March 1997 arXiv papers — page 6

M. J. Hardcastle, P. Alexander, G. G. Pooley, J. M. Riley

We present observations made with the VLA at 1.5 and 8.4 GHz of the nearby FRI radio galaxy 3C296. The most recent models of FRI radio galaxies suggest that substantial deceleration must take place in their jets, with strongly relativistic velocities on parsec scales giving place to at most mildly relativistic velocities on scales of tens of kiloparsecs. The

Peter R. McCullough

A 13x13 degree image of Balmer H-alpha emission at galactic latitude -65 degrees is presented. Sensitivity is limited in part by confusion: the peak-to-valley anisotropy of the H-alpha surface brightness is 0.2 Rayleighs on angular scales of 0.1 to 1.0 degrees. The morphology of the H-alpha emission is similar to that of the 100 um emission previously observ

S. Chaty, I. F. Mirabel

A near-infrared jet emanating from the galactic superluminal source GRS 1915+105, discovered at $λ$ = 2.2 micrometer by Sams et al. (1996) on 18-21 July 1995, was not seen later anymore, neither in the Mirabel et al. (1996) images, taken on 4 August 1995 and that we analyze here, nor by Eikenberry & Fazio (1997) on 16-17 October 1995. Therefore, the radiativ

Shiv K. Sethi, Biman B. Nath

We use the recent detection of He II absorption at $z=2.2-2.6$ in the line of sight of the quasar HS1700+64 to put bounds on the sources of ionization. We find that given the uncertainty in $\tauhgp$ and the model of absorption in the intergalactic medium (IGM), a wide range of possible sources of ionization is still allowed by the observations. We show that

J. Richard Bond, James W. Wadsley

Observations indicate galaxies are distributed in a filament-dominated web-like structure; classic examples are the Coma and Perseus-Pisces superclusters. Numerical experiments at high and low redshift of viable structure formation theories also show filament-dominance; in particular, the gasdynamical simulations of Lyman alpha clouds at redshifts 2-6 that w

Mina Teicher

The group described in this paper appeared while studying fundamental groups of complements of branch curves. It turned out that a certain quotient of the braid group acts on those fundamental groups and studying this action is essential for understanding the structure of the fundamental groups. We describe here the quotient of the Artin braid group by commu

J. Kaluzny, K. Z. Stanek, M. Krockenberger, D. D. Sasselov

We undertook a long term project, DIRECT, to obtain the direct distances to two important galaxies in the cosmological distance ladder -- M31 and M33, using detached eclipsing binaries (DEBs) and Cepheids. While rare and difficult to detect, detached eclipsing binaries provide us with the potential to determine these distances with an accuracy better than 5%

B. Roy Frieden, H. C. Rosu

Fisher's arrow of `time' in a cosmological phase space defined as in quantum optics (i.e., whose points are coherent states) is introduced as follows. Assuming that the phase space evolution of the universe starts from an initial squeezed cosmological state towards a final thermal one, a Fokker-Planck equation for the time-dependent, cosmological Q p

Debajyoti Choudhury, Sreerup Raychaudhuri

We re-examine like-sign dilepton signals at the Fermilab Tevatron assuming that the excess high-$Q^2$ events recently seen at HERA are due to scalar resonances such as squarks of $R$-parity-violating supersymmetry. For gluinos in the mass range of 200--350 GeV, the like-sign dilepton signal can help to make the crucial distinction between the most favoured s

R. Pantfoerder, H. Rollnik, W. Pfeil

We study the current-algebra approach to the Gerasimov-Drell-Hearn sum rule, paying particular attention to the infinite-momentum limit. Employing the order-alpha^2 Weinberg-Salam model of weak interactions as a testing ground, we find that the legitimacy of the infinite-momentum limit is intimately connected with the validity of the naive equal-times algebr

N. N. Achasov, V. V. Gubin

It is shown that the reactions $e^+e^-\toγπ^0π^0(η)$ give a good chance for observing scalar $a_0$ and $f_0$ mesons. In the photon energy region less then 100 MeV the vector meson contributions $e^+e^-\to V^0\toπ^0 V'^0\toγπ^0π^0(η)$ are negligible in comparison with the scalar mesons $e^+e^-\toϕ\toγf_0(a_0)\toγπ^0π^0(η)$ for $BR(ϕ\toγf_0(a_0)\toγπ^0π^0(

Mirjam Cvetic, Ingo Gaida

We present duality invariant structure of the thermodynamic quantities of non-extreme black hole solutions of torodially compactified Type II (M-theory) and heterotic string in five and four dimensions. These quantities are parameterized by duality invariant combinations of charges and the non-extremality parameter, which measures a deviation from the BPS-sa

B. Sathiapalan

The matrix model for IIB Superstring proposed by Ishibashi, Kawai, Kitazawa and Tsuchiya is investigated. Consideration of planar and non-planar diagrams suggests that the large N perturbative expansion is consistent with the double scaling limit proposed by the above authors. We write down a Wilson loop that can be interpreted as a fundamental string vertex

Takashi Okamura

The scattering amplitudes for the perturbed fields of the N=2 supergravity about the extreme Reissner-Nordström black hole is examined. Owing to the fact that the extreme hole is a BPS state of the theory and preserves an unbroken global supersymmetry(N=1), the scattering amplitudes of the component fields should be related to each other. In this paper, we d

A. N. Gorban

The paper gives a systematic analysis of singularities of transition processes in dynamical systems. General dynamical systems with dependence on parameter are studied. A system of relaxation times is constructed. Each relaxation time depends on three variables: initial conditions, parameters $k$ of the system and accuracy $ε$ of the relaxation. The singular

Lev A. Borisov

It was noticed in a very recent preprint of T. Eguchi, K. Hori, and Ch.-Sh. Xiong (hep-th/9703086) that a curious identity between Betti numbers and Chern classes holds for many examples of Fano varieties. The goal of this paper is to prove that for varieties with trivial odd cohomology groups this identity is equivalent to having zero Hodge numbers $h^{p,q}

Kenneth Dalton

Einstein rejected the differential law of energy-momentum conservation $ T^{μν}_{;ν} = 0 $. In doing so, he violated the principle of general covariance. Here, we prove the conservation law $ T^{μν}_{;ν} = 0 $ and discuss its significance for general relativity.

R. A. Kraenkel, J. G. Pereira, E. C. de Rey Neto

We show in this letter that the perturbed Burgers equation $u_t = 2uu_x + u_{xx} + ε( 3 α_1 u^2 u_x + 3α_2 uu_{xx} + 3α_3 u_x^2 + α_4 u_{xxx} )$ is equivalent, through a near-identity transformation and up to order ε, to a linearizable equation if the condition $3α_1 - 3α_3 - 3/2 α_2 + 3/2 α_4 = 0$ is satisfied. In the case this condition is not fulfilled, a

Artur Ekert

This is a semi-popular overview of quantum entanglement as an important physical resource in the field of data security and quantum computing. After a brief outline of entanglement's key role in philosophical debates about the meaning of quantum mechanics I describe its current impact on both cryptography and cryptanalysis. The paper is based on the lect

Holger F. Hofmann, Ortwin Hess

We investigate the polarization fluctuations caused by quantum noise in quantum well vertical cavity surface emitting lasers (VCSELs). Langevin equations are derived on the basis of a generalized rate equation model in which the influence of competing gain-loss and frequency anisotropies is included. This reveals how the anisotropies and the quantum well con

M. J. Steel, D. F. Walls

We consider extensions of the twin-trap Bose-Einstein condensate system of Javaneinen and Yoo [Phys. Rev. Lett., 76, 161--164 (1996)] to include pumping and output couplers. Such a system permits a continual outflow of two beams of atoms with a relative phase coherence maintained by the detection process. We study this system for two forms of thermal pumping

Boguslaw Broda

A path-integral approach to non-perturbative topological invariants of knots, links and manifolds of dimension three and four using topological quantum field theory of Schwarz (Chern-Simons) type is presented.

S. Bastea, J. L. Lebowitz

We carried out three-dimensional simulations, with about 1.4 million particles, of phase segregation in a low density binary fluid mixture, described mesoscopically by energy and momentum conserving Boltzmann-Vlasov equations. Using a combination of Direct Simulation Monte Carlo(DSMC) for the short range collisions and a version of Particle-In-Cell(PIC) evol

Alfred Stadler, Franz Gross, Michael Frank

The covariant spectator (or Gross) equations for the bound state of three identical spin 1/2 particles, in which two of the three interacting particles are always on shell, are developed and reduced to a form suitable for numerical solution. The equations are first written in operator form and compared to the Bethe-Salpeter equation, then expanded into plane

J. Schnack, H. Feldmeier

The time evolution of excited nuclei, which are in equilibrium with the surrounding vapour, is investigated. It is shown that the finite nuclear systems undergo a first oder phase transition. The caloric curve is presented for excited Oxygen, Magnesium, Aluminum and Calcium and the critical temperature is estimated for Oxygen.

Andrzej Lenarcik

Let h = \sum h_{αβ} X^αY^βbe a polynomial with complex coefficients. The Lojasiewicz exponent of the gradient of h at infinity is the upper bound of the set of all real λsuch that |grad h(x, y)| >= c|(x,y)|^λin a neighbourhood of infinity in C^2, for c > 0. We estimate this quantity in terms of the Newton diagram of h. The equality is obtained in the nondege

Mario Belloni, Lusheng Chen, Kurt Haller

We use a unitary operator constructed in earlier work to transform the Hamiltonian for QCD in the temporal ($A_0=0$) gauge into a representation in which the quark field is gauge-invariant, and its elementary excitations -- quark and antiquark creation and annihilation operators -- implement Gauss's law. In that representation, the interactions between g

J. L. F. Barbon

We discuss different criteria for `classical size&#39; of extremal Dirichlet p-branes in type-II supergravity. Using strong-weak coupling duality, we find that the size of the strong-coupling region at the core of the (p<3)-branes, is always given by the asymptotic string scale, if measured in the weakly coupled dual string metric. We also point out how the

R. S. Dunne

The properties of the deformed bosonic oscillator, and the quantum groups ${\cal U}_q(SL(2))$ and $GL_q(2)$ in the limit as their deformation parameter $q$ goes to a root of unity are investigated and interpreted physically. These properties are seen to be related to fractional supersymmetry and intrinsic anyonic spin. A simple deformation of the Klein-Gordo

R. Dijkgraaf

Notes of my 14 `lectures on everything&#39; given at the 1995 Les Houches school. An introductory course in topological and conformal field theory, strings, gauge fields, supersymmetry and more. The presentation is more mathematical then usual and takes a modern point of view stressing moduli spaces, duality and the interconnectedness of the subject. An apoc

Vipul Periwal

Bialek, Callan and Strong have recently given a solution of the problem of determining a continuous probability distribution from a finite set of experimental measurements by formulating it as a one-dimensional quantum field theory. This letter gives a reparametrization-invariant solution of the problem, obtained by coupling to gravity. The case of a large n

Heng Fan, Bo-yu Hou, Kang-jie Shi, Wen-li Yang

Based on the bosonization of vertex operators for $A_{n-1}^{(1)}$ face model by Asai,Jimbo, Miwa and Pugai, using vertex-face correspondence we obtain vertex operators for Zn symmetric Belavin model,which are constructed by deformed boson oscilllators. The correlation functions are also obtained.

A Donnachie, P V Landshoff

Existing data on total cross sections, on elastic scattering at small, moderate and large values of $t$, and on diffraction dissociation, reveal a surprisingly simple phenomenology, but they throw up many questions for the LHC to answer.

Pervez Hoodbhoy

Diffractive production of $J/Ψ$ particles by virtual photons on a proton target is studied with a view towards understanding two important corrections to the leading order result. First, the effect of Fermi motion of the heavy quarks is studied by performing a systematic expansion in the relative velocity, and a simple correction factor is derived. This is c

Dae Sung Hwang, Gwang-Hee Kim

We calculate the decay constant ratios $f_{η_c}/f_{J/ψ}$ and $f_{η_b}/f_Υ$. In the calculation we take into account the mock meson structures of the mesons, as well as the difference of the wave functions at origin of the vector and pseudoscalar mesons studied by Ahmady and Mendel. We find that the different spin structures of the mesons much affect the rati

Xiangdong Ji, W. Melnitchouk

Matrix elements of spin-dependent twist-four operators are extracted from recent data on the spin-dependent g_1 structure function of the proton and deuteron in the resonance region. We emphasize the need to include the elastic contributions to the first moments of the structure functions at Q^2 < 2 GeV^2. The coefficients of the 1/Q^2 corrections to the Ell

Yuri A. Kordyukov

We construct spectral triples in a sense of noncommutative differential geometry, associated with a Riemannian foliation on a compact manifold, and describe its dimension spectrum.

G. T. Barkema, M. E. J. Newman

We describe a number of recently developed cluster-flipping algorithms for the efficient simulation of classical spin models near their critical temperature. These include the algorithms of Wolff, Swendsen and Wang, and Niedermeyer, as well as the limited cluster algorithm, the multigrid methods of Kandel and co-workers, and the invaded cluster algorithm. We

E. R. Mucciolo, R. A. Jalabert, J. -L. Pichard

We investigate the statistical properties of the scattering matrix $S$ describing the electron transport through quasi-one dimensional disordered systems. For weak disorder (metallic regime), the energy dependence of the phase shifts of $S$ is found to yield the same universal parametric correlations as those characterizing chaotic Hamiltonian eigenvalues dr

M. Huecker, J. Pommer, B. Buechner, V. Kataev

The ESR signal of Gd spin probes (0.5 at %) as well as the static normal state susceptibility of Eu (J(Eu^{3+})=0) doped La_{2-x-y}Sr_xEu_yCuO_4 reveal pronounced changes of the Cu magnetism at the structural transition from the orthorhombic to the low temperature tetragonal phase for all non-superconducting compositions. Both a jumplike decrease of χas well

Synge Todo

A singularity on the negative fugacity axis of the hard-square lattice gas is investigated in terms of numerical diagonalization of transfer matrices. The location of the singular point $z_c^-$ and the critical exponent $ν$ are accurately determined by the phenomenological renormalization technique as -0.11933888188(1) and 0.416667(1), respectively. It is al

Giovanni Sartoni, Attilio L. Stella

A directed polymer is allowed to branch, with configurations determined by global energy optimization and disorder. A finite size scaling analysis in 2D shows that, if disorder makes branching more and more favorable, a critical transition occurs from the linear scaling regime first studied by Huse and Henley [Phys. Rev. Lett. 54, 2708 (1985)] to a fully bra

Susumu Shinohara, Yoji Aizawa

We determined the exact location of the shearless KAM curve in the quadratic map and numerically investigate the breakup thresholds of those curves in the entire parameter space. The breakup diagram reveals many sharp singularities like fractals on the reconnection thresholds of the twin-chains with rational rotation numbers.

S. T. Myers, J. E. Baker, A. C. S. Readhead, E. M. Leitch

This paper reports the measurement of the Sunyaev-Zeldovich effect (SZE) in the nearby clusters A478, A2142 and A2256 at 32 GHz. These clusters are part of a complete X-ray flux limited sample, which includes the previously measured Coma cluster. We find surface baryonic mass densities for the hot IGM within the 7.35&#39; FWHM Gaussian beam of the OVRO 5.5-m

R. Capuzzo-Dolcetta, P. Miocchi

We present tests of comparison between our versions of the Fast Multipole Algorithm (FMA) and ``classic&#39;&#39; tree-code to evaluate gravitational forces in particle systems. We have optimized the Greengard&#39;s original version of FMA allowing for a more efficient criterion of well-separation between boxes, to improve the adaptivity of the method (which

S. Colafrancesco, P. Mazzotta, Y. Rephaeli, N. Vittorio

The mean sky-averaged Comptonization parameter, y, describing the scattering of the CMB by hot gas in clusters of galaxies is calculated in an array of flat and open cosmological and dark matter models. The models are globally normalized to fit cluster X-ray data, and intracluster gas is assumed to have evolved in a manner consistent with current observation

E. Cohen, J. I. Katz, T. Piran, R. Sari

Relativistic shock models of gamma-ray bursts may be tested by comparison of their predicted low energy asymptotic spectral indices s to observations. Synchrotron radiation theory predicts that the instantaneous spectrum has s = - 1/3 and the spectrum integrated over the radiative decay of the electrons&#39; energies has s = 1/2, with other cases lying betwe

Ludwig Balke

P-resolutions of a cyclic quotient singularity are known to be in one-to-one correspondence with the components of the base space of its semi-universal deformation. Stevens and Christophersen have shown that P-resolutions are parametrized by so-called chains representing zero or, equivalently, certain subdivisions of polygons. I give here a purely combinator

E. Frenkel, D. Gaitsgory, D. Kazhdan, K. Vilonen

We prove the equivalence of two conjectural constructions of unramified cuspidal automorphic functions on the adelic group GL_n(A) associated to an irreducible l-adic local system of rank n on an algebraic curve X over a finite field. The existence of such a function is predicted by the Langlands conjecture. The first construction, which was proposed by Shal

Lorenzo Cornalba, Frank Wilczek

We identify a class of 2+1 dimensional models, involving multiple Chern-Simons gauge fields, in which a form of classical confinement occurs. This confinement is not cumulative, but allows finite mass combinations of individually confined objects, as in baryons. The occurrence and nature of the phenomena depends on number theoretic properties of the coupling

Alexander Polishchuk

To a symmetric, relatively ample line bundle on an abelian scheme one can associate a linear combination of the determinant bundle and the relative canonical bundle, which is a torsion element in the Picard group of the base. We improve the bound on the order of this element found by Faltings and Chai. In particular, we obtain an optimal bound when the degre

German Rodrigo, Arcadi Santamaria, Mikhail Bilenky

The basic box and phase space integrals needed to compute at second order the three-jet decay rate of the Z-boson into massive quarks are presented in this paper. Dimensional Regularization is used to regularize the infrared divergences that appear in intermediate steps. Finally, the cancellation of these divergences among the virtual and the real contributi

C. Adam

Although axial QED suffers from a gauge anomaly, gauge invariance may be maintained by the addition of a nonlocal counterterm. Such nonlocal conterterms, however, are expected to ruin unitarity of the theory. We explicitly investigate some relevant Feynman diagrams and show that, indeed, unitarity is violated, contrary to recent claims.

Daniele Guido, Roberto Longo, Hans-Werner Wiesbrock

Starting with a conformal Quantum Field Theory on the real line, we show that the dual net is still conformal with respect to a new representation of the Moebius group. We infer from this that every conformal net is normal and conormal, namely the local von Neumann algebra associated with an interval coincides with its double relative commutant inside the lo

John C. Baez, Laurel Langford

Just as links may be algebraically described as certain morphisms in the category of tangles, compact surfaces smoothly embedded in R^4 may be described as certain 2-morphisms in the 2-category of `2-tangles in 4 dimensions&#39;. In this announcement we give a purely algebraic characterization of the 2-category of unframed unoriented 2-tangles in 4 dimension

William E. Brown, Ian I. Kogan

We discuss three dimensional compact QED with a theta term due to an axionic field. The variational gauge invariant functional is considered and it is shown that the ground state energy is independent of theta in a leading approximation. The mass gap of the axionic field is found to be dependent upon theta, the mass gap of the photon field and the scalar pot

S. Kasuya, M. Kawasaki

We study the dynamics of a scalar field Φwith the potential g(|Φ|^2-η^2)^2/2 (g=self-coupling constant, η=symmetry breaking scale) after inflation and make clear whether topological defects can ever be formed during preheating. In particular, we pay attention to GUT defects (η\sim 10^{15}GeV - 10^{17}GeV), and consider three types of fluctuations. The first

C. M. Baugh, S. Cole, C. S. Frenk, C. G. Lacey

We use a semi-analytic model of galaxy formation in hierarchical clustering theories to interpret recent data on galaxy formation and evolution, focussing primarily on the recently discovered population of Lyman-break galaxies at $z\simeq 3$. For a variety of cold dark matter (CDM) cosmologies we construct mock galaxy catalogues subject to identical selectio

Jiro Arafune, Masafumi Koike, Joe Sato

We show simple methods how to separate pure CP violating effect from matter effect in long baseline neutrino oscillation experiments with three generations of neutrinos. We give compact formulae for neutrino oscillation probabilities assuming one of the three neutrino masses (presumably tau-neutrino mass) to be much larger than the other masses and the effec

V. E. Kravtsov, K. A. Muttalib

Three recently suggested random matrix ensembles (RME) are linked together by an exact mapping and plausible conjections. Since it is known that in one of these ensembles the eigenvector statistics is multifractal, we argue that all three ensembles belong to a new class of critical RME with multifractal eigenfunction statistics and a universal critical spect

J. Acacio de Barros, Gary Oas, P. Suppes

This paper has been withdrawn. A significantly revised version will be posted in the near future.

Kaundinya S. Gopinath, Dallas C. Kennedy, James M. Gelb

The original version of this paper has been withdrawn by the authors and merged with the revised version of astro-ph/9702014.

M. A. Nielsen, Isaac L. Chuang

We show how to construct quantum gate arrays that can be programmed to perform different unitary operations on a data register, depending on the input to some program register. It is shown that a universal quantum gate array - a gate array which can be programmed to perform any unitary operation - exists only if one allows the gate array to operate in a prob

B. Bodmann, H. Leschke, S. Warzel

A generalized Feynman-Kac formula based on the Wiener measure is presented. Within the setting of a quantum particle in an electromagnetic field it yields the standard Feynman-Kac formula for the corresponding Schrödinger semigroup. In this case rigorous criteria for its validity are compiled. Finally, phase-space path-integral representations for more gener

Jonathan Gratus

The underlying algebra for a noncommutative geometry is taken to be a matrix algebra, and the set of derivatives the adjoint of a subset of traceless matrices. This is sufficient to calculate the dual 1-forms, and show that the space of 1-forms is a free module over the algebra of matrices. The concept of a generalised algebra is defined and it is shown that

H. Ahmedov, I. H. Duru

Following the introduction of the invariant distance on the non-commutative C-algebra of the quantum group SU_q(2), the Green function and the Kernel on the q-homogeneous space M=SU(2)_q/U(1) are derived. A path integration is formulated. Green function for the free massive scalar field on the non-commutative Einstein space R^1xM is presented.

Irina Shchepochkina, Gerhard Post

This note is devoted to a more detailed description of one of the five simple exceptional Lie superalgebras of vector fields, cvect(0|3)_*, a subalgebra of vect(4|3). We derive differential equations for its elements, and solve these equations. Hence we get an exact form for the elements of cvect(0|3)_*. Moreover we realize cvect(0|3)_* by &#34;glued&#34; pa

James J. Griffin

The report of Ahmad et al., states that ``No evidence is found for sharp peaks in the present data.&#39;&#39; But this statement is factually inaccurate. Figure 1 exhibits the APEX&#39; published U + Th ``wedge cut&#39;&#39; data, and background, which show a distinct (3.2 sigma) maximum of 83 excess pair counts in the 20 keV bin near 790 keV. A one-gaussian

G. Q. Li, G. E. Brown, C. -H. Lee, C. M. Ko

We study strangeness (K^+, K^-, and Lambda) production and flow in Ni+Ni collisions at 1-2 AGeV, based on the relativistic transport model including the strangeness degrees of freedom. We find that strangeness spectra and flow are sensitive to the properties of strange hadrons in nuclear medium. The predictions of the chiral perturbation theory that the K^+

S. Drozdz, S. Nishizaki, J. Speth, M. Wojcik

The mechanism of collectivity coexisting with chaos is investigated on the quantum level. The complex spectra are represented in the basis of two-particle two-hole states describing the nuclear double-charge exchange modes in $^{48}$Ca. An example of $J^π=0^-$ excitations shows that the residual interaction, which generically implies chaotic behavior, under

N. Tanaka, Y. Suzuki, K. Varga

The energy and the width of resonance states are determined by analytic continuation of bound-state energies as a function of the coupling constant (potential strength). The advantage of the method is that the existing techniques for calculation of bound states can be applied, without any modifications, to determine the position of resonances. Various numeri

Stephen L. Adler

We show that rigid supersymmetry theories in four dimensions can be extended to give supersymmetric trace (or generalized quantum) dynamics theories, in which the supersymmetry algebra is represented by the generalized Poisson bracket of trace supercharges, constructed from fields that form a trace class noncommutative graded operator algebra. In particular,

Igor Bandos, Kurt Lechner, Alexei Nurmagambetov, Paolo Pasti

We show that the field equations for the supercoordinates and the self--dual antisymmetric tensor field derived from the recently constructed kappa-invariant action for the M theory five-brane are equivalent to the equations of motion obtained in the doubly supersymmetric geometrical approach at the worldvolume component level.

Lara De Nardo, Dmitri V. Fursaev, Gennaro Miele

The one-loop effective potential for gauge models in static de Sitter space at finite temperatures is computed by means of the $ζ$--function method. We found a simple relation which links the effective potentials of gauge and scalar fields at all temperatures. In the de Sitter invariant and zero-temperature states the potential for the scalar electrodynamics

M. de Roo

We consider intersecting M-brane solutions of supergravity in eleven dimensions. Supersymmetry turns out to be a powerful tool in obtaining such solutions and their generalizations.

Ergin Sezgin

A supersymmetric Yang-Mills system in (11,3) dimensions is constructed with the aid of two mutually orthogonal null vectors which naturally arise in a generalized spacetime superalgebra. An obstacle encountered in an attempt to extend this result to beyond 14 dimensions is described. A null reduction of the (11,3) model is shown to yield the known super Yang

Mou Roy, Jose Wudka

We analyze the possibility of encountering resonant transitions of high energy Majorana neutrinos produced in Active Galactic Nuclei (AGN). We consider gravitational, electromagnetic and matter effects and show that the latter are ignorable. Resonant oscillations due to the gravitational interactions are shown to occur at energies in the PeV range for magnet

B. C. Allanach, S. F. King, G. K. Leontaris, S. Lola

In this letter, we show how the combination of both a gauged U(1)_X family symmetry and an extended vertical gauge symmetry in a single model, allows for the presence of additional Clebsch texture zeroes in the fermion mass matrices. This leads to new structures for the textures, with increased predictivity, as compared to schemes with enhanced family symmet

Germán Rodrigo

The effects induced by the quark masses in three-jet observables have been studied in this thesis. In particular, we have explored a new method: the study of three-jet observables at LEP, different from QCD Sum Rules and Lattice calculations, for determining the b-quark mass. Among other advantages, it would allow to extract the b quark mass far from thresho

German Rodrigo, Arcadi Santamaria, Mikhail Bilenky

We present the first results of next-to-leading order QCD corrections to three jet heavy quark production at LEP including mass effects. Among other applications, this calculation can be used to extract the bottom quark mass from LEP data, and therefore to test the running of masses as predicted by QCD.

V. A. Smirnov

Recently presented explicit formulae for asymptotic expansions of Feynman diagrams in the Sudakov limit are applied to typical two-loop diagrams. For a diagram with one non-zero mass these formulae provide an algorithm for analytical calculation of all powers and logarithms, i.e. coefficients in the corresponding expansion $(Q^2)^{-2} \sum_{n,j=0} c_{nj} t^{

L. Mankiewicz, M. Maul, E. Stein

We have calculated $\bar{MS}$ Wilson coefficients and anomalous dimensions for the non-singlet part of the structure function F_2 in the large-N_F limit. Our result agrees with exact two and three loop calculations and gives the leading N_F dependence of the perturbative non-singlet Wilson coefficients to all orders in $α_S$.

Michael Spira

Recent theoretical progress in the evaluation of Higgs boson production at the LHC within the Standard Model and its minimal supersymmetric extension is reviewed. In particular the two-loop QCD corrections to the squark loop contributions to scalar Higgs production in the MSSM and soft gluon resummation effects in Standard and SUSY Higgs production via the g

M. Ciuchini, E. Franco, G. Martinelli, L. Silvestrini

Full expressions of the $B^0_d \to π^+ π^-$ and $B^0_d \to π^0 π^0$ amplitudes, given in terms of matrix elements of operators of the effective weak Hamiltonian, are used to study the dependence of the relevant branching ratios on the different contributions. The uncertainty in the extraction of the weak phase $α$ from the measurement of the time-dependent a

B. V. Geshkenbein

We investigate restrictions on the hadronic contribution to the muon $(g-2)$ factor and to the pion electromagnetic formfactor from the analytical properties of the pion formfactor and the experimental data of the pion formfactor in the space-like [1] region. The values of the pion formfactor of [1] have been improved (see Table 1) and the values of the pion

K. -I. Izawa, T. Yanagida

We construct R-invariant unification models where a pair of massless Higgs doublets is naturally obtained. The masslessness of the Higgs doublets is guaranteed by the unbroken R symmetry. Mass generation for the Higgs doublets is considered from various viewpoints.

Christoph Greub, Tobias Hurth

The order $α_s$ corrections to the Wilson coefficients of the dipole operators ($O_7,O_8$) at the matching scale $μ=m_W$ are a crucial ingredient for a complete next- to-leading logarithmic calculation of the branching ratio for $b \to s γ$. Given the phenomenological relevance and the fact that this two-loop calculation has been done so far only by one grou

John Ellis, Klaus Geiger

We propose possible signatures of `exogamous&#39; combinations between partons in the different W+ and W- hadron showers in e+e- -> W+W- events with purely hadronic final states. Within the space-time model for hadronic shower development that we have proposed previously, we find a possible difference of about 10 % between the mean hadronic multiplicity in s

M. C. Gonzalez-Garcia, S. F. Novaes

A contact four-fermion interaction between light quarks and electrons has been evoked as a possible explanation for the excess of events observed by HERA at high-$Q^2$. We explore the 1-loop effects of such interaction in $Γ(Z^0 \to e^+ e^-)$ measured at LEP and impose strong bounds on the lower limit of the effective scale. Our results are able to discard s

Kurt Langfeld, Hugo Reinhardt

We show that the scenario of vortex induced confinement of center--projected SU(2) lattice gauge theory is not necessarily in conflict with the findings in the positive plaquette model.

CLEO Collaboration, R. Godang

We use the CLEO detector at the Cornell electron-positron storage ring, CESR, to search for the two-photon production of the glueball candidate f_J(2220) in its decay to K_s K_s. We present a restrictive upper limit on the product of the two-photon partial width and the K_s K_s branching fraction. We use this limit to calculate a lower limit on the stickines

T. Chang

This paper proposes a gravitodynamic theory because there are similarities between gravitational theory and electrodynamics. Based on Einstein&#39;s principle of equivalence, two coordinate conditions are proposed into the four-dimensional line element and transformations. As a consequence,the equation of motion for gravitational force or inertial force has

T. Matos, H. Villegas

We study a solution of the field equations for dilatonic gravity and obtain its post-post-newtonian limit. It turns out that terms to this and higher orders in the expansion may become important in strong gravitational fields, even though the post-newtonian limit coincides with that of General Relativity. This suggests that strong gravitational fields can on

Peter Breitenlohner, George Lavrelashvili, Dieter Maison

We analyze the interior geometry of static, spherically symmetric black holes of the Einstein-Yang-Mills-Higgs theory. Generically the solutions exhibit a behaviour that may be described as ``mass inflation&#39;&#39;, although with a remarkable difference between the cases with and without a Higgs field. Without Higgs field the YM field induces a kind of cyc

Sergio M. C. V. Goncalves, Ian G. Moss

Two-point functions of the scalar curvature for metric fluctuations on the four-sphere are analysed. The two-point function for points separated by a fixed distance and for metrics of fixed volume is calculated using spacetime foam methods. This result can be used for comparison between the continuum approach to quantum gravity and numerical quantum gravity

T. Padmanabhan

The action for a relativistic free particle of mass m receives a contribution $-m R(x,y)$ from a path of length R(x,y) connecting the events $x^i$ and $y^i$. Using this action in a path integral, one can obtain the Feynman propagator for a spinless particle of mass m in any background spacetime. If one of the effects of quantizing gravity is to introduce a m

Christopher Beetle, Alejandro Corichi

This bibliography attempts to give a comprehensive overview of all the literature related to the Ashtekar connection and the Rovelli-Smolin loop variables. The original version was compiled by Peter Hübner in 1989, and it has been subsequently updated by Gabriela Gonzalez, Bernd Brügmann, Monica Pierri, Troy Schilling, Alejandro Corichi and Christopher Beetl

Z. Ya. Turakulov

An explicit model of fiber bundle with local fibers being disinct copies of vector 3-space is introduced. They are endowed with frames which are used as local isotopic ones. The field local of isotopic frames is considered as gauge field itself while the form of gauge connections is derived from it. A covariant equation for the field of local frames is found

Viktor L. Ginzburg, Richard Montgomery

A geometric quantization of a Kähler manifold, viewed as a symplectic manifold, depends on the complex structure compatible with the symplectic form. The quantizations form a vector bundle over the space of such complex structures. Having a canonical quantization would amount to finding a natural (projectively) flat connection on this vector bundle. We prove

M. V. Feigel&#39;man, S. E. Korshunov, A. B. Pugachev

We reconsider the issue of Berezinskii-Kosterlitz-Thouless (BKT) transition into an insulating state in the Coulomb-dominated Josephson junction arrays. We show that previously predicted picture of the Cooper-pair BKT transtion at T = T_2 is valid only under the condition that T_2 is considerably below the parity-effect temperature (which is usually almost 1