Cohomology of the Siegel modular group of degree two and level four
نویسندگان
چکیده
We compute the cohomology of the subgroup of the integral symplectic group of degree 2 consisting of matrices γ ≡ 1 mod 4. This is done by computing the cohomology of the moduli space of principally polarized abelian surfaces with a level 4 structure. This space has a projective smooth compactification whose topology was analyzed by Lee and Weintraub in a recent work.
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