Existence of minimal maps of degree one in $W^{\frac1p,p}(\mathbb S^1,\mathbb S^1)$ for $p \in [p',2]$, where $p' \approx 1.13924$

Abstract

In this note, we show how the results of Mazowiecka--Schikorra, combined with those of Bourgain--Brezis--Mironescu, imply the existence of minimal maps of degree one in $ W^{\frac{1}{p},p}(\mathbb{S}^1,\mathbb{S}^1) $ for $ p \in [p', 2] $, where $ p' \approx 1.13924 $. This provides an affirmative answer in this range to a question posed by Mironescu and Brezis--Mironescu. In order to do so, we complement the results of Mazowiecka--Schikorra by extending them to the case $ n = 1 $ and $ 1 < p < 2 $, which had been excluded there for technical reasons.