Thursday, October 3, 2019, 16:00
WHGA Auditorium
Ido Ben-Dayan, Ariel University
Abstract:
The expansion rate of the Universe dubbed "Hubble parameter" or "Hubble
constant" is the most important Cosmology discovery ever made, and is
the cornerstone of Modern Cosmology. The existence of an expansion
forces the Universe as a whole object to have dynamics. I will start
with a recap of the history of Hubble parameter measurements in the last
100 years. I will then describe two of the most common practices of
determining the Hubble parameter today - CMB observations and Type Ia
supernovae. These two measurements, sometimes along with other probes,
are in disagreement with a growing level of significance in the past
decade, leading to the "Hubble tension". Taken at face value, this
tension is the most promising signal of New Physics that deviates from
the Concordance or LCDM Model of Cosmology. I will discuss some
possibilities of resolving the tension either via systematics or New
Physics.