I am a mathematician working at the CNRS in Rennes. My research interests include geometric group theory, small cancellation theory, monster groups, dynamical systems. I am also involved in outreach activities realizing objects, pictures, videos, etc to illustrate mathematics.
Habilitation à diriger des recherches, 2021
Université de Rennes 1
PhD in Mathematics, 2010
Université de Strasbourg
Master in Mathematics, 2007
Université de Paris-Sud
Cycle Ingénieur, 2003-2006
École Polytechnique
Find all my publications and other works on this page
Here a few realizations. Find all of them on this page .
Projective geometry is an important mathematical discovery that goes back to the work of Desargues in the XVIIth century.
A space filling curve is a continuous map $\gamma \colon [0,1] \to \mathbb R^n$ whose range reaches every point in a higher dimensional region. Examples are the Peano curve or the Hilbert curve whose image is a unit square.
The above photo displays the four-step approximation of a three-dimensional space filling curve whose image is cube.
This “paradox” was explain to me by a colleague. Take a square whose side have length $1$ (on blue on the figure below) and subdivide it in four squares of side $1/2$. In the middle of each smaller square place a disc which is tangent to the four sides (on white on the picture below). In particular the radius of these disc is $1/4$. Now place a fifth disc (red on the picture below), centered at the center of the original (blue) square which is tangent to the four other discs.