The smallness is proved of fundamental groups for arithmetic schemes. This is a higher dimensional analogue of the Hermite-Minkowski theorem. We also refer to the case of varieties over finite fields. As an application, we prove certain finiteness results of representations of the fundamental groups over algebraically closed fields.
Comment: 16 pages, v3:Major revision on Section 3,4. Version published in J. Number Theory 129(2009), 2702-2712