activity
20182026
collaborators

10 papers

math.AG2026

Modularity of special cycles on Shimura varieties: a survey

François Greer, Salim Tayou

We survey recent results on a conjecture of Kudla regarding the modularity of generating series of special cycle classes in toroidal compactifications of orthogonal and unitary Shi…

math.AG2026

Failure of the invariant cycle theorem over

Donu Arapura, François Greer, Yilong Zhang

We initiate a study of the local invariant cycle theorem with integral coefficients for 1-parameter semistable families of varieties. We show that it always holds for , and it…

math.NT2025

The cohomological Kudla conjecture for unitary Shimura varieties

François Greer, Salim Tayou

We construct natural extensions of the Kudla--Millson generating series of cohomology classes of special cycles in compactified unitary Shimura varieties of signature and…

math.AG2025

Boundedness of some fibered K-trivial varieties

Philip Engel, Stefano Filipazzi, François Greer +2

We prove that irreducible Calabi-Yau varieties of a fixed dimension, admitting a fibration by abelian varieties or primitive symplectic varieties of a fixed analytic deformation cl…

math.AG2024

Modularity of -elliptic loci with level structure

François Greer, Carl Lian, Naomi Sweeting

We consider the generating series of special cycles on , with full level structure, valued in the cohomology of degree . The modula…

math.AG2024

Elliptic-elliptic surfaces and the Hesse pencil

François Greer, Yilong Zhang

We construct a family of elliptic surfaces with that arise from base change of the Hesse pencil. We identify explicitly a component of the higher Noether-Lefschetz locus…

math.AG2024

-elliptic loci and the Torelli map

François Greer, Carl Lian

We show that two natural cycle classes on the moduli space of compact type stable maps to a varying elliptic curve agree. The first is the virtual fundamental class from Gromov-Wit…

math.AG2023

Severi curves of rational elliptic surfaces

François Greer, Joseph Helfer, John Sheridan

We study Severi curves parametrizing rational bisections of elliptic fibrations associated to general pencils of plane cubics. Our main results show that these Severi curves are co…

math.AG2023

Mixed mock modularity of special divisors

Philip Engel, François Greer, Salim Tayou

We prove that the generating series of special divisors in toroidal compactifications of orthogonal Shimura varieties is a mixed mock modular form. More precisely, we find an expli…

math.AG2018

Quasi-modular forms from mixed Noether-Lefschetz theory

François Greer

The Gromov-Witten theory of threefolds admitting a smooth K3 fibration can be solved in terms of the Noether-Lefschetz intersection numbers of the fibration and the reduced invaria…