arXiv subjects

Bayram Tekin

Publications and source records attributed to Bayram Tekin.

153 records · Page 9Linked to original sources

arXiv2000

Toroidal Compactification in String Theory from Chern-Simons Theory

A detailed study of the charge spectrum of three dimensional Abelian Topological Massive Gauge Theory (TMGT) is given. When this theory is defined on a manifold with two disconnected boundaries there are induced chiral Conformal Field Theories (CFT's) on the boundaries which can be interpreted as the left and right sectors of closed strings. We show that Narain constraints on toroidal compactification (integer, even, self-dual momentum lattice) have a natural interpretation in purely three dimensional terms. This is an important result which is necessary to construct toroidal compactification and heterotic string from Topological Membrane (TM) approach to string theory. We also derive the block structure of $c=1$ Rational Conformal Field Theory (RCFT) from the three dimensional gauge theory.

hep-th↗

arXiv2000

Multi-instantons in R^4 and Minimal Surfaces in R^{2,1}

It is known that self-duality equations for multi-instantons on a line in four dimensions are equivalent to minimal surface equations in three dimensional Minkowski space. We extend this equivalence beyond the equations of motion and show that topological number, instanton moduli space and anti-self-dual solutions have representations in terms of minimal surfaces. The issue of topological charge is quite subtle because the surfaces that appear are non-compact. This minimal surface/instanton correspondence allows us to define a metric on the configuration space of the gauge fields. We obtain the minimal surface representation of an instanton with arbitrary charge. The trivial vacuum and the BPST instanton as minimal surfaces are worked out in detail. BPS monopoles and the geodesics are also discussed.

hep-th↗

arXiv2000

Gravitating Instantons In 3 Dimensions

We study the Einstein-Chern-Simons gravity coupled to Yang-Mills-Higgs theory in three dimensional Euclidean space with cosmological constant. The classical equations reduce to Bogomol'nyi type first order equations in curved space. There are BPS type gauge theory instanton (monopole) solutions of finite action in a gravitational instanton which itself has a finite action. We also discuss gauge theory instantons in the vacuum (zero action) AdS space. In addition we point out to some exact solutions which are singular.

hep-th↗

arXiv1999

On the Relevance of Singular Solutions in dS_3 and AdS_3 Gravity

Canonical quantization of three dimensional gravity in the first order formalism suggests that one should allow singular solutions. This paper addresses the importance of singular solutions in the path integral approach to quantum gravity. Using a simple ansatz for the dreibein and the spin connection in the de-Sitter and the anti-de-Sitter spaces we propose that the sum over the 3D manifolds in the path integral should be extended to include 2D surfaces.

hep-th↗

arXiv1999

Monopole-Instanton Type Solutions In 3D Gravity

Three dimensional Euclidean gravity in the dreibein-spin connection formalism is investigated. We use the monopole-instanton ansatz for the dreibein and the spin connection. The equations of motion are solved. We point out a two dimensional solution with a vanishing action.

hep-th↗

arXiv1998

Complex Monopoles in the Georgi-Glashow-Chern-Simons Model

We investigate the three dimensional Georgi-Glashow model with a Chern-Simons term. We find that there exist complex monopole solutions of finite action. They dominate the path integral and disorder the Higgs vacuum, but electric charges are not confined. Subtleties in the gauge fixing procedure in the path integral and issues related to Gribov copies are noted.

hep-th↗

arXiv1998

Complex Monopoles in YM + Chern-Simons Theory in 3 Dimensions

In this talk, we give a brief discussion of complex monopole solutions in the three dimensional Georgi-Glashow model with a Chern-Simons term. We find that there exist complex monopole solutions of finite action. They dominate the path integral and disorder the Higgs vacuum, but electric charges are not confined. Subtleties in the model and issues related to Gribov copies are also noted.

hep-th↗

arXiv1997

Maxwell-Chern-Simons Scalar Electrodynamics at Two Loop

The Maxwell-Chern-Simons gauge theory with charged scalar fields is analyzed at two loop level. The effective potential for the scalar fields is derived in the closed form, and studied both analytically and numerically. It is shown that the U(1) symmetry is spontaneously broken in the massless scalar theory. Dimensional transmutation takes place in the Coleman-Weinberg limit in which the Maxwell term vanishes. We point out the subtlety in defining the pure Chern-Simons scalar electrodynamics and show that the Coleman-Weinberg limit must be taken after renormalization. Renormalization group analysis of the effective potential is also given at two loop.

hep-th↗

arXiv1996

Spontaneous Symmetry Breaking at Two Loop in 3-d Massless Scalar Electrodynamics

In three dimensional Maxwell-Chern-Simons massless scalar electrodynamics with $ ϕ^6$ coupling, the $U(1)$ symmetry is spontaneously broken at two loop order regardless of the presence or absence of the Maxwell term. Dimensional transmutation takes place in pure Chern-Simons scalar electrodynamics. The beta function for the $ϕ^6$ coupling is independent of gauge couplings.

hep-th↗