English

R-closedness and Upper semicontinuity

Dynamical Systems 2012-11-07 v2

Abstract

Let F\mathcal{F} be a pointwise almost periodic decomposition of a compact metrizable space XX. Then F\mathcal{F} is RR-closed if and only if F^\hat{\mathcal{F}} is usc. Moreover, if there is a finite index normal subgroup HH of an RR-closed flow GG on a compact manifold such that the orbit closures of HH consist of codimension kk compact connected elements and "few singularities" for k=1k = 1 or 2, then the orbit class space of GG is a compact kk-dimensional manifold with conners. In addition, let vv be a nontrivial RR-closed vector field on a connected compact 3-manifold MM. Then one of the following holds: 1) The orbit class space M/v^M/ \hat{v} is [0,1][0,1] or S1S^1 and each interior point of M/v^M/ \hat{v} is two dimensional. 2) Per(v)\mathrm{Per}(v) is open dense and M=Sing(v)Per(v)M = \mathrm{Sing}(v) \sqcup \mathrm{Per}(v). 3) There is a nontrivial non-toral minimal set. On the other hand, let GG be a flow on a compact metrizable space and HH a finite index normal subgroup. Then we show that GG is RR-closed if and only if so is HH.

Keywords

Cite

@article{arxiv.1209.0166,
  title  = {R-closedness and Upper semicontinuity},
  author = {Tomoo Yokoyama},
  journal= {arXiv preprint arXiv:1209.0166},
  year   = {2012}
}
R2 v1 2026-06-21T21:58:34.123Z