The theorists at APC have a very broad range of interests. Part of their research is closely linked with the observational side of work carried out at the institute; the rest is on fundamental theories which, as yet, have no direct observational predictions. This development of fundamental theories of the very early universe (quantum gravity, string theory, brane worlds...) together with the interplay between theory and observation puts the theory group at the core of APC.
Linked to both these aspects is, of course, the increasingly numerical and computational component of modern theoretical physics: APC aims to be at the forefront of technological developments. The main research subjects of APC theory department are: