Primordial Standard Clocks

Abstract

Oscillating massive fields in the primordial universe can be used as Standard Clocks. The ticks of these oscillations induce features in the density perturbations, which directly record the time evolution of the scale factor of the primordial universe; thus if detected, provide a direct evidence for the inflation scenario or possible alternatives. The speaker and his research group study models of primordial standard clocks, and compare the predictions with Cosmic Microwave Background data. An interesting candidate is identified for future tests.