Weinberg Institute Seminar with Simeon Bird

Abstract: I will talk about our recent work building a new simulation suite, emulator and likelihood to make cosmological parameter constraints from the Lyman-alpha forest, absorption from neutral hydrogen gas spread throughout the intergalactic medium. The PRIYA simulations are a large suite of cosmological hydrodynamic simulations, with 50 different cosmologies. Using them we found that the Lyman-alpha forest prefers a low amplitude of matter clustering, mirroring the S8 tension seen in weak lensing surveys.

Bio: Simeon Bird is an associate professor at the University of California, Riverside. He has a PhD from Cambridge. Postdocs at Johns Hopkins University, Carnegie Mellon and the Institute for Advanced Study. He is interested in theoretical and numerical cosmology, having been involved in the Illustris, Bahamas, and Astrid simulation projects. His most highly cited paper asked whether LIGO detected dark matter.