Cohomology of Congruence Subgroups of Sl4(z). Iii
نویسندگان
چکیده
In two previous papers [AGM02,AGM08] we computed cohomology groups H(Γ0(N);C) for a range of levels N , where Γ0(N) is the congruence subgroup of SL4(Z) consisting of all matrices with bottom row congruent to (0, 0, 0, ∗) mod N . In this note we update this earlier work by carrying it out for prime levels up to N = 211. This requires new methods in sparse matrix reduction, which are the main focus of the paper. Our computations involve matrices with up to 20 million nonzero entries. We also make two conjectures concerning the contributions to H(Γ0(N);C) for N prime coming from Eisenstein series and Siegel modular forms.
منابع مشابه
On the cohomology of congruence subgroups of SL4 (Z)
We survey our joint work with Avner Ash and Mark McConnell that computationally investigates the cohomology of conguence subgroups of SL4(Z).
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