Jun 8 – 12, 2026
Perimeter Institute for Theoretical Physics
America/Toronto timezone

Learning the Universe with CAMELS-SAM: Joint Simulation-Based Inference of Cosmology and Astrophysics on SDSS Galaxy Clustering

Jun 10, 2026, 3:00 PM
20m
PI/4-405 - Bob Room (Perimeter Institute for Theoretical Physics)

PI/4-405 - Bob Room

Perimeter Institute for Theoretical Physics

60
Contributed Talk

Speaker

Lucia Perez (Flatiron Institute)

Description

As part of the Learning the Universe collaboration, we have pushed the CAMELS-SAM simulation suite into observational photometric space, and present initial results for constraints on cosmological and astrophysical parameters for galaxy population statistics for the SDSS Main Galaxy Sample. CAMELS-SAM already included more than 1000 N-body simulations of (100 cMpc)$^3$, covering a vast cosmological parameter space in $\Omega_M$ and $\sigma_8$. Our new and unique forward-model combines: the CAMELS-SAM simulations and framework with the Santa Cruz semi-analytic model for galaxy formation (varying several new parameters for galaxy formation processes); the powerful and flexible Synthesizer software to model synthetic astrophysical observables for simulated galaxies; and physically-motivated analyses for galaxy dust attenuation. With these components, we test how clustering statistics and other galaxy population statistics perform in a simulation-based inference pipeline directly in the observed lightcone. We present initial results and lessons learned in this ambitious application of SBI and galaxy forward modeling, and discuss how it can be scaled up for the next generation of galaxy surveys. Finally, we detail the value of the expanded CAMELS-SAM simulation suite for the testing and development of new field-level methods for galaxy surveys.

Author

Lucia Perez (Flatiron Institute)

Co-authors

Austen Gabrielpillai (Columbia University) Chris Lovell (University of Cambridge) Kartheik Iyer (Center for Computational Astrophysics) Laura Sommovigo (Columbia University) Matt Ho (Columbia University) Rachel Somerville (Center for Computational Astrophysics) Tjitske Starkenburg (Northwestern University) L.Y. Aaron Yung (Space Telescope Science Institute)

Presentation materials