Almost Parallel Structures
Differential Geometry
2007-05-23 v1
Abstract
A discussion of torsion of Riemannian G-structures leads to a survey of contributions of Alfred Gray and others on almost Hermitian manifolds, G_2-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.
Cite
@article{arxiv.math/0107146,
title = {Almost Parallel Structures},
author = {Simon Salamon},
journal= {arXiv preprint arXiv:math/0107146},
year = {2007}
}
Comments
Proceedings, Congress in memory of Alfred Gray, to appear in AMS Contemporary Mathematics