Daniel Bragg

collaborators

5 papers

math.AG2025

Moduli of lattice-polarized K3 surfaces and boundedness of Brauer groups

Danny Bragg, Emma Brakkee, Anthony VÃ¡rilly-Alvarado

Inspired by constructions over the complex numbers of Dolgachev and Alexeev-Engel, we define moduli stacks $M_{(L, A) / Z}$ of lattice-polarized K3 surfac…

math.AG2025

On the logarithmic Hodge-de Rham spectral sequence for curves on K3 surfaces

Daniel Bragg

We show that if $X$ is a supersingular K3 surface then there exists a curve $D$ on $X$ such that the logarithmic Hodge-de Rham spectral sequence for $(X, D)$ is nondegenerate.

math.AG2025

Representability of cohomology of finite flat abelian group schemes

Daniel Bragg, Martin Olsson

We prove various finiteness and representability results for cohomology of finite flat abelian group schemes. In particular, we show that if $f : X \to Spec (k)$ …

math.AG2025

Hodge numbers are not derived invariants in positive characteristic

Nicolas Addington, Daniel Bragg

We study a pair of Calabi-Yau threefolds X and M, fibered in non-principally polarized Abelian surfaces and their duals, and an equivalence D^b(X) = D^b(M), building on work of Gro…

math.AG2025

Unipotent morphisms

Daniel Bragg, Jack Hall, Siddharth Mathur

We introduce the theory of unipotent morphisms of algebraic stacks and prove a surprising local to global principle for a class of vector bundles. Two sample applications of our me…