3 papers
math.AG2025
Cohomology classes on moduli of curves from Theta Characteristics
Andrés Jaramillo Puentes, Roberto Pirisi
Using Galois-Stiefel-Whitney classes of theta characteristics we show that over a totally real base field the moduli stack of smooth genus curves and the moduli stack of princi…
math.AG2024
The Brauer groups of moduli of genus three curves, abelian threefolds and plane curves
Andrea Di Lorenzo, Roberto Pirisi
We compute the -primary torsion of the Brauer group of the moduli stack of smooth curves of genus three over any field of characteristic different from two and the Brauer gro…
math.AG2024
Cohomological invariants and Brauer groups of algebraic stacks in positive characteristic
Andrea Di Lorenzo, Roberto Pirisi
We introduce a theory of cohomological invariants with mod coefficients for algebraic stacks in characteristic . Using these new tools we complete the computation of the B…