This week’s department-wide colloquium, on Thursday, March 28th, will be given by our own Adam Riess, Bloomberg Distinguished Professor, senior member of the science staff at STScI, and 2011 Nobel Laureate in Physics. His title is “A New Measurement of the Expansion rate of the Universe: Hints of New Physics?”

The talk will take place at 3:30 pm in the Schafler Auditorium (Bloomberg 272) and will be followed by a wine and cheese reception.

Colloquium Abstract:

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 <2% 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 significant 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.