Kloosterman sums for Clifford algebras and a lower bound for the positive eigenvalues of the Laplacian for congruence subgroups acting on hyperbolic spaces.
@article{GDZPPN002107783,
title = {Kloosterman sums for Clifford algebras and a lower bound for the positive eigenvalues of the Laplacian for congruence subgroups acting on hyperbolic spaces.},
journal = {Inventiones mathematicae},
volume = {100},
year = {1990},
pages = {641-686},
zbl = {0737.11013},
url = {http://dml.mathdoc.fr/item/GDZPPN002107783}
}
Mennicke, J.; Elstrodt, J.; Grunewald, F. Kloosterman sums for Clifford algebras and a lower bound for the positive eigenvalues of the Laplacian for congruence subgroups acting on hyperbolic spaces.. Inventiones mathematicae, Tome 100 (1990) pp. 641-686. http://gdmltest.u-ga.fr/item/GDZPPN002107783/