A 3–manifold which supports a periodic flow is a Seifert fibered space. We define a notion of almost periodic flow and give conditions under which a manifold supporting an almost periodic flow is Seifert fibered. It is well-known that does not support fixed point free periodic flows, and our results include that does not support certain almost periodic flows.
"Almost periodic flows on 3–manifolds." Algebr. Geom. Topol. 7 (1) 157 - 180, 2007. https://doi.org/10.2140/agt.2007.7.157