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JOURNALS // Itogi Nauki i Tekhniki. Sovremennaya Matematika i ee Prilozheniya. Tematicheskie Obzory // Archive

Itogi Nauki i Tekhniki. Sovrem. Mat. Pril. Temat. Obz., 2019 Volume 169, Pages 56–66 (Mi into515)

Lie algebra of killing vector fields and its stationary subalgebra

V. A. Popov

Financial University under the Government of the Russian Federation, Moscow

Abstract: Let $\mathfrak{g}$ be the Lie algebra of all Killing vector fields on a locally homogeneous, analytic Riemannian manifold $M$, $\mathfrak{h}$ be a stationary subalgebra of $\mathfrak{g}$, $G$ be the simply connected group generated by the algebra $\mathfrak{g}$, $H$ be the subgroup of $G$ generated by the subalgebra $\mathfrak{h}$, $\mathfrak{z}$ be the center of the algebra $\mathfrak{g}$, $\mathfrak{r}$ be its radical, and $[\mathfrak{g};\mathfrak{g}]$ be its commutator subgroup. If $\dim\big(\mathfrak{h}\cap\big(\mathfrak{z} + [\mathfrak{g}, \mathfrak{g}] \big)\big) = \dim \big(\mathfrak{h} \cap [\mathfrak{g}, \mathfrak{g}]\big)$, then $H$ is closed in $G$. If for any semisimple subalgebra $\mathfrak{p}\subset\mathfrak{g}$ satisfying the condition $\mathfrak{p}+\mathfrak{r}=\mathfrak{g}$, the relation $(\mathfrak{p}+\mathfrak{z})\cap\mathfrak{h} =\mathfrak{p}\cap\mathfrak{h}$ holds, then $H$ is closed in $G$. We also examine the analytic continuation of the given local, analytic Riemannian manifold.

Keywords: Riemannian manifold, Lie algebra, analytic continuation, vector field, Lie group, closed subgroup.

UDC: 514.764

MSC: 53C20, 54H15

DOI: 10.36535/0233-6723-2019-169-56-66



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