July 1995 arXiv papers — page 4

Cong Xu, George Helou

Large-scale dust heating and cooling in the diffuse medium of M31 is studied using the HiRes IRAS maps in conjunction with UV, optical (UBV) and the HI maps. A dust heating/cooling model is developed based on a radiative transfer model which assumes a `Sandwich' configuration of dust and stars and takes fully into account the effect of scattering of dust

Cong Xu, George Helou

The morphology of the IR emission and the properties of discrete FIR sources in M31 disk are studied using the HiRes maps from IRAS. Very thin and bright FIR arm segments are shown in these maps, which have similar structure as the HI gas but with much enhanced arm/inter-arm contrast, typically a factor of 5 on the 60$μ$m image. We identify 39 unconfused sou

F. Caputo, V. Castellani, S. Degl'Innocenti

Star luminosity function, already recognized as an age indicator for old galactic globular clusters, can be used to contrains the age of younger stellar systems like the nearby dwarfs spheroidal Leo I. We compare the observed luminosity function of Leo I, presented by Lee et al. 1993, with theoretical expectations for three selected ages, 1, 1.5 and 2 billio

M. C. Bento, O. Bertolami

We discuss, in the context of $N=1$ hidden sector non-minimal supergravity chaotic inflationary models, constraints on the parameters of a polynomial superpotential resulting from existing bounds on the reheating temperature and on the amplitude of the primordial energy density fluctuations as inferred from COBE. We present a specific two-parameter chaotic i

V. Bistolas, Y. Hoffman

The linear algorithm of the the full non-linear large scale structure of Gaussian random fields is extended here to to perform non-linear CRs. The procedure consists of: (1) Using linear CR of low resolution data to construct a high resolution realization of the underlying field, as if the linear theory is valid; (2) Taking the linear CR backwards in time, b

Sergei F. Shandarin

The history and the major results of the study of the topology of the large-scale structure are briefly reviewed. Two techniques based on percolation theory and the genus curve are discussed. The preliminary results of the percolation analysis of the Wiener reconstruction of the IRAS $1.2 Jy$ redshift catalog are reported.

Sergei F. Shandarin

As galaxy redshift surveys probe deeper into the universe, they uncover ever more dramatic structures in the large-scale distribution of galaxies. In particular, the CfA2 and SSRS2 surveys to an apparent magnitude limit of 15.5 exhibit an impressive complex of sheets, filaments, and clusters. The formation of the large-scale structure in the universe results

Zhu-Pei Shi, Rajiv R. P. Singh

We develop series expansions for the ground state properties of the Hubbard model, by introducing an Ising anisotropy into the Hamiltonian. For the two-dimensional (2D) square lattice half-filled Hubbard model, the ground state energy, local moment, sublattice magnetization, uniform magnetic susceptibility and spin stiffness are calculated as a function of $

G. Tondo

A bi--Hamiltonian formulation for stationary flows of the KdV hierarchy is derived in an extended phase space. A map between stationary flows and restricted flows is constructed: in a case it connects an integrable Henon--Heiles system and the Garnier system. Moreover a new integrability scheme for Hamiltonian systems is proposed, holding in the standard pha

O. I. Kartavtsev

Metastable antiprotonic helium atoms $^{3,4}\! H\! e\bar pe$ have been discovered recently in experiments of the delayed annihilation of antiprotons in helium media. These exotic atoms survive for an enormous time (about tens of microseconds) and carry the extremely large total angular momentum $L\sim 30-40$. The theoretical treatment of the intrinsic proper

R. D. Simmons

Following a review of the dual description of the non-linear sigma model we investigate the one-loop quadratic divergences. We use the covariant background field method for the general case and apply the results to the important example of $SU(2)$.

G. Kaniadakis, A. Lavagno, P. Quarati

We show that the kinetic approach to statistical mechanics permits an elegant and efficient treatment of fractional exclusion statistics. By using the exclusion-inclusion principle recently proposed [Phys. Rev. E49, 5103 (1994)] as a generalization of the Pauli exclusion principle, which is based on a proper definition of the transition probability between t

M. Martinis, V. Mikuta-Martinis

We propose an intensity-dependent pion-nucleon coupling Hamiltonian within a unitary multiparticle-production model of the AABS type in which the pion field is represented by the thermal-density matrix. Using this Hamiltonian, we explain the appearance of the negative- binomial (NB) distribution for pions and the well-known empirical relation, the so-called

B. A. Kniehl, M. Steinhauser

We present the next-to-leading-order QCD corrections of O(alpha_s^2 G_F M_t^2) to the low-M_H effective l^+l^-H, ZZH, and W^+W^-H interaction Lagrangians in the high-M_t limit. In the on-shell scheme formulated with G_F, the O(alpha_s^2 G_F M_t^2) corrections support the O(alpha_s G_F M_t^2) ones and further increase the screening of the O(G_F M_t^2) terms.

Xiaoyi He, Qisu Zou

In this paper, we study the two dimensional lattice Boltzmann BGK model (LBGK) by analytically solving a simple flow in a 2~-D channel. The flow is driven by the movement of upper boundary with vertical injection fluid at the porous boundaries. The velocity profile is shown to satisfy a second-order finite-difference form of the simplified incompressible Nav

Takashi Nakamura, Ken-ichi Nakao, Takeshi Chiba, Tetsuya Shiromizu

Under four assumptions such that 1) Einstein's theory of gravity is correct, 2) existence of foliation by geodesic slicing, 3) the trace of the extrinsic curvature, $K$, is negative at the present time in observed region, that is, the observed universe is now expanding, 4) the strong energy condition is satisfied, we show that $H_{v0} t_{0} \leq 1$, wher

Roger E. Behrend, Paul A. Pearce, David L. O'Brien

We use boundary weights and reflection equations to obtain families of commuting double-row transfer matrices for interaction-round-a-face models with fixed boundary conditions. In particular, we consider the fusion hierarchy of the Andrews-Baxter-Forrester models, for which we find that the double-row transfer matrices satisfy functional equations with an s

J. Machta, Y. S. Choi, A. Lucke, T. Schweizer

A new cluster algorithm based on invasion percolation is described. The algorithm samples the critical point of a spin system without a priori knowledge of the critical temperature and provides an efficient way to determine the critical temperature and other observables in the critical region. The method is illustrated for the two- and three-dimensional Isin

Pablo M. Llatas

A simple field theoretical approach to Mathai-Quillen topological field theories of maps $X: M_I \to M_T$ from an internal space to a target space is presented. As an example of applications of our formalism we compute by applying our formulas the action and Q-variations of the fields of two well known topological systems: Topological Quantum Mechanics and t

Chengxing Zhai, Boris Kastening

We compute the free energy density $F$ for gauge theories, with fermions, at high temperature and zero chemical potential. In the expansion $F=T^4 [c_0+c_2 g^2+c_3 g^3+(c'_4\ln g+c_4)g^4+ (c'_5\ln g+c_5)g^5+O(g^6)]$, we determine $c'_5$ and $c_5$ analytically by calculating two- and three-loop diagrams. The $g^5$ term constitutes the first correc

Michael Dine, Ann E. Nelson, Yosef Nir, Yuri Shirman

We report the construction of large new classes of models which break supersymmetry dynamically. We then turn to model building. Two of the principal obstacles to constructing simple models of dynamical supersymmetry breaking are the appearance of Fayet-Iliopoulos D terms and difficulties in generating a $μ$ term for the Higgs fields. Among the new models ar

Paolo Ciafaloni, Andrea Romanino, Alessandro Strumia

In supersymmetric~SO(10) with large $\tanβ$ and Yukawa coupling unification $λ_t=λ_b=λ_τ$, we compute the rates for lepton flavour violating processes. Experiments in progress or foreseen for $μ\to eγ$, $μ\to e$ conversion (and the dipole moment of the electron) are shown to provide very significant tests of the theory for all slepton masses up to about $1\T

M. A. Ivanov, V. E. Lyubovitskij

The results for observables of semileptonic decays of bottom and charm baryons (Isgur-Wise functions, decay rates, distributions, asymmetry parameters) are given within relativistic quark model. A comparison with recent experimental data (CLEO Collaboration) is made.

E. Alvarez, L. Alvarez-Gaume, I. Bakas

We analyze in detail the possible breaking of spacetime supersymmetry under T-duality transformations. We find that when appropiate world-sheet effects are taken into account apparent puzzles concerning supersymmetry in spacetime are solved. We study T-duality in general heterotic $σ$-models analyzing possible anomalies, and we find some modifications of Bus

Gabriel Lopes Cardoso, Dieter Lüst, Thomas Mohaupt

We address non-perturbative effects and duality symmetries in $N=2$ heterotic string theories in four dimensions. Specifically, we consider how each of the four lines of enhanced gauge symmetries in the perturbative moduli space of $N=2$ $T_2$ compactifications is split into 2 lines where monopoles and dyons become massless. This amounts to considering non-p

S. Mrowczynski, B. Muller

The chirally symmetric quark-gluon plasma produced in energetic heavy-ion collisions is predicted to supercool at the late stages of its evolution. The thermal energy is then transformed into the potential energy associated with an energetically unfavorable field configuration. Since the system is in an unstable state it eventually rolls down to the true min

I. Andrić, V. Bardek, L. Jonke

We consider a large-N Chern-Simons theory for the attractive bosonic matter (Jackiw-Pi model) in the Hamiltonian, collective-field approach based on the 1/N expansion. We show that the dynamics of density excitations around the ground-state semiclassical configuration is governed by the Calogero or by the Sutherland Hamiltonian, depending on the symmetry of

Vladimir I. Fal'ko, K. Efetov

The distribution function of local amplitudes of single-particle states in disordered conductors is calculated on the basis of the supersymmetric $σ$-model approach using a saddle-point solution of its reduced version. Although the distribution of relatively small amplitudes can be approximated by the universal Porter-Thomas formulae known from the random ma

V. Ponomarenko

I consider the effect of the finite width of the resonant level on its thermodynamics and tunneling transport properties in the single electron charging regime. The finite width of the levels results from their delocalization with formation of a narrow band due to their mutual overlap. Making use of $1/N$ technique one can show that there is a fixed energy l

V. Ponomarenko

Properties of 1D transport strongly depend on the proper choice of boundary conditions. It has been frequently stated that the Luttinger Liquid (LL) conductance is renormalized by the interaction as $g \frac{e^2} {h} $. To contest this result I develop a model of 1D LL wire with the interaction switching off at the infinities. Its solution shows that there i

Marco Lanzagorta, Graham G. Ross

We show that the soft SUSY breaking mass terms may have infra-red stable fixed points at which they are related to the gaugino masses and argue that in a generic unification these masses should lie close to their fixed points. We consider the implications for the family dependence of squark and slepton masses and the related flavour changing neutral currents

I. I. Bigi

A theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology as it applies to total lifetimes and the underlying theoretical issues are sketched. Predictions are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly shorter than ex

T. Nishino, K. Okunishi

We propose a new fast numerical renormalization group method,the corner transfer matrix renormalization group (CTMRG) method, which is based on a unified scheme of Baxter's corner transfer matrix method and White's density matrix renormalization groupmethod. The key point is that a product of four corner transfer matrices gives the densitymatrix. We

K. Ishikawa, N. Maeda, K. Tadaki

A theory of integer quantum Hall effect(QHE) in realistic systems based on von Neumann lattice is presented. We show that the momentum representation is quite useful and that the quantum Hall regime(QHR), which is defined by the propagator in the momentum representation, is realized. In QHR, the Hall conductance is given by a topological invariant of the mom

Jose D. Edelstein, Carlos Núñez

We study the connection between N=2 supersymmetry and a topological bound in a two-Higgs-doublet system having an $SU(2)\times U(1)_Y\times U(1)_{Y'}$ gauge group. We derive Bogomol'nyi equations from supersymmetry considerations showing that they hold provided certain conditions on the coupling constants, which are a consequence of the huge symmetry

B. M. Zupnik

We consider the quantum-group self-duality equation in the framework of the gauge theory on a deformed twistor space. Quantum deformation of the Atiyah-Drinfel'd-Hitchin-Manin and t'Hooft multi-instanton solutions are constructed.

Aurel Bulgac, Giu Do Dang, Dimitri Kusnezov

We address the question of the microscopic origin of dissipation in collective motion of a quantum many--body system in the framework of a parametric random matrix approach to the intrinsic dynamics. We show that the fluctuation--dissipation theorem is generally violated and, moreover, energy diffusion has a markedly non--Gaussian character and the correspon

Pablo Arés Gastesi

This paper contains some results about Teichmüller spaces of non-orientable surfaces (Klein surfaces). We prove several theorems giving isomorphisms between deformation spaces of Klein surfaces. These results show the similarity between the deformation theory of Klein surfaces, and the theory of Riemann surfaces. We also use the results of I. Kra to give exp

Matthew G. Brin

The automorphism groups of several of Thompson's countable groups of piecewise linear homeomorphisms of the line and circle are computed and it is shown that the outer automorphism groups of these groups are relatively small. These results can be interpreted as stability results for certain structures of PL functions on the circle. Machinery is developed

J. Feigenbaum, P. G. O. Freund

The algebra of observables of $SO_{q}(3)$-symmetric quantum mechanics is extended to include the inverse $\frac{1}{R}$ of the radial coordinate and used to obtain eigenvalues and eigenfunctions of a \q-deformed Coulomb Hamiltonian.

I. Antoniadis, E. Gava, K. S. Narain, T. R. Taylor

We test the recently conjectured duality between $N=2$ supersymmetric type II and heterotic string models by analysing a class of higher dimensional interactions in the respective low-energy Lagrangians. These are $F$-terms of the form $F_g W^{2g}$ where $W$ is the gravitational superfield. On the type II side these terms are generated at the $g$-loop level

E. Abdalla, K. D. Rothe

Using a formulation of QCD_2 as a perturbed conformally invariant theory involving fermions, ghosts, as well as positive and negative level Wess-Zumino-Witten fields, we show that the BRST conditions become restrictions on the conformally invariant sector, as described by a G/G topological theory. By solving the corresponding cohomology problem we are led to

Hideaki Aoyama, Toshiyuki Harano, Masatoshi Sato, Shinya Wada

The instanton configuration in the SU(2)-gauge system with a Higgs doublet is constructed by using the new valley method. This method defines the configuration by an extension of the field equation and allows the exact conversion of the quasi-zero eigenmode to a collective coordinate. It does not require ad-hoc constraints used in the current constrained ins

Dimitrios Metaxas, Erick J. Weinberg

In field theories where a metastable false vacuum state arises as a result of radiative corrections, the calculation of the rate of false vacuum decay by bubble nucleation depends on the effective potential and the other functions that appear in the derivative expansion of the effective action. Beginning with the Nielsen identity, we derive a series of ident

B. de Carlos, J. A. Casas, J. M. Moreno

In the absence of any additional assumption it is natural to conjecture that sizeable flavour-mixing mass entries, $Δm^2$, may appear in the mass matrices of the scalars of the MSSM, i.e. $Δm^2\sim O(m^2)$. This flavour violation can still be reconciled with the experiment if the gaugino mass, $M_{1/2}$, is large enough, leading to a {\em gaugino dominance}

Carl H. Albright, Satyanarayan Nandi

We construct a supersymmetric $SO(10) \times U(1)_F$ model of the Yukawa interactions at the grand unification scale from knowledge of a phenomenological set of mass matrices obtained by a previous bottom-up approach. The $U(1)_F$ family symmetry determines the textures for the Majorana and generic Dirac mass matrices, while the $SO(10)$ symmetry relates eac

Jonathan L. Rosner

The impact of atomic parity violation experiments on determination of the weak mixing parameter $\sin^2 θ$ and the Peskin-Takeuchi parameters $S$ and $T$ is reassessed in the light of recent electroweak measurements at LEP, SLAC, and Fermilab. Since the weak charge $Q_W$ provides unique information on $S$, its determination with a factor of four better accur

George Siopsis

We apply the relativistic Bethe-Salpeter formalism to the calculation of final-state effects in the production of a t-tbar pair at threshold. We find that final-state rescattering does not affect the momentum distribution of the t-tbar pair to lowest order in the strong coupling constant. This result correctly extends earlier results based on the non-relativ

A. Denner, S. Dittmaier, M. Strobel

The cross-section for $γγ\to t \bar t$ with arbitrary polarized photons is calculated within the electroweak Standard Model including the complete virtual and soft-photonic $O(α)$ corrections. We present a detailed numerical discussion of the radiative corrections with particular emphasis on the purely weak corrections. These are usually of the order of 1--1

E. J. Chun, A. S. Joshipura, A. Yu. Smirnov

The existence of sterile neutrino is hinted by simultaneous explanation of diverse neutrino anomalies. We suggest that the quasi Goldstone fermions (QGF) arising in supersymmetric theory as a result of spontaneous breaking of global symmetry like the Peccei-Quinn symmetry or the lepton number symmetry can play a role of the sterile neutrino. The smallness of

R. Alkofer, H. Weigel, H. Reinhardt, A. Abada

In the chirally symmetric Nambu--Jona-Lasinio model baryons are described as chiral solitons of mesonic quark--antiquark bound states. Hyperons are investigated in two complementary pictures: the bound state approach of Callan and Klebanov and the collective approach of Yabu and Ando. The latter is used to compute the strange vector form factors of the nucle

Guido Nolte, Jutta Kunz, Burkhard Kleihaus

We consider level crossing in the background of the sphaleron barrier for nondegenerate fermions. The mass splitting within the fermion doublets allows only for an axially symmetric ansatz for the fermion fields. In the background of the sphaleron we solve the partial differential equations for the fermion functions. We find little angular dependence for our

Graham G. Ross

We argue that in a wide class of theories the fermion and soft supersymmetry breaking mass structure is largely determined by the infra-red fixed point structure of the theory lying beyond the \smp We show how knowlege of the symmetries and multiplet content of this theory is sufficient to determine the infra-red structure, illustrating the idea for the case

Paul Hoyer, C. S. Lam

In leading twist deep inelastic $ep$ scattering, the virtual photon interaction is fast compared to the time scale of soft color rearrangement. We compare the Pomeron exchange model, in which a neutral cluster is preformed, with a gluon exchange model, in which color is exchanged after the hard interaction. We find several features of the DIS data and of dat

Klaus Geiger

A quantum kinetic formalism is developed to study the dynamical interplay of quantum and statistical-kinetic properties of non-equilibrium multi-parton systems produced in high-energy QCD processes. The approach provides the means to follow the quantum dynamics in both space-time and energy-momentum, starting from an arbitrary initial configuration of high-m

G. M. de Divitiis, R. Frezzotti, M. Guagnelli, M. Masetti

We estimate the effects of dynamical fermions by extrapolating to positive flavour numbers the results from negative values obtained by adding to the pure gauge sector a fermion action where the fields obey a Bose statistics: the bermions.

J. Fernando Barbero, Madhavan Varadarajan

The constraint hypersurfaces defining the Witten and Ashtekar formulations for 2+1 gravity are very different. In particular the constraint hypersurface in the Ashtekar case is not a manifold but consists of several sectors that intersect each other in a complicated way. The issue of how to define a consistent dynamics in such a situation is then rather non-

R. Fehrenbacher, T. M. Rice

We argue that an effective single-particle model to explain the destructive role of Pr on superconductivity in PrBa$_2$Cu$_3$O$_7$, is inconsistent with the experimental ac conductivity in that compound.

F. C. MacKintosh, J. Kas, P. A. Janmey

We develop a model for gels and entangled solutions of semiflexible biopolymers such as F-actin. Such networks play a crucial structural role in the cytoskeleton of cells. We show that the rheologic properties of these networks can result from nonclassical rubber elasticity. This model can explain a number of elastic properties of such networks {\em in vitro

M. J. Thill, H. J. Hilhorst

We analyse the critical region of finite-($d$)-dimensional Ising spin glass, in particular the limit of $d$ closely above the lower critical dimension $d_\ell$. At criticality the thermally active degrees of freedom are surfaces (of width zero) enclosing clusters of spins that may reverse with respect to their environment. The surfaces are organised in finit

C. Rascon, L. Mederos, G. Navascues

A thermodynamically consistent density functional-perturbation theory is used to study the isostructural solid-to-solid transition which takes place in the hard sphere/attractive Yukawa system when the Yukawa tail is sufficiently short-ranged. A comparison with results for the square well potential allows us to study the effect of the attractive potential fo

Norbert E. Fuchs, Rolf Schwitter

Writing specifications for computer programs is not easy since one has to take into account the disparate conceptual worlds of the application domain and of software development. To bridge this conceptual gap we propose controlled natural language as a declarative and application-specific specification language. Controlled natural language is a subset of nat

Kemal Oflazer, Okan Yilmaz

In Turkish, (and possibly in many other languages) verbs often convey several meanings (some totally unrelated) when they are used with subjects, objects, oblique objects, adverbial adjuncts, with certain lexical, morphological, and semantic features, and co-occurrence restrictions. In addition to the usual sense variations due to selectional restrictions on

Christer Samuelsson

A method is given that "inverts" a logic grammar and displays it from the point of view of the logical form, rather than from that of the word string. LR-compiling techniques are used to allow a recursive-descent generation algorithm to perform "functor merging" much in the same way as an LR parser performs prefix merging. This is an improvem

M. G. Cosenza

The collective behavior of a coupled map lattice having {\it unbounded} chaotic local dynamics is investigated through the properties of its mean field. The presence of unstable periodic orbits in the local maps determines the emergence of nontrivial collective behavior. Windows of collective period-two states are found in parameter space.

Joel R. Primack

Theoretical models for structure formation with Gaussian initial fluctuations have been worked out in considerable detail and compared with observations on various scales. It is on nonlinear scales $\lsim 10 \ h^{-1}\ {\rm Mpc}$ that the greatest differences exist between $Ω=1$ models that have been normalized to agree on the largest scales with the COBE dat

Gerard Jungman, Marc Kamionkowski, Arthur Kosowsky, David N. Spergel

Variations in $Ω$, the total density of the Universe, leave a clear and distinctive imprint on the power spectrum of temperature fluctuations in the cosmic microwave background (CMB). This signature is virtually independent of other cosmological parameters or details of particular cosmological models. We evaluate the precision with which $Ω$ can be determine

Henri Gillet, Christophe Soule

To an arbitrary variety over a field of characteristic zero, we associate a complex of Chow motives, which is, up to homotopy, unique and bounded. We deduce that any variety has a natural Euler characteristic in the Grothendieck group of Chow motives. We show that the cohomology with integer coefficients of any singular variety over the complex numbers has a

A. J. Millis, Boris I. Shraiman, R. Mueller

A model for $La_{1-x}Sr_xMnO_3$ which incorporates the physics of dynamic Jahn-Teller and double-exchange effects is presented and solved via a dynamical mean field approximation. In an intermediate coupling regime the interplay of these two effects is found to reproduce the behavior of the resistivity and magnetic transition temperature observed in $La_{1-x

George M. Frichter, John P. Ralston, Douglas W. McKay

Interactions of ultrahigh energy neutrinos of cosmological origin in large volumes of dense, radio-transparent media can be detected via coherent Cherenkov emission from accompanying electromagnetic showers. Antarctic ice meets the requirements for an efficient detection medium for a radio frequency neutrino telescope. We carefully estimate the sensitivity o

E. Oset, F. Cano, J. A. Gómez Tejedor, E. Hernández

In this talk we cover several issues concerning pion production. The first one is the p p ----> p p pi^0 reaction where an alternative explanation based on the off shell extrapolation of the pi N amplitude is offered. A recent model for the gamma N ----> pi pi N reaction is presented and a new kind of exchange current is constructed from it which allows one

Mar Bastero-Gil, Biswajoy Brahmachari

In a SUSY GUT having an extra reverse doublet-triplet splitting near the GUT scale, where the mass of an extra doublet is greater than the mass of an extra triplet by two orders of magnitude, a low prediction of $α_s$ can be achieved through threshold corrections via the heavy scalars in the fundamental representations, making the prediction consistent with

H. W. L. Naus, T. Gasenzer, H. --J. Pirner

We use a Gaussian wave functional for the ground state to reorder the Hamiltonian into a free part with a variationally determined mass and the rest. Once spontaneous symmetry breaking is taken into account, the residual Hamiltonian can, in principle, be treated perturbatively. In this scheme we analyze the $O(1)$ and $O(2)$ scalar models. For the $O(2)$--th

John T. Whelan

Hartle's generalized quantum mechanics in the sum-over-histories formalism is used to describe a nonabelian gauge theory. Predictions are made for certain alternatives, with particular attention given to coarse-grainings involving the constraint. In this way, the theory is compared to other quantum-mechanical descriptions of gauge theories in which the c

Hiraku Nakajima

I have just replaced the first line by %&amslplain in order to be compiled by AMS-LaTeX.

Renat Z. Zhdanov, Ihor V. Revenko, Wilhelm I. Fushchych

We suggest an effective approach to separation of variables in the Schrödinger equation with two space variables. Using it we classify inequivalent potentials $V(x_1,x_2)$ such that the corresponding Schr\" odinger equations admit separation of variables. Besides that, we carry out separation of variables in the Schr\" odinger equation with the aniso

John C. Baez, Stephen Sawin

Let $G$ be a compact connected Lie group and $P \to M$ a smooth principal $G$-bundle. Let a `cylinder function' on the space $\A$ of smooth connections on $P$ be a continuous function of the holonomies of $A$ along finitely many piecewise smoothly immersed curves in $M$, and let a generalized measure on $\A$ be a bounded linear functional on cylinder fun

Mico Durdevic

It is shown that every quantum principal bundle with a compact structure group is a Hopf-Galois extension. This property naturally extends to the level of general differential structures, so that every differential calculus over a quantum principal bundle with a compact structure group is a graded-differential variant of the Hopf-Galois extension.

Mico Durdevic

A generalization of classical gauge theory is presented, in the framework of a noncommutative-geometric formalism of quantum principal bundles over smooth manifolds. Quantum counterparts of classical gauge bundles, and classical gauge transformations, are introduced and investigated. A natural differential calculus on quantum gauge bundles is constructed and

Mico Durdevic

A noncommutative-geometric formalism of framed principal bundles is sketched, in a special case of quantum bundles (over quantum spaces) possessing classical structure groups. Quantum counterparts of torsion operators and Levi-Civita type connections are analyzed. A construction of a natural differential calculus on framed bundles is described. Illustrative

Mico Durdevic

A theory of principal bundles possessing quantum structure groups and classical base manifolds is presented. Structural analysis of such quantum principal bundles is performed. A differential calculus is constructed, combining differential forms on the base manifold with an appropriate differential calculus on the structure quantum group. Relations between t

Mico Durdevic

The structure of quantum principal bundles is studied, from the viewpoint of Tannaka-Krein duality theory. It is shown that if the structure quantum group is compact, principal G-bundles over a quantum space M are in a natural correspondence with certain contravariant functors defined on the category of finite-dimensional unitary representations of G, with t

Mico Durdevic

A noncommutative-geometric generalization of classical Weil theory of characteristic classes is presented, in the conceptual framework of quantum principal bundles. A particular care is given to the case when the bundle does not admit regular connections. A cohomological description of the domain of the Weil homomorphism is given. Relations between universal

Mico Durdevic

The paper deals with braided Clifford algebras, understood as Chevalley-Kahler deformations of braided exterior algebras. It is shown that Clifford algebras based on involutive braids can be naturally endowed with a braided quantum group structure. Basic group entities are constructed explicitly.

J"org Teschner

The recently proposed expression for the general three point function of exponential fields in quantum Liouville theory on the sphere is considered. By exploiting locality or crossing symmetry in the case of those four-point functions, which may be expressed in terms of hypergeometric functions, a set of functional equations is found for the general three po

C. Muñoz

The connection between Supergravity and the low-energy world is analyzed. In particular, the soft Supersymmetry-breaking terms arising in Supergravity, the $μ$ problem and various solutions proposed to solve it are reviewed. The soft terms arising in Supergravity theories coming from Superstring theory are also computed and the solutions proposed to solve th

R. Hong Tuan

In order to use the Gaussian representation for propagators in Feynman amplitudes, a representation which is useful to relate string theory and field theory, one has to prove first that each $α$- parameter (where $α$ is the parameter associated to each propagator in the $α$-representation of the Feynman amplitudes) can be replaced by a constant instead of be

P. M. Lavrov

A superfield version on superspace $(x^μ,θ^a)$ is proposed for the $Sp(2)$-- covariant Lagrangian quantization of general gauge theories. The BRST- and antiBRST- transformations are realized on superfields as supertranslations in the $θ^a$-- directions. A new (geometric) interpretation of the Ward identities in the quantum gauge theory is given.

P. M. Lavrov, P. Yu. Moshin, A. A. Reshetnyak

Lagragian quantization rules for general gauge theories are proposed on a basis of a superfield formulation of the standard BRST symmetry. Independence of the $S$-matrix on a choice of the gauge is proved. The Ward identities in terms of superfields are derived.

Hiroshi Suzuki

We derive a simple calculation rule for Aoyama--Tamra's prescription for path integral with degenerated potential minima. Non-perturbative corrections due to the restricted functional space (fundamental region) can systematically be computed with this rule. It becomes manifest that the prescription might give Borel summable series for finite temperature

A. I. Bugrij, L. L. Jenkovszky, V. N. Shadura

The two-point Green function of the massive scalar $(3+1)$-quantum field theory with $λϕ^4$ interaction at finite temperature is evaluated up to the 2nd order of perturbation theory. The averaging on the vacuum fluctuations is separated from the averaging on the thermal fluctuations explicitly. As a result, the temperature dependent part of the propagator is

Jung-Ho Cha, Yong-Wan Kim, Young-Jai Park, Yongduk Kim

We quantize the chiral Schwinger Model by using the Batalin-Tyutin formalism. We show that one can systematically construct the first class constraints and the desired involutive Hamiltonian, which naturally generates all secondary constraints. For $a>1$, this Hamiltonian gives the gauge invariant Lagrangian including the well-known Wess-Zumino terms, while

Edmond L. Berger, Harry Contopanagos

We present a calculation of the total cross section for top quark production based on a new perturbative resummation of gluon radiative corrections to the basic QCD subprocesses. We use Principal Value Resummation to calculate all relevant large threshold corrections. Advantages of this method include its independence from arbitrary infrared cutoffs and spec

F. Halzen, T. Stanev

Underground detectors measure the directions of up-coming muons of neutrino origin. They can also observe down-going muons made by gamma rays in the Earth's atmosphere. Although gamma ray showers are muon-poor, they produce a sufficient number of muons to detect the sources observed by GeV and TeV telescopes. With a threshold higher by one hundred and a

Gottfried Holzwarth

The electro-magnetic form factors of the proton are calculated in a chiral soliton model with relativistic corrections. The magnetic form factor $G_M$ is shown to agree well with the new SLAC data for spacelike $Q^2$ up to 30 (GeV/c)$^2$ if superconvergence is imposed. The direct continuation through a Laurent series to the timelike region above the physical

K. K. Sharma, A. C. Katoch, R. C. Verma

We investigate nonfactorizable contributions to two-body hadronic decays of the charmed mesons to a pseudoscalar meson and a vector meson in Cabibbo-favored mode. Employing SU(3)-flavor symmetry for the nonfactorizable matrix elements, we obtain branching ratios of the decays in consistent agreement with experiment.

Ulf-G. Meißner

Chiral perturbation theory is the effective field theory of the standard model. In this talk, I discuss some applications of this framework to the pion--nucleon system. These are chiral corrections to the S--wave pion--nucleon scattering lengths, the reaction $πN \to ππN$ at threshold and low--energy theorems in $π^0$ photoproduction.

J. R. Mureika, R. B. Mann

Neutrinos can undergo flavor--oscillations if they possess flavor--dependent couplings to the surrounding gravitational field (the VEP mechanism). The neutrino fields can be massless, in accord with the Minimal Standard Model, but at the expense of the Einstein Equivalence Principle. We show that it is possible to explain the observed Solar Neutrino data fro

M. Gluck, E. Reya, W. Vogelsang

A leading order QCD analysis of spin asymmetries in polarized deep inelastic lepton nucleon scattering is presented within the framework of the radiative parton model. Two resulting sets of plausible leading order spin dependent parton distributions are presented, respecting the fundamental positivity constraints down to the low resolution scale $Q^2=μ_{LO}^

Michelangelo L. Mangano

We review recent progress made in the theory of quarkonium production in hadronic collisions.