Stockholm University, Sweden
Wednesday, May 19, 2021
Chain inflation is an alternative to slow roll inflation in which the universe undergoes a series of transitions between different vacua. The role of the inflation can be played by an axion which tunnels from minimum to minimum in a quasiperiodic potential. I will determine the scalar power spectrum of chain inflation and show that it is fully consistent with a CDM cosmology. Then I will turn to the Hubble tension, the apparent discrepancy between local measurements of the Hubble constant H0 = 74 km=s=Mpc and H0 = 67 km=s=Mpc inferred from the CMB. I will propose chain early dark energy - the low-energy analog of chain inflation - as a solution of the H0 tension and point to a connection to today's dark energy.