Non-kinetic homotopy coherent actions on four-manifolds
Abstract
We give the first example of a non-kinetic smooth homotopy coherent action of order two on a closed simply connected smooth four-manifold. This action is obtained by restricting a nontrivial smooth homotopy coherent action of the discrete circle group on a stabilized K3 surface. We also construct relatively non-kinetic smooth homotopy coherent extensions of boundary involutions over compact smooth $4$-manifolds. In addition, we exhibit boundary involutions that admit locally linear topological extensions but no smooth extensions over the same stabilized fillings. Nevertheless, we prove a Wall-type theorem showing that every free involution on a disjoint union of integral homology spheres extends smoothly over any simply connected smooth filling after sufficiently many stabilizations by S2× S2.
Related
- Some homotopy coherent finite group actions on spheres
- Simple homotopy types of smooth four-manifolds with finite fundamental group
- Homotopy rigidity for quasitoric manifolds over a product of simplices
- Smooth manifolds homotopy equivalent to products of spheres
- Rational homotopy theory of flag manifolds
BibTeX
@misc{kang2026nonkinetic,
title = {{Non-kinetic homotopy coherent actions on four-manifolds}},
author = {Sungkyung Kang and JungHwan Park and Masaki Taniguchi},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.24548},
eprint = {2607.24548},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.24548},
}
RIS
TY - UNPB
TI - Non-kinetic homotopy coherent actions on four-manifolds
AU - Sungkyung Kang
AU - JungHwan Park
AU - Masaki Taniguchi
PY - 2026
DA - 2026/10/21
PB - arXiv
DO - 10.48550/arxiv.2607.24548
UR - https://arxiv.org/abs/2607.24548
AB - We give the first example of a non-kinetic smooth homotopy coherent action of order two on a closed simply connected smooth four-manifold. This action is obtained by restricting a nontrivial smooth homotopy coherent action of the discrete circle group on a stabilized K3 surface. We also construct relatively non-kinetic smooth homotopy coherent extensions of boundary involutions over compact smooth $4$-manifolds. In addition, we exhibit boundary involutions that admit locally linear topological extensions but no smooth extensions over the same stabilized fillings. Nevertheless, we prove a Wall-type theorem showing that every free involution on a disjoint union of integral homology spheres extends smoothly over any simply connected smooth filling after sufficiently many stabilizations by S^2× S^2.
ER -