Paul-Henry Leemann

SNF postdoctoral fellow at ENS-Lyon.

Curriculum Vitæ

Research Interests:

My research interests lie in geometric and combinatorial group theory. In particular, I am interested in limits and coverings of (Schreier) graphs, groups acting on rooted trees and (extensively) amenable actions.

I did my PhD thesis under Tatiana Smirnova-Nagnibeda supervision.

Publications, Preprints and Projects:

  1. Schreier graphs: Transitivity and Coverings
    Published in Internat. J. Algebra Comput., Vol. 26, Issue 1 (2016).
    published (arXiv)
  2. Weakly maximal subgroups in regular branch groups
    with K. Bou-Rabee and T. Nagnibeda.
    Published in Journal of Algebra, Vol. 455 (2016).
    published ( arXiv)
  3. Lamplighter groups, de Bruijn graphs, spider-web graphs and their spectra
    with R. Grigorchuk and T. Nagnibeda.
    Published in Journal of Physics A: Mathematical and Theoretical, Vol. 49, Number 20 (2016).
    published ( arXiv )
  4. Subgroups and Actions of Grigorchuk group
    In preparation.
    Preliminary version
  5. Limits of Rauzy graphs and horocyclic products of trees
    In preparation.
    Preliminary version
  6. De Bruijn Graphs, Lamplighter Groups and Spectral Computations
    with T. Nagnibeda.
    In preparation. See


Conference Talks:

June 2015
“De Bruijn Graphs, Lamplighter Groups and Spectral Computations”, Joint AMS-EMS-SPM Meeting, Porto, Portugal. Talk given by T. Nagnibeda. Slides
November 2014
“Paroles aux jeunes chercheurs en géométrie et dynamique”, GDR Platon 3341 CNRS, Université de Bordeaux, France.
June 2014
“Workshop in Algebra and Geometry”, University of Bern, Switzerland.

Seminar Talks:

October 2016
“Séminaire de Géométrie, Groupes et Dynamiques”, ENS Lyon, France.
September 2015
“Graduate Seminar”, Université de Genève, Switzerland.
May 2015
“Ergodic and Geometric Group Theory Seminar”, EPFL, Lausanne, Switzerland.
September 2014
“Séminaire Groupes et Géométrie”, Université de Genève, Switzerland.