{ "id": "1104.2664", "version": "v2", "published": "2011-04-14T04:38:26.000Z", "updated": "2011-04-28T14:37:16.000Z", "title": "Geodesic orbit manifolds and Killing fields of constant length", "authors": [ "Yu. G. Nikonorov" ], "comment": "7 pages, some typos are corrected", "categories": [ "math.DG" ], "abstract": "The goal of this paper is to clarify connections between Killing fields of constant length on a Rimannian geodesic orbit manifold $(M,g)$ and the structure of its full isometry group. The Lie algebra of the full isometry group of $(M,g)$ is identified with the Lie algebra of Killing fields $\\mathfrak{g}$ on $(M,g)$. We prove the following result: If $\\mathfrak{a}$ is an abelian ideal of $\\mathfrak{g}$, then every Killing field $X\\in \\mathfrak{a}$ has constant length. On the ground of this assertion we give a new proof of one result of C. Gordon: Every Riemannian geodesic orbit manifold of nonpositive Ricci curvature is a symmetric space.", "revisions": [ { "version": "v2", "updated": "2011-04-28T14:37:16.000Z" } ], "analyses": { "subjects": [ "53C20", "53C25", "53C35" ], "keywords": [ "killing field", "constant length", "full isometry group", "rimannian geodesic orbit manifold", "lie algebra" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1104.2664N" } } }