17–24 Jul 2024
Prague
Europe/Prague timezone

Reconstruction of cosmological initial conditions with sequential simulation-based inference

20 Jul 2024, 17:00
15m
South Hall 2B

South Hall 2B

Parallel session talk 08. Astro-particle Physics and Cosmology Astro-particle Physics and Cosmology

Speaker

Oleg Savchenko (GRAPPA, University of Amsterdam)

Description

Knowledge of the primordial matter density field from which the present non-linear observations formed is of fundamental importance for cosmology, as it contains an immense wealth of information about the physics, evolution, and initial conditions of the universe. Reconstructing this density field from the galaxy survey data is a notoriously difficult task, requiring sophisticated statistical methods, advanced cosmological simulators, and exploration of a multi-million-dimensional parameter space. In this talk, I will discuss how simulation-based inference implemented through sliced score matching allows us to tackle this problem and obtain data-constrained realisations of the primordial dark matter density field in a simulation-efficient way for general non-differentiable simulators. In addition, I will describe how graph neural networks can be used to get optimal data summaries for galaxy maps, and how our results compare to those obtained with classical likelihood-based methods.

Alternate track 14. Computing, AI and Data Handling
I read the instructions above Yes

Primary author

Oleg Savchenko (GRAPPA, University of Amsterdam)

Presentation materials