Second bounded cohomology and WWPD
arXiv:1901.01301 · doi:10.1215/21562261-2021-0017
Abstract
Given a group acting on a Gromov hyperbolic space, Bestvina and Fujiwara introduced the WPD property --- weak proper discontinuity --- for studying the 2nd bounded cohomology of the group. We carry out a more general study of second bounded cohomology using a 'really' weak property discontinuity property known as WWPD that was introduced by Bestvina, Bromberg, and Fujiwara.
32 pages. This paper was split off from an earlier version (arXiv:1511.06913v4) of our work "Hyperbolic actions and 2nd bounded cohomology of subgroups of Out(F_n). Part I: Infinite lamination subgroups" (arXiv:1511.06913)