Conformal symmetry, anomaly and effective action for metric-scalar gravity with torsion

We consider some aspects of conformal symmetry in a metric-scalar-torsion system. It is shown that, for some special choice of the action, torsion acts as a compensating field and the full theory is conformally equivalent to General Relativity on classical level. Due to the introduction of torsion, this equivalence can be provided for the positively-defined gravitational and scalar actions. One-loop divergences arising from the scalar loop are calculated and both the consequent anomaly and the anomaly-induced effective action are derived.Comment: 15 pages, LaTeX. Essentially extended version, in particular the discussion of the stability of the conformal factor in gravity theory with torsion and scalar added. Title also modified. To be published in Physics Letters

Renormalization of the Fayet-Iliopoulos Term in Softly Broken SUSY Gauge Theories

It is shown that renormalization of the Fayet-Iliopoulos term in a softly broken SUSY gauge theory, in full analogy with all the other soft terms renormalizations, is completely defined in a rigid or an unbroken theory. However, contrary to the other soft renormalizations, there is no simple differential operator that acts on the renormalization functions of a rigid theory and allows one to get the renormalization of the F-I term. One needs an analysis of the superfield diagrams and some additional diagram calculations in components. The method is illustrated by the four loop calculation of some part of renormalization proportional to the soft scalar masses and the soft triple couplings.Comment: Latex2e, 14 pages, uses axodraw.sty. References adde

Bosonization and Duality in Arbitrary Dimensions: New Results

A generic massive Thirring Model in three space-time dimensions exhibits a correspondence with a topologically massive bosonized gauge action associated to a self-duality constraint, and we write down a general expression for this relationship. We also generalize this structure to $d$ dimensions, by adopting the so-called doublet approach, recently introduced. In particular, a non- conventional formulation of the bosonization technique in higher dimensions (in the spirit of $d=3$), is proposed and, as an application, we show how fermionic (Thirring-like) representations for bosonic topologically massive models in four dimensions may be built up.Comment: Revised version, to appear in Phys. Rev.

Tachyons on Dp-branes from Abelian Higgs sphalerons

We consider the Abelian Higgs model in a (p+2)-dimensional space time with topology M^{p+1} x S^1 as a field theoretical toy model for tachyon condensation on Dp-branes. The theory has periodic sphaleron solutions with the normal mode equations resembling Lame-type equations. These equations are quasi-exactly solvable (QES) for specific choices of the Higgs- to gauge boson mass ratio and hence a finite number of algebraic normal modes can be computed explicitely. We calculate the tachyon potential for two different values of the Higgs- to gauge boson mass ratio and show that in comparison to previously studied pure scalar field models an exact cancellation between the negative energy contribution at the minimum of the tachyon potential and the brane tension is possible for the simplest truncation in the expansion about the field around the sphaleron. This gives further evidence for the correctness of Sen's conjecture.Comment: 14 Latex pages including 3 eps-figure

On a five-dimensional Chern–Simons AdS supergravity without gravitino

Based on recent discussions on the so-called unconventional supersymmetry, we propose a 5D Chern–Simons AdS-N-SUGRA formulation without gravitino fields and show that a residual local SUSY is preserved. We explore the properties of CS theories to find a solution to the field equations in a 5D manifold. With a Randall–Sundrum-type ansatz, we show that this particular dimensional reduction is compatible with SUSY, and some classes of 4D solutions are then analyzed

The superspace gauging of (2,0) non-linear sigma-models in the presence of torsion

SIGLEITItal