Vector Fields on Manifolds

Vector Fields on Manifolds PDF

Author: Michael Francis Atiyah

Publisher: Springer

Published: 2013-03-09

Total Pages: 30

ISBN-13: 3322985032

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This paper is a contribution to the topological study of vector fields on manifolds. In particular we shall be concerned with the problems of exist ence of r linearly independent vector fields. For r = 1 the classical result of H. Hopf asserts that the vanishing of the Euler characteristic is the necessary and sufficient condition, and our results will give partial extens ions of Hopf's theorem to the case r > 1. Arecent article by E. Thomas [10] gives a good survey of work in this general area. Our approach to these problems is based on the index theory of elliptic differential operators and is therefore rather different from the standard topological approach. Briefly speaking, what we do is to observe that certain invariants of a manifold (Euler characteristic, signature, etc. ) are indices of elliptic operators (see [5]) and the existence of a certain number of vector fields implies certain symmetry conditions for these operators and hence corresponding results for their indices. In this way we obtain certain necessary conditions for the existence of vector fields and, more generally , for the existence of fields of tangent planes. For example, one of our results is the following THEOREM (1. 1). Let X be a compact oriented smooth manifold 0/ dimension 4 q, and assume that X possesses a tangent fteld of oriented 2-planes (that is, an oriented 2-dimensional sub-bundle 0/ the tangent vector bundle).

The Volume of Vector Fields on Riemannian Manifolds

The Volume of Vector Fields on Riemannian Manifolds PDF

Author: Olga Gil-Medrano

Publisher: Springer Nature

Published: 2023-07-31

Total Pages: 131

ISBN-13: 3031368576

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This book focuses on the study of the volume of vector fields on Riemannian manifolds. Providing a thorough overview of research on vector fields defining minimal submanifolds, and on the existence and characterization of volume minimizers, it includes proofs of the most significant results obtained since the subject’s introduction in 1986. Aiming to inspire further research, it also highlights a selection of intriguing open problems, and exhibits some previously unpublished results. The presentation is direct and deviates substantially from the usual approaches found in the literature, requiring a significant revision of definitions, statements, and proofs. A wide range of topics is covered, including: a discussion on the conditions for a vector field on a Riemannian manifold to determine a minimal submanifold within its tangent bundle with the Sasaki metric; numerous examples of minimal vector fields (including those of constant length on punctured spheres); a thorough analysis of Hopf vector fields on odd-dimensional spheres and their quotients; and a description of volume-minimizing vector fields of constant length on spherical space forms of dimension three. Each chapter concludes with an up-to-date survey which offers supplementary information and provides valuable insights into the material, enhancing the reader's understanding of the subject. Requiring a solid understanding of the fundamental concepts of Riemannian geometry, the book will be useful for researchers and PhD students with an interest in geometric analysis.

Harmonic Vector Fields

Harmonic Vector Fields PDF

Author: Sorin Dragomir

Publisher: Elsevier

Published: 2011-10-26

Total Pages: 529

ISBN-13: 0124158269

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An excellent reference for anyone needing to examine properties of harmonic vector fields to help them solve research problems. The book provides the main results of harmonic vector ?elds with an emphasis on Riemannian manifolds using past and existing problems to assist you in analyzing and furnishing your own conclusion for further research. It emphasizes a combination of theoretical development with practical applications for a solid treatment of the subject useful to those new to research using differential geometric methods in extensive detail. A useful tool for any scientist conducting research in the field of harmonic analysis Provides applications and modern techniques to problem solving A clear and concise exposition of differential geometry of harmonic vector fields on Reimannian manifolds Physical Applications of Geometric Methods

New Uses for Farm Products

New Uses for Farm Products PDF

Author: United States. Agricultural Research Service

Publisher:

Published: 1959

Total Pages: 44

ISBN-13:

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This bulletin tells the story of utilization research in the Department of Agriculture--of its problems and some of its achievements, and its prospects for the future.

Waters of Coweeta

Waters of Coweeta PDF

Author: United States. Forest Service

Publisher:

Published: 1953

Total Pages: 24

ISBN-13:

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This publication is designed to highlight the results of 20 years of streamflow studies at Coweeta, borrowing text and pictorial illustrations from the documentary film, "Waters of Coweeta."