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▶︎ CANCELED: Physics Colloquium

Thursday, April 2, 2020
4:00pm to 5:00pm
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East Bridge 201 (Richard P. Feynman Lecture Hall)
From single to statistical: gravitational-wave populations
Daniel Holz, University of Chicago,

The detections of GW150914 and GW170817 were watershed events in astronomy. These two singular events provided a wealth of discoveries, including dramatic new limits on modifications to general relativity, insights into gamma-ray bursts and relativistic astrophysics, advances in our understanding the synthesis of the elements, and entirely novel cosmological constraints. However, these are just baby steps: the promise of gravitational-wave astronomy and cosmology still lies ahead of us. We are now entering the era of gravitational-wave populations. This talk will present some of my recent results, including exploration of the upper and lower black hole mass gaps, mass ratio constraints on black hole formation channels, constraints on the equation-of-state of neutron stars, constraints from host galaxy properties, and standard siren cosmology. For example, I will describe our current ~15% standard-siren measurement of the Hubble constant, argue that additional detections will measure the Hubble constant to 2% within five years, and present a new method to provide direct percent-level constraints on the expansion history of the universe at redshift z~1.