4 papers
Periodicity of traces of Hecke operators modulo prime powers
Jonas Bergström, Sjoerd de Vries
We study traces of Hecke operators on spaces of elliptic cusp forms and Drinfeld cusp forms and show that, modulo any prime power, these traces are periodic in the weight.
Abelian varieties over finite fields with commutative endomorphism algebra: theory and algorithms
Jonas Bergström, Valentijn Karemaker, Stefano Marseglia
We give a categorical description of all abelian varieties with commutative endomorphism ring over a finite field with elements in a fixed isogeny class in terms of pairs c…
Stable cohomology of moduli spaces of hyperelliptic curves on Hirzebruch surfaces
Jonas Bergström, Angelina Zheng
We compute the stable cohomology of moduli spaces of hyperelliptic curves of a fixed genus embedded on a fixed Hirzebruch surface. We also describe these moduli spaces of embedded…
Dimension formulas for spaces of vector-valued Siegel modular forms of degree two and level two
Jonas Bergström, Fabien Cléry
Using a description of the cohomology of local systems on the moduli space of abelian surfaces with a full level two structure, together with a computation of Euler characteristics…