Almost Parallel Structures

2001/07/20 by Simon Salamon
Mathematics · #math.DG #msc:53C25

paper · pdf

published as Contemp. Math. 288 (2001), 162-181. · Proceedings, Congress in memory of Alfred Gray, to appear in AMS Contemporary Mathematics

arxiv created 2001/07/20 · arxiv updated 2009/11/30

Abstract

A discussion of torsion of Riemannian G-structures leads to a survey of contributions of Alfred Gray and others on almost Hermitian manifolds, G₂-manifolds, curvature identities, volume expansions, plotting geodesics, and the geometry of nilmanifolds. The paper concludes with a new example of a compact 8-manifold with a quaternionic 4-form that is closed but not parallel.

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