11-13【Zheng Zhang】Cubic threefolds with an involution and their intermediate Jacobians

Time:2023-10-29Views:18

Speaker: Zheng Zhang(ShanghaiTech University)

Time: 10:00-11:00, Nov 13, 2023

Room: Room 1124, Material Science Research Building (Section C)


  

We study the moduli space of cubic threefolds admitting an involution via the period map sending such a cubic threefold to the invariant/anti-invariant part of the intermediate Jacobian.  Our main result is global Torelli holds for the period map. Key ingredients of the proof include a description of the invariant/anti-invariant part of the intermediate Jacobian as a Prym variety and a detailed study of certain positive dimensional fibers of the corresponding Prym map. The proof also relies on the results of Donagi-Smith, Ikeda and Naranjo-Ortega on related Prym maps. This is joint work with S. Casalaina-Martin and L. Marquand.