3:30–5:00 pm ERC 161
Title: Why Everyone Wants Something Better Than LambdaCDM
Abstract: The success of LambdaCDM has allowed cosmologists to ask bigger and more profound questions about the birth and evolution of the Universe -- and raised their expectations. Precision tests of the model have revealed possible “cracks in the cosmic egg," which may point to its successor. I will focus on two, the DESI/DES evidence for evolving dark energy and the Hubble tension. Either or both could be evidence for a problem with LambdaCDM and an indication of missing – new! – physics. Or not. The Hubble tension and the evidence for evolving dark energy could be related. Or not. I will discuss the challenges of combining precision high-redshift (z ~ 1000 or greater) data, e.g., the CMB, with precision low-redshift (z ~ 0 – 3) data, e.g., DESI, DES, and SN, in the absence of a comprehensive model of dark energy, and how these challenges might be overcome.
Zoom: https://uchicago.zoom.us/j/99103268158?pwd=a39TsQXFkueaSGfGla9KcFzA52DfI4.1
