homology of simplicial commutative $\ell$-algebras, $\ell$ a field, having certain vanishing properties. When $\ell$ has non-zero characteristic, we obtain an algebraic version of a theorem of J.-P. Serre and Y. Umeda that characterizes such simplicial algebras having bounded homotopy groups. We further discuss how t

James M Turner

In this paper, we study simplicial commutative algebras with finite André-Quillen homology. Here we restrict our focus to simplicial algebras having characteristic 2. Our aim is to find a generalization of results established by the author. Our goal is to replace the finiteness condition on homotopy with a weaker condition expressed in terms of nilpotency fo

Tomasz Brzezinski

The notion of a Frobenius coring is introduced, and it is shown that any such coring produces a tower of Frobenius corings and Frobenius extensions. This establishes a one-to-one correspondence between Frobenius corings and extensions.

Ilan Hirshberg

We classify spectrum-preserving endomorphisms of stable continuous-trace C^*-algebras up to inner automorphism by a surjective multiplicative invariant taking values in finite dimensional vector bundles over the spectrum. Specializing to automorphisms, this gives a different approach to results of Phillips and Raeburn.

Hajime Tsuji

We prove a subadjunction theorem which relates the multi-adjoint linear system of the ambient space and the linear system of the restricted bundle on a subvariety.

T. Mansour, A. Vainshtein

We study generating functions for the number of permutations in $\SS_n$ subject to two restrictions. One of the restrictions belongs to $\SS_3$, while the other to $\SS_k$. It turns out that in a large variety of cases the answer can be expressed via Chebyshev polynomials of the second kind.

C. Bizdadea

A two-dimensional nonlinear gauge theory that can be proposed for generalization to higher dimensions is derived by means of cohomological arguments.

L. L. Salcedo

It is argued that the derivative expansion is a suitable method to deal with finite temperature field theory, if it is restricted to spatial derivatives only. Using this method, a simple and direct calculation is presented for the radiatively induced Chern-Simons--like piece of the effective action of (2+1)-dimensional fermions at finite temperature coupled

Miloslav Znojil

SUSY partnership between singular potentials often breaks down. Via regularization it can be restored on certain ad hoc subspaces of Hilbert space [Das and Pernice, Nucl. Phys. B 561 (1999) 357]. Within the naturally complexified (so called PT symmetric) quantum mechanics we show how SUSY between strongly singular harmonic oscillators can completely be re-es

Kang-Sin Choi, Jihn E. Kim, Hyun Min Lee

We present a short review of the recent 5D self-tuning solution of the cosmological constant problem with $1/H^2$ term, and present the dual description of the solution. In the dual description, we show that the presence of the coupling of the dual field($σ$) to the brane(which is a bit different from the original theory) maintains the self-tuning property.

Hitoshi Ito

This short note was born out of discussions on anyons in the FQHE at the YITP workshop &#34;Fundamental problems of quantum field theories&#34; (December 19-21, 2001, YITP, Kyoto). At that time, I felt that there might not be a sound consensus of opinion on the subject. Now, I would like to show my understanding here, the essential part of which is based on

O. L. G. Peres, A. Yu. Smirnov

We study the possible manifestation of the interference between the effects produced in the atmospheric neutrinos due to oscillation driven by the solar parameters parameters $Δm^2_{21}$, $\sin^2 2θ_{21}$ and due to oscillation driven by $U_{e3}$.

R. L. Jaffe

I describe a few of the most exciting open questions in high energy spin physics. After a brief look at (g-2)_μand the muon electric dipole moment, I concentrate on QCD spin physics. Pressing questions include the interpretation of new asymmetries seen in semi-inclusive DIS, measuring the polarized gluon and quark transversity distributions in the nucleon, t

J. D. Jackson

A classical calculation, modified by Compton-recoil kinematics, of the radiation emitted by a relativistic neutrino with mass and a magnetic moment passing through a transverse magnetic field. The calculation is performed in the neutrinos rest frame by the method of virtual quanta. The total number N of virtual quanta scattered by the neutrino is determined.

K. A. Oganessyan

The leading and sub-leading order results for pion electroproduction in polarized and unpolarized semi-inclusive deep-inelastic scattering, are considered putting emphasis on transverse momentum dependent effects appearing in azimuthal asymmetries. In particular the spin-dependent (single, double) and spin-independent asymmetries of the distributions in the

Agnes Roberts

Classical-mechanical oscillating systems are analyzed to model CP violating neutral kaon oscillations. Through the identification of the key features of the quantum effective hamiltonian we search for similarities in the characteristic matrix of the classical systems. Some no-go results are found for undamped systems and for systems using two one-dimensional

V. Barone

The role of time reversal invariance in the phenomenology of transverse spin is discussed.