Geodesic vector fields, induced contact structures and tightness in dimension three

Fuente: arXiv
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1. Verfasser: Becker, Tilman
Format: Preprint
Veröffentlicht: 2024
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author Becker, Tilman
author_facet Becker, Tilman
contents In this paper, we provide new and simpler proofs of two theorems of Gluck and Harrison on contact structures induced by great circle or line fibrations. Furthermore, we prove that a geodesic vector field whose Jacobi tensor is parallel along flow lines (e.g. if the underlying manifold is locally symmetric) induces a contact structure if the 'mixed' sectional curvatures are nonnegative, and if a certain nondegeneracy condition holds. Additionally, we prove that in dimension three, contact structures admitting a Reeb flow which is either periodic, isometric, or free and proper, must be universally tight. In particular, we generalise an earlier result of Geiges and the author, by showing that every contact form on $\mathbb{R}^3$ whose Reeb vector field spans a line fibration is necessarily tight. Furthermore, we provide a characterisation of isometric Reeb vector fields. As an application, we recover a result of Kegel and Lange on Seifert fibrations spanned by Reeb vector fields, and we classify closed contact $3$-manifolds with isometric Reeb flows (also known as $R$-contact manifolds) up to diffeomorphism.
format Preprint
id arxiv_https___arxiv_org_abs_2403_12903
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Geodesic vector fields, induced contact structures and tightness in dimension three
Becker, Tilman
Symplectic Geometry
Differential Geometry
53C22, 53D35, 57K33
In this paper, we provide new and simpler proofs of two theorems of Gluck and Harrison on contact structures induced by great circle or line fibrations. Furthermore, we prove that a geodesic vector field whose Jacobi tensor is parallel along flow lines (e.g. if the underlying manifold is locally symmetric) induces a contact structure if the 'mixed' sectional curvatures are nonnegative, and if a certain nondegeneracy condition holds. Additionally, we prove that in dimension three, contact structures admitting a Reeb flow which is either periodic, isometric, or free and proper, must be universally tight. In particular, we generalise an earlier result of Geiges and the author, by showing that every contact form on $\mathbb{R}^3$ whose Reeb vector field spans a line fibration is necessarily tight. Furthermore, we provide a characterisation of isometric Reeb vector fields. As an application, we recover a result of Kegel and Lange on Seifert fibrations spanned by Reeb vector fields, and we classify closed contact $3$-manifolds with isometric Reeb flows (also known as $R$-contact manifolds) up to diffeomorphism.
title Geodesic vector fields, induced contact structures and tightness in dimension three
topic Symplectic Geometry
Differential Geometry
53C22, 53D35, 57K33
url https://arxiv.org/abs/2403.12903