Postdoctoral researcher attached to the Zahlentheorie Lehrstuhl of Michael Dettweiler; recently Principal Investigator in the research program SPP1786 on homotopy theory and algebraic geometry coordinated by M. Levine (2015-18). My previous positions were in Michael Weiss' Leray AG in Algebraic Topology at WW Universität Münster and at the Institute of Mathematics of Jussieu - PRG at Paris 6 University Pierre and Marie Curie.


My research focuses on various aspects of the Arithmetic Geometry of moduli stacks of curves in terms of the Deligne-Mumford and the stack inertia stratifications. My approach covers the topics of simplicial and homotopical algebraic geometry -- i.e. model category and motivic considerations for stacks à la Morel-Voevodsky --, of the arithmetic of the geometry of curves -- e.g. G-covers, irreducible components of Hurwitz spaces, étale fundamental group --, methods from Grothendieck-Teichmüller theory -- e.g. mapping class groups, pants decompositions, Serre bonté --, and the arithmetic of operads -- in genus 0 via Friedlander étale topological type and prospaces.

Recent Activities

See here for more talks by topics, or here for organization of conferences and seminars, and here for international invitations.



Thesis : Groupes de Grothendieck-Teichmüller et inertie champêtre des espaces de modules de courbes de genre zéro et un.




During the Summer semester 2018: advanced lecture for PhD and posdoctoral students on ``Stacks and homotopy algebraic geometry'', see the moodle page of the lecture for programme and references.

Contact Informations

Benjamin Collas :: Universität Bayreuth, Mathematisches Institut, Lehrstuhl für Zahlentheorie, D-95440 Bayreuth, Germany :: Tel: +49 (0)921/55-3288 * :: :: PGP Key :: Office: NW II, Raum 734.

:: G+ Profile :: MatSciNet Profile

Update: 2018 -- 3D tags sphere