Convex functions defined on metric spaces are pulled back to subharmonic ones by harmonic maps

Hugo Lavenant, Léonard Monsaingeon, Luca Tamanini +1

If $u:\Omega \subset {\mathbb{R}}^d\to \mathrm{X}$ is a harmonic map valued in a metric space $\mathrm{X}$ and $\mathsf{E}:\mathrm{X}\to \mathbb{R}$ is a convex function, in the sense that it ge…