Electromagnetic Counterparts to Gravitational Wave Detections: Bridging the Gap between Theory and Observation

LIGO has proven that gravitational waves (GWs) from black hole binary mergers are detectable, and we expect within years it will detect GWs from double neutron star and black hole--neutron star mergers as well.In the extreme violence of merger, intense tidal forces can become sufficient to rip the neutron star(s) apart, which can lead to significant electromagnetic (EM) emission. If detected, a coincident EM and GW observation could for the first time reveal the anatomy of a gamma-ray burst or kilonova and provide the deepest probe yet into the behavior and composition of degenerate nuclear matter. However, the scientific understanding gained from these observations will be limited by the accuracy of our theoretical modeling, which must fully account for the effects of general relativity. To this end, I will review the physics behind current numerical relativity (NR) simulations of these extreme merger events and preview the next generation of NR simulations, which will be capable of predicting not only gravitational wave timeseries with unprecedented accuracy, but also electromagnetic spectra.  

Prof. Zach Etienne
West Virginia University (WVU) Department of Mathematics
Speaker Introduction: 

Zach Etienne (田哲何) is an Assistant Professor in the West Virginia University (WVU) Department of Mathematics. He earned his PhD in 2009 at the University of Illinois under the direction of Prof. Stuart L.Shapiro. After earning his PhD but before joining the faculty at WVU, he was awarded two prestigious postdoctoral fellowships: the U.S.National Science Foundation Astronomy and Astrophysics Postdoctoral Fellowship and the Joint-Space Sciences Institute Postdoctoral Prize Fellowship--a joint position between NASA Goddard Space Flight Center and the University of Maryland.  Prof. Etienne has been a senior member of the LIGO Scientific Collaboration since April 2015, and his work in LIGO has improved the performance of a key parameter estimation pipeline by more than two orders of magnitude. His work in numerical relativity has spanned more than a decade, with a primary focus on pioneering general relativistic magnetohydrodynamic (GRMHD) simulations of compact binary systems, including black hole, neutron star, and black hole--neutron star binaries. He is the principal author of several open-source numerical relativity codes, and his current work in this area focuses on GRMHD simulations and the development super-efficient, next-generation numerical relativity codes.

KIAA-PKU Auditorium
Yingjie Peng
Thursday, June 1, 2017 - 4:00pm to 5:00pm