Consistent equivalence principle tests with fast radio bursts

May 17, 2021
4:00pm to 5:00pm

Zoom webinar

Theoretical Physics, general interest
Speaker: 
Robert Reischke
Institution: 
Astronomisches Institut, Ruhr-Universität Bochum
Location&Place: 

Zoom webinar

Abstract: 

Fast radio bursts (FRBs) are very short astrophysical transients of predominantly extragalactic origin. As these radio pulses get dispersed while travelling through the ionized intergalactic medium, their observed dispersion measure (DM) is a probe of the line-of-sight integrated electron density. In this talk, I will briefly introduce FRBs and summarize their observational and theoretical status. After this introduction, I will discuss how FRBs have been used in the past to put limits on the equivalence principle and why these tests cannot be used to set any limits. Instead, I will demonstrate,  how statistical properties of the DM of an ensemble of FRBs can be used to provide a consistent test of Einstein’s equivalence principle. I will close the talk with a brief discussion of the DM as a noisy distance estimate and how it can be used to put constraints on the expansion rate of the Universe.