1,006 research outputs found
Covariant Coordinate Transformations on Noncommutative Space
We show how to define gauge-covariant coordinate transformations on a
noncommuting space. The construction uses the Seiberg-Witten equation and
generalizes similar results for commuting coordinates.Comment: 11 pages, LaTeX; email correspondence to [email protected]
Scalar Field Theory at Finite Temperature in D=2+1
We discuss the theory defined in -dimensional space-time and
assume that the system is in equilibrium with a thermal bath at temperature
. We use the expansion and the method of the composite
operator (CJT) for summing a large set of Feynman graphs.We demonstrate
explicitly the Coleman-Mermin-Wagner theorem at finite temperature.Comment: 12 pages, 1 figure. To be published in Journal Mathematical Physics,
typos adde
Conformal Symmetry on the Instanton Moduli Space
The conformal symmetry on the instanton moduli space is discussed using the
ADHM construction, where a viewpoint of "homogeneous coordinates" for both the
spacetime and the moduli space turns out to be useful. It is shown that the
conformal algebra closes only up to global gauge transformations, which
generalizes the earlier discussion by Jackiw et al. An interesting
5-dimensional interpretation of the SU(2) single-instanton is also mentioned.Comment: 7 pages, LaTeX, version to appear in J. Phys. A: Math. Ge
Coordinate noncommutativity in strong non-uniform magnetic fields
Noncommuting spatial coordinates are studied in the context of a charged
particle moving in a strong non-uniform magnetic field. We derive a relation
involving the commutators of the coordinates, which generalizes the one
realized in a strong constant magnetic field. As an application, we discuss the
noncommutativity in the magnetic field present in a magnetic mirror.Comment: 4 page
Calorons in Weyl Gauge
We demonstrate by explicit construction that while the untwisted
Harrington-Shepard caloron is manifestly periodic in Euclidean time,
with period , when transformed to the Weyl () gauge,
the caloron gauge field is periodic only up to a large gauge
transformation, with winding number equal to the caloron's topological charge.
This helps clarify the tunneling interpretation of these solutions, and their
relation to Chern-Simons numbers and winding numbers.Comment: 10 pages, 10 figures, a sign typo in equation 27 is correcte
Canonical Formalism for a 2n-Dimensional Model with Topological Mass Generation
The four-dimensional model with topological mass generation that was found by
Dvali, Jackiw and Pi has recently been generalized to any even number of
dimensions (2n-dimensions) in a nontrivial manner in which a Stueckelberg-type
mass term is introduced [S. Deguchi and S. Hayakawa, Phys. Rev. D 77, 045003
(2008), arXiv:0711.1446]. The present paper deals with a self-contained model,
called here a modified hybrid model, proposed in this 2n-dimensional
generalization and considers the canonical formalism for this model. For the
sake of convenience, the canonical formalism itself is studied for a model
equivalent to the modified hybrid model by following the recipe for treating
constrained Hamiltonian systems. This formalism is applied to the canonical
quantization of the equivalent model in order to clarify observable and
unobservable particles in the model. The equivalent model (with a gauge-fixing
term) is converted to the modified hybrid model (with a corresponding
gauge-fixing term) in a Becchi-Rouet-Stora-Tyutin (BRST)-invariant manner.
Thereby it is shown that the Chern-Pontryagin density behaves as an observable
massive particle (or field). The topological mass generation is thus verified
at the quantum-theoretical level.Comment: 29 pages, no figures, minor corrections, published versio
Quantum-mechanical model for particles carrying electric charge and magnetic flux in two dimensions
We propose a simple quantum mechanical equation for particles in two
dimensions, each particle carrying electric charge and magnetic flux. Such
particles appear in (2+1)-dimensional Chern-Simons field theories as charged
vortex soliton solutions, where the ratio of charge to flux is a constant
independent of the specific solution. As an approximation, the charge-flux
interaction is described here by the Aharonov-Bohm potential, and the
charge-charge interaction by the Coulomb one. The equation for two particles,
one with charge and flux () and the other with () where
is a pure number is studied in detail. The bound state problem is solved
exactly for arbitrary and when . The scattering problem is
exactly solved in parabolic coordinates in special cases when takes integers or half integers. In both cases the cross sections obtained
are rather different from that for pure Coulomb scattering.Comment: 12 pages, REVTeX, no figur
Dynamical masses of quarks in quantum chromodynamics
Using Dyson-Schwinger equations we obtain an ultraviolet asymptotics for the
dynamical mass of quark in QCD. We also determine a numerical value for the \pi
meson decay constant f_\pi.Comment: Electronic version of the published paper, latex, 4 page
Only hybrid anyons can exist in broken symmetry phase of nonrelativistic Chern-Simons theory
We present two examples of parity-invariant Chern-Simons-Higgs
models with spontaneously broken symmetry. The models possess topological
vortex excitations. It is argued that the smallest possible flux quanta are
composites of one quantum of each type . These hybrid anyons will
dominate the statistical properties near the ground state. We analyse their
statistical interactions and find out that unlike in the case of Jackiw-Pi
solitons there is short range magnetic interaction which can lead to formation
of bound states of hybrid anyons. In addition to mutual interactions they
possess internal structure which can lead upon quantisation to discrete
spectrum of energy levels.Comment: 10 pages in plain Latex (one argument added, version accepted for
publication in Phys.Rev.D(Rapid Communications)
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