ITP |
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Teilchentee WS 2019/20
Seminar at the Institute for Theoretical Physics, Heidelberg University
on Thursdays, 4 pm
organizers: S. Westhoff, L. Amendola
Before each seminar, the speaker gives an informal Pre-Talk, introducing the MSc and PhD students at the ITP to the broader context of the topic of the seminar.
Pre-Talks start at 3:30 pm
Date: 21.10.2019
Speaker: Adria Gomez-Valent
Title: Current status of the H0-tension
Abstract
The Hubble-Lemaitre parameter, H0, is a pivotal quantity in cosmology, since it is in charge of setting important distance and time cosmological scales. Although it was firstly measured already 90 years ago, and despite having achieved remarkably precise observational determinations for it, we still lack a general consensus of which is the right value among those in dispute. Local distance ladder and strong lensing measurements point to central values of H0 which are a 7-10% higher than those obtained from the analysis of the anisotropies of the cosmic microwave background radiation when the standard model of cosmology is assumed. The tension between the former and the latter has reached the >4 sigma c.l., despite other intermediate and high redshift data sets also favor the low band of H0 estimations. Whether this tension really calls for new physics or not will have to be ultimately dictated by observations, of course. In this talk I will review the current status of the H0-tension, presenting a quite detailed description of the various probes that have allowed its measurement, and also some of the theoretical frameworks that have been explored till now to try to reconcile the various observational results.
