3 papers
math.DS2026
Non-Birkhoff periodic orbits in symmetric billiards
Casper Oelen, Bob Rink, Mattia Sensi
We study non-Birkhoff periodic orbits in symmetric convex planar billiards. Our main result provides a quantitative criterion for the existence of such orbits with prescribed minim…
math.RA2025
Normal forms of elliptic automorphic Lie algebras and Landau-Lifshitz type of equations
Sara Lombardo, Casper Oelen
We present normal forms of elliptic automorphic Lie algebras with dihedral symmetry of order 4, which arise naturally in the context of Landau-Lifshitz type of equations. These nor…
math.RA2024
A classification of automorphic Lie algebras on complex tori
Vincent Knibbeler, Sara Lombardo, Casper Oelen
We classify the automorphic Lie algebras of equivariant maps from a complex torus to . For each case we compute a basis in a normal form. The automorph…