VeranstaltungThe trouble with Hubble, new physics from the cosmological expansion rate?
|Titel der Veranstaltung
|The trouble with Hubble, new physics from the cosmological expansion rate?
|Prof. Dr. Martin Schmaltz
|The expansion rate of our universe, the "Hubble rate", is one of the key observables
in big bang Cosmology. It has been measured to a precision of 1.4% and it can be
predicted using Einstein's equation in General Relativity. The prediction requires
knowledge of the dominant energy densities in the universe. In our Standard (LCDM)
Model of the universe these energy densities are ordinary matter, dark matter, and
dark energy, and their abundance is well-determined thanks to precision measurements
of the Cosmic Microwave Background radiation and the large scale distribution of
matter. The "trouble with Hubble" is that the state of the art prediction disagrees
with observations at the 5 sigma level. In this colloquium, we will review the two
disagreeing determinations of the Hubble rate and conclude that a fundamental change
of the LCDM model may be required. I will speculate that the evidence points towards
an undetected dark radiation component in our universe.
|Beginn: 11.12.2023, 16:30 Uhr
Ende: 11.12.2023 , 17:30 Uhr
Fakultät für Physik (Friedrich-Hund-Platz 1)
Hoersaal 2 - A00.102