1987/11/01 by Robert L. Bryant · 583 citations
Mathematics · Physics and Astronomy · #Geometric Analysis and Curvature Flows #Geometry and complex manifolds #Advanced Differential Geometry Research #Holonomy #Mathematics #Pure mathematics #Algebra over a field
paper · doi:10.2307/1971360
published in Annals of Mathematics 126(3), 525 (Princeton University)
openalex publication_date 1987/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/12
It is proved that there exist metrics with G2 and Spin(7), thus settling the remaining cases in Berger's list of possible groups. We first reformulate the holonomy H condition as a set of differential equations for an associated H-structure on a given manifold. We collect the needed algebraic facts about G2 and Spin(7). We then apply the machinery of over-determined partial differential equations (in the form of the Cartan-Kahler theorem) to prove the existence of solutions whose is G2 or Spin(7). We also provide explicit examples and some information about the generality of the space of