May 2002 arXiv papers — page 4

M. Milata, K. Wojcik, K. Zieleniec

Single crystals of KNbO3 and KNbO3 : Fe have been grown using the flux method at various technological conditions. The investigations of optical absorption of these crystals were carried out. Marked influence of technological conditions and doping with iron on optical absorption has been found. Observed changes of the absorption spectra are associated with l

C. Cheng

Based on a previously proposed thermodynamic analysis, we study the relative stabilities of five Si phases under uniaxial compression using ab initio methods. The five phases are diamond, beta-tin, sh, sc, and hcp structures. The possible phase-transition patterns were investigated by considering the phase transitions between any two chosen phases of the fiv

H. Hong, Beom Jun Kim, M. Y. Choi

We investigate the stochastic resonance phenomena in the field-driven Ising model on small-world networks. The response of the magnetization to an oscillating magnetic field is examined by means of Monte Carlo dynamic simulations, with the rewiring probability varied. At any finite value of the rewiring probability, the system is found to undergo a dynamic p

A. S. Mishchenko, N. Nagaosa, N. V. Prokof'ev, A. Sakamoto

We performed quantum Monte Carlo study of the exciton-polaron model which features the self-trapping phenomenon when the coupling strength and/or particle momentum is varied. For the first time accurate data for energy, effective mass, the structure of the polaronic cloud, dispersion law, and spectral function are available throughout the crossover region. W

C. Howald, H. Eisaki, N. Kaneko, A. Kapitulnik

One of the most important outstanding problems in condensed matter physics is determination the ground state of strongly correlated electron system, in particular high-temperature superconductors (HTSC). For these materials, theoretical1-6 and experimental7-13 evidence has been mounting in support of the possibility that their ground state exhibits spin and

P. J. Huggins, T. Forveille, R. Bachiller, P. Cox

We report high resolution imaging of a prominent cometary globule in the Helix nebula in the CO J=1-0 (2.6 mm) and H2 v=1-0 S(1) (2.12 micron) lines. The observations confirm that globules consist of dense condensations of molecular gas embedded in the ionized nebula. The head of the globule is seen as a peak in the CO emission with an extremely narrow line

Gregory Laughlin, John Chambers, Debra Fischer

The mass and period ratios of the two planets orbiting 47 UMa suggest a possible kinship to the Jupiter-Saturn pair in our solar system. We explore the current dynamical state of the 47 UMa system with numerical integrations, and compare the results with analytic secular theory. We find that the planets in the system are likely participating in a secular res

Guillermo Torres, Andrew F. Boden, David W. Latham, Margaret Pan

We report spectroscopic and interferometric observations of the moderately metal-poor double-lined binary system HD 195987, with an orbital period of 57.3 days. By combining our radial-velocity and visibility measurements we determine the orbital elements and derive absolute masses for the components of M(A) = 0.844 +/- 0.018 Msun and M(B) = 0.6650 +/- 0.007

STACEE Collaboration, D. S. Hanna, D. Bhattacharya, L. M. Boone

We describe the design and performance of the Solar Tower Atmospheric Cherenkov Effect Experiment detector in its initial configuration (STACEE-32). STACEE is a new ground-based gamma ray detector using the atmospheric Cherenkov technique. In STACEE, the heliostats of a solar energy research array are used to collect and focus the Cherenkov photons produced

Amara Graps, Eberhard Grün

We investigated the electrostatic charging behavior of submillimeter-sized dust particles located in Saturn's magnetosphere. The charging effects we considered included electron/ion capture from the magnetospheric plasma, electron/ion capture from the solar-wind plasma, the photoelectric effect from solar radiation, and secondary electron emission from e

G. Cecil, J. Bland-Hawthorn, S. Veilleux

Using Chandra and HST we show that X-ray and H$α$ filaments that form the 1.3-kpc diameter superbubble of NGC 3079 have strikingly similar patterns at 0."8 resolution. This tight match seems to arise from cool disk gas that has been driven by the wind, with X-rays being emitted from upstream, stand-off bowshocks or by conductive cooling at the cloud/wind

Chris J. Willott, Steve Rawlings, Katherine M. Blundell, Mark Lacy

We present optical spectroscopy of all 49 radio galaxies in the 7C-I and 7C-II regions of the 7C Redshift Survey (7CRS). The low-frequency (151 MHz) selected 7CRS sample contains all sources with flux-densities S_151 > 0.5 Jy in three regions of the sky; 7C-I and 7C-II were chosen to overlap with the 5C6 and 5C7 surveys respectively, and cover a total sky ar

G. M. Bernstein, P. Norberg

We test a sample of satellites of isolated primary galaxies, extracted from the 2dF Galaxy Redshift Survey (2dFGRS), for any tendency to be aligned along (or against) the primary-to-satellite radius vector. If tidal effects induce such an alignment, it would contaminate recent measurements of galaxy halo masses which use the coherent alignment induced on bac

Kazuhiro Yamamoto

In this paper we obtain constraints on the cosmological density parameters, Ω_m and Ω_b, by comparing the preliminary measurement of the QSO power spectrum from the two degree field QSO redshift survey with results from an analytic technique of power spectrum estimation, described in this paper. We demonstrate the validity of the analytic approach by compari

C. J. A. P. Martins

The idea of possible time or space variations of the `fundamental' constants of nature, although not new, is only now beginning to be actively considered by large numbers of researchers in the particle physics, cosmology and astrophysics communities. This revival is mostly due to the claims of possible detection of such variations, in various different c

Cecile Gry, Francois Boulanger, Cyrine Nehme, Guillaume Pineau Des Forets

We use far-UV absorption spectra obtained with FUSE towards three late B stars to study the formation and excitation of H2 in the diffuse ISM. The data interpretation relies on a model of the chemical and thermal balance in photon-illuminated gas. The data constrain well the nR product between gas density and H2 formation rate on dust grains: nR = 1 to 2.2 e

Alan B. Whiting, G. K. T. Hau, Mike Irwin

We present observations of 82 Local Group dwarf galaxy candidates, of which 62 were chosen visually from ESO-SRC survey plates of the southern sky (32 of which were not previously catalogued) and the rest suggested by various sources in the literature. Two are the Local Group galaxies Antlia and Cetus; nine are more distant galaxies, though still within a fe

M. A. T. Groenewegen, L. Girardi, E. Hatziminaoglou, C. Benoist

(abridged) Stellar catalogues in five passbands (UBVRI) over an area of approximately 0.3 deg^2, comprising about 1200 objects, and in seven passbands (UBVRIJK) over approximately 0.1 deg^2, comprising about 400 objects, in the direction of the Chandra Deep Field South are presented. The 90% completeness level of the number counts is reached at approximately

F. Mannucci

We present the characteristics and the current status of the "Telescopio Infrarosso del Gornergrat" (Tirgo), the national infrared facility operating from the beginning of the 80s over the swiss alps. We describe its current instrumentation and resume its activities during its 20 years of life.

HEGRA Collaboration, F. Aharonian

The nearby BL Lacertae (BL Lac) object Markarian~421 (Mkn~421) at a red shift z=0.031 was observed to undergo strong TeV Gamma-ray outbursts in the observational periods from December 1999 until May 2001. The time averaged energy spectrum is well described by a power law with an exponential cut-off energy at 3.6(+0.4-0.3)_{stat}(+0.9-0.8)_{sys} TeV. The ener

S. Ortolani, G. Carraro, S. Covino, E. Bica

We present UBV CCD observations obtained in the field of the northern open cluster NGC 1220, for which little information is available. We provide also BV CCD photometry of a field 5$^{\prime}$ northward of NGC 1220 to take into account field star contamination. We argue that NGC 1220 is a young compact open cluster, for which we estimate a core radius in th

Keiichi Asada, Makoto Inoue, Yutaka Uchida, Seiji Kameno

Both in the Faraday Rotation Measure and the intrinsic polarization angle, new features are revealed to indicate a helical magnetic field operating along the jet of the bright active galactic nuclei 3C 273. The helical field has been suggested to be related to the formation and collimation of jets by magnetohydrodynamic models. The distribution of the RM sho

Valentin D. Ivanov, Ray Jayawardhana

The Small Magellanic Cloud (SMC) is an excellent laboratory to study the formation of solar-mass stars in a low-metallicity environment, similar to the conditions expected in the early phases of galactic evolution. Here we present preliminary results from a search for low-mass pre-main-sequence stars in the SMC based on Hubble Space Telescope archival data.

A. Mukherjee, I. V. Musatov, H. C. Pauli, A. V. Radyushkin

We propose a model for generalized parton distributions of the pion based on the power-law ansatz for the effective light-cone wave function.

Neepa T. Maitra, Ivo Souza, Kieron Burke

The response of an extended periodic system to a homogeneous field (of wave-vector $q=0$) cannot be obtained from a $q=0$ time-dependent density functional theory (TDDFT) calculation, because the Runge-Gross theorem does not apply. Time-dependent {\em current}-density functional theory is needed and demonstrates that one key ingredient missing from TDDFT is

David Mateos, Selena Ng

The Penrose limits of a D5-brane wrapped on the sphere of AdS_5 x S^5 and connected to the boundary by M fundamental strings, which is dual to the baryon vertex of the N=4 SU(M) super Yang-Mills theory, are investigated. It is shown that, for null geodesics that lead to the maximally supersymmetric Hpp-wave background, the resulting D5-brane is a 1/2-supersy

Vijay Balasubramanian, Simon F. Ross

We consider ``bubbles of nothing'' constructed by analytically continuing black hole solutions in Anti-de Sitter space. These provide interesting examples of smooth time-dependent backgrounds which can be studied through the AdS/CFT correspondence. Our examples include bubbles constructed from Schwarzschild-AdS, Kerr-AdS and Reissner-Nordstrom AdS. T

Albion Lawrence

String propagation on a three-dimensional Lorentzian string orbifold with a null singularity has been studied by Horowitz and Steif, and more recently by Liu, Moore and Seiberg. We analyze the target space as a classical gravitational background. The singularity becomes spacelike when an arbitrarily small amount of matter is thrown at the singularity. This c

Romulus Breban

We consider a five dimensional (5D) space-time with a space-like fifth dimension. We implement a quantum formalism by path integrals, and postulate that all the physical information on a 5D massless particle propagation is provided by the statistics over null paths in this 5D space-time. If the 5D metric is independent of the fifth coordinate, then the propa

Edward Anderson

GR can be interpreted as a theory of evolving 3-geometries. A recent such formulation, the 3-space approach of Barbour, Foster and Ó Murchadha, also permits the construction of a limited number of other theories of evolving 3-geometries, including conformal gravity and strong gravity. In this paper, we use the 3-space approach to construct a 1-parameter fami

Vadim Rodin, Amand Faessler

The renormalized quasiparticle-RPA is reformulated for even-even nuclei using restrictions imposed by the commutativity of the phonon creation operator with the total particle number operator. This new version, Fully-Renormalized QRPA (FR-QRPA), is free from the spurious low-energy solutions. Analytical proof is given that the Ikeda sum rule is fullfiled wit

ZEUS Collaboration

Cross sections for e-p charged current deep inelastic scattering have been measured at a centre-of-mass energy of 318 GeV with an integrated luminosity of 16.4 pb-1 using the ZEUS detector at HERA. Differential cross-sections dσ/dQ2, dσ/dx and dσ/dy are presented for Q2>200 GeV2. In addition, d2σ/dxdQ2 was measured in the kinematic range 280 GeV2 < Q2 < 3000

Bernd A. Kniehl, Fantina Madricardo, Matthias Steinhauser

We calculate the QCD corrections to the cross section of e^+ e^- -> t anti-b H^- and its charge-conjugate counterpart within the minimal supersymmetric extension of the Standard Model. This process is particularly important if m_t < m_H + m_b and root(s) < 2 m_H, so that t -> b H^+ and e^+ e^- -> H^+ H^- are not allowed kinematically. Large logarithmic corre

Angel Ferrandez, Angel Gimenez, Pascual Lucas

The simplest (2+1)-dimensional mechanical systems associated with light-like curves, already studied by Nersessian and Ramos, are reconsidered. The action is linear in the curvature of the particle path and the moduli spaces of solutions are completely exhibited in 3-dimensional Minkowski background, even when the action is not proportional to the pseudo-arc

B. L. G. Bakker, A. I. Veselov, M. A. Zubkov

We consider the SU(2) lattice gauge model and investigate numerically the continuum limit of the simple center vortices which are singular configurations of the gauge fields. We found that the vortices remain alive in the continuum theory. Also we investigate the Creutz ratio and found that for all $β$ it vanishes for those field configurations which do not

Pavel Lipavský, Jan Kolá{č}ek, Klaus Morawetz, Ernst Helmut Brandt

The NMR and NQR spectra of $^{63}$Cu in the CuO$_2$ plane of YBa$_2$Cu$_3$O$_7$ in the superconducting state are discussed in terms of the phenomenological theory of Ginzburg-Landau type extended to lower temperatures. We show that the observed spectra, Kumagai {\em et al.}, PRB {\bf 63}, 144502 (2001), can be explained by a standard theory of the Bernoulli

Johannes Berg, Michael Lässig

We develop a statistical theory of networks. A network is a set of vertices and links given by its adjacency matrix $\c$, and the relevant statistical ensembles are defined in terms of a partition function $Z=\sum_{\c} \exp {[}-β\H(\c) {]}$. The simplest cases are uncorrelated random networks such as the well-known Erdös-Rény graphs. Here we study more gener

Jan L. Cieslinski, Marek Czachor, Nikolai V. Ustinov

Lax pairs with operator valued coefficients, which are explicitly connected by means of an additional condition, are considered. This condition is proved to be covariant with respect to the Darboux transformation of a general form. Nonlinear equations arising from the compatibility condition of the Lax pairs in the matrix case include, in particular, Nahm eq

Shin&#39;ichi Nojiri, Sergei D. Odintsov

Using gauge formulation of gravity the three-dimensional SU(2) YM theory equations of motion are presented in equivalent form as FRW cosmological equations. With the radiation, the particular (periodic, big bang-big crunch) three-dimensional universe is constructed. Cosmological entropy bounds (so-called Cardy-Verlinde formula) have the standard form in such

Mikael Rordam

We show that there exists a purely infinite AH-algebra. The AH-algebra arises as an inductive limit of C*-algebras of the form C_0([0,1),M_k) and it absorbs the Cuntz algebra O_\infty tensorially. Thus one can reach an O_\infty-absorbing C*-algebra as an inductive limit of the finite and elementary C*-algebras C_0([0,1),M_k). As an application we give a new

Dingping Li, Baruch Rosenstein

Flux line lattice in type II superconductors undergoes a transition into a &#34;disordered&#34; phase like vortex liquid or vortex glass, due to thermal fluctuations and random quenched disorder. We quantitatively describe the competition between the thermal fluctuations and the disorder using the Ginzburg -- Landau approach. The following T-H phase diagram

Banibrata Mukhopadhyay

We present a pseudo-Newtonian potential for accretion disk modeling around the rotating black holes. This potential can describe the general relativistic effects on accretion disk. As the inclusion of rotation in a proper way is very important at an inner edge of disk the potential is derived from the Kerr metric. This potential can reproduce all the essenti

Masahide Yamaguchi, Jun&#39;ichi Yokoyama

We establish a method to trace the Lagrangian evolution of extended objects consisting of a multicomponent scalar field in terms of a numerical calculation of field equations in three dimensional Eulerian meshes. We apply our method to the cosmological evolution of global strings and evaluate the energy density, peculiar velocity, Lorentz factor, formation r

Nobuyasu Haga, Sei-ichiro Suga

We investigate dynamical properties of $S=1/2$ two-leg spin ladder systems. In a strong coupling region, an isolated mode appears in the lowest excited states, while in a weak coupling region, an isolated mode is reduced and the lowest excited states become a lower bound of the excitation continuum. We find in the system with equal intrachain and interchain

Yonina C. Eldar, Alexandre Megretski, George C. Verghese

We consider the problem of designing an optimal quantum detector to minimize the probability of a detection error when distinguishing between a collection of quantum states, represented by a set of density operators. We show that the design of the optimal detector can be formulated as a semidefinite programming problem. Based on this formulation, we derive a

David Petrosyan, Gershon Kurizki

We propose a realization of a scalable, high-performance quantum processor whose qubits are represented by the ground and subradiant states of effective dimers formed by pairs of two-level systems coupled by resonant dipole-dipole interaction. The dimers are implanted in low-temperature solid host material at controllable nanoscale separations. The two-qubit

Robert Alicki

The following statements belonging to the folklore of the theory of environmental decoherence are shown to be incorrect: 1) linear coupling to harmonic oscillator bath is a universal model of decoherence, 2) chaotic environments are more efficient decoherers.

B. G. Sidharth

Terrestrial and extraterrestrial theories of the origin of life are discussed in the light of latest observations. The available data suggest a dual mode of origin, some of the ingredients, including possibly sugars, were brought to earth from outer space, which combined with other ingredients, such as proteins, already available on the earth leading to the

L. N. Labzowsky, A. Prosorov, A. V. Shonin, I. Bednyakov

A rigorous QED theory of the spectral line profiles is applied to transition probabilities in few-electron highly charged ions. Interelectron interaction corrections are included as well as radiative corrections. Parity nonconserving (PNC) amplitudes with effective weak interactions between the electrons and nucleus are also considered. QED and interelectron

G. G. Kozlov

The simple device for scanning image is described. It has much in common with usual TV camera, with an electron beam replaced by an optical one. After the general description of the device, we present a simple experimental illustration.

T. S. Jensen, V. E. Markushin

The atomic cascades in mu-p and pbar-p atoms have been studied in detail using new results for the cross-sections of the scattering of highly excited exotic atoms from molecular hydrogen. The cascade calculations have been done with an updated version of the extended standard cascade model that computes the evolution in the kinetic energy from the beginning

T. S. Jensen, V. E. Markushin

The deexcitation of exotic hydrogen atoms in highly excited states in collisions with hydrogen molecules has been studied using the classical-trajectory Monte Carlo method. The Coulomb transitions with large change of principal quantum number n have been found to be the dominant collisional deexcitation mechanism at high n. The molecular structure of the hyd

P. Tomassini, M. Galimberti, A. Giulietti, D. Giulietti

The spectrum of relativistic electron bunches with large energy dispersion is hardly obtainable with conventional magnetic spectrometers. We present a novel spectroscopic concept, based on the analysis of the photons generated by Thomson Scattering of a probe laser pulse inpinging with arbitrary incidence angle onto the electron bunch. The feasibility of a s

Niels Asger Mortensen, Jacob Riis Folkenberg

The transition from the near to the far field of the fundamental mode radiating out of a photonic crystal fiber is investigated experimentally and theoretically. It is observed that the hexagonal shape of the near field rotates two times by pi/6 when moving into the far field, and eventually six satellites form around a nearly gaussian far-field pattern. A s

D. Tsiklauri, I. Beresnev

The present study investigates novelties brought about into the classic Biot&#39;s theory of propagation of elastic waves in a fluid-saturated porous solid by inclusion of non-Newtonian effects that are important, for example, for hydrocarbons. Based on our previous results (Tsiklauri and Beresnev: 2001, Phys. Rev. E, 63, 046304), we have investigated the pr

C. L. Korpa, M. F. M. Lutz

We investigate properties of antikaons and hyperon resonances in isospin-asymmetric nuclear medium, using a self-consistent, covariant scheme based on vacuum antikaon-nucleon scattering amplitude.

M. Amarian

We present data on the inclusive scattering of polarized electrons from a polarized He-3 target at energies from 0.862 to 5.06 GeV, obtained at a scattering angle of 15.5 degrees. Our data include measurements from the quasielastic peak, through the resonance region, to the beginning of the deep inelastic regime, and were used to determine the spin differenc

Rama Govindarajan, Victor S. L&#39;vov, Itamar Procaccia

Motivated by the large effect of turbulent drag reduction by minute concentrations of polymers we study the effects of a weakly space-dependent viscosity on the stability of hydrodynamic flows. In a recent Letter [Phys. Rev. Lett. {\bf 87}, 174501, (2001)] we exposed the crucial role played by a localized region where the energy of fluctuations is produced b

G. Boffetta, M. Cencini, J. Davoudi

Inverse energy cascade regime of two dimensional turbulence is investigated by means of high resolution numerical simulations. Numerical computations of conditional averages of transverse pressure gradient increments are found to be compatible with a recently proposed self-consistent Gaussian model. An analogous low order closure model for the longitudinal p

Hiroki Suyari

The Shannon-Khinchin axioms are generalized to nonextensive systems and the uniqueness theorem for the nonextensive entropy is proved rigorously. In the present axioms, Shannon additivity is used as additivity in contrast to pseudoadditivity in Abe&#39;s axioms. The results reveal that Tsallis entropy is the simplest among all nonextensive entropies which ca

Hiroki Suyari

Nonextensive entropies are divided into three classes, each of which is characterized by Shannon additivity and pseudoadditivity. One of the three classes has properties of both additivities. The remaining classes have only one property of the two additivities, respectively. An example of nonextensive entropy is shown concretely for each class. In particular

Henry Cohn, Michael Larsen, James Propp

Using a calculus of variations approach, we determine the shape of a typical plane partition in a large box (i.e., a plane partition chosen at random according to the uniform distribution on all plane partitions whose solid Young diagrams fit inside the box). Equivalently, we describe the distribution of the three different orientations of lozenges in a rand

G. Pacelli Bessa, Luquesio P. Jorge

We show that immersed minimal surfaces of $\mathbb{R}^{3}$ with bounded curvature and proper self intersections are proper. We also show that the restriction of the immersing map to a wide component is always proper. When the immersing map is injective the whole surface is a wide component. Prior to these results it was only known that injectively immersed m

David Applegate, E. M. Rains, N. J. A. Sloane

An asymmetric covering D(n,R) is a collection of special subsets S of an n-set such that every subset T of the n-set is contained in at least one special S with |S| - |T| <= R. In this paper we compute the smallest size of any D(n,1) for n <= 8. We also investigate ``continuous&#39;&#39; and ``banded&#39;&#39; versions of the problem. The latter involves the

A. Buckley, M. Zompatori

We extend the range of linear systems of plane curves for which it is known that the dimension is equal to the expected dimension. We use a degeneration technique due to C. Ciliberto and R. Miranda. From our result we deduce, as a Corollary, a theorem due to Evain on homogeneous systems of curves through a number of base points given by a power of 4.

Mira Bernstein, N. J. A. Sloane

Extending earlier work of R. Donaghey and P. J. Cameron, we investigate some canonical &#34;eigen-sequences&#34; associated with transformations of integer sequences. Several known sequences appear in a new setting: for instance the sequences (such as 1, 3, 11, 49, 257, 1531, ...) studied by T. Tsuzuku, H. O. Foulkes and A. Kerber in connection with multiply

E. M. Rains, N. J. A. Sloane, John Stufken

If the number of runs in a (mixed-level) orthogonal array of strength 2 is specified, what numbers of levels and factors are possible? The collection of possible sets of parameters for orthogonal arrays with N runs has a natural lattice structure, induced by the ``expansive replacement&#39;&#39; construction method. In particular the dual atoms in this latti

Hiroshi Sato

In this paper, we obtain a complete classification of smooth toric Fano varieties equipped with extremal contractions which contract divisors to curves for any dimension. As an application, we obtain a complete classification of smooth projective toric varieties which can be equivariantly blown-up to Fano along curves.

Norbert Poncin

The space D(k,p) of differential operators of order at most k, from the differential forms of degree p of a smooth manifold M into the functions of M, is a module over the Lie algebra of vector fields of M, when it&#39;s equipped with the natural Lie derivative. In this paper, we compute all equivariant i.e. intertwining operators from D(k,p) into D(k&#39;,p

Francis Comets, Ofer Zeitouni

We prove a law of large numbers for a class of multidimensional random walks in random environments where the environment satisfies appropriate mixing conditions, which hold when the environment is a weak mixing field in the sense of Dobrushin and Shlosman. Our result holds if the mixing rate balances moments of some random times depending on the path. It ap

Pavol Severa

We describe a deformation quantization of a modification of Poisson geometry by a closed 3-form. Under suitable conditions it gives rise to a stack of algebras. The basic object used for this aim is a kind of families of Poisson structures given by a Maurer-Cartan equation; they are easily quantized using Kontsevich&#39;s Formality theorem.

Willem Veys

The stringy Euler number and E-function of Batyrev for log terminal singularities can in dimension 2 also be considered for a normal surface singularity with all log discrepancies nonzero in its minimal log resolution. Here we obtain a structure theorem for resolution graphs with respect to log discrepancies, implying that these stringy invariants can be def

Su Gao, Vladimir Pestov

We show that every abelian Polish group is the topological factor-group of a closed subgroup of the full unitary group of a separable Hilbert space with the strong operator topology. It follows that all orbit equivalence relations induced by abelian Polish group actions are Borel reducible to some orbit equivalence relations induced by actions of the unitary

Y. Khakimdjanov, M. Goze, A. Medina

We study left invariant contact forms and left invariant symplectic forms on Lie groups. We give the classification of all symplectic structures on nilpotent Lie algebras up the dimension 6.

J. Barcelos-Neto, E. C. Marino

A bosonic string coupled to the generalized Chern-Simons theory in 3+1D acquires a magnetic field along itself, when it is closed, and a topological charge at its extremity, when it is open. We construct the creation operators for the full quantum field states associated to these strings and determine the dual algebra satisfied by them. We show that the crea

Edwin Langmann

I present a novel class of exactly solvable quantum field theories. They describe non-relativistic fermions on even dimensional flat space, coupled to a constant external magnetic field and a four point interaction defined with the Groenewold-Moyal star product. Using Hamiltonian quantization and a suitable regularization, I show that these models have a dyn

Harald Dorn, Christoph Sieg

We study for subgroups $G\subseteq U(N)$ partial summations of the $θ$-expanded perturbation theory. On diagrammatic level a summation procedure is established, which in the U(N) case delivers the full star-product induced rules. Thereby we uncover a cancellation mechanism between certain diagrams, which is crucial in the U(N) case, but set out of work for $

G. M. Graf, D. Hasler, J. Hoppe

We define an operator which for odd-dimensional compact gauge group furnishes unitary equivalence of the bosonic and fermionic sector in the supersymmetric quantum-mechanical matrix model obtained by dimensional reduction from 3-dimensional supersymmetric Yang-Mills theory.

Mary K. Gaillard

Effective theories based on experimental data provide powerful probes and tests of underlying theories in elementary particle physics. Examples within and beyond the Standard Model are discussed, including a specific model for supersymmetry breaking within the context of the weakly coupled heterotic string.

Hsin-Chia Cheng, Konstantin T. Matchev, Martin Schmaltz

We define a minimal model with Universal Extra Dimensions, and begin to study its phenomenology. The collider signals of the first KK level are surprisingly similar to those of a supersymmetric model with a nearly degenerate superpartner spectrum. The lightest KK particle (LKP) is neutral and stable because of KK-parity. KK excitations cascade decay to the L

J. Syska

The &#34;non-linear&#34; self-consistent theory of classical fields in the electroweak model is proposed. Homogeneous boson ground state solutions in the GSW model at the presence of a non-zero extended fermionic charge densities are reviewed and fully reinterpreted to make the theory with non-zero charge densities fruitful. Consequences of charge density fl

Guy Raz

We study the applicability of the mass insertion approximation (MIA) for calculations of neutral meson mixing when squark masses are not degenerate and, in particular, in models of alignment. We show that the MIA can give results that are much better than an order of magnitude estimate as long as the masses are not strongly hierarchical. We argue that, in an

H. V. Klapdor-Kleingrothaus

After our publication of the observed first indication for neutrinoless double beta decay in [KK-Evid01], a number of papers have been published [KK-Sar_Evid01,KK2-Sar_Evid01,KK3-Sar_Evid01,Ma02-Ev,Barg02-Ev,Ueh02-Ev,Mi n-Evid02,Chat-Evid02,Xing-Evid02,Ham-Evid02,Ahl-Kirch-Evid02,Ma-Evid2-02,Hab-Su z02,Mohap02-Evid,Kays02-Evid,Fodor02-Evid,Pakv02-Evid,Rodej0

D. I. Kazakov

We consider N=1 SUSY gauge theory in six dimensions in components and show that provided the Dynkin indices of the matter fields representations satisfy the relation $\sum T(R)= C_2(G)$, the gauge sector is completely one-loop finite. In the matter sector the UV divergences form several invariant structures some of which are cancelled in physical amplitudes.

J. Chung

We have searched for neutron-antineutron oscillations using the 5.56 fiducial kiloton-year exposure of the Soudan 2 iron tracking calorimeter. We require candidate n-nbar occurrences to have .GE. 4 prongs (tracks and showers) and to have kinematics compatible with nbar-N annihilation within a nucleus. We observe five candidate events, with an estimated backg

M. Rescigno

After a hiatus of almost 6 years and an extensive upgrade, Tevatron, the world largest proton--antiproton collider, has resumed the operation for the so called RUN II. In this paper we give a brief overview of the many new features of the Tevatron complex and of the upgraded CDF experiment, and show the presently achieved detector performances as well as hig

Bernd Surrow

The first run of transverse polarized protons at RHIC was recently completed which opened a new era exploring the spin structure of the proton. A first measurement of the single transverse spin asymmetry, $A_{N}$, for leading $π_{0}$ production from transverse colliding polarized protons at $\sqrt(s)=200 $GeV, $X_{F}>0.25$ and $p_{T}\simeq 1-4 $GeV was a foc

Milind V Diwan

In this paper I will describe the search for rare kaon decay processes $K^+\to π^+ ν\barν$ and $K^0_L \to π^0 ν\barν$. The small decay rate for these processes is considered a key prediction of the standard model. We searched for the charged kaon decay $K^+\to π^+ ν\barν$ using kaons decaying at rest in the E787 detector at Brookhaven National Laboratory in

Imad Laktineh

More than one year after the end of LEPII, many analysis activities are still going on to translate the negative search results of the four LEP experiments into solid limits on cross-sections and masses of SUSY particles. Many analyses based on the MSSM and Msugra models are presented in this paper. Preliminary results including the limit on the mass of the

Ruediger Vaas

For Lee Smolin, our universe is only one in a much larger cosmos (the Multiverse) - a member of a growing community of universes, each one being born in a bounce following the formation of a black hole. In the course of this, the values of the free parameters of the physical laws are reprocessed and slightly changed. This leads to an evolutionary picture of

Paul S. Wesson

It is possible that null paths in 5D appear as the timelike paths of massive particles in 4D, where there is an oscillation in the fifth dimension around the hypersurface we call spacetime. A particle in 5D may be regarded as multiply imaged in 4D, and the 4D weak equivalence principle may be regarded as a symmetry of the 5D metric.

A. Zhuk

A multidimensional cosmological model with space-time consisting of n (n>1) Einstein spaces M_i is investigated in the presence of a cosmological constant Lambda and a homogeneous minimally coupled free scalar field. Generalized de Sitter solution was found for Lambda > 0 and Ricci-flat external space for the case of static internal spaces with fine tuning o

L. Conti, M. De Rosa, F. Marin, L. Taffarello

We present the full implementation of a room-temperature gravitational wave bar detector equipped with an opto-mechanical readout. The mechanical vibrations are read by a Fabry--Perot interferometer whose length changes are compared with a stable reference optical cavity by means of a resonant laser. The detector performance is completely characterized in te

C. Barrabes, P. A. Hogan

We construct a model of a relativistic fireball or light--like shell of matter by considering a spherically symmetric moving gravitating mass experiencing an impulsive deceleration to rest. We take this event to be followed by the mass undergoing a deformation leading to the emission of gravitational radiation while it returns to a spherically symmetric stat

K. H. Mariwalla

Basis and limitations of singularity theorems for Gravity are examined. As singularity is a critical situation in course of time, study of time paths, in full generality of Equivalence principle, provides two mechanisms to prevent singularity. Resolution of singular Time translation generators into space of its orbits, and essential higher dimensions for Rel

Sergiu Vacaru, Panayiotis Stavrinos

This is the first monograph on the geometry of anisotropic spinor spaces and its applications in modern physics. The main subjects are the theory of gravity and matter fields in spaces provided with off--diagonal metrics and associated anholonomic frames and nonlinear connection structures, the algebra and geometry of distinguished anisotropic Clifford and s

Jacob D. Bekenstein

First, the relation between black holes and limitations on information of other systems is developed. After reviewing the relation of entropy to information, we derive the entropy bound, review its applications to cosmology and its extensions to higher dimensions, and discuss why black holes behave as 1-D objects when emitting entropy. We also discuss fundam

Vincent Conitzer, Tuomas Sandholm

The aggregation of conflicting preferences is a central problem in multiagent systems. The key difficulty is that the agents may report their preferences insincerely. Mechanism design is the art of designing the rules of the game so that the agents are motivated to report their preferences truthfully and a (socially) desirable outcome is chosen. We propose a

Vincent Conitzer, Tuomas Sandholm

Noncooperative game theory provides a normative framework for analyzing strategic interactions. However, for the toolbox to be operational, the solutions it defines will have to be computed. In this paper, we provide a single reduction that 1) demonstrates NP-hardness of determining whether Nash equilibria with certain natural properties exist, and 2) demons

Xiaoming Liu, Tim Brody, Stevan Harnad, Les Carr

This paper discusses the requirements of current and emerging applications based on the Open Archives Initiative (OAI) and emphasizes the need for a common infrastructure to support them. Inspired by HTTP proxy, cache, gateway and web service concepts, a design for a scalable and reliable infrastructure that aims at satisfying these requirements is presented