String Theory, Quantum Field Theory
The standard model for particle physics is based on gauge theory. It does not explain gravitation. We need a unified understanding of gravity and gauge theory to comprehend physics beyond the standard model such as dark energy and inflation. String theory is a promising candidate for a unified theory and already suggests new pictures of spacetime. We are investigating the fundamental structure of string theory and spacetime through matrix models and other means. In string theory gauge theory and gravity are the different faces of the same coin. We use this gauge/gravity duality to understand the nonperturbative aspects of gauge theory. Black holes and exponentially expanding universes exhibit interesting quantum effects. We are performing research to resolve these fundamental questions.
