文摘
Let Γ be the group GLN(OD), where OD is the ring of integers in the imaginary quadratic field with discriminant D<0. In this paper we investigate the cohomology of Γ for N=3,4 and for a selection of discriminants: D≥−24 when 207a0652db0ec9b156d96dda83dbb" title="Click to view the MathML source">N=3, and D=−3,−4 when N=4. In particular we compute the integral cohomology of Γ up to p-power torsion for small primes p. Our main tool is the polyhedral reduction theory for Γ developed by Ash [4, Ch. II] and Koecher [24]. Our results extend work of Staffeldt [40], who treated the case 207a0652db0ec9b156d96dda83dbb" title="Click to view the MathML source">N=3, D=−4. In a sequel [15] to this paper, we will apply some of these results to computations with the K -groups 20583f83e8d6e593fa" title="Click to view the MathML source">K4(OD), when D=−3,−4.