16 citations · 35 across the 14 of their papers we have counts for
17 papers
Moduli of lattice-polarized K3 surfaces and boundedness of Brauer groups
Danny Bragg, Emma Brakkee, Anthony Várilly-Alvarado
Inspired by constructions over the complex numbers of Dolgachev and Alexeev-Engel, we define moduli stacks of lattice-polarized K3 surfac…
On the logarithmic Hodge-de Rham spectral sequence for curves on K3 surfaces
Daniel Bragg
We show that if is a supersingular K3 surface then there exists a curve on such that the logarithmic Hodge-de Rham spectral sequence for is nondegenerate.
Ample vector bundles and moduli of tame stacks
Daniel Bragg, Martin Olsson, Rachel Webb
We explain how to define an embedding of a tame stack over a noetherian ring into a certain generalization of a weighted projective stack using a notion of ample vector bundle on t…
Fourier--Mukai transforms commuting with Frobenius
Daniel Bragg
We show that a Fourier--Mukai equivalence between smooth projective varieties of characteristic which commutes with either pushforward or pullback along Frobenius is a composit…
Murphy's Law for Algebraic Stacks
Daniel Bragg, Max Lieblich
We show that various natural algebro-geometric moduli stacks, including the stack of curves, have the property that every Deligne-Mumford gerbe over a field appears as the residual…
Automorphism groups of curves over arbitrary fields
Daniel Bragg
We show that if is an arbitrary field and is a finite group then there exists a curve over with automorphism group . We also give a positive solution to the weak inv…
Projectivity of the moduli space of vector bundles on a curve
Jarod Alper, Pieter Belmans, Daniel Bragg +2
We discuss the projectivity of the moduli space of semistable vector bundles on a curve of genus . This is a classical result from the 1960s, obtained using geometric inva…
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…
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 …
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…
Twisted Derived Equivalences and Isogenies between K3 Surfaces in Positive Characteristic
Daniel Bragg, Ziquan Yang
We study isogenies between K3 surfaces in positive characteristic. Our main result is a characterization of K3 surfaces isogenous to a given K3 surface in terms of certain inte…
Lifts of twisted K3 surfaces to characteristic 0
Daniel Bragg
Deligne showed that every K3 surface over an algebraically closed field of positive characteristic admits a lift to characteristic 0. We show the same is true for a twisted K3 surf…
Derived invariants from topological Hochschild homology
Benjamin Antieau, Daniel Bragg
We consider derived invariants of varieties in positive characteristic arising from topological Hochschild homology. Using theory developed by Ekedahl and Illusie-Raynaud in their…
Perfect points on genus one curves and consequences for supersingular K3 surfaces
Daniel Bragg, Max Lieblich
We describe a method to show that certain elliptic surfaces do not admit purely inseparable multisections (equivalently, that genus one curves over function fields admit no points…
Derived equivalences of twisted supersingular K3 surfaces
Daniel Bragg
We study the derived categories of twisted supersingular K3 surfaces. We prove a derived crystalline Torelli theorem for twisted supersingular K3 surfaces, characterizing Fourier-M…
Twistor spaces for supersingular K3 surfaces
Daniel Bragg, Max Lieblich
We develop a theory of twistor spaces for supersingular K3 surfaces, extending the analogy between supersingular K3 surfaces and complex analytic K3 surfaces. Our twistor spaces ar…
Restrictions of rainbow supercharacters
Daniel Bragg, Nathaniel Thiem
The maximal subgroup of unipotent upper-triangular matrices of the finite general linear groups are a fundamental family of -groups. Their representation theory is well-known to…