8 papers · 1 filter
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…
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…
Cohomological invariants of root stacks and admissible double coverings
Andrea Di Lorenzo, Roberto Pirisi
We give a formula for the cohomological invariants of a root stack, which we apply to compute the cohomological invariants and the Brauer group of the stack of admissible double co…
Brauer groups of moduli of hyperelliptic curves via cohomological invariants
Andrea Di Lorenzo, Roberto Pirisi
We compute the Brauer group of the moduli stack of hyperelliptic curves over any field of characteristic zero. In positive characteristic, we compute the part of th…
A complete description of the cohomological invariants of even genus hyperelliptic curves
Andrea Di Lorenzo, Roberto Pirisi
When the genus is even, we extend the computation of mod 2 cohomological invariants of to non algebraically closed fields, we give an explicit functorial descri…
The Brauer group of the universal moduli space of vector bundles over smooth curves
Roberto Fringuelli, Roberto Pirisi
We compute the Brauer group of the universal moduli stack of vector bundles on (possibly marked) smooth curves of genus at least three over the complex numbers. As consequence, we…