Left-invariant Pseudo-Riemannian metrics on Lie groups: The null cone

Autor:	Hervik, Sigbjorn
Rok vydání:	2024
Předmět:	Mathematics - Differential Geometry Mathematical Physics Mathematics - Group Theory
Druh dokumentu:	Working Paper
Popis:	We study left-invariant pseudo-Riemannian metrics on Lie groups using the bracket flow of the corresponding Lie algebra. We focus on metrics where the Lie algebra is in the null cone of the $G=O(p,q)$-action; i.e., Lie algebras $\mu$ where zero is in the closure of the orbits: $0\in\overline{G\cdot \mu}$. We provide examples of such Lie groups in various signatures and give some general results. For signatures $(1,q)$ and $(2,q)$ we classify all cases belonging to the null cone. More generally, we show that all nilpotent and completely solvable Lie algebras are in the null cone of some $O(p,q)$ action. In addition, several examples of non-trivial Levi-decomposable Lie algebras in the null cone are given. Comment: 22pages, 1 figure, V2: Changed structure, fixed typos. To appear in Diff. Geo. Appl
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2402.03536 Zobrazit plný text záznamu View this record from Arxiv