Investigating Fast Radio Bursts with H.E.S.S.: Multi-Wavelength Follow-Up and Constraints on Gamma-Ray Emission

Fast Radio Bursts (FRBs) are brief, highly energetic radio flashes of unknown origin. Their high luminosity, short duration, and large dispersion measures suggest an extragalactic origin, potentially linked to extreme astrophysical objects such as magnetars. The growing number of detected FRBs, including repeating sources, has driven extensive multi-wavelength follow-up efforts. While FRB 20200428A has been associated with the Galactic magnetar SGR 1935+2154, no other FRB has yet been conclusively linked to a multi-wavelength counterpart. In this contribution, we present the follow-up program developed by the High Energy Stereoscopic System (H.E.S.S.) to search for gamma-ray counterparts to FRBs. We provide an overview of FRB observations conducted by H.E.S.S. from 2015 to 2022, including targeted follow-ups and coordinated multi-wavelength campaigns with radio and X-ray observatories. Among the observed FRBs, 10 have well-determined redshifts ranging from 0.11 to 0.49. No significant very high energy (VHE) emission was detected, allowing us to place constraints on VHE luminosity across different timescales.