37 research outputs found
Stringy Instantons as Strong Dynamics
We study the relation between stringy instantons and strong dynamics effects
in type IIB toric quiver gauge theories. By exploiting the involutive property
of Seiberg duality we relate the classical constraint on the moduli space of
the gauge theory with the stringy instanton contribution to the superpotential.
The result holds for unitary, orthogonal and symplectic gauge groups.Comment: Minor corrections, reference added, published in JHE
S-Duality in N=4 Yang-Mills Theories
Evidence in favor of S-duality in supersymmetric Yang-Mills
theories in four dimensions and with general compact, simple gauge groups is
presented. (Contribution to the Proceedings of the Strings '95 conference,
March 13-18, 1995, USC, and the Proceedings of the Trieste Conference on
S-Duality and Mirror Symmetry, June 5-9, 1995.)Comment: 11 page
From N=2 Supergravity to Constrained Moduli Spaces
In this talk we review some results concerning a mechanism for reducing the
moduli space of a topological field theory to a proper submanifold of the
ordinary moduli space. Such mechanism is explicitly realized in the example of
constrained topological gravity, obtained by topologically twisting the N=2
Liouville theory.Comment: (Talk given at the Trieste Workshop on String Theory, April 1994)
LaTeX file, 17 pages, SISSA 66/94/EP, IFUM 470/F
Spontaneous Breaking of N=2 to N=1 in Rigid and Local Supersymmetric Theories
We analyze the relation between rigid and local supersymmetric N=2 field
theories, when half of the supersymmetries are spontaneously broken. In
particular, we show that the recently found partial supersymmety breaking
induced by electric and magnetic Fayet-Iliopoulos terms in rigid theories can
be obtained by a suitable flat limit of previously constructed N=2 supergravity
models with partial super-Higgs in the observable sector.Comment: 9 pages, plain Late
PP-wave and Non-supersymmetric Gauge Theory
We extend the pp-wave correspondence to a non supersymmetric example. The
model is the type 0B string theory on the pp-wave R-R background. We explicitly
solve the model and give the spectrum of physical states. The field theory
counterpart is given by a sector of the large N SU(N) x SU(N) CFT living on a
stack of N electric and N magnetic D3-branes. The relevant effective coupling
constant is g_{eff}=g_sN/J^2. The string theory has a tachyon in the spectrum,
whose light-cone energy can be exactly computed as a function of g_{eff}. We
argue that the perturbative analysis in g_{eff} in the dual gauge theory is
reliable, with corrections of non perturbative type. We find a precise
state/operator map, showing that the first perturbative corrections to the
anomalous dimensions of the operators have the behavior expected from the
string analysis.Comment: 19 pages. Revised versio
Metastable Vacua in Superconformal SQCD-like Theories
We study dynamical supersymmetry breaking in vector-like superconformal N=1
gauge theories. We find appropriate deformations of the superpotential to
overcome the problem of the instability of the non supersymmetric vacuum. The
request for long lifetime translates into constraints on the physical couplings
which in this regime can be controlled through efficient RG analysis.Comment: 17 pages, 7 figures, JHEP3.cl
Topological First-Order Systems with Landau-Ginzburg Interactions
We consider the realization of N=2 superconformal models in terms of free
first-order -systems, and show that an arbitrary
Landau-Ginzburg interaction with quasi-homogeneous potential can be introduced
without spoiling the (2,2)-superconformal invariance. We discuss the
topological twisting and the renormalization group properties of these
theories, and compare them to the conventional topological Landau-Ginzburg
models. We show that in our formulation the parameters multiplying deformation
terms in the potential are flat coordinates. After properly bosonizing the
first-order systems, we are able to make explicit calculations of topological
correlation functions as power series in these flat coordinates by using
standard Coulomb gas techniques. We retrieve known results for the minimal
models and for the torus.Comment: 37 page
Constrained Topological Gravity from Twisted N=2 Liouville Theory
In this paper we show that there exists a new class of topological field
theories, whose correlators are intersection numbers of cohomology classes in a
constrained moduli space. Our specific example is a formulation of 2D
topological gravity. The constrained moduli-space is the Poincare' dual of the
top Chern-class of the bundle , whose sections are
the holomorphic differentials. Its complex dimension is , rather then
. We derive our model by performing the A-topological twist of N=2
supergravity, that we identify with N=2 Liouville theory, whose rheonomic
construction is also presented. The peculiar field theoretical mechanism,
rooted in BRST cohomology, that is responsible for the constraint on moduli
space is discussed, the key point being the fact that the graviphoton becomes a
Lagrange multiplier after twist. The relation with conformal field theories is
also explored. Our formulation of N=2 Liouville theory leads to a
representation of the N=2 superconformal algebra with , instead of the
value that is obtained by untwisting the Verlinde and Verlinde
formulation of topological gravity. The reduced central charge is the shadow,
in conformal field theory, of the constraint on moduli space.Comment: 48 pages, LaTex file, SISSA 49/94/EP, IFUM 468/F
Pseudomoduli Dark Matter and Quiver Gauge Theories
We investigate supersymmetric models for dark matter which is represented by
pseudomoduli in weakly coupled hidden sectors. We propose a scheme to add a
dark matter sector to quiver gauge theories with metastable supersymmetry
breaking. We discuss the embedding of such scheme in string theory and we
describe the dark matter sector in terms of D7 flavour branes. We explore the
phenomenology in various regions of the parameters.Comment: 24 pages, 12 figures, JHEP3.cl
Metastable vacua and geometric deformations
We study the geometric interpretation of metastable vacua for systems of D3
branes at non isolated toric deformable singularities. Using the L^{aba}
examples, we investigate the relations between the field theoretic susy
breaking and restoration and the complex deformations of the CY singularities.Comment: Minor corrections, references added, published in JHE