"The spaces of non-descendible quasimorphisms and bounded characteristic classes"Maruyama, ShuheiA quasimorphism on a group $G$ is a real-valued function $\mu \colon G \to \mathbb{R}$ with uniformly bounded $|\mu(gh) - \mu(g) - \mu(h)|$. In this talk, we provide an isomorphism between two vector spaces; the space of homogeneous quasimorphisms on a universal covering group $\widetilde{G}$ that do not descend to $G$ and the space of second bounded characteristic classes of foliated $G$-bundles. This is joint work with Morimichi Kawasaki (Aoyama Gakuin University). |
« back