Aut-invariant quasimorphisms on free products

Research output: Contribution to journalArticle

3 Downloads (Pure)


Let G = A ∗ B be a free product of freely indecomposable groups. We explicitly construct quasimorphisms on G which are invariant with respect to all automorphisms of G. We also prove that the space of such quasimorphisms is infinite-dimensional whenever G is not the infinite dihedral group. As an application we prove that an invariant analogue of stable commutator length recently introduced by Kawasaki and Kimura is non-trivial for these groups.
Original languageEnglish
Publication statusSubmitted - 2021


Dive into the research topics of 'Aut-invariant quasimorphisms on free products'. Together they form a unique fingerprint.

Cite this