On automorphism groups of -adic Schottky curves
On Invariant Measures, Minimal Sets and a Lemma of Margulies.
On the Generation of Dyadic Integral Orthogonal Groups.
On the isomorphisms of the projective orthogonal groups and their congruence subgroups.
On the Maximality of the Orthogonal Groups in the Symplectic Groups in Characteristic Two.
On the orthogonal groups of unimodular quadratic forms. II.
On volumes of arithmetic quotients of
We apply G. Prasad’s volume formula for the arithmetic quotients of semi-simple groups and Bruhat-Tits theory to study the covolumes of arithmetic subgroups of . As a result we prove that for any even dimension there exists a unique compact arithmetic hyperbolic -orbifold of the smallest volume. We give a formula for the Euler-Poincaré characteristic of the orbifolds and present an explicit description of their fundamental groups as the stabilizers of certain lattices in quadratic spaces. We...
Orthogonal representations of Galois groups, Stiefel-Whitney classes and Hasse-Witt invariants.