Informal Pizza Seminar

Strings and the cosmo

Edna Cheung

Perimeter Institute

I will introduce some basic notions of string theory. While Yang-Mills theory is built on the notion of a one-form gauge potential that couples to the worldlines of particles, the corresponding object in string theory is the two-form gauge potential called Neveu-Schwarz B-field. Indeed, if strings are more fundamental than particles, this NS B-field should play a role that is even more fundamental than gauge fields! When this potential takes a constant value it already modifies our notion of spacetime drastically: the theory can be equivalently formulated on a noncommutative space where B is related to the noncommutativity parameter. The recent convergence of cosmological observations and theory promises an exciting era ahead of us, specifically the potentially profound implications of existence of this field will be within reach of cosmological observations in the coming round of experiments.