1,734 research outputs found

### 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

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