Department of Physics & Astronomy
University of New Mexico

Physics and Astronomy Colloquium

Surprises from the Expansion of the Universe

Presented by Dr. Adam Riess is a Bloomberg Distinguished Professor, the Thomas J. Barber Professor in Space Studies at Johns Hopkins with a joint appointment with the Space Telescope Science Institute. He is an observational cosmologist and a member of the National Academy of Sciences. A past winner of a MacArthur Grant, the Breakthrough Prize in Physics, the Einstein Medal, the Shaw Prize and the Gruber Prize; Adam's observations of the accelerating expansion of the universe earned him the 2011 Nobel Prize in Physics. -- PASSWORD class

The Hubble constant remains one of the most important parameters in the cosmological model, setting the size and age scales of the Universe. Present uncertainties in the cosmological model including the nature of dark energy, the properties of neutrinos and the scale of departures from flat geometry can be constrained by measurements of the Hubble constant made to higher precision than was possible with the first generations of Hubble Telescope instruments. A streamlined distance ladder constructed from infrared observations of Cepheids and type Ia supernovae with ruthless attention paid to systematics now provide 1.4% precision and offer the means to do much better. By steadily improving the precision and accuracy of the Hubble constant, we now see evidence for 5 sigma deviations from the standard model, referred to as LambdaCDM, and thus the exciting chance, if true, of discovering new fundamental physics such as exotic dark energy, a new relativistic particle, or a small curvature to name a few possibilities. I will review recent and expected progress, most recently based on measurements by the SH0ES Team from the Hubble Space Telescope and Gaia EDR3.

3:30 pm, Friday, September 30, 2022


Disability NoticeIndividuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact the Physics Department (phone: 505-277-2616, email: well in advance to ensure your needs are accomodated. Event handouts can be provided in alternative accessible formats upon request. Please contact the Physics front office if you need written information in an alternative format.

A schedule of talks within the Department of Physics and Astronomy is available on the P&A web site at