Triangle Seminars

Abstract:
Motivated by string theory arguments, we analyse quantum field theory in
a specific space time with closed timelike curves. We conjecture and
partly show that, for discrete values of the gravitational coupling
constant, the resulting theory is unitary. These discrete values are
obtained in two independent ways, using high energy scattering in quantum
gravity and using string dualities to rephrase the quantization condition
as quantization of charge of certain extended objects.

Abstract:
We show that certain exactly marginal and relevant deformations
of N=4 theory which preserve N=1 supersymmetry, exhibit rich infrared
dynamics. These theories have moduli spaces with discrete (Higgs)
branches. On certain branches the theory flows to the Klebanov-Witten
conifold SCFT, while on other branches the theory undergoes a Seiberg
duality cascade terminating in an N=1 theory with a mass gap. Using the
matrix model approach the quantum moduli spaces and quantum
superpotentials of these theories can be computed exactly. In the D-brane
picture these quantum moduli spaces correspond to the Calabi-Yau space in
the geometric dual description of the gauge theory.