Title: Sharp quantitative rigidity results for maps from $S^2$ to $S^2$ of
general degree
Authors: Melanie Rupflin
Categories: math.AP math.DG
MSC-class: 53C43, 58E20, 30C70, 26D10,
\\
As the energy of any map $v$ from $S^2$ to $S^2$ is at least $4\pi \vert
deg(v)\vert$ with equality if and only if $v$ is a rational map one might ask
whether maps with small energy defect $\delta_v=E(v)-4\pi \vert deg(v)\vert$
are necessarily close to a rational map. While such a rigidity statement turns
out to be false for maps of general degree, we will prove that any map $v$ with
small energy defect is essentially given by a collection of rational maps that
describe the behaviour of $v$ at very different scales and that the
corresponding distance is controlled by a quantitative rigidity estimate of the
form $dist^2\leq C \delta_v(1+\vert\log\delta_v\vert)$ which is indeed sharp.
\\ ( https://arxiv.org/abs/2305.17045 , 45kb)