Astronomy & Astrophysics Seminar: Probing Dark Matter and Dark Energy from Our Cosmic Neighbourhood

Zoom: https://tau-ac-il.zoom.us/j/87185167411?pwd=FpTUyIgXaOturzOFSetA6pPVYQilen.1

Abstract:

The standard cosmological model, while remarkably successful, faces growing tensions. A major challenge lies in our limited ability to measure only line-of-sight velocities, which constrains how accurately we can map the distribution of dark matter and assess the role of dark energy on local scales. I will show how data from the Local Universe, from binary systems like the Local Group and other nearby galaxy groups to massive clusters such as Coma, can be used to probe the interplay between gravity, dark matter, and dark energy. By combining CosmicFlows-4 velocity data with high-precision astrometry from Gaia and upcoming spectroscopic surveys such as DESI and 4MOST, we can independently constrain both the mass distribution and the local effects of dark energy. I will present new analyses extending different mass estimation techniques to account for the influence of the cosmological constant in galaxy groups, highlighting which systems exhibit measurable deviations from standard dynamics. These results proviΛCDM on megaparsec scales and open a new window into understanding how dark matter and dark energy shape our cosmic neighbourhood.

Seminar Organizer: Dr. Jonathan Stern