With the most recent advances in cosmic-ray physics, from both theoretical and experimental aspects, particles beyond the GZK cut-off (E > 10^20 eV) have been detected by leading collaborations such as Pierre Auger Observatory and Telescope Array. Such observations raise many questions as to how such tremendous energies can be reached and what source can possibly produce them. Although at...
The years 2015 and 2016 marked the start of gravitational wave (GW) astronomy with the discovery of gravitational waves originating from massive black hole mergers. Although searches were performed with a range of dedicated satellites for an electro-magnetic (EM) counter-part no such radiation was detected. As the sensitivity of the GW detectors increased the first detection of a GW produced...