Cosmic Flows 2025: Probing the Universe with Peculiar Velocities

Session

Session 10

6 Feb 2025, 11:00

Tamborine Mountain Glades (Brisbane, Australia)

Conveners

Session 10: Thursday

• Yuyu Wang

17. Testing gravity with DESI and supernovae correlations

Andrew Nguyen (Swinburne University of Technology)

06/02/2025, 11:00

Correlations between new large-scale structure and transient surveys allow us to perform novel tests of gravitational physics. Peculiar velocities create magnitude fluctuations in transient sources. In this talk I will present correlation measurements using data from the Dark Energy Spectroscopic Instrument and Pantheon+ supernovae magnitudes along with matched simulations. By fitting...

39. Maximum likelihood inference of growth rate with SNIa velocity and galaxy density fields

Corentin RAVOUX (LPCA, Clermont-Ferrand, France)

06/02/2025, 11:20

Using supernovae of type Ia for inferring the growth rate of structure (fσ8) has seen a significant gain in interest in recent years. In particular, maximizing the potential of fσ8 constraints can be achieved by coupling peculiar velocity estimators with the underlying density field. I will present a recent software called flip (Ravoux et al. in prep.(a),...

21. Dipoles and structures in cosmological numerical relativity simulations

Mr Michael Williams

06/02/2025, 11:40

We apply fully general relativistic (GR) ray-tracing to large cosmological simulations. The simulations of Macpherson et al. integrate the full Einstein equations from initial conditions at the cosmic microwave background (CMB) to the present epoch. These simulations reproduce a realistic cosmic web from the initial matter power spectrum, which is already well studied.

For the first time,...

23. HI galaxy simulations for SKAO peculiar velocities

Joël Mayor (ETH Zürich)

06/02/2025, 12:00

With the advent of next-generation radio observations with the upcoming SKA Observatory, HI Galaxy surveys will be able to probe the late-time Universe with unprecedented sensitivity, offering the possibility to constraint cosmology in a complementary manner to standard spectroscopic surveys. In preparation for this scientific case, realistic simulations of large-sky volumes with good...

66. Constraining matter-radiation equality with peculiar velocity

Yan Lai (The University of Queensland)

06/02/2025, 12:20

The latest Dark Energy Spectroscopic Instrument (DESI) survey results show that dark energy could evolve with time. This is achieved by constraining one of the standard rulers: the sound horizon at the drag epoch, with DESI Baryon Acoustic Oscillation, Cosmic Microwave Background, and supernovae. However, we could also constrain cosmological parameters with the other standard ruler: the...