6 papers
Anabelian geometry for Deligne-Mumford curves
Benjamin Collas, Séverin Philip, Naganori Yamaguchi
We develop an anabelian framework for general Deligne-Mumford curves, showing that their stack and orbifold structures are encoded in the group-theoretic properties of their étale…
The local obstruction to semi-stable reduction for abelian varieties
Séverin Philip
Grothendieck defined a group that represents the local obstruction for an abelian variety to have semi-stable reduction. These groups were studied by Silverberg and Zarhin and more…
The -inertial groups as finite monodromy groups
Séverin Philip
Silverberg and Zarhin introduced the notion of a -inertial group in the hope of having a group theoretic characterization of the finite groups that appear as finite monodr…
On Oda's problem and special loci
Benjamin Collas, Séverin Philip
Oda's problem, which deals with the fixed field of the universal monodromy representation of moduli spaces of curves and its independence with respect to the topological data, is a…
On the degree of semi-stable reduction
Séverin Philip
For an abelian variety over a number field we study bounds depending only on the dimension of for the minimal degree of a field extension over which acquires sem…
Fields of definition of abelian subvarieties
Séverin Philip
In this paper we study the field of definition of abelian subvarieties for an abelian variety over a field of characteristic . We show that,…