3 papers
math.GR2025
The Hamiltonian surface of $\Aut(F_2)$
Sylvain Barré, Mikaël Pichot
The group of automorphisms of the free group on two generators is known to act geometrically, in an essentially unique way, on a 2-dimensional CAT(0) space X. We prove that X conta…
math.GR2025
On the classification of CW complexes with prescribed links
Sylvain Barré, Mikaël Pichot
Reporting on a computer--assisted search for nonpositively curved CW complexes of intermediate rank conducted some years ago. Not intended for publication.
math.CO2025
The odd triangle ring puzzle problem
Sylvain Barré, Othmane Oukrid, Mikaël Pichot
Ring puzzles are tessellations of the Euclidean plane respecting local constraints around vertices. Such puzzles may arise in geometric group theory, for example, as embedded flat…