BCCP Seminars

Tuesday, April 22
Location: UCB, Hearst Field Annex B-1, 1:10 pm
Speaker: Leonardo Senatore, Stanford
Title: “The Effective Field Theory of Large Scale Structures”
Abstract: After discussing briefly some implications for Inflation after BICEP2, I will focus on Large Scale Structures surveys, as they promise to be the next leading probe of cosmological information. It is therefore crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbation theory for the weakly non-linear regime of dark matter, where correlation functions are computed in an expansion of the wavenumber k of a mode over the wavenumber associated with the non-linear scale k_nl. Since most of the information is contained at high wavenumbers, it is necessary to compute higher order corrections to correlation functions. I will present the predictions of the EFTofLSS up to 2-loops. We find that it matches to percent accuracy the non-linear matter power spectrum up to k~0.6 h/Mpc, requiring just one unknown coupling constant that needs to be fit to observations. Given that Standard Perturbation Theory stops converging at k~0.1 h/Mpc, our results demonstrate the possibility of accessing a factor of order 200 more dark matter quasi-linear modes than naively expected. If the remaining observational challenges to accessing these modes can be addressed with similar success, our results show that there is tremendous potential for large scale structure surveys to explore the primordial universe.

Tuesday, April 29
Location: UCB, Hearst Field Annex B-1, 1:10 pm
Speaker: Charlie Conroy, UCSC
Title: “Extragalactic Archeology”
Abstract: One of the primary avenues for understanding the formation and evolution of galaxies is through studying their stellar populations. A new generation of population synthesis tools that we have been developing are now capable of measuring an unprecedented amount of information from high quality spectra of galaxies. In this talk, I will present results from an ongoing program aimed at measuring the stellar initial mass function, ages, and detailed elemental abundance patterns of early-type galaxies over the interval 0 < z < 1. Constraints on the abundances of the alpha, iron peak, and neutron capture elements offer the promise of reconstructing the detailed star formation histories of these now dormant galaxies. By measuring the evolution of these quantities through cosmic time, we are gaining fresh insights into the assembly histories of galaxies. The techniques we are developing will enable `extragalactic chemical tagging’ and, more generally, will open up the low resolution universe for detailed study.