# Biermann Lectures 2017: Neutron star mergers and gravitational waves

Gravitational waves have become a very hot topic in astrophysics since their detection by LIGO in 2015. This means that also possible precursors are in the focus of research – general relativistic research because these objects are either black holes or neutron stars. The 2017 Biermann Lecturer, Masaru Shibata from the Kyoto University, uses numerical simulations and general relativity (or numerical relativity for short) to study the merger of such extreme objects and the properties of both the electromagnetic radiation and gravitational waves emitted during these events.

The formation of neutron stars and black holes or their mergers in binary systems are very difficult to reconstruct from basic physical laws, because one needs not only to fully solve Einstein’s equation but also the equations of motion for the matter involved. Due to the complexity of the mathematics – these are nonlinear, partial differential equations – theoreticians need to use numerical simulations on high-performance computers. Masaru Shibata has been working in this area for many years, developing numerical simulations for a range of astrophysical processes such as the merger of binary neutron stars, black hole-neutron star binaries, or the formation of black holes. In his Biermann lectures at MPA, he will give an introduction into this field and will explain how gravitational waves and electromagnetic emission from these events can be predicted.

Masaru Shibata received his PhD from Kyoto University in 1994 and worked at assistant professor at Osaka University until 2000. After a brief stay at the University of Illinois at Urbana-Champaign, he returned to Japan and the University of Tokyo and in 2009 became Professor at the Yukawa Institute for Theoretical Physics, Kyoto University. He received the Outstanding Paper Award of the Physical Society of Japan in 2008, the Prize by the Japan Society for the Promotion of Science in 2010 and became a member of the International Society on General Relativity and Gravitation in 2013. Even though Masaru Shibata is working on similar topics as researchers at MPA, he has never visited the institute before. His stay as Biermann lecturer will provide many opportunities for discussions with his colleagues in Garching.

**Biermann lectures 2017**

Professor Masaru Shibata (Kyoto University)

Overall title:

**"Neutron-star mergers and gravitational waves"**

Tuesday, October 10 (first lecture):

**"Coalescences of neutron-star binaries"**

Tuesday, October 17 (second lecture):

**"Gravitational waves from neutron-star binaries and constraining neutron-star equation of state"**

Tuesday, October 24 (last lecture):

**"Mass ejection and electromagnetic counterparts from neutron-star mergers"**

All lectures will be given at 15:30 at MPA (Large seminar room E.0.11) and will be preceded by tea, coffee and cookies at 15:15.