January 1995 arXiv papers — page 4

P Bowcock, E Corrigan, PE Dorey, RH Rietdijk

Boundary conditions compatible with classical integrability are studied both directly, using an approach based on the explicit construction of conserved quantities, and indirectly by first developing a generalisation of the Lax pair idea. The latter approach is closer to the spirit of earlier work by Sklyanin and yields a complete set of conjectures for perm

Douglas Singleton

In this paper we extend our previously discovered exact solution for an SU(2) gauge theory coupled to a massless, non-interacting scalar field, to the general group SU(N+1). Using the first-order formalism of Bogomolny, an exact, spherically symmetric solution for the gauge and scalar fields is found. This solution is similiar to the Schwarzschild solution o

M. Bershadsky, A. Johansen, V. Sadov, C. Vafa

By considering a (partial) topological twisting of supersymmetric Yang-Mills compactified on a 2d space with `t Hooft magnetic flux turned on we obtain a supersymmetric $σ$-model in 2 dimensions. For N=2 SYM this maps Donaldson observables on products of two Riemann surfaces to quantum cohomology ring of moduli space of flat connections on a Riemann surface.

J. C. Brunelli, Ashok Das

We study systematically the Lax description of the KdV hierarchy in terms of an operator which is the geometrical recursion operator. We formulate the Lax equation for the $n$-th flow, construct the Hamiltonians which lead to commuting flows. In this formulation, the recursion relation between the conserved quantities follows naturally. We give a simple and

K. Kirsten, D. J. Toms

We consider the model of self-interacting complex scalar fields with a rigid gauge invariance under an arbitrary gauge group $G$. In order to analyze the phenomenon of Bose-Einstein condensation finite temperature and the possibility of a finite background charge is included. Different approaches to derive the relevant high-temperature behaviour of the theor

Edwin Langmann

We discuss a non--commutative integration calculus arising in the mathematical description of anomalies in fermion--Yang--Mills systems. We consider the differential complex of forms $u_0\ccr{\eps}{u_1}\cdots\ccr{\eps}{u_n}$ with $\eps$ a grading operator on a Hilbert space $\cH$ and $u_i$ bounded operators on $\cH$ which naturally contains the compactly sup

C. Klimcik

A new method of gauging of WZNW models is presented, leading to a class of exact string solutions with a target space metric of Minkowskian signature. The corresponding models may be interpreted as $σ$-model analogues of the Toda field theories.

G B Tupper, F G Scholtz

We generalize and extend a quantization procedure proposed by the present authors which is designed to quantize SU(N) gauge theories in the continuum without fixing the gauge and thereby avoid the Gribov problem. In particular we discuss the BRS symmetry underlying the effective action. We proceed to use this BRS symmetry to discuss the perturbative renormal

O. Foda, S. O. Warnaar

We obtain a bijection between certain lattice paths and partitions. This implies a proof of polynomial identities conjectured by Melzer. In a limit, these identities reduce to Rogers--Ramanujan-type identities for the $χ_{1,1}^{(p,p+1)}(q)$ Virasoro characters, conjectured by the Stony Brook group.

Stuart Raby

In this talk I summarize published work on a systematic operator analysis for fermion masses in a class of effective supersymmetric SO(10) GUTs\cite{adhrs}~\footnote{This work is in collaboration with G. Anderson, S. Dimopoulos, L.J. Hall, and G. Starkman.}. Given a minimal set of four operators at $M_G$, we have just 6 parameters in the fermion mass matrice

J. O. Eeg, I. Picek

We discuss some flavour-changing effective Lagrangians, obtained from scales above 1 GeV, which vanish on the quark mass shell. Although the effects of such effective Lagrangians are zero in the limit of vanishing bound-state interactions, we have shown that they have a significant impact on the processes $K\rightarrowγγ$ and $B_s \rightarrowγγ$.

S. P. Rosen, Waikwok Kwong

We propose an effective mass matrix for light neutrinos which is consistent with the mixing pattern indicated by solar and atmospheric neutrino experiments. Two scenarios for the mass eigenvalues are discussed and the connection with double beta decay is noted.

D. Kekez, D. Klabucar, K. Kumericki, I. Picek

We present a new piece of evidence in favour of the importance of the quark off-shellness in the kaon. The matrix elements of the flavour-changing operators for $K_{L}\toγγ$ comply with the general behaviour of the matrix elements expected in the pairing bound-state model used here. The present calculation in essence agrees with previous chiral-quark results

Stuart Raby

This paper is based on four lectures given at the Trieste Summer School 1994 on theories of fermion masses. The first two lectures introduce three mechanisms which have been used to construct models of fermion masses. We then discuss some recent applications of these ideas. In the last lecture we briefly review SO(10) and some predictive theories of fermion

Felix. M. Lev

The phenomenon of scaling in deep inelastic lepton-nucleon scattering is usually explained in terms of the Feynman parton model, and the logarithmic corrections to scaling are explained in the framework of perturbative QCD. For testing the validity of the parton model, we consider the deep inelastic electron scattering in a model in which the system electrom

G. C. Branco, P. A. Parada, M. N. Rebelo

We analyse $ΔC=2$ transitions in the framework of a minimal extension of the Standard Model where either a $Q=2/3$ or a $Q=-1/3$ isosinglet quark is added to the standard quark spectrum. In the case of a $Q=2/3$ isosinglet quark, it is shown that there is a significant region of parameter space where $D^0 - \bar D^0$ mixing is sufficiently enhanced to be obs

Aharon Levy

The recent F$_2$ measurements at HERA are discussed in the framework of virtual photon--proton cross section. The energy behaviour of the cross section is studied for different $Q^2$ values, ranging from 0 to 1000 GeV$^2$ for center of mass energies $1.75 < W < 300$ GeV.

I. V. Andreev, M. Biyajima, I. M. Dremin, N. Suzuki

The role of Bose-Einstein correlations in a widely discussed intermittency phenomenon is reviewed. In particular, it is shown that particle correlations of different origin are better displayed when analysed as functions of appropriately chosen variables. Correspondingly, if the shape of Bose-Einstein contribution is chosen to be Gaussian in 3-momentum trans

W. Kerler, C. Rebbi, A. Weber

We show that the phases of the 4-dimensional compact U(1) lattice gauge theory are unambiguously characterized by the topological properties of minimal Dirac sheets as well as of monopole currents lines. We obtain the minimal sheets by a simulated-annealing procedure. Our results indicate that the equivalence classes of sheet structures are the physical rele

David Hochberg, Thomas W. Kephart

Scalar fields coupled to gravity via $ξR Φ^2$ in arbitrary Friedmann-Robertson-Walker backgrounds can be represented by an effective flat space field theory. We derive an expression for the scalar energy density where the effective scalar mass becomes an explicit function of $ξ$ and the scale factor. The scalar quartic self-coupling gets shifted and can vani

M. Tsuda, T. Shirafuji, H. -J. Xie

It has been shown for low-spin fields that the use of only the self-dual part of the connection as basic variable does not lead to spurious equations or inconsistencies. We slightly generalize the form of the chiral Lagrangian of half-integer spin fields and express its imaginary part in a simple form. If the imaginary part is non-vanishing, it will lead to

Yoshinari Inoue

With respect to the Dolbeault complex over the flat manifold $\C^n$, an explicit description of the inverse correspondence of the twistor correspondence is given.

Bruno Nachtergaele

We prove rigorous lower and upper bounds for the mass gap of the ferromagnetic spin 1/2 XXZ chain. The two bounds coincide asymptotically in the Ising limit $Δ\to\infty$. Near the isotropic point, $Δ=1$, the estimates are good enough to determine the critical behaviour of the mass gap unambiguously. The derivation does not rely on exact solutions.

C. Borgs, J. Jȩdrzejewski, R. Kotecký

We study the phase diagram of the extended Hubbard model in the atomic limit. At zero temperature, the phase diagram decomposes into six regions: three with homogeneous phases (characterized by particle densities $ρ=0$, 1, and 2 and staggered charge density $Δ=0$) and three with staggered phases (characterized by the densities $ρ=\frac12$, 1, and $\frac32$ a

E. Diez, A. Sanchez, F. Dominguez-Adame

We study disordered quantum-well-based semiconductor superlattices where the disorder is intentional and short-range correlated. Such systems consist of quantum-wells of two different thicknesses randomly distributed along the growth direction, with the additional constraint that wells of one kind always appears in pairs. Imperfections due to interface rough

A. Comtet, J. Desbois, C. Monthus

A model of localization based on the Witten Hamiltonian of supersymmetric quantum mechanics is considered. The case where the superpotential $ϕ(x)$ is a random telegraph process is solved exactly. Both the localization length and the density of states are obtained analytically. A detailed study of the low energy behaviour is presented. Analytical and numeric

D. Poilblanc, D. J. Scalapino, W. Hanke

The spin and charge excitations of the t--J ladder are studied by exact diagonalization techniques for several electron densities. The various modes are classified according to their spin (singlet or triplet excitations) and their parity under a reflection with respect to the symmetry axis along the chains and a finite size scaling of the related gaps is per

D. Olguín, R. Baquero

In a previous paper [\prb {\bf 50}, 1980 (1994)] we gave account of the nondispersive band first found experimentally at --4.4 eV for CdTe(001) by Niles and Höchst. We have characterized this band as a surface--induced bulk state. In a second paper we showed that a similar state does exist in II--VI and III--V zincblende semiconductor compounds. In this pape

I. A. Luk&#39;yanchuk, M. E. Zhitomirsky

The article reviews recent developments on magnetic properties of superconductors with anisotropic Cooper pairing. In particular, we show how the concept of broken symmetries is applied to the investigation of the mixed state in superconductors with a multicomponent order parameter. Starting from the phenomenological description in the framework of the gener

A. M. Tikofsky, D. B. Bailey

We consider a layered superconductor with a complex order parameter whose phase switches sign from one layer to the next. This system is shown to exhibit gapless superconductivity for sufficiently large interlayer pairing or interlayer hopping. In addition, this description is consistent with experiments finding signals of time-reversal symmetry breaking in

F. De Paolis, G. Ingrosso, Ph. Jetzer, A. Quadir

Molecular hydrogen clouds can contribute substantially to the galactic halo< dark matter and may lead to the birth of massive halo objects (MHOs) observed indirectly by microlensing. We present a method to detect these molecular clouds in the halo of M31 using the Doppler shift effect. We also consider the possibility to directly observe MHOs in the halo of

Takahiko Matsubara

The gravitational evolution of the genus and other statistics of isodensity contours of the density field is derived analytically in a weakly nonlinear regime using second-order perturbation theory. The effect of final smoothing in perturbation theory on the statistics of isodensity contours is also evaluated. The resulting analytic expression for the genus

N. Zacharias

Residuals of a conventional plate adjustment of 5,687 plates of the Second Cape Photographic Catalogue (CPC2) using the Southern Reference Star (SRS) Catalog were analyzed to search for systematic errors depending on the location of the star images on the plate. Even after correcting for third order optical distortion, such coordinate depending systematic er

Eduard Looijenga

We prove among other things that any product of tautological classes of $\M_g$ of degree $d$ (in the Chow ring of $\M _g$ with rational coefficients) vanishes for $d>g-2$ and is proportional to the class of the hyperelliptic locus in degree $g-2$.

M. J. Hudson, A. Dekel, S. Courteau, S. M. Faber

The mass density field in the local universe, recovered by the POTENT method from peculiar velocities of $\sim$3000 galaxies, is compared with the density field of optically-selected galaxies. Both density fields are smoothed with a Gaussian filter of radius 12 $h^{-1}$ Mpc. Under the assumptions of gravitational instability and a linear biasing parameter $b

P. B. Price

The depth-dependence of bubble concentration at pressures above the transition to the air hydrate phase and the optical scattering length due to bubbles in deep ice at the South Pole are modeled using diffusion-growth data from the laboratory, taking into account the dependence of age and temperature on depth in the ice. The model fits the available data on

The AMANDA collaboration

The first four strings of phototubes for the AMANDA high-energy neutrino observatory are now frozen in place at a depth of 800 to 1000 m in ice at the South Pole. During the 1995-96 season an additional six strings will be deployed at greater depths. Provided absorption, scattering, and refraction of visible light are sufficiently small, the trajectory of a

H. F. Jones, I. S. Solovtsov

By using a non-perturbative expansion and the dispersion relation for the Adler $D$--function we propose a new method for constructing the QCD effective coupling constant in the timelike region.

V. Keiner

A simple model for the photoproduction of kaons off protons with a lambda hyperon in the final state is presented. In a quark model, the interaction is modelled by the pair-creation of the (anti-) strange quarks in the final state which recombine with the three quarks of the proton to form the lambda and kaon. The calculated scattering cross sections for pho

Denis Bernard

The random vector potential model describes massless fermions coupled to a quenched random gauge field. We study its abelian and non-abelian versions. The abelian version can be completely solved using bosonization. We analyse the non-abelian model using its supersymmetric formulation and show, by a perturbative renormalisation group computation, that it is

J. Lorenzana, G. A. Sawatzky

We calculate the effective charge for multimagnon infrared (IR) absorption assisted by phonons in the parent insulating compounds of cuprate superconductors and the spectra for two-magnon absorption using interacting spin-wave theory. Recent measured bands in the mid IR [Perkins et al. Phys. Rev. Lett. {\bf 71} 1621 (1993)] are interpreted as involving one p

Gaetano Fiore

We briefly describe the construction of a consistent $q$-deformation of the quantum mechanical isotropic harmonic oscillator on ordinary $\rn^N$ space.

F. Matthäus, H. Sauermann

A transversally driven isotropic ferromagnet being under the influence of a static external and an uniaxial internal anisotropy field is studied. We consider the dissipative Landau-Lifshitz equation as the fundamental equation of motion and treat it in $1+1$~dimensions. The stability of the spatially homogeneous magnetizations against inhomogeneous perturbat

Akira Ohnishi, Jorgen Randrup

We formulate a method for incorporating quantum fluctuations into molecular- dynamics simulations of many-body systems, such as those employed for energetic nuclear collision processes. Based on Fermi&#39;s Golden Rule, we allow spontaneous transitions to occur between the wave packets which are not energy eigenstates. The ensuing diffusive evolution in the

L. L. Frankfurt, E. J. Moniz, M. M. Sargsyan, M. I. Strikman

The Glauber approximation is used to calculate the contribution of nucleon correlations in high-energy $A(e,e&#39;N)$ reactions. When the excitation energy of the residual nucleus is small, the increase of the nuclear transparency due to correlations between the struck nucleon and the other nucleons is mostly compensated by a decrease of the transparency due

Jean-Marc RICHARD

A brief review of antiproton--nucleus physics is presented. Some topics are related to early LEAR experiments, and others to more recent measurements or proposals. These include: exotic molecules, elastic and inelastic scattering, deep annihilation, strangeness production, neutron--antineutron oscillations, halo nuclei, antiproton production in nuclear react

David Gale, James Propp, Scott Sutherland, Serge Troubetzkoy

We discuss some properties of a class of cellular automata sometimes called a &#34;generalized ant&#34;. This system is perhaps most easily understood by thinking of an ant which moves about a lattice in the plane. At each vertex (or &#34;cell&#34;), the ant turns right or left, depending on the the state of the cell, and then changes the state of the cell a

Alexander A. Kirillov

These are the notes from a series of lectures the author gave at Harvard University in the Fall of 1994. The goal of these lectures is to give a self-contained exposition of recent result of Cherednik (\cite{C6}), who proved Macdonald&#39;s inner product conjectures (see \cite{M2}) for arbitrary root systems, using the algebraic structure he called ``double

Gerald KELNHOFER

The 3+1 dimensional Yang-Mills theory with the Pontryagin term included is studied on manifolds with a boundary. Based on the geometry of the universal bundle for Yang-Mills theory, the symplectic structure of this model is exhibited. The topological type of the quantization line bundles is shown to be determined by the torsion elements in the cohomology of

M. Navarro, V. Aldaya, M. Calixto

New features of a previously introduced Group Approach to Quantization are presented. We show that the construction of the symmetry group associated with the system to be quantized (the &#34;quantizing group&#34;) does not require, in general, the explicit construction of the phase space of the system, i.e., does not require the actual knowledgement of the g

Stephen Hwang, Henric Rhedin

We study the cohomology arising in the BRST formulation of G/H gauged WZNW models, i.e. in which the states of the gauged theory are projected out from the ungauged one by means of a BRST condition. We will derive for a general simple group $H$ with arbitrary level, conditions for which the cohomology is non-trivial. We show, by introducing a small perturbat

Ivan J. Muzinich, Stamatis Vokos

We calculate the leading quantum and semi-classical corrections to the Newtonian potential energy of two widely separated static masses. In this large-distance, static limit, the quantum behaviour of the sources does not contribute to the quantum corrections of the potential. These arise exclusively from the propagation of massless degrees of freedom. Our on

Frank Wilczek

The standard model of particle physics is marvelously successful. However, it is obviously not a complete or final theory. I shall argue here that the structure of the standard model gives some quite concrete, compelling hints regarding what lies beyond. Taking these hints seriously, one is led to predict the existence of new types of very weakly interacting

Alan Kostelecky, Rob Potting

Spontaneous breaking of CPT is possible in string theory. We show that it can arise at a level within reach of experiments at meson factories currently being built or designed. For $ϕ$, $B$, and $τ$-charm factories, we discuss the likely experimental string signatures and provide estimates of the bounds that might be attained in these machines.

J. R. Mureika, R. B. Mann

Some implications of the proposal that flavor nondiagonal couplings of neutrinos to gravity might resolve the solar neutrino problem are considered in the context of three neutrino flavours. Using an adiabatic approximation iso-SNU curves are calculated for the neutrinos which most likely contribute to the observed solar neutrino deficiency. We show that res

Aida X. El-Khadra, B. P. Mertens

We report on the status of the determination of the heavy quark masses from our calculation of the quarkonia spectra. All sources of systematic errors that enter the quark mass determination are accounted for. We explicitly keep $ma \neq 0$ in the perturbative calculation relating the bare lattice mass to a renormalized mass. Our results are still preliminar

J. B. Kogut, K. -C. Wang

Non-compact lattice QED is simulated for various numbers of fermion species $N_f$ ranging from 8 through 40 by the exact Hybrid Monte Carlo algorithm. Over this range of $N_f$, chiral symmetry breaking is found to be strongly correlated with the effective monopoles in the theory. For $N_f$ between 8 and 16 the chiral symmetry breaking and monopole percolatio

Lee Lin

According to one-loop perturbation theory, fermions whose masses are totally generated from Yukawa couplings do not decouple in the heavy mass limit. We investigate this issue nonperturbatively in a 4-dimensional $Z_2$ scalar-fermion model with staggered fermions. Our data at intermediate and stronger Yukawa couplings on $8^4$ and $12^4$ lattices suggest the

G. Dal Maso, I. V. Skrypnik

If $Au=-div(a(x,Du))$ is a monotone operator defined on the Sobolev space $W^{1,p}(R^n)$, $1<p<+\infty$, with $a(x,0)=0$ for a.e. $x\in R^n$, the capacity $C_A(E,F)$ relative to $A$ can be defined for every pair $(E,F)$ of bounded sets in $R^n$ with $E\subset F$. We prove that $C_A(E,F)$ is increasing and countably subadditive with respect to $E$ and decreas

N. Read

A recent theory of a compressible Fermi-liquid like state at Landau level filling factors $ν=1/q$ or $1-1/q$, $q$ even, is reviewed, with emphasis on the basic physical concepts.

A. J. Bray

The theory of phase ordering dynamics -- the growth of order through domain coarsening when a system is quenched from the homogeneous phase into a broken-symmetry phase -- is reviewed, with the emphasis on recent developments. Interest will focus on the scaling regime that develops at long times after the quench. How can one determine the growth laws that de

T. Giamarchi, P. Le Doussal

The effect of disorder on flux lattices at equilibrium is studied quantitatively in the absence of free dislocations using both the Gaussian variational method and the renormalization group. Our results for the mean square relative displacements clarify the nature of the crossovers with distance. We find three regimes: (i) a short distance regime (``Larkin r

R. Hlubina, T. M. Rice

We calculate the resistivity $ρ$ as a function of temperature $T$ for two models currently discussed in connection with high temperature superconductivity: nearly antiferromagnetic Fermi liquids and models with van Hove singularities on the Fermi surface. The resistivity is calculated semiclassicaly by making use of a Boltzmann equation which is formulated a

Karlo Penc, Frédéric Mila, Hiroyuki Shiba

We show that the one-particle spectral functions of the one-dimensional Hubbard model diverge at the Fermi energy like $|ω-\varepsilon_F|^{-3/8}$ in the $U\to +\infty $ limit. The Luttinger liquid behaviour $|ω-\varepsilon_F|^α$, where $α\to 1/8$ as $U\to +\infty $, should be limited to $|ω-\varepsilon_F| \sim t^2/U$ (for $U$ large but finite), which shrinks

B. A. Sanborn

This paper investigates the mobility of electrons scattering from the coupled system of electrons and longitudinal optical (LO) phonons in n-type GaAs. The Boltzmann equation is solved exactly for low electric fields by an iterative method, including electron-electron and electron-LO phonon scattering dynamically screened in the random-phase-approximation (R

B. A. Sanborn

This paper describes a simple and general method for deriving the inelastic collision term in the electron Boltzmann equation for scattering from a coupled electron-phonon system, and applies the method to the case of doped polar semiconductors. In the Born approximation, the inelastic differential scattering rate $W^{inel}$ can be expressed in terms of the

Dany PAGE

We consider, in general terms, the early thermal evolution of an isolated neutron star, i.e., during the first $10^5$ years after the supernova explosion when the cooling is driven by neutrino emission from the core. It is shown that, if fast neutrino emission is occuring, the surface temperature is actually determined by the critical temperature $T_c$ at wh

A. H. Jaffe

Recent observations by the Hubble Space Telescope of Cepheids in the Virgo cluster imply a Hubble Constant $H_0=80\pm17$\ km/sec/Mpc. We attempt to clarify some issues of interpretation of these results for determining the global cosmological parameters $Ω$ and $Λ$. Using the formalism of Bayesian model comparison, the data suggest a universe with a nonzero

Frederick M. Walter, Lynn D. Matthews, Jeffrey L. Linsky

Using new and archival spectra from the Goddard High Resolution Spectrograph, we have searched for evidence of chromospheric and transition region emission in six stars of mid- to late-A spectral type. Two of the stars, alpha Aql (A7 IV-V) and alpha Cep (A7 IV-V), show emission in the C~II 1335 A doublet, confirming the presence of hot plasma with temperatur

Hans-Walter Rix, Max-Planck- Inst. fuer Astrophysik

The shapes of dark halos (e.g. spherical, oblate or triaxial) provide important clues to the formation history of the halos, to their baryon content and to the nature of the dark matter. The halo shapes also influence the dynamics of the galaxy they harbor. This review discusses the current status of theoretical predictions (halo formation in a cosmological

Hans-Walter Rix, Max-Planck- Inst. fuer Astrophysik

In this paper I review how near-infrared (NIR) observations can constrain the opacity of spiral disks. Basic considerations show that NIR photometry provides a powerful probe of the optical depths in spiral galaxy disks in the regime of interest, where the optical depth in the V-band is near unity. I review the existing opacity constraints from the analysis

A. Bottino, C. W. Kim, J. Song

The amount of dark matter in the Milky Way and beyond is examined by taking into account the possible running of the gravitational constant $G$ as a function of distance scale. If the running of $G$, as suggested by the Asymptotically-Free Higher-Derivative quantum gravity, is incorporated into the calculation of the total dark matter in the galactic halo, t

J. Ohnemus

The cross section for producing $WZ$ pairs at hadron colliders is calculated to order $α_s$ for general $C$ and $P$ conserving $WWZ$ couplings. The effects of the next-to-leading-order corrections on the derived sensitivity limits for anomalous $WWZ$ couplings are discussed. The prospects for observing the approximate amplitude zero, which is present in the

F. Abe

The charge asymmetry has been measured using $19,039~W$ decays recorded by the CDF detector during the 1992-93 run of the Tevatron Collider. The asymmetry is sensitive to the ratio of $d$ and $u$ quark distributions to $x<0.01$ at $Q^2 \approx M_W^2$, where nonperturbative effects are minimal. It is found that of the two current sets of parton distributions,

N. J. MacKay

By placing theories with Yangian charges on the lattice in the analogue of the St Petersburg school&#39;s approach to the sine-Gordon system, we exhibit the Yangian structure of the auxiliary algebra, and explain how the two Yangians are related.

Marcus Hutter

The gluon propagator is calculated in the instanton background in a form appropriate for extracting the momentum dependent gluon mass. In background-$ξ$-gauge we get for the mass $400$MeV for small $p^2$ independent of the gauge parameter $ξ$.

Peter Peldan

The issue of how to deal with the modular transformations -- large diffeomorphisms -- in (2+1)-quantum gravity on the torus is discussed. I study the Chern-Simons/connection representation and show that the behavior of the modular transformations on the reduced configuration space is so bad that it is possible to rule out all finite dimensional unitary repre

W. Fischer, H. Leschke, P. Mueller

The capabilities of the functional-analytic and of the functional-integral approach for the construction of the Hamiltonian as a self-adjoint operator on Hilbert space are compared in the context of non-relativistic quantum mechanics. Differences are worked out by taking the one-dimensional hydrogen atom as an example, that is, a point mass on the Euclidean

M. Meyer-Hermann, A. Schäfer, W. Greiner

The concept of QCD sum rules is extended to bound states composed of particles with finite mass such as scalar quarks or strange quarks. It turns out that mass corrections become important in this context. The number of relevant corrections is analyzed in a systematic discussion of the IR- and UV-divergencies, leading in general to a finite number of correct

Anjan S. Joshipura, Probir Roy

Working group II at WHEPP3 concentrated on issues related to the supersymmetric standard model as well as SUSY GUTS and neutrino properties. The projects identified by various working groups as well as progress made in them since WHEPP3 are briefly reviewed.

N. Berglund, H. Kunz

We consider classical billiards in plane, connected, but not necessarily bounded domains. The charged billiard ball is immersed in a homogeneous, stationary magnetic field perpendicular to the plane. The part of dynamics which is not trivially integrable can be described by a &#34;bouncing map&#34;. We compute a general expression for the Jacobian matrix of

Ralph Sinkus

Feedforward neural networks with error backpropagation (FFBP) are widely applied to pattern recognition. One general problem encountered with this type of neural networks is the uncertainty, whether the minimization procedure has converged to a global minimum of the cost function. To overcome this problem a novel approach to minimize the error function is pr

Charilaos Aneziris

The goal of this paper is to discuss the possibility of finding an algorithm that can give all distinct knots up to a desired complexity. Two such algorithms are presented, one based on projections on a plane, the other on closed self-avoiding walks.

C. P. Burgess, J. -P. Derendinger, F. Quevedo, M. Quiros

We show how to formulate the phenomenon of gaugino condensation in a super-Yang-Mills theory with a field-dependent gauge coupling described with a linear multiplet. We prove the duality equivalence of this approach with the more familiar formulation using a chiral superfield. In so doing, we resolve a longstanding puzzle as to how a linear-multiplet formula

C. Borgs, R. Kotecky

We consider classical lattice models describing first-order phase transitions, and study the finite-size scaling of the magnetization and susceptibility. In order to model the effects of an actual surface in systems like small magnetic clusters, we consider models with free boundary conditions. For a field driven transition with two coexisting phases at the

P. G. Grinevich, S. P. Novikov

Beginning from 1981 one of the present authors (S.Novikov) published a series of papers, (some of them in collaboration with I.Schmelzer and I.Taimanov) dedicated to the development of the analog of Morse theory for the closed 1-forms -- multivalued functions and functionals -- on the finite - and infinite-dimensional manifolds ({\bf Morse-Novikov Theory}).

M. Czachor, A. Posiewnik

It is shown that the spin operator can be described by an algebra which is in between so(3) and e(2). Relativistic version of the singlet state for two Dirac electrons is discussed. It is shown that a measure of massless particle&#39;s extension can be naturally constructed and that this measure corresponds at the classical level to the radius of the Robinso

Raymond Y. Chiao, Paul G. Kwiat, Aephraim M. Steinberg

We review some of our experiments performed over the past few years on two-photon interference. These include a test of Bell&#39;s inequalities, a study of the complementarity principle, an application of EPR correlations for dispersion-free time-measurements, and an experiment to demonstrate the superluminal nature of the tunneling process. The nonlocal cha

A. Bianconi, S. Jeschonnek, N. N. Nikolaev, B. G. Zakharov

The strength of final state interaction (FSI) between struck proton and spectator neutron in $^2\vec{H}(e,e&#39;p)$ scattering depends on the alignment of the deuteron. We study the resulting FSI effects in the tensor analyzing power in detail and find substantial FSI effects starting at still low missing momentum $p_m \gsim 0.9 fm^{-1}$. At larger $p_m \gsi

N. N. Nikolaev, J. Speth, B. G. Zakharov

We develop the Glauber theory description of final-state interaction (FSI) in quasielastic $A(e,e&#39;p)$ scattering. The important new effect is an interaction between the two trajectories which enter the calculation of FSI-distorted one-body density matrix and are connected with incoherent elastic rescatterings of the struck proton on spectator nucleons. W

Gregory Pelts

We demonstrate in detail how the space of two-dimensional quantum field theories can be parametrized by off-shell closed string states. The dynamic equation corresponding to the condition of conformal invariance includes an infinite number of higher order terms, and we give an explicit procedure for their calculation. The symmetries corresponding to equivale

N. R. F. Braga, C. Wotzasek

The chiral boson actions of Floreanini and Jackiw (FJ), and of McClain,Wu and Yu (MWY) have been recently shown to be different representations of the same chiral boson theory. MWY displays manifest covariance and also a (gauge) symmetry that is hidden in the FJ side, which, on the other hand, displays the physical spectrum in a simple manner. We make use of

R. J. Henderson, S. G. Rajeev

We obtain a bilocal classical field theory as the large $N$ limit of the chiral Gross--Neveu (or non--abelian Thirring) model. Exact classical solutions that describe topological solitons are obtained. It is shown that their mass spectrum agrees with the large $N$ limit of the spectrum of the chiral Gross--Neveu model.

J. Underwood, B. Spence

We quantise the reduced theory obtained by substituting the soliton solutions of affine Toda theory into its symplectic form. The semi-classical S-matrix is found to involve the classical Euler dilogarithm.

Daniel Kastler, Thomas Schucker

We give a detailed account of the computation of the Yang-Mills action for the Connes-Lott model with general coupling constant in the commutant of the $K$-cycle. This leads to tree-approximation results amazingly compatible with experiment, yielding a first indication on the Higgs mass.

Andre LeClair

We present a new application of affine Lie algebras to massive quantum field theory in 2 dimensions, by investigating the $q\to 1$ limit of the q-deformed affine $\hat{sl(2)}$ symmetry of the sine-Gordon theory, this limit occurring at the free fermion point. We describe how radial quantization leads to a quasi-chiral factorization of the space of fields. Th

Matthias Blau, George Thompson

We review localization techniques for functional integrals which have recently been used to perform calculations in and gain insight into the structure of certain topological field theories and low-dimensional gauge theories. These are the functional integral counterparts of the Mathai-Quillen formalism, the Duistermaat-Heckman theorem, and the Weyl integral

Alexei Yu. Nurmagambetov, Vladimir I. Tkach

A generalization of the twistor shift procedure to the case of superparticle interacting with the background D=3 N=1 Maxwell and D=3 N=1 supergravity supermultiplet is considered. We investigate twistor shift effects and discuss the structure of the resulting constraint algebra.

H. Arodz

Relativistic domain walls are studied in the framework of a polynomial approximation to the field interpolating between different vacua and forming the domain wall. In this approach we can calculate evolution of a core and of a width of the domain wall. In the single, cubic polynomial approximation used in this paper, the core obeys Nambu-Goto equation for a

Ralph Blumenhagen, Andreas Wisskirchen

We present a dual formulation of the construction of N=2 nonlinear sigma-model type conformal field theories with c=9 which are mainly used as internal sectors of Calabi-Yau heterotic string compactifications. The supercurrents and the higher components of the spectral flow superfields turn out in each case to be tensor products of two simple currents of a c