3 papers
math.AG2026
Finite generation of Noether-Lefschetz divisors and the slope of the moduli space of cubic fourfolds
Ignacio Barros, Shi He, Paul Kiefer
We study divisors on moduli spaces of cubic fourfolds with simple singularities and of quasi-polarized K3 surfaces of degree . For the moduli space of cubic fourfolds, we intro…
math.AG2025
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…
math.AG2025
Cones of Noether-Lefschetz divisors and moduli spaces of hyperkähler manifolds
Ignacio Barros, Pietro Beri, Laure Flapan +1
We give a general formula for generators of the NL-cone, the cone of effective linear combinations of irreducible components of Noether-Lefschetz divisors, on an orthogonal modular…