Simply transitive NIL-affine actions of solvable Lie groups

• Autores: Deré, Jonas; Origlia, Marcos Miguel
• Año de publicación: 2021
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: ALGEBRAIC HULL; LIE ALGEBRA; SEMISIMPLE SPLITTING; SIMPLY TRANSITIVE ACTION; SOLVABLE LIE GROUP
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Every simply connected and connected solvable Lie group G admits a simply transitive action on a nilpotent Lie group H via affine transformations. Although the existence is guaranteed, not much is known about which Lie groups G can act simply transitively on which Lie groups H. So far, the focus was mainly on the case where G is also nilpotent, leading to a characterization depending only on the corresponding Lie algebras and related to the notion of post-Lie algebra structures. This paper studies two different aspects of this problem. First, we give a method to check whether a given action : G Aff(H) is simply transitive by looking only at the induced morphism p: G → aff(h) between the corresponding Lie algebras. Secondly, we show how to check whether a given solvable Lie group G acts simply transitively on a given nilpotent Lie group H, again by studying properties of the corresponding Lie algebras. The main tool for both methods is the semisimple splitting of a solvable Lie algebra and its relation to the algebraic hull,whichwe also define on the level of Lie algebras. As an application, we give a full description of the possibilities for simply transitive actions up to dimension 4.
Fil: Deré, Jonas. Katholikie Universiteit Leuven; Bélgica
Fil: Origlia, Marcos Miguel. Monash University; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentina