Prof. Stefan Hilbert - "Strong Gravitational Lensing, the Hubble Constant, and Dark Energy"

Tuesday 4 Apr 2017, 16:15 → 17:15 Europe/Berlin

Main Auditorium (MPP)

The nature of dark energy, the force driving the accelerated expansion of the Universe, is one of the biggest open questions in cosmology. Accurate measurements of the current expansion rate of our Universe, as quantified by the Hubble constant, provide us with crucial data for constraining models of dark energy. I discuss measurements of the Hubble constant by the H0LiCOW collaboration based on strong gravitational lensing time delays. In accordance with earlier results based on Cepheids and supernovae, these results indicate that the Universe currently is expanding faster than one would expect from observations of the cosmic microwave background radiation with Planck and WMAP. The tension between the 'local' and the 'early Universe' measurements may hint at novel physics beyond the current standard model of cosmology.