Math Subject Class: 11F75
Abstract: Let G be a neat finite-index subgroup of SL(n,Z) or GL(n,Z), and let d be the cohomological dimension of G. We present an algorithm to compute the eigenvalues of the Hecke operators on the integral cohomology of degree d-1 for n = 2, 3, and 4. In addition, we describe a modification of the modular symbol algorithm of Ash-Rudolph for computing Hecke eigenvalues for the integral cohomology of degree d.
@misc{math.NT/9811134,
title = {Computing Hecke eigenvalues below the cohomological dimension},
author = {Paul E. Gunnells},
eprint = {math.NT/9811134}}