A p-adic Interpolation of the Cogdell Lift
Time: 2026-06-03
Published By: He Liu
Speaker(s): Francesco Iudica (BICMR)
Time: 15:00-16:00 June 5, 2026
Venue: Room 77201, Jingchunyuan 78, BICMR
The Cogdell lift is the analogue for Picard modular surfaces of the celebrated Hirzebruch-Zagier theorem. Roughly speaking, the lift takes a class in middle cohomology of a fixed modular surface, and lifts it to a Fourier series whose coefficients are intersection multiplicities of special cycles. Cogdell's result states that the Fourier expansion is in fact an elliptic modular form. In this talk, we apply Lœffler's formalism of spherical varieties to obtain a p-adic analytic version of Cogdell's theorem.
