6 papers
An adelic approach to the Kudla-Millson lifts over totally real number fields
Yingkun Li, Mingkuan Zhang, Riccardo Zuffetti
We compute the Fourier expansions of the Kudla-Millson theta lifts of vector-valued Hilbert cusp forms of parallel weight. These expansions are with respect to 0-dimensional cusps…
The Siegel-Weil formula in geometry and arithmetic
Jan Hendrik Bruinier, Riccardo Zuffetti
The present paper is an extended version of the lecture notes of a course given by the first author at the summer school on Formulas of Siegel and Weil (Bielefeld, September 2025).…
Extremal divisors on moduli spaces of K3 surfaces
Ignacio Barros, Laure Flapan, Riccardo Zuffetti
We establish criteria for when Noether--Lefschetz divisors generate an extremal ray in the cone of pseudoeffective divisors of an orthogonal modular variety. In particular, we exhi…
Lefschetz decompositions of Kudla-Millson theta functions
Jan Hendrik Bruinier, Riccardo Zuffetti
In the 1980's Kudla and Millson introduced a theta function in two variables. It behaves as a Siegel modular form with respect to the first variable, and is a closed differential f…
Injectivity of the genus 1 Kudla-Millson lift on locally symmetric spaces
Ingmar Metzler, Riccardo Zuffetti
Let be an even indefinite lattice. We show that if splits off a hyperbolic plane and a scaled hyperbolic plane, then the Kudla-Millson lift of genus associated to i…
Strongly ambiguous Hilbert squares of projective K3 surfaces with Picard number one
Riccardo Zuffetti
We provide a criterion for when Hilbert squares of complex projective K3 surfaces with Picard number one are strongly ambiguous. This criterion is the same as [DM, Proposition 3.14…