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arXiv · 1603.09269

Morse Index of Willmore spheres in $S^3$

Alexis Michelat
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Abstract

We obtain an upper bound for the Morse index of Willmore spheres $\Sigma\subset S^3$ coming from an immersion of $S^2$. The quantization of Willmore energy shows that there exists an integer $m$ such that $\mathscr{W}(\Sigma)=4\pi m$. Then we show that $\mathrm{Ind}_{\mathscr{W}}(\Sigma)\leq m$. The proof relies on an explicit computation relating the second derivative of $\mathscr{W}$ for $\Sigma$ with the Jacobi operator of the minimal surface in $\mathbb{R}^3$ it is the image of by stereographic projection thanks of the fundamental classification of Robert Bryant.

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Alexis Michelat. 2016-03-30. Morse Index of Willmore spheres in $S^3$. https://arxiv.org/abs/1603.09269

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