The recent detection of gravitational waves (GWs) from a binary neutron star (BNS) merger, in coincidence with a weak short GRB, opened the era of multi-messenger astronomy and provided the first direct evidence that at least a fraction of BNSs are progenitors of short GRBs. One of the challenges for future multi-messenger observations will be the detection of short GRBs at very-high energies (VHE, > 20 GeV) in association with GWs: this will allow us to better understand the physics of the GRB outflow and their radiation mechanisms. The Cherenkov Telescope Array (CTA), an advanced, next generation ground-based facility, will be fundamental for the EM follow-up of transient GW events at VHE, owing to its unprecedented sensitivity, rapid response (few tens of seconds) and capability to monitor large sky areas via survey-mode operation.
In this talk I discuss what we learned from the recent GW and multi-messenger detections and I present a comprehensive study on the prospects for joint GW and VHE EM observations of merging BNSs with Advanced LIGO, Advanced Virgo and CTA.
