c-regular cyclically ordered groups

For N = 5, 6 and 7, using the classification of perfect quadratic forms, we compute the homology of the Voronoï cell complexes attached to the modular groups SL N ( Z ) and GL N ( Z

Voronoï (1907) has shown that, modulo the action of GL N ( Z ) and the multiplication by positive real numbers, there is a finite set of particular lattices (called the