Explicit $\ell^1$-efficient cycles and amenable normal subgroups
Geometric Topology
2017-05-01 v2
Abstract
By Gromov's mapping theorem for bounded cohomology, the projection of a group to the quotient by an amenable normal subgroup is isometric on group homology with respect to the -semi-norm. Gromov's description of the diffusion of cycles also implicitly produces efficient cycles in this situation. We present an elementary version of this explicit construction.
Cite
@article{arxiv.1704.05345,
title = {Explicit $\ell^1$-efficient cycles and amenable normal subgroups},
author = {Clara Loeh},
journal= {arXiv preprint arXiv:1704.05345},
year = {2017}
}
Comments
9 pages; surveyish note without original results; v2: corrected arxiv title