Resolving the Hubble Tension with New Early Dark Energy <a href="https://zoom.us/j/3483696034?pwd=Z0Q4QmFVeHczc3JzWlBDVXJ2VWR0UT09">Zoom Link</a>
by
Martin Sloth(Odense U.)
→
Europe/Berlin
Description
Recently local measurements of the expansion rate of the universe using Super Novae data have exhibited a significant tension with the expansion rate inferred from measurements of the Cosmic Microwave Background within the Lambda-CDM model. This tension is often referred to as the Hubble tension. In this talk I will discuss the basis of the Hubble tension and its possible resolution. After reviewing different proposals for solving the Hubble tensions, discussing their merits and their problems, I will discuss in more depth how New Early Dark Energy (NEDE) can resolve the Hubble tension. NEDE is a new component of vacuum energy which decays in a first order phase transition, creating small scale anisotropic stress and gravitational radiation, which can be searched for with future pulsar timing arrays. The net effect of NEDE is an increase of the present expansion rate as inferred from CMB and BAO, bringing it in agreement with SN measurements. Combining CMB, BAO and SN data we find a strong evidence for a non-vanishing NEDE component with a 4.4 sigma significance.