Forthcoming colloquia and seminars are shown in the Events Calendar.
Organiser and contact for Colloquia: Matteo Cirillo
Organiser and contact for Seminars: Gianfranco Pradisi
There is a "Astrophysics Seminars" section on the Departmental YouTub channel.
Most seminars are online; in the Italian version of this page are shown the available seminar rooms when in person.