Unstable minimal surfaces in symmetric spaces of non-compact type

Abstract

We prove that if $\Sigma$ is a closed surface of genus at least $3$ and $G$ is a split real semisimple Lie group of rank of at least $3$ acting faithfully by isometries on a Riemannian symmetric space $N$, then there exists a Hitchin representation $\rho\colon \pi_1(\Sigma)\to G$ and a $\rho$-equivarient unstable minimal map from the universal cover of $\Sigma$ to $N$. This follows from a new lower bound on the index of high energy minimal maps into an arbitrary symmetric space of non-compact type. Taking $G=\mathrm{PSL}(n,\mathbb{R})$, $n\ge 4$, this disproves the Labourie Conjecture

Authors

Nathaniel Sagman

University of Luxembourg, Esch-sur-Alzette, Luxembourg

Current address:

University of North Carolina at Chapel Hill, Chapel Hill, NC, USA Peter Smillie

Universität Heidelberg, Heidelberg, Germany

Current address:

Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany