Lichnerowicz-Obata Estimate, Almost Parallel $p$-form and Almost Product Manifolds
Differential Geometry
2021-01-07 v5
Abstract
We show a Lichnerowicz-Obata type estimate for the first eigenvalue of the Laplacian of -dimensional closed Riemannian manifolds with an almost parallel -form () in -sense, and give an almost decomposition result of the manifold under some pinching conditions when .
Cite
@article{arxiv.1904.06533,
title = {Lichnerowicz-Obata Estimate, Almost Parallel $p$-form and Almost Product Manifolds},
author = {Masayuki Aino},
journal= {arXiv preprint arXiv:1904.06533},
year = {2021}
}
Comments
66 pages v2:some error corrected, Appendix B added, v3:some error corrected, v4:some proofs simplified, v5: some error corrected, some descriptions simplified