Physics Theory Seminar with Thomas Celora and Peter Hammond on Neutron Star Simulations

In order to extract the precise physical information encoded in the gravitational and electromagnetic signals from powerful neutron-star merger events, we need to include as much of the relevant physics as possible in our numerical simulations. In this talk, we focus on the role of nuclear reactions and the effective bulk-viscosity associated with them. We use multi-scale arguments to show that a reactive system can be described in terms of a bulk viscosity when the reaction timescale is fast. Combining such theoretical discussion with an analysis connecting to state-of-the-art simulations, we demonstrate that in order to properly account for nuclear reactions, future simulations must be able to handle different regimes where rather different assumptions/approximations are appropriate.

Zoom link available upon request at physics@wustl.edu.
Post-docs and students' Q&A with the speaker starts at 2:15 pm. Contact Garrett King for the Q&A Zoom link.