Consistent equivalence principle tests with fast radio bursts

Fast radio bursts (FRBs) are astrophysical transients of still debated origin. So far several hundred events have been detected, mostly at extragalactic distances, and this number is expected to grow significantly over the next years. The signals from burst experience dispersion as they travel through free electrons along line-of-sight characterised by measure (DM) pulse. In addition, each photon also experiences a gravitational Shapiro time delay while travelling potentials generated large-scale structure. If equivalence principle (EP) holds, same for photons all frequencies. case EP broken, one would expect an additional occur which could be either positive or negative individual sources. Here we suggest use angular statistics DM fluctuations put constraints on parametrized post-Newtonian parameter $\gamma$. Previous studies suffer problem that potential responsible diverges in cosmological setting, our approach avoids. We carry out forecast population FRBs observable within years show any significant detection power spectrum will place few orders magnitude more stringent than current limits.