Resumen: S-structures on Lie algebras, introduced by Vinberg, represent a broad generalization of the notion of gradings by abelian groups. Gradings by, not necessarily reduced, root systems provide many examples of natural S-structures. Here we deal with a situation not covered by these gradings: the short (SL2xSL2)-structures, where the reductive group is the simplest semisimple but not simple reductive group. The algebraic objects that coordinatize these structures are the J-ternary algebras of Allison, endowed with a nontrivial idempotent. Idioma: Inglés DOI: 10.1007/s13398-023-01541-4 Año: 2024 Publicado en: Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales - Serie A: Matematicas 118 (2024), 45 [21 pp.] ISSN: 1578-7303 Factor impacto JCR: 1.6 (2024) Categ. JCR: MATHEMATICS rank: 53 / 483 = 0.11 (2024) - Q1 - T1 Factor impacto SCIMAGO: 0.922 - Algebra and Number Theory (Q1) - Analysis (Q1) - Geometry and Topology (Q1) - Computational Mathematics (Q1) - Applied Mathematics (Q1)