HESS J1731-347 and the existence of exotic matter: Kaon condensation in neutron stars Polychronis Koliogiannis, Vlasios Petousis, Martin Veselský and Charalampos Moustakidis EPJ Web Conf., 304 (2024) 02006 Published online: 08 October 2024 DOI: 10.1051/epjconf/202430402006