Séminaire Analyse Harmonique
                    
                    
                        
                            An overview of Kato limit spaces
                        
                    
                
                                    02
Dec. 2025
                                Dec. 2025
| Intervenant : | David Tewodrose | 
| Institution : | Department of Mathematics and Data Science, Vrije Universiteit Brussel (Belgium). | 
| Heure : | 14h00 - 15h00 | 
| Lieu : | Bâtiment 307, salle 2L8 | 
I will report on a series of joint papers with Gilles Carron (Nantes Université) and Ilaria Mondello (Université Paris-Est Créteil), in which we investigate the geometric and analytic properties of Kato limit spaces. These are defined as Gromov-Hausdorff (GH) limits of complete Riemannian manifolds satisfying uniform Kato bounds on the Ricci curvature. After reviewing these Kato bounds, I will provide a simple 2D example of a branching Kato limit space that cannot be GH-approximated by manifolds with a uniform Ricci curvature lower bound. I will also explain why this example does not lie in the GH closure of the set of manifolds satisfying a small Ricci curvature Lp bound in the sense of Petersen-Wei.