4,226 research outputs found
Covariant hamiltonian dynamics
We discuss the covariant formulation of the dynamics of particles with
abelian and non-abelian gauge charges in external fields. Using this
formulation we develop an algorithm for the construction of constants of
motion, which makes use of a generalization of the concept of Killing vectors
and tensors in differential geometry. We apply the formalism to the motion of
classical charges in abelian and non-abelian monopole fieldsComment: 15 pages, no figure
Effective action of magnetic monopole in three-dimensional electrodynamics with massless matter and gauge theories of superconductivity
We compute one-loop effective action of magnetic monopole in
three-dimensional electrodynamics of massless bosons and fermions and find that
it contains an infrared logarithm. So, when the number of massless matter
species is sufficiently large, monopoles are suppressed and in the weak
coupling limit charged particles are unconfined. This result provides some
support to gauge theories of high-temperature superconductors. It also provides
a mechanism by which interlayer tunneling of excitations with one unit of the
ordinary electric charge can be suppressed while that of a doubly charged
object is allowed.Comment: 8 pages, LATEX, UCLA/93/TEP/41 (the last sentence of the paragraph
concerning applications at the end of the paper has been deleted; mailing
problems have been corrected
Large-scale Ferrofluid Simulations on Graphics Processing Units
We present an approach to molecular-dynamics simulations of ferrofluids on
graphics processing units (GPUs). Our numerical scheme is based on a
GPU-oriented modification of the Barnes-Hut (BH) algorithm designed to increase
the parallelism of computations. For an ensemble consisting of one million of
ferromagnetic particles, the performance of the proposed algorithm on a Tesla
M2050 GPU demonstrated a computational-time speed-up of four order of magnitude
compared to the performance of the sequential All-Pairs (AP) algorithm on a
single-core CPU, and two order of magnitude compared to the performance of the
optimized AP algorithm on the GPU. The accuracy of the scheme is corroborated
by comparing the results of numerical simulations with theoretical predictions
Supersymmetry Breaking Triggered by Monopoles
We investigate N = 1 supersymmetric gauge theories where monopole
condensation triggers supersymmetry breaking in a metastable vacuum. The
low-energy effective theory is an O'Raifeartaigh-like model of the kind
investigated recently by Shih where the R-symmetry can be spontaneously broken.
We examine several implementations with varying degrees of phenomenological
interest.Comment: 20 pages, 4 figures (v2: minor clarifications and typos fixed
K*-couplings for the antidecuplet excitation
We estimate the coupling of the K* vector meson to the N-->Theta+ transition
employing unitary symmetry, vector meson dominance, and results from the GRAAL
Collaboration for eta photoproduction off the neutron. Our small numerical
value for the coupling constant is consistent with the non-observation of the
Theta+ in recent CLAS searches for its photoproduction. We also estimate the
K*-coupling for the N-->Sigma* excitation, with Sigma* being the Sigma-like
antidecuplet partner of the Theta+-baryon.Comment: 9 pages, 1 figure. Minor changes in text and abstract, references
added; version to appear in Phys. Rev.
BRST invariance and de Rham-type cohomology of 't Hooft-Polyakov monopole
We exploit the 't Hooft-Polyakov monopole to define closed algebra of the
quantum field operators and the BRST charge . In the first-class
configuration of the Dirac quantization, by including the -exact
gauge fixing term and the Faddeev-Popov ghost term, we find the BRST invariant
Hamiltonian to investigate the de Rham-type cohomology group structure for the
monopole system. The Bogomol'nyi bound is also discussed in terms of the
first-class topological charge defined on the extended internal 2-sphere.Comment: 8 page
Gravitating magnetic monopole in Vaidya geometry
A magnetic-monopole solution of a non-Abelian gauge theory as proposed by 't
Hooft and Polyakov is studied in the Vaidya spacetime. We find that the
solutions of Einstein equations generates a geometry of the Bonnor-Vaidya
corresponding to magnetically charged null fluid with Higgs field contributing
a cosmological term. In the absence of the scalar fields the corresponding
Wu-Yang solution of the gauge theory still generates the Bonnor-Vaidya
geometry, but with no cosmological term.Comment: 5 RevTeX pages, no figures, minor changes, to appear in Physical
Review
Temperature Dependence of Extended and Fractional SU(3) Monopole Currents
We examine in pure SU(3) the dependence of extended monopole current k and
cross-species extended monopole current k^{cross} on temperature t, monopole
size L, and fractional monopole charge 1/q. We find that features of both k and
k^{cross} are sensitive to t for a range of L and q. In particular, the
spatial-temporal asymmetry ratios of both k and k^{cross} are sensitive over a
range of L and q to the SU(3) deconfinement transition. The motivation for
studying cross, extended, and fractional monopoles in SU(3) is given.Comment: 15 pages (archiving final publication version; very minor revisions
Supersymmetric N=2 Einstein-Yang-Mills monopoles and covariant attractors
We present two generic classes of supersymmetric solutions of N=2, d=4
supergravity coupled to non-Abelian vector supermultiplets with a gauge group
that includes an SU(2) factor. The first class consists of embeddings of the 't
Hooft-Polyakov monopole and in the examples considered it has a fully regular,
asymptotically flat space-time metric without event horizons. The other class
of solutions consists of regular non-Abelian extreme black holes. There is a
covariant attractor at the horizon of these non-Abelian black holes.Comment: 14 pages, Late
Effective Monopole Action at Finite Temperature in SU(2) Gluodynamics
Effective monopole action at finite temperature in SU(2) gluodynamics is
studied on anisotropic lattices. Using an inverse Monte-Carlo method and the
blockspin transformation for space directions, we determine 4-dimensional
effective monopole action at finite temperature. We get an almost perfect
action in the continuum limit under the assumption that the action is composed
of two-point interactions alone. It depends on a physical scale and the
temperature . The temperature-dependence appears with respect to the
spacelike monopole couplings in the deconfinement phase, whereas the timelike
monopole couplings do not show any appreciable temperature-dependence. The
dimensional reduction of the 4-dimensional SU(2) gluodynamics ((SU(2)))
at high temperature is the 3-dimensional Georgi-Glashow model ().
The latter is studied at the parameter region obtained from the dimensional red
uction. We compare the effective instanton action of with the
timelike monopole action obtained from (SU(2)). We find that both agree
very well for at large region. The dimensional reduction
works well also for the effective action.Comment: 34 pages, 23 figure
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