"Trouble with Hubble" Neal Weiner (NYU)

Department Colloquium with Neal Weiner (NYU) Title: Trouble with Hubble Abstract: Hubble’s law relates the rate at which galaxies recede with their distance. The Hubble Parameter (H) changes with time in a simple way predicted by general relativity. Precision cosmology allows us to now study whether the simple LCDM model (dark matter plus dark energy) agrees with data. Interestingly, a tension has arisen between measurements of Hubble from the recent universe compared with values extracted from the early universe. I will discuss this tension and some ideas of how to address it requiring physics beyond LCDM, and the prospects for resolving this in the future.