On structure of effective action in four-dimensional quantum dilaton supergravity

A general structure of effective action in new chiral superfield model associated with $N=1$, $D=4$ supergravity is investigated. This model corresponds to finite quantum field theory and does not demand the regularization and renormalization at effective action calculation. It is shown that in local approximation the effective action is defined by two objects called general superfield effective lagrangian and chiral superfield effective lagrangian. A proper-time method is generalized for calculation of these two effective lagrangians in superfield manner. Power expansion of the effective action in supercovariant derivatives is formulated and the lower terms of such an expansion are calculated in explicit superfield form

Dynamically SUSY Breaking SQCD on F-Theory Seven-Branes

We study how dynamically breaking SQCD can be obtained on two intersecting seven-branes in F-theory. In the mechanism which we present in this paper one of the seven-branes is responsible for producing the low-energy gauge group and the other one is for generating vector bundle moduli. The fundamental matter charged under the gauge group is localized on the intersection. The mass of the matter fields is controlled by the vector bundle moduli. The analysis of under what conditions a sufficient number of the fundamental flavors becomes light turns out to be equivalent to the analysis of non-perturbative superpotentials for vector bundle moduli in Heterotic M-theory. We give an example in which we present an explicit equation in the moduli space whose zero locus corresponds to the fundamental fields becoming light. This allows us to provide a local F-theory realization of massive ${\cal N}=1$, $SU(N_c)$ SQCD in the free magnetic range which dynamically breaks supersymmetry.Comment: 40 pages. v2:references added; v3:minor changes, version published in JHE

Construction of Low-Energy Effective Action in N=4 Super Yang-Mills Theories

We review a recent progress in constructing low-energy effective action in N=4 super Yang-Mills theories. Using harmonic superspace approach we consider N=4 SYM in terms of unconstrained N=2 superfield and apply N=2 background field method to finding effective action for N=4 SU(n) SYM broken down to U(1)^(n-1). General structure of leading low-energy corrections to effective action is discussed.Comment: 8 pages, Based on a plenary talk given at the 9th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY01), Dubna, Russia, June 11-17, 2001, to appear in the Proceeding

Back reaction of vacuum and the renormalization group flow from the conformal fixed point

We consider the GUT-like model with two scalar fields which has infinitesimal deviation from the conformal invariant fixed point at high energy region. In this case the dominating quantum effect is the conformal trace anomaly and the interaction between the anomaly-generated propagating conformal factor of the metric and the usual dimensional scalar field. This interaction leads to the renormalization group flow from the conformal point. In the supersymmetric conformal invariant model such an effect produces a very weak violation of sypersymmetry at lower energies.Comment: 15 pages, LaTex, ten figures, uuencoded fil

Constructing the Cubic Interaction Vertex of Higher Spin Gauge Fields

We propose a method of construction of a cubic interaction in massless Higher Spin gauge theory both in flat and in AdS space-times of arbitrary dimensions. We consider a triplet formulation of the Higher Spin gauge theory and generalize the Higher Spin symmetry algebra of the free model to the corresponding algebra for the case of cubic interaction. The generators of this new algebra carry indexes which label the three Higher Spin fields involved into the cubic interaction. The method is based on the use of oscillator formalism and on the Becchi-Rouet-Stora-Tyutin (BRST) technique. We derive general conditions on the form of cubic interaction vertex and discuss the ambiguities of the vertex which result from field redefinitions. This method can in principle be applied for constructing the Higher Spin interaction vertex at any order. Our results are a first step towards the construction of a Lagrangian for interacting Higher Spin gauge fields that can be holographically studied.Comment: Published Version; comments added in introduction; minor typos and references correcte