#24 Colin Hill - Modern Cosmology, Hubble Tension, Exotic Physics

Video Description

In this week's episode, David is joined by Colin Hill, Professor of Physics at Columbia University. Colin is a world renowned expert working at the cutting edge of modern cosmology, giving us the opportunity to do a deep dive into the state of the field. To support this podcast and our research lab, head to https://coolworldslab.com/support Cool Worlds Podcast Theme by Hill [https://open.spotify.com/artist/1hdkvBtRdOW4SPsnxCXOjK] Chapters 0:00:00 Host welcome & guest introduction 0:04:18 What is ΛCDM and why it’s our standard model 0:08:57 Evidence for the accelerated universe 0:13:42 The Hubble constant puzzle 0:18:23 Early dark energy: motivation & constraints 0:22:55 Other proposed solutions to H0 tension 0:27:44 Baryon acoustic oscillations as standard rulers 0:31:36 CMB anisotropies and lensing 0:36:14 Weak lensing surveys & the S8 tension 0:40:58 Photometric redshift challenges & improvements 0:45:40 How latest data shift S8 picture 0:49:25 The role of CMB lensing in growth measurements 0:53:03 Neutrino mass limits from cosmology 0:57:44 Why precision measurements matter 1:02:29 Surprises from past precision campaigns 1:06:08 Primordial gravitational waves & inflation energy scale 1:09:53 Detecting non-Gaussianity in primordial fluctuations 1:14:36 Spherex & Simons Observatory science goals 1:18:27 How a deviation from Gaussianity would change cosmology 1:22:05 Funding, public support & large collaborations 1:25:51 Speculation on ΛCDM’s fate in coming decades