Efficient and differentiable simulations for cosmological forward modelling - the DISCO framework

par Prof. Oliver Hahn (Institut für Astrophysik - Wien)

mardi 1 oct. 2024, 14:00 → 16:00 Europe/Paris

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In cosmology, forward modelling plays a crucial role in understanding the large-scale structure of the universe by simulating the evolution of matter from the early universe to the present day. I discuss our new “DISCO-DJ” (‘DIfferential Simulations for COsmology, Done with JAX) approach to cosmological forward modelling that leverages efficient and differentiable simulation techniques. Combining non-linear N-body simulations with a linear Einstein-Boltzmann in a single framework enables the first fully end-to-end differentiable simulations for gradient-based inference. By building new perturbation-theory informed integrators with well-controlled numerics, we enable faster, more accurate predictions of cosmic structure formation in the non-linear regime and at the field-level. This will facilitate the inference of cosmological parameters, field-level inference, easy forecasting, and exploration of covariances, among others.

 

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