A global Morse index theorem and applicationsto Jacobi fields on CMC surfaces

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Communications in Contemporary Mathematics
(2024) 2350064 (44 pages)
The Author(s)
DOI: 10.1142/S0219199723500645

Wu-Hsiung Huang
Department of Mathematics
National Taiwan University, Taipei 106, Taiwan
whuang0706@gmail.com


Received 15 September 2022
Revised 1 November 2023
Accepted 30 November 2023
Published 28 February 2024


In this paper, we establish a “global” Morse index theorem. Given a hypersurface Mn of constant mean curvature, immersed in Rn+1. Consider a continuous deformation of “generalized” Lipschitz domain D(t) enlarging in Mn. The topological type of D(t) is permitted to change along t, so that D(t) has an arbitrary shape which can “reach afar” in Mn, i.e. cover any preassigned area. The proof of the global Morse index theorem is reduced to the continuity in t of the Sobolev space Ht of variation functions on D(t), as well as the continuity of eigenvalues of the stability operator. We devise a “detour” strategy by introducing a notion of “set-continuity” of D(t) in t to yield the required continuities of Ht and of eigenvalues. The global Morse index theorem thus follows and provides a structural theorem of the existence of Jacobi fields on domains in Mn.

Keywords: Constant mean curvature; Sobolev space of variations; Jacobi field; Morse index theorem; continuity of eigenvalues.

Mathematics Subject Classification 2020: 53C23, 58E12, 35J25, 46E35, 49R05

全文檔案: huang-2024-a-global-morse-index-theorem-and-applications-to-jacobi-fields-on-cmc-surfaces