Cohomology of the Siegel modular group of degree two and level four
We compute the cohomology of the principal congruence subgroup Γ2(4) ⊂ Sp4(ℤ) consisting of matrices γ≡ 1 mod 4. This is done by computing the cohomology of the moduli space M4. We determine the mixed Hodge structure on this cohomology, as well as the intersection cohomology of the Satake compactification of M4.
Publication Source (Journal or Book title)
Memoirs of the American Mathematical Society
Hoffman, J., & Weintraub, S. (1998). Cohomology of the Siegel modular group of degree two and level four. Memoirs of the American Mathematical Society, 133 (631) Retrieved from https://digitalcommons.lsu.edu/mathematics_pubs/506