O. Kowalski and J. Szenthe [KS] proved that every homogeneous Riemannian manifold admits at least one homogeneous geodesic, i.e\. one geodesic which is an orbit of a one-parameter group of isometries. In [KNV] the related two problems were studied and a negative answer was given to both ones: (1) Let $M=K/H$ be a homogeneous Riemannian manifold where $K$ is the largest connected group of isometries and $\dim M\geq 3$. Does $M$ always admit more than one homogeneous geodesic? (2) Suppose that $M=K/H$ admits $m = \dim M$ linearly independent homogeneous geodesics through the origin $o$. Does it admit $m$ mutually orthogonal homogeneous geodesics? In this paper the author continues this study in a three-dimensional connected Lie group $G$ equipped with a left invariant Riemannian metric and investigates the set of all homogeneous geodesics.
@article{119318, author = {Rosa Anna Marinosci}, title = {Homogeneous geodesics in a three-dimensional Lie group}, journal = {Commentationes Mathematicae Universitatis Carolinae}, volume = {43}, year = {2002}, pages = {261-270}, zbl = {1090.53038}, mrnumber = {1922126}, language = {en}, url = {http://dml.mathdoc.fr/item/119318} }
Marinosci, Rosa Anna. Homogeneous geodesics in a three-dimensional Lie group. Commentationes Mathematicae Universitatis Carolinae, Tome 43 (2002) pp. 261-270. http://gdmltest.u-ga.fr/item/119318/
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