Physical Society Colloquium

Interview for Faculty Position

What Has String Theory Taught Us About The Quantum Structure of Space-Time?

M. Sheikh-Jabbari

Institute for Studies in Theoretical Physics and Mathematics

String theory is the most widely accepted model for quantum gravity and as such it should bear an answer to the fundamental question of “what is the nature of the quantum space-time”. A handle on this question was provided through two of the recent conceptual advancements in string theory, the (BFSS-type) matrix models and the AdS/CFT duality. In my talk I'll focus on the second and discuss two places where the AdS/CFT has shed light on the question posed in the title. In particular I'll focus on a matrix theory formulation I proposed to describe the DLCQ of strings on the AdS geometry, the tiny graviton matrix theory, according which the quantum structure of the AdS₅×S⁵ geometry contains two noncommutative fuzzy three spheres as well as a noncommutative Moyal plane. We'll argue that appearance of noncommutative geometries is a generic feature of these matrix theories.