Linear gravity in Schwarzschild spacetime under the harmonic gauge.
Dr. Pei-Ken Hung
In this talk, we will discuss the linearized Einstein equation under the harmonic gauge, which is equivalent to a hyperbolic system for symmetric 2-tensors. We will begin with an overview of the vector field method for scalar wave equations. Based on this technique, we study the tensorial wave equation for 1-forms in the Schwarzschild spacetime and, as an application, the linearized Einstein equation. This is a joint work with S. Brendle.
Black Holes: The Next Generation — Repeated Mergers in Dense Star Clusters and their Gravitational-Wave Properties
Dr. Carl Rodriguez
When an isolated binary black hole merges in the field of a galaxy, its gravitational-wave story is complete. But when black holes merge in a dense star cluster, their merger products can remain in the cluster, where they continue to participate in dynamical encounters, form binaries, and potentially merge again. In this talk I will describe the production of repeated mergers in globular clusters, and how the rate of mergers depends on the initial properties (e.g. spin) of black holes formed from stars. I will show how these “second-generation” black holes differ from black holes
formed from stellar collapse, and how Advanced LIGO and Virgo can already distinguish these unique astrophysical populations.