The LNGS theory group activity is focused on fundamental physics.

The research topics concern five main areas: astroparticle physics, compact stellar objects and dense nuclear matter, cosmology, large scale structures and dark matter, computer simulations of gauge theories and particle physics phenomenology. There is a long tradition of collaboration between the LNGS theory group and several experimental groups.

In addition to the 3 INFN permanent staff scientist, 3 L’Aquila University faculty members and 1 Gran Sasso Science Institute permanent staff scientist, at any one time there are roughly five postdoctoral fellows and several PhD students belonging to L’Aquila University and to the Gran Sasso Science Institute.