Simon Fraser University
SFU Cosmology Seminars

For seminars and other local announcements, please subscribe to sfu-cosmo mailing list.


Monday, 16 March 2026, 14:30 in Zoom

Prof. Lloyd Knox (UC Davis)

The Hubble Constant problem

Two different methods of inferring the current rate of expansion of space (the Hubble constant) agree to within 10% but nevertheless disagree at greater than 7 sigma. This discrepancy is interesting for the possibility that its origin lies in a failure of the standard cosmological model, our standard model for over two decades. In this talk I will describe what the expansion of space is, for those who don't think about general relativity every day, before presenting the two different methods, and discussing the case against systematic errors. Then I will mention the types of changes to the cosmological model that could potentially solve this Hubble constant problem, before focusing in on one solution method in particular: modifications to the transition from an ionized plasma to a neutral gas that occurred when the universe was a few hundred thousand years old. These modifications lead to observable predictions that are being tested now.

Zoom: Zoom

Upcoming Seminars:

2026-03-23 14:30 in P8445B - Farrukh Chishtie (Science and Innovation Foundation): Unified Standard Model with Emergent Gravity-Effective Field Theory

Past Seminars:

2026-03-16 14:30 in Zoom - Lloyd Knox (UC Davis): The Hubble Constant problem
2026-03-02 15:00 in P8445B - Nick Rodd (LBNL): Discovering Dark Matter at CTAO
2026-02-23 14:30 in P8445B - Bryce Cyr (MIT): CMB spectral distortions: The HOW, WHAT, and WHEN?
2026-01-26 14:30 in P8445B - Javier Acevedo (UVic): Celestial probes of dark matter in the galactic center
2026-01-19 14:30 in P8445B - Jiayi Chen (SFU): Probing new physics with the Higgs-vector-boson coupling with the ATLAS detector
2025-12-01 14:30 in P8445B - Kevork Abazajian (UC Irvine): Successes and challenges in neutrino cosmology and structure formation
2025-11-24 15:30 in P8445B - Gopolang Mohlabeng (SFU): Searching for light accelerated dark matter
2025-11-17 14:30 in P8445B - Afif Omar (UVic): Probing Hadronic Dark Matter Annihilation with Big Bang Nucleosynthesis
2025-11-10 14:30 in P8445B - Qinrui Liu (SFU): High-energy cosmic neutrinos: A unique window to the universe
2025-10-27 14:30 in SSB7109 - Levon Pogosian (SFU): A theorist's perspective on cosmological tensions
2025-10-20 14:30 in P8445B - Meng-Xiang Lin (SFU): Cosmological tensions and interactions between dark matter and dark energy
2025-10-10 14:30 in AQ3149 - Francis Halzen (University of Wisconsin-Madison): IceCube: The first decade of neutrino astronomy (physics colloquium)

[ See complete seminar archives | iCal feed ]


Modified by Andrei Frolov <frolov@sfu.ca> on 2026-03-19