English

Higher-degree bounded cohomology of transformation groups

Group Theory 2021-05-19 v1

Abstract

For MM a compact Riemannian manifold Brandenbursky and Marcinkowski constructed a transfer map Hb(π1(M))Hb(Homeovol,0(M))H_b^*(\pi_1(M))\to H_b^*(Homeo_{vol,0}(M)) and used it to show that for certain MM the space EHb3(Homeovol,0(M))\overline{EH}_b^3(Homeo_{vol,0}(M)) is infinite-dimensional. Kimura adapted the argument to Diffvol(D2,D2)Diff_{vol}(D^2,\partial D^2). We extend both results to the higher degrees EHb2n\overline{EH}_b^{2n}, n1n\geq 1. We also show that for certain MM the ordinary cohomology H(Homeovol,0(M))H^*(Homeo_{vol,0}(M)) is non-trivial in all degrees. In our computations we view the transfer map as being induced by a coupling of groups.

Keywords

Cite

@article{arxiv.2105.08698,
  title  = {Higher-degree bounded cohomology of transformation groups},
  author = {Martin Nitsche},
  journal= {arXiv preprint arXiv:2105.08698},
  year   = {2021}
}