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Erwann Aubry Bruno Colbois Patrick Ghanaat Ernst A. Ruh 《Annals of Global Analysis and Geometry》2003,23(3):227-246
For closed n-dimensional Riemannian manifolds M with almostnonnegative Ricci curvature, the Laplacian on one-forms is known toadmit at most n small eigenvalues. If there are n small eigenvalues, or if M is orientable and has n – 1 small eigenvalues, then M isdiffeomorphic to a nilmanifold, and the metric is almost left invariant.We show that our results are optimal for n 4. 相似文献
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Molecular Diversity - Synthesis of bioactive heterocyclic compounds having effective biological activity is an essential research area for wide-ranging applications. In this study, a conventional... 相似文献
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