ChangHoon Hahn is a Postdoctoral Research Associate at Princeton University. His research focuses on developing and applying data science and statistical techniques to large galaxy surveys in order to understand galaxy formation/evolution and test fundamental physics with the large-scale structures of the Universe. Before Princeton, ChangHoon was a postdoctoral fellow at the Lawrence Berkeley National Lab and Berkeley Center for Cosmological Physics. He completed his PhD in Physics at New York University Center for Cosmology and Particle Physics.
Talk title and abstract:
Constraining Neutrino Mass with the Galaxy Bispectrum
Massive neutrinos suppress the growth of structure below their free-streaming scale and leave an imprint on large-scale structure. Measuring this imprint allows us to constrain the sum of neutrino masses, Mnu, a key parameter in particle physics beyond the Standard Model. However, degeneracies among cosmological parameters, especially between Mnu and sigma8, limit the constraining power of standard two-point clustering statistics. In this talk, I will present how we can break these degeneracies and constrain Mnu with the next higher-order correlation function — the bispectrum. Furthermore, I will present the full information content of the redshift-space galaxy bispectrum measured using 22,000 N-body simulations and 195,000 galaxy catalogs of the Quijote suite. Finally, I will present crucial developments in simulation-based (or likelihood-free) inference and data compression that will unlock the constraining power in the nonlinear regime and fully exploit the statistical power of upcoming surveys such as the Dark Energy Spectroscopic Instrument.
Would you like to join this Zoom seminar? Please email Donna Hayes.