Improving estimates of the growth rate of structure with galaxy-velocity cross correlations

Wednesday 13 Oct 2021 @ 12:00 p.m., Zoom
Ryan Turner, Swinburne University; Email: rjturner[at]


A key method for understanding the physics of dark energy and gravity in the Universe is to measure the growth of cosmic structure with time. A powerful technique for tracing the growth of structure is to use the peculiar velocities of galaxies, and their correlations. Peculiar velocities describe the velocity of a galaxy relative to the background expansion of the Universe, imposed by the gravitational influence of the local environment. In this talk I will present new tests using cosmological simulations to show how combining information from the local peculiar velocity field and galaxy density field provide the tightest constraints on the growth rate. I will demonstrate how velocity and galaxy survey information can be optimally combined in a correlation function approach, discuss how these tests can be applied to existing datasets, and show how future peculiar velocity surveys will provide competitive tests of gravitational growth.