Modular forms, moduli and invariant theory

Speaker:Gerard van der Geer (University of Amsterdam)
Schedule:Thur., 16:00-17:00, Sept. 28, 2023
Venue:Lecture Hall C548, Tsinghua University Shuangqing Complex Building A(清华大学双清综合楼A座C548报告厅); Zoom Meeting ID: 271 534 5558 Passcode: YMSC

Siegel modular forms generalize the usual elliptic modular forms and show up in many parts of mathematics: algebraic geometry, number theory and even in mathematical physics. But they are difficult to construct. We show that invariant theory enables us to efficiently construct all (vector valued) Siegel modular forms of degree two and three from from certain basic modular forms provided by the geometry of curves.
This is joint work with Fabien Cléry, Carel Faber and Alexis Kouvidakis.

Gerard van der Geer is professor emeritus at the University of Amsterdam. He works in algebraic geometry and arithmetic geometry with emphasis on moduli spaces and modular forms. He worked on Hilbert modular surfaces,curves over finite fields, cycle classes on moduli of abelian varieties and on modular forms. He got a honorary doctorate of the University of Stockholm.