A Note on the Discontinuous Subgroups of the Orthogonal Group.
A note on the Hasse principle. Addenda
A spectral gap theorem in SU
We establish the spectral gap property for dense subgroups of SU, generated by finitely many elements with algebraic entries; this result was announced...
Addendum to: On volumes of arithmetic quotients of SO (1, n)
There are errors in the proof of uniqueness of arithmetic subgroups of the smallest covolume. In this note we correct the proof, obtain certain results which were stated as a conjecture, and we give several remarks on further developments.
An alternative proof of Scheiderer's theorem on the Hasse principle for principal homogeneous spaces.