Is it permissible for a group of students to study in the mosque without seeking the permission of the Imaam of the mosque? Thanks.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

There is no problem in that, providing that they observe the due etiquette of the mosque and respect its sanctity and sacredness. However, it is better for such students to seek the Imaam's permission and he has no right to refuse their request.