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Sep 21, 2013
09/13

by
D. C. Zheng; B. R. Barrett; L. Jaqua; J. P. Vary; R. J. McCarthy

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We perform large-space shell-model calculations for the low-lying energy spectra of a few light nuclei, $^4\mbox{He}$, $^5\mbox{He}$, $^6\mbox{Li}$ and $^7\mbox{Li}$, in a no-core model space with a realistic effective two-body interaction (Brueckner G-matrix). Our G-matrices are calculated for the Reid-soft-core potential in a harmonic oscillator basis. Single-particle ``-U'' insertions are replaced by two-particle ``-U'' insertions and are included in the G matrix calculations, which sum them...

Source: http://arxiv.org/abs/nucl-th/9304025v1

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Sep 21, 2013
09/13

by
Emil Martinec

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The causal boundary of string propagation -- defined as the hypersurface in loop space bordering the timelike(spacelike) domains in which two successive measurements of the string field do(do not) interfere with one another -- is argued to be $0=\int d\sigma\bigl(\delta X(\sigma)\bigr)^2 = \sum_{\ell=-\infty}^\infty \delta x^\mu_{-\ell}\delta x_{\mu \ell}.$ Some possible consequences are discussed.

Source: http://arxiv.org/abs/hep-th/9304037v2

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Sep 21, 2013
09/13

by
Heiko Rieger; A. P. Young

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The phase transition of the three--dimensional random field Ising model with a discrete ($\pm h$) field distribution is investigated by extensive Monte Carlo simulations. Values of the critical exponents for the correlation length, specific heat, susceptibility, disconnected susceptibility and magnetization are determined simultaneously via finite size scaling. While the exponents for the magnetization and disconnected susceptibility are consistent with a first order transition, the specific...

Source: http://arxiv.org/abs/hep-lat/9304007v1

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Sep 21, 2013
09/13

by
C. J. Horowitz; H. O. Meyer; D. Griegel

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Recent calculations of $s$-wave pion production have severely underestimated the accurately known $pp\rightarrow pp\pi^0$\ total cross section near threshold. In these calculations, only the single-nucleon axial-charge operator is considered. We have calculated, in addition to the one-body term, the two-body contributions to this reaction that arise from the exchange of mesons. We find that the inclusion of the scalar $\sigma$-meson exchange current (and lesser contributions from other mesons)...

Source: http://arxiv.org/abs/nucl-th/9304004v1

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Sep 21, 2013
09/13

by
G. Barnich; M. Henneaux

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The antibracket in BRST theory is known to define a map $\rm{H^p \times H^q \longrightarrow H^{p+q+1}}$ associating with two equivalence classes of BRST invariant observables of respective ghost number p and q an equivalence class of BRST invariant observables of ghost number p+q+1. It is shown that this map is trivial in the space of all functionals, i.e., that its image contains only the zeroth class. However it is generically non trivial in the space of local functionals. Implications of...

Source: http://arxiv.org/abs/hep-th/9304057v1

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Sep 21, 2013
09/13

by
O. Golinelli; Th. Jolicoeur; R. Lacaze

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We investigate the magnetic field behaviour of an antiferromagnetic Heisenberg spin-1 chain with the most general single-ion anisotropy. We discuss the regime in which the magnetic field is below the transition value. The splitting of the Haldane triplet is obtained as a function of a field applied in an arbitrary orientation by means of a Lancz\H os exact diagonalization of chains of up to 16 spins. Our results are nicely summarized in terms of a first-order perturbation theory. We explain...

Source: http://arxiv.org/abs/cond-mat/9304041v1

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Sep 21, 2013
09/13

by
H. C. Eggers; P. Lipa; P. Carruthers; B. Buschbeck

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We report on a considerable improvement in the technique of measuring multiparticle correlations via integrals over correlation functions. A modification of measures used in the characterization of chaotic dynamical sytems permits fast and flexible calculation of factorial moments and cumulants as well as their differential versions. Higher order correlation integral measurements even of large multiplicity events such as encountered in heavy ion collisons are now feasible. The change from...

Source: http://arxiv.org/abs/hep-ph/9304208v1

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Sep 21, 2013
09/13

by
R. Manka; I. Bednarek; D. Karczewska

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It is suggested that the nonorthodox model of a quasar as a neutrino ball described in terms of the standard model extended by adding right-handed neutrinos and the Majorana scalar field can be presented in order to explain a quasar as a body of weak interacting neutrinos. Neutrino interaction with the scalar Majorana field violates the lepton number and produces the mass splitting of the neutrino due to the sea-saw mechanism. In this model a quasar is an object which appears in the result of...

Source: http://arxiv.org/abs/astro-ph/9304007v1

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Sep 21, 2013
09/13

by
Penny D. Sackett; Andrew Gould

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If massive compact halo objects (\ms) are detected in ongoing searches, then \tsmctlmc, the ratio of the optical depth toward the Small and Large Magellanic Clouds, will be a robust indicator of the flattening of the Galactic dark matter halo. For a spherical halo, \tsmctlmc\ is about 1.45, independent of details of the shape of the Galactic rotation curve, the assumed mass of the Galactic disk and spheroid, and the truncation distance (if any) of the dark halo. For an E6 halo (axis ratio $c/a...

Source: http://arxiv.org/abs/astro-ph/9304023v1

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Sep 21, 2013
09/13

by
J. A. McNeil; C. E. Price

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We study a hybrid chiral model for the nucleon based on the linear sigma model with explicit quarks. We solve the model using a Fock-space configuration consisting of three quarks plus three quarks and a pion as the ground state ansatz in place of the ``hedgehog'' ansatz. We minimize the expectation value of the chiral hamiltonian in this ground state configuration and solve the resulting equations for nucleon quantum numbers. We calculate the canonical set of nucleon observables and compare...

Source: http://arxiv.org/abs/nucl-th/9304007v1

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Sep 21, 2013
09/13

by
Mirjam Cvetic

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We study dilatonic domain walls specific to superstring theory. Along with the matter fields and metric the dilaton also changes its value in the wall background. We found supersymmetric (extreme) solutions which in general interpolate between isolated superstring vacua with non-equal value of the matter potential; they correspond to the static, planar domain walls with {\it flat} metric in the string (sigma model) frame. We point out similarities between the space-time of dilatonic walls and...

Source: http://arxiv.org/abs/hep-th/9304062v1

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Sep 21, 2013
09/13

by
Hans-Walter Rix; Marcia J. Rieke

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We present optical and IR surface photometry of M51 (NGC~5194) at B~V~R~I~J~K and CO$(2.3\mu )$. These data are used to establish whether K-band ($2.2\mu$) images of spiral galaxies provide reliable maps of stellar surface mass density features such as massive spiral arms or bars. The main distorting agents in the mapping at shorter wavelengths are dust extinction and luminous young stars. From modeling the color changes across the main dust lanes in M51, we find that the K-band flux is...

Source: http://arxiv.org/abs/astro-ph/9304006v1

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Sep 21, 2013
09/13

by
Yves Brihaye; Jutta Kunz

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We consider non-perturbative solutions of the Weinberg-Salam model at finite temperature. We employ an effective temperature-dependent potential yielding a first order phase transition. In the region of the phase transition, there exist two kinds of static, spherically symmetric solutions: sphalerons and bubbles. We analyze these solutions as functions of temperature. We consider the most general spherically symmetric fluctuations about the two solutions and construct the discrete modes in the...

Source: http://arxiv.org/abs/hep-ph/9304256v1

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Sep 21, 2013
09/13

by
Alexander Sevrin; Kris Thielemans; Walter Troost

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The effective actions for $d=2$, $N=3,4$ chiral supergravities with a linear and a non-linear gauge algebra are related to each other by a quantum reduction, the latter is obtained from the former by putting quantum currents equal to zero. This implies that the renormalisation factors for the quantum actions are identical.

Source: http://arxiv.org/abs/hep-th/9304020v1

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Sep 21, 2013
09/13

by
J. Soto; R. Tzani

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Extra symmetries are shown to exist in the effective theory of heavy quarks when both quarks and anti-quarks with the same velocity are included. These symmetries mix the quark with the anti-quark sector and they resemble axial-type of symmetries. Together with the known flavor and spin symmetries they form a $u(4)$ algebra when a single flavor is considered. It is shown that the full $U(4)$ set of symmetries breaks spontaneously down to $ U(2) \otimes U(2)$. The Goldstone modes corresponding...

Source: http://arxiv.org/abs/hep-ph/9304305v1

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Sep 21, 2013
09/13

by
Claudio Coriano'

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We extend previous work on sum rules for the invariant amplitudes of pion Compton scattering by deriving a complete lowest order perturbative spectral function - and its leading non perturbative power corr ections - for a specific combination of the two helicities $(H_1 + H_2)$ of this process. Using some properties of a modified version of the Borel transform, we develop a method of calculation of the gluonic corrections which can be easily extended to other similar reactions, such as proton...

Source: http://arxiv.org/abs/hep-ph/9304210v1

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Sep 21, 2013
09/13

by
P. Binetruy; E. A. Dudas; F. Pillon

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The dynamical breakdown of the $SU(2) \times U(1)$ symmetry triggered by a top-antitop condensate is studied in a supersymmetric version of the gauged Nambu-Jona-Lasinio model. An effective potential approach is used to investigate the vacuum structure and the equivalence with the minimal supersymmetric standard model. The role of the soft supersymmetry breaking terms is analyzed in detail in a version of the model where the electroweak gauge interactions are turned off.

Source: http://arxiv.org/abs/hep-ph/9304278v1

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Sep 21, 2013
09/13

by
Patrick Dorey

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The affine Toda field theories based on the non simply-laced Lie algebras are discussed. By rewriting the S-matrix formulae found by Delius et al, a universal form for the coupling-constant dependence of these models is obtained, and related to various general properties of the classical couplings. This is illustrated via the S-matrix associated with the dual pair of algebras $f_4^{(1)}$ and $e_6^{(2)}$.

Source: http://arxiv.org/abs/hep-th/9304149v1

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Sep 21, 2013
09/13

by
Lizeng Zhang

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A hard-core disordered boson system is mapped onto a quantum spin 1/2 XY-model with transverse random fields. It is then generalized to a system of spins with an arbitrary magnitude S and studied through a 1/S expansion. The first order 1/S expansion corresponds to a spin-wave theory. The effect of weak disorder is studied perturbatively within such a first order 1/S scheme. We compute the reduction of the speed of sound and the life time of the Bloch phonons in the regime of weak disorder....

Source: http://arxiv.org/abs/cond-mat/9304016v1

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Sep 21, 2013
09/13

by
Göran Fäldt; Per Osland

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We evaluate, in the high-energy limit, $s\gg|t|\gg m^2\gg\lambda^2$, the sum of amplitudes corresponding to a class of Feynman diagrams describing two-loop virtual photonic corrections to Bhabha scattering. The diagrams considered are box and crossed box diagrams with a vacuum polarization insertion in one of the photon lines.

Source: http://arxiv.org/abs/hep-ph/9304301v1

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Sep 21, 2013
09/13

by
Denny H. Leung

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A Banach space is polyhedral if the unit ball of each of its finite dimensional subspaces is a polyhedron. It is known that a polyhedral Banach space has a separable dual and is $c_0$-saturated, i.e., each closed infinite dimensional subspace contains an isomorph of $c_0$. In this paper, we show that the Orlicz sequence space $h_M$ is isomorphic to a polyhedral Banach space if $\lim_{t\to 0}M(Kt)/M(t) = \infty$ for some $K < \infty$. We also construct an Orlicz sequence space $h_M$ which is...

Source: http://arxiv.org/abs/math/9304206v1

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Sep 21, 2013
09/13

by
Vassil Kanev

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With every smooth, projective algebraic curve $\tilde{C}$ with involution $\sigma :\tilde{C}\longrightarrow \tilde{C}$ without fixed points is associated the Prym data which consists of the Prym variety $P:=(1-\sigma )J(\tilde{C})$ with principal polarization $\Xi$ such that $2\Xi$ is algebraically equivalent to the restriction on $P$ of the canonical polarization $\Theta $ of the Jacobian $J(\tilde{C})$. In contrast to the classical Torelli theorem the Prym data does not always determine...

Source: http://arxiv.org/abs/alg-geom/9304006v1

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Sep 21, 2013
09/13

by
Edwin Langmann

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We discuss the restricted linear group in infinite dimensions modeled by the Schatten class of rank $2p=4$ which contains $(3+1)$-dimensional analog of the loop groups and is closely related to Yang-Mills theory with fermions in $(3+1)$-dimensions. We give an alternative to the construction of the ``highest weight'' representation of this group found by Mickelsson and Rajeev. Our approach is close to quantum field theory, with the elements of this group regarded as Bogoliubov transformations...

Source: http://arxiv.org/abs/hep-th/9304114v2

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Sep 21, 2013
09/13

by
P. Azaria; B. Delamotte; F. Delduc; Th. Jolicoeur

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We study a non linear sigma model $O(N)\otimes O(2)/O(N-2)\otimes O(2)$ describing the phase transition of N-components helimagnets up to two loop order in $D=2+\epsilon$ dimensions. It is shown that a stable fixed point exists as soon as $N$ is greater than 3 (or equal). In the N=3 case, the symmetry of the system is dynamically enlarged at the fixed point to O(4) We show that the order parameter for Heisenberg helimagnets involves a tensor representation of $O(4)$. We show that for large $N$...

Source: http://arxiv.org/abs/cond-mat/9304049v1

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Sep 21, 2013
09/13

by
Paul A. Pearce; Yu-kui Zhou

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Intertwiners between \ade lattice models are presented and the general theory developed. The intertwiners are discussed at three levels: at the level of the adjacency matrices, at the level of the cell calculus intertwining the face algebras and at the level of the row transfer matrices. A convenient graphical representation of the intertwining cells is introduced. The utility of the intertwining relations in studying the spectra of the \ade models is emphasized. In particular, it is shown that...

Source: http://arxiv.org/abs/hep-th/9304009v2

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Sep 21, 2013
09/13

by
M. Gleiser; G. C. Marques; R. O. Ramos

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We examine the computation of the nucleation barrier used in the expression for false vacuum decay rates in finite temperature field theory. By a detailed analysis of the determinantal prefactor, we show that the correct bounce solution used in the computation of the nucleation barrier should not include loop corrections coming from the scalar field undergoing decay. Temperature corrections to the bounce appear from loop contributions from other fields coupled to the scalar field. We compute...

Source: http://arxiv.org/abs/hep-ph/9304234v1

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Sep 21, 2013
09/13

by
C. J. Benesh; T. Goldman; G. J. Stephenson Jr

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We calculate order $\alpha_s$ color magnetic corrections to the valence quark distributions of the proton using the Los Alamos Model Potential wavefunctions. The spin-spin interaction breaks the model SU(4) symmetry, providing a natural mechanism for the difference between the up and down distributions. For a value of $\alpha_s$ sufficient to produce the $N-\Delta$ mass splitting, we find up and down quark distributions in reasonable agreement with experiment.

Source: http://arxiv.org/abs/nucl-th/9304016v1

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Sep 21, 2013
09/13

by
Hai-Yang Cheng; B. Tseng

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Cabibbo-allowed nonleptonic weak decays of charmed baryons $\lamc,~\xin,~\xip$ and $\Omega_c^0$ into an octet baryon and a pseudoscalar meson are analyzed. The nonfactorizable contributions are evaluated under pole approximation, and it turns out that the $s$-wave amplitudes are dominated by the low-lying $\halfm$ resonances, while $p$-wave ones governed by the ground-state $\halfp$ poles. The MIT bag model is employed to calculate the coupling constants, form factors and baryon matrix...

Source: http://arxiv.org/abs/hep-ph/9304286v1

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Sep 21, 2013
09/13

by
T. Eguchi; Y. Yamada; S. -K. Yang

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We discuss topological Landau-Ginzburg theories coupled to the 2-dimensional topological gravity. We point out that the basic recursion relations for correlation functions of the 2-dimesional gravity have exactly the same form as the Gauss-Manin differential equations for the period integrals of superpotentials. Thus the one-point functions on the sphere of the Landau-Ginzburg theories are given exactly by the period integrals. We discuss various examples, A-D-E minimal models and the $c=3$...

Source: http://arxiv.org/abs/hep-th/9304121v1

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Sep 21, 2013
09/13

by
Yosef Nir; Nathan Seiberg

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For generic squark masses, box diagrams with squarks and gluinos give unacceptably large contributions to neutral meson ($K$, $B$ and $D$) mixing. The standard solution to this problem is to assume that squarks are degenerate to a very good approximation. We suggest an alternative mechanism to suppress squark contributions to flavor changing neutral currents: the alignment of quark with squark mass matrices. This mechanism arises naturally in the framework of Abelian horizontal symmetries.

Source: http://arxiv.org/abs/hep-ph/9304307v1

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Sep 21, 2013
09/13

by
Aric Hagberg; Ehud Meron

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Domain walls in equilibrium phase transitions propagate in a preferred direction so as to minimize the free energy of the system. As a result, initial spatio-temporal patterns ultimately decay toward uniform states. The absence of a variational principle far from equilibrium allows the coexistence of domain walls propagating in any direction. As a consequence, *persistent* patterns may emerge. We study this mechanism of pattern formation using a non-variational extension of Landau's model for...

Source: http://arxiv.org/abs/patt-sol/9304002v1

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Sep 21, 2013
09/13

by
Ranjeet S. Tate

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From the point of view of canonical quantum gravity, it has become imperative to find a framework for quantization which provides a {\em general} prescription to find the physical inner product, and is flexible enough to accommodate non-canonical variables. In this dissertation I consider an algebraic formulation of the Dirac approach to the quantization of constrained systems, due to A. Ashtekar. The Dirac quantization program is augmented by a general principle to find the inner product on...

Source: http://arxiv.org/abs/gr-qc/9304043v2

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Sep 21, 2013
09/13

by
T. Jungwirth; L. Smrcka

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The effect of strong magnetic fields parallel to GaAs/AlGaAs interface on the subband structure of a 2D electron layer is ivestigated theoretically. The system with two levels occupied in zero magnetic field is considered and the magnetic field induced depletion of the second subband is studied. The confining potential and the electron dispersion relations are calculated self-consistently, the electron- electron interaction is taken into account in the Hartree approximation.

Source: http://arxiv.org/abs/cond-mat/9304036v1

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Sep 21, 2013
09/13

by
Garvin Melles

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Let V be the universe of sets and V_{\alpha} the sets of rank \leq\alpha. We develop some axiom schemata for set theory based on the following three assumptions: 1. V \models ZFC 2. V is large with respect to the class of ordinals 3. V is large with respect to each of the V_{\alpha}

Source: http://arxiv.org/abs/math/9304202v1

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Sep 21, 2013
09/13

by
K. Krisciunas; C. Aspin; T. R. Geballe; H. Akazawa; C. F. Claver; E. F. Guinan; H. J. Landis; K. D. Luedeke; N. Ohkura; O. Ohshima; D. R. Skillman

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The F0 V star 9 Aur A exhibits an irregular variability of amplitude $\approx $0.1 magnitude at optical wavelengths. The variations are too slow for it to be a $\delta$ Scuti-type star. There is no evidence for a close, interacting companion or ring of dust, either from infrared, ultraviolet, or speckle data. The photometric variability of 9 Aur A is similar to two other early F dwarf stars: $\gamma$ Doradus and HD 96008. 9 Aur B appears to be an M dwarf, 9 Aur C is an early- to mid-K dwarf...

Source: http://arxiv.org/abs/astro-ph/9304008v1

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Sep 21, 2013
09/13

by
Sanjay K. Ghosh; S. C. Phatak; Pradip K. Sahu

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An exact numerical calculation of neutrino emissivity of two and three flavour quark matter have been carried out. We find that the neutrino emissivity obtained from the Iwamoto formula is in qualitative agreement with our calculation for two flavour quark matter. For three flavour case, on the other hand we find that the Iwamoto formula overestimates the numerical values by $\sim$2 orders of magnitude or more for d decay and agrees with the s decay results within a factor of 3-4. The...

Source: http://arxiv.org/abs/astro-ph/9304020v1

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Sep 21, 2013
09/13

by
I. Hauser; F. J. Ernst

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Following an idea close to one given by C. G. Torre (private communication), we prove that Riemannian spaces (M,g) and (M,h) that are related by a Gurses type (b) transformation [M. Gurses, Phys. Rev. Lett. 70, 367 (1993)] or, equivalently, by a Torre-Anderson generalized diffeomorphism [C. G. Torre and I. M. Anderson, Phys. Rev. Lett. xx, xxx (1993)] are neighborhood-isometric, i.e., every point x in M has a corresponding diffeomorphism phi of a neighborhood V of x onto a generally different...

Source: http://arxiv.org/abs/gr-qc/9304013v1

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Sep 21, 2013
09/13

by
S. M. Bilenky; C. Giunti; V. Wataghin

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The discussion on the asymptotical behaviour of the form factors in the space-like and time-like regions have been corrected and clarified. Fig.3 has been replaced by an improved analysis of the data.

Source: http://arxiv.org/abs/hep-ph/9304221v2

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Sep 21, 2013
09/13

by
Satchidananda Naik

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The coefficient of the O(a)-improved Sheikholeslami-Wohlert action for Wilson fermions are perturbatively determined at one-loop level and estimated at two-loop level.

Source: http://arxiv.org/abs/hep-lat/9304013v1

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Sep 21, 2013
09/13

by
B. V. Danilin; M. V. Zhukov; J. S. Vaagen; I. J. Thompson; J. M. Bang

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The electric dipole response of the halo nucleus $^{11}$Li is calculated in a hyperspherical three-body formulation, and is studied as a function of the interaction employed for $n-^9$Li to reflect the Pauli principle. Strength concentrations at lower energies are found but no narrow resonances. Only one possible scenario of $^{11}$Li structure is in close correspondence with MSU and RIKEN experimental data.

Source: http://arxiv.org/abs/nucl-th/9304018v1

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Sep 21, 2013
09/13

by
L. P. Grishchuk

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It is shown that only a narrow class of inflationary models can possibly agree with the available observational data on the anisotropy of the cosmic microwave background radiation (CMBR). These models may be governed by ``matter'' with the effective equation of state $-1.2

Source: http://arxiv.org/abs/gr-qc/9304018v1

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Sep 21, 2013
09/13

by
Noboru Kawamoto

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Recent numerical results on the fractal structure of two-dimensional quantum gravity coupled to $c=-2$ matter are reviewed. Analytic derivation of the fractal dimensions based on the Liouville theory and diffusion equation is also discussed. Excellent agreements between the numerical and theoretical results are obtained. Some problems on the non-universal nature of the fractal structure in the continuum limit are pointed out....

Source: http://arxiv.org/abs/hep-th/9304117v1

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Sep 21, 2013
09/13

by
Enrico Celeghini; M. Tarlini

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The first ``Convegno Informale su Quantum Groups'' was held in Florence from February 3 to 6, 1993. This Convegno was conceived as an informal meeting to bring together all the italian people working in the field of quantum groups and related topics. We are very happy indeed that about 30 theoretical physicists decided to take part presenting many aspects of this interesting and live subject of research. We thank all the participants for the stimulating and nice atmosphere that has...

Source: http://arxiv.org/abs/hep-th/9304160v1

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Sep 21, 2013
09/13

by
Z. Neda

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We show that instantaneous configurations of 180 degree domain walls constructed on a square lattice in a two-dimensional and S=1/2 Ising-type model exhibit fractal structure. The fractal dimension depends on the coupling parameters and it is a continious function of the temperature. The wall thickness in the neighbourhood of Tc presents scaling properties in good agreement with the classical theory by Landau.

Source: http://arxiv.org/abs/cond-mat/9304048v1

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Sep 21, 2013
09/13

by
Kikuo Harigaya

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Effects on C$_{60}$ by thermal fluctuations of phonons, misalignment of C$_{60}$ molecules in a crystal, and other intercalated impurities (remaining C$_{70}$, oxygens, and so on) are simulated by disorder potentials. The Su-Schrieffer-Heeger--type electron-phonon model for doped C$_{60}$ is solved with gaussian bond disorders and also with site disorders. Sample average is performed over sufficient number of disorder configurations. The distributions of bond lengths and electron densities are...

Source: http://arxiv.org/abs/cond-mat/9304042v1

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Sep 21, 2013
09/13

by
Vittorio Del Duca; Wai-Keung Tang

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The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at very high energies.

Source: http://arxiv.org/abs/hep-ph/9304296v1

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Sep 19, 2013
09/13

by
Yu. Makeenko

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I show that the strong coupling solution of the Kazakov--Migdal model with a general interaction potential $V(\Phi)$ in $D$ dimensions coincides at large $N$ with that of the hermitean one-matrix model with the potential $\tilde{V}(\Phi)$: $$ (2D-1)\tilde{V}'= (D-1)V'+ D\sqrt{(V')^2+4(1-2D)\Phi^2}, $$ whose solution is known. The proof is given for an even potential $V(\Phi)=V(-\Phi)$ by solving loop equations.

Source: http://arxiv.org/abs/hep-th/9303138v3

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Sep 21, 2013
09/13

by
Arne L. Larsen

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A general family of charge-current carrying cosmic string models is investigated. In the special case of circular configurations in arbitrary axially symmetric gravitational and electromagnetic backgrounds the dynamics is determined by simple point particle Hamiltonians. A certain "duality" transformation relates our results to previous ones, obtained by Carter et. al., for an infinitely long open stationary string in an arbitrary stationary background.

Source: http://arxiv.org/abs/hep-th/9304086v1

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Sep 21, 2013
09/13

by
M. Asorey; S. Carlip; F. Falceto

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In an abelian topologically massive gauge theory, any eigenstate of the Hamiltonian can be decomposed into a factor describing massive propagating gauge bosons and a Chern-Simons wave function describing a set of nonpropagating ``topological'' excitations. The energy depends only on the propagating modes, and energy eigenstates thus occur with a degeneracy that can be parametrized by the Hilbert space of the pure Chern-Simons theory. We show that for a {\em nonabelian} topologically massive...

Source: http://arxiv.org/abs/hep-th/9304081v1

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Sep 21, 2013
09/13

by
Viqar Husain

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A four dimensional generally covariant field theory is presented which describes non-dynamical three geometries coupled to scalar fields. The theory has an infinite number of physical observables (or constants of the motion) which are constructed from loops made from scalar field configurations. The Poisson algebra of these observables is closed and is the same as that for the 3+1 gravity loop variables in the Ashtekar formalism. The theory also has observables that give the areas of open...

Source: http://arxiv.org/abs/gr-qc/9304010v1