Constraining growth rate from SNIa peculiar velocities and galaxy density field

par Corentin Ravoux (LPC Clermont-Ferrand CNRS/IN2P3)

mardi 1 avr. 2025, 14:00 → 16:00 Europe/Paris

Using the peculiar velocities of type Ia supernovae (SNe Ia) to infer the growth rate of structure (f) has seen a significant gain in interest. Recent simulations (Carreres et al. 2023) have shown the potential constraints achievable using ZTF SNe Ia. Maximizing the potential of growth rate constraints can be achieved by coupling peculiar velocities with the impact of those velocities on the underlying density field, called redshift space distortion (RSD). A recent development (Ravoux et al. 2025, flip software https://github.com/corentinravoux/flip) allows this measurement to be performed with a likelihood-based field-level inference method. This framework allows for fast analytical field covariance matrix generation for various recent models, as well as the simultaneous inference of cosmological and nuisance parameters. Currently, this software is being tested to measure the fσ8 combination with Pantheon+ data (Carr et al. in prep.), on LSST simulations (Rosselli et al. in prep., Carrerres et al. in prep.), and on simulations coupling ZTF SN Ia with DESI bright galaxy field (Ravoux et al. in prep.). I will give a general presentation of the use of peculiar velocities for growth rate inference, the core concepts of the flip software, and the results associated with the previously mentioned studies.

flip-webinar-adecophy-25.pdf