There were three scientific contributions during the group’s meeting on Tuesday 22.6.21. . Dr. Sajal Mukherjee from ASU gave a talk on “Detectability of hyperbolic encounters with the gravitational wave observatories“, Dr. Robert Švarc from UTF talked about “Spherical Black Holes in Quadratic Gravity” and Dr. Filip Hejda from FZU talked about “Collisional Penrose process and extraction of energy from extremal electrovacuum black holes“.