Tag Archives: signature

Chiral subsurface projection, asymmetric metrics and quasimorphisms

Last week I was at Oberwolfach for a meeting on geometric group theory. My friend and collaborator Koji Fujiwara gave a very nice talk about constructing actions of groups on quasi-trees (i.e. spaces quasi-isometric to trees). The construction is inspired … Continue reading

Posted in Groups, Hyperbolic geometry, Surfaces | Tagged , , , , , , , , | 4 Comments

Quasimorphisms from knot invariants

Last week, Michael Brandenbursky from the Technion gave a talk at Caltech on an interesting connection between knot theory and quasimorphisms. Michael’s paper on this subject may be obtained from the arXiv. Recall that given a group , a quasimorphism … Continue reading

Posted in 3-manifolds, Groups | Tagged , , , , , , , | 2 Comments