November 14, 2023
Speaker: Fabian Schmidt (Max Planck Institute for Astrophysics)
Contact Information: fabians@mpa-garching.mpg.de
Title: How much (robust) cosmological information can we obtain from galaxy clustering?
Abstract: All large-scale structure cosmologists are faced with the question: how do we robustly extract cosmological information, such as on dark energy, gravity, and inflation, from observed tracers such as galaxies whose astrophysics is extremely complex and incompletely understood? I will describe why guaranteeing this robustness is so difficult, and how a perturbative effective-field-theory (EFT) approach offers such a guarantee when focusing on galaxy clustering on large scales. The natural next question then is: how much cosmological information is left on these large scales if we marginalize over all the free parameters introduced in the EFT? To answer this question, I will introduce our implementation of the EFT on a lattice as an explicit field-level forward model, which can be used both for full Bayesian inference at the field level and for likelihood-free inference based on summary statistics. One crucial advantage of this forward model is the non-perturbative treatment of the displacement from initial positions to observed coordinates, with ramifications for BAO reconstruction and redshift-space distortions.
Visitor's room: 103A
Visit Schedule:
Wednesday (November 15, 2023):
9:30 a.m.: Robert Lupton
10:00 a.m.: Alice Pisani
10:30 a.m.:
11:00 a.m.: Jake Nibauer
11:30 a.m.: Peter Melchior
12:00 p.m.: Wunch
12:30 p.m.: Wunch
1:00 p.m.: Adrian Bayer (Peyton 109)
1:30 p.m.: He Jia
2:00 p.m.: Nick Kokron
2:30 p.m.:
3:00 p.m.: James Sunseri
3:30 p.m.:
4:00 p.m.: Michael Strauss (113 Peyton)
5:00 p.m.:
Dinner Sign-up - add your name here:
Wednesday (November 15, 2023)
Fabian Schmidt
Faculty Host: Michael Strauss
Postdoc Host: Nickolas Kokron
He Jia
Nick Loudas
Christian Kragh Jespersen
Justin Myles
James Sunseri
STUDENTS HAVE PRIORITY.
PLEASE NO MORE THAN 8 PEOPLE (it is more difficult to properly interact with the speaker in larger groups).