Simple totally disconnected locally compact groups separated by finiteness properties
Abstract
We construct a sequence of simple non-discrete totally disconnected locally compact (tdlc) groups separated by finiteness properties; that is, for every positive integer there exists a simple non-discrete tdlc group that is of type but not of type . This generalizes a result for discrete groups of Skipper--Witzel--Zaremsky. Furthermore, we construct a simple non-discrete tdlc group that is of type over but not compactly presented. Our examples arise as Smith universal groups associated to permutation groups and . We generalize a theorem of Haglund--Wise to tdlc groups and show that under mild conditions on and the finiteness properties of reflect those of its local actions and .
Cite
@article{arxiv.2509.05101,
title = {Simple totally disconnected locally compact groups separated by finiteness properties},
author = {Laura Bonn and Sebastian Giersbach},
journal= {arXiv preprint arXiv:2509.05101},
year = {2026}
}
Comments
15 pages, 1 figure; v2: The main theorem now holds more generally for finite graphs of groups instead of finite trees of groups; v3: Added reference, fixed hyperlinks and typos