Effective Field Theory Approach to the Dynamics of Compact Binaries in Scalar-Tensor Theories

Tuesday 2 Jun 2026, 14:00 → 16:00 Asia/Shanghai

6620 (South building)

Speaker: Robin Fynn Diedrichs (University of Hannover)

Abstract: Theories beyond General Relativity typically contain at least one additional scalar degree of freedom, effectively mediating an additional force. While this force must be highly suppressed in low-density environments to pass current constraints, it generically leads to deviations from General Relativity in high-density / high-curvature environments, such as neutron stars and black holes, and thus impacts their observables. I will discuss how binary systems in theories that feature such a fifth force can be treated using an effective field theory approach and present results regarding observables such as the power loss and the gravitational wave signal.

Biography: Robin Fynn Diedrichs is currently a postdoctoral fellow at Leibniz University Hannover, Germany. His research focuses on analytical modeling of gravitational waves from compact binaries in modified gravity using effective field theories. From 2021 to 2026, he carried out his doctoral research at Goethe University Frankfurt, Germany, with a thesis entitled “Impact of Dark Matter and Modified Gravity on Compact Binary Systems”.