Conformal invariance and microscopic sensitivity in cosmic inflation

Abstract

Phenomenologically, cosmic inflation is a satisfying and well-tested description of the physics of the very early universe. During this epoch, the universe was dominated by high energy phenomena that can only be truly understood in a quantum gravity theory such as string theory. In this thesis we show that the embedding of inflation in a string theoretic framework is very sensitive to the details of the theory. We consider both the low energy supergravity limit as well as a worldsheet set-up. Moreover, we investigate the constraints imposed by supersymmetry and conformal symmetry. Conformal symmetry is important both in the worldsheet theory as well as in a holographic description of inflation. In the latter case we investigate the imprints of conformal invariance on the (observable) statistical correlations in the cosmic microwave background radiation.