This talk is based on my paper Intersections of the automorphism and the Ekedahl-Oort strata in the moduli space of genus two curves(Gonzalez-Hernandez, 2025).
We compute the intersections between the automorphism strata and the pullback by the Torelli map of the Ekedahl-Oort strata inside the moduli space of genus two curves. We first describe explicitly which possible automorphism groups a genus two curve can have over a field of positive characteristic, and parametrise the families of curves with a prescribed automorphism group. Then, we describe an algorithm to compute the strata of genus two curves whose Jacobian variety has a fixed Ekedahl-Oort type. Finally, we compute the dimension and number of irreducible components of the intersections between the strata.
@article{Gonzalez-Hernandez2025IntersectionsStrata,title={{Intersections of the automorphism and the Ekedahl-Oort strata in the moduli space of genus two curves}},author={Gonzalez-Hernandez, Alvaro},year={2025},pages={21},publisher={arXiv},eprint={2507.07278},journal={arXiv preprint. Comments are welcome!}}