Abstract
Let H3 be three-dimensional hyperbolic space and Γ a group of isometries of H3 that acts discontinuously on H3 and that has a fundamental domain of finite hyperbolic volume. The laplace operator –δ of H3 gives rise to a positive, essentiallv selfadjoint operator on L 2 (Γ\H3). The nature of its discrete spectrum dspec Γ is still not well understood if Γ is not cocompact.
This paper contains a report on a numerical study of dspec Γ for various noncocompact groups Γ. Particularly interesting are the results for some nonarithmetic groups Γ.