Benjamin Collas

Visiting Researcher
Research Institute for Mathematical Sciences, Kyoto University,
Kyoto 606-8502 JAPAN


Office: NW II, Raum 734.

G+ Profile MatSciNet Profile

RIMS - Kyoto University.

Former positions
Mathematisches Institut, Bayreuth;
Homotopy Theory and Algebraic Geometry (PI);
WWU Münster, Topology Group;
UPMC - Paris 6, Analyse Algébrique.

Dr. Benjamin Collas

I now have moved to the RIMS Kyoto, Japan. Below is an excerpt of my mathematical activities in Bayreuth University; You will find more material on my arithmetic homotopy geometry activity in terms of publications, talks and workshop organization on my CNRS and RIMS webpages.

For future updates:Scientific Activity; International invitations; RIMS Activity.

Publications in Bayreuth

See here for Full Publications List.


  • Monodromy of Elliptic Curve Convolution, Seven-point sheaves of G2-type, and Motives of Beauville type, 2018. With M. Dettweiler, S. Reiter and W. Sawin (v2, 26 pages, 12 figures) [ArXiv], [PDF].
  • Hurwitz Stacks of Groups Extensions and Irreducibility, 2018 (v2-2020: major update, 26 pages,1 fig.) With S. Maugeais, [ArXiv].


Workshops and Seminars organization

See here for full list of Workshops Organization.

  • Towards Chromatic Homotopy Theory. On Landweber Exact Functor Theorem, the stack of formal groups, Thom cobordism and complex-oriented cohomology theories, see programme and references (03.2019).
  • Abelian Schemes over Spec Z. Following the proof of Fontaine, on Tate Theorem for elliptic curves, finite flat group schemes and ramification theory, see programme and references (06.2017).
  • Arithmetic-Geometry Seminar, LII-IV Bayreuth, Germany, weekly joint seminar of Prof. Dettweiler and Prof. Stoll (2012-14).

Lectures in Bayreuth

During the Summer semester 2018: advanced lecture on ``Stacks and homotopy algebraic geometry'', see the moodle page of the lecture for programme and references. During Winter and Summer semester 2019: tutorials on Linear Algebra I & II.

Universität Bayreuth -