2 papers
math.AG2009
Composantes connexes et irréductibles en familles
Matthieu Romagny
For an algebraic stack $\sX$ flat and of finite presentation over a scheme , we introduce various notions of {\em relative connected components} and {\em relative irreducible co…
math.AG2007
Champs de Hurwitz
José Bertin, Matthieu Romagny
We give a thorough study of Hurwitz stacks both in Galois and non galois case. The construction is applied to revisit somme classical examples, the stack of stable curves equipped…