Lionel Pournin

Lionel Pournin is a Professor in the combinatorics group at the University of Paris 13. Previously, he was a lecturer at the École Polytechnique Fédérale de Lausanne (EPFL), where he completed his PhD under Théophile Liebling. His research focuses on discrete and convex geometry, polyhedral combinatorics, geometric topology, and numerical simulation of granular media. He holds a habilitation from the University of Paris 7 and has contributed to extending contact detection methods in granular media simulations using weighted Delaunay triangulations.

Key research areas include the flip-graph connectivity of polytopes, with groundbreaking work on the connectedness of the 4-dimensional cube's flip-graph. His work bridges geometry and computational methods, particularly in modeling non-spherical particles like spheropolyhedra. Pournin has collaborated extensively on granular media phenomena, including jamming behaviors and crystallization processes of spherocylinders under vibration.

His academic contributions include over 40 peer-reviewed articles, with recent focus on polytope geometry, geometric scaling, and flip-graph theory. Notable works address the diameter of lattice polytopes and optimization challenges in geometric algorithms. Pournin’s research is characterized by interdisciplinary approaches, combining computational methods with theoretical insights in discrete and computational geometry.