Testing General Relativity with Cosmological Observations | Prof. Ruth Durrer скачать в хорошем качестве

Testing General Relativity with Cosmological Observations | Prof. Ruth Durrer

Date: 1 November, 2024 Speaker: Prof. Ruth Durrer General Relativity (GR) is immensely successful. With the discovery of gravitational waves from black hole and neutron star mergers in 2015, it has passed all the tests with flying colors. But so far, observations have mainly tested the vacuum equations of GR. The most important non-vacuum case, cosmology, is in agreement with GR only after the introduction of two otherwise unknown and unconfirmed components, 'Dark Matter' and 'Dark Energy' which amount to about 95% of the total energy budget of the present Universe. This led people in the field to question the validity of GR for cosmology. Might it be that GR is flawed on large, cosmological scales? Or in the presence of matter in general? But how can we test Einstein's equation in the presence of matter? Can't we simply move any modification of the Einstein tensor to the righthand side and call it a 'dark matter/energy' component? In my talk I shall discuss possible ways (partially) out of this dilemma. I shall show that using observations of gravitational clustering of matter in cosmology, we can in principle test both, the left and the righthand side of Einstein's equations with cosmological observations