Seminario Teoría de Grupos
Fine projection complex and subsurface homeomorphisms with positive scl
Ponente: Yusen Long (Université Paris-Est Créteil)Fecha: miércoles 09 de septiembre de 2026 - 11:30Lugar: Aula Naranja, ICMAT
Resumen:
In this talk, we will explain the construction of a family of quasi-trees on which the group of identity-isotopic homeomorphisms of a surface acts coboundedly by isometries. As a central application, we construct non-trivial quasi-morphisms on this group that homeomorphisms supported on essential non-sporadic subsurfaces achieve positive stable commutator length (scl). This work is joint with Yongsheng Jia.
