BHI Colloquium


Tuesday, October 8, 2019, 1:30pm to 2:30pm


BHI Meeting Room

Kento Yagi (Virginia University)

Title: Theory-agnostic Tests of Gravity with Gravitational Waves

Abstract: Compact binary merger events recently discovered by the LIGO and Virgo Collaboration offer us excellent testbeds for probing fundamental physics. In this talk, I will focus on two theory-agnostic ways of probing gravity in the strong- and dynamical-field regime. I will first review the current status with the observed binary black hole merger events. I will then describe how such tests will improve in the future. I will also comment on how these model-independent tests can be used to probe fundamental aspects of General Relativity, such as the equivalence principle.


Paul Tiede (Perimeter Institute)

Title: Spacetime Tomography with the Event Horizon Telescope

Abstract: Sgr A* flares across wavelengths every one to three days. One possible explanation for these flares is from magnetic reconnection events in the accretion disk.  This leads to the formation of orbiting features or hotspots in the accretion disk around Sgr A*. If these hotspots exist, they could be observable by the Event Horizon Telescope (EHT).   To assess this, we developed a semi-analytical model for hotspots and explored the ability of the EHT to recover them. Furthermore, we analyze how multiple flares can be used to tomographically map spacetime, providing a new test of general relativity in the strong-field regime.