Homogeneous geodesics in pseudo-Riemannian nilmanifolds

We study the geodesic orbit property for nilpotent Lie groups N when endowed with a pseudo-Riemannian left-invariant metric. We consider this property with respect to different groups acting by isometries. When N acts on itself by left-translations we show that it is a geodesic orbit space if and on...

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Bibliographic Details
Author: del Barco, Viviana Jorgelina
Format: article
Status:Published version
Publication Date:2016
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/52639
Online Access:http://hdl.handle.net/11336/52639
Access Level:Open access
Keyword:HOMOGENEOUS PSEUDO-RIEMANNIAN SPACES
HOMOGENEOUS GEODESICS
PSEUDO-RIEMANNIAN NILPOTENT LIE GROUPS
https://purl.org/becyt/ford/1.1
https://purl.org/becyt/ford/1
Description
Summary:We study the geodesic orbit property for nilpotent Lie groups N when endowed with a pseudo-Riemannian left-invariant metric. We consider this property with respect to different groups acting by isometries. When N acts on itself by left-translations we show that it is a geodesic orbit space if and only if the metric is bi-invariant. Assuming N is 2-step nilpotent and with non-degenerate center we give algebraic conditions on the Lie algebra n of N in order to verify that every geodesic is the orbit of a one-parameter subgroup of N ⋊ Auto(N). In addition we present an example of an almost g.o. space such that for null homogeneous geodesics, the natural parameter of the orbit is not always the affine parameter of the geodesic.