Physics Spring 2023 Colloquium: The Physical Halo Model

Eduardo Rozo, Associate Professor of Physics, The University of Arizona

When

3 – 4 p.m., Feb. 24, 2023

Where

Abstract: Halos have been one of the fundamental building blocks for our understanding the large scale structure of the Universe for over half a century. However, accurate halo-based models of matter and galaxy clustering are hard to come by. I will argue that these difficulties are not inherent to the halo model, but are instead definitional in nature. Specifically, traditional halo definitions are only loosely motivated in theory. I will argue these traditional definitions are inherently flawed, and that a careful consideration of the particle dynamics in halos leads one to a new, physically motivated definition. This definition is effectively parameter free and unique. Remarkably, the statistical properties of the newly defined halos can be accurately described with simple analytic models, opening the door for the halo model to make a comeback as a tool for precision cosmology.

In-person only. Refreshments at 2:45PM, PAS 218