Pseudo-K\"ahler structure on the $\mathrm{SL}(3,\mathbb{R})$-Hitchin component and Goldman symplectic form

Abstract

The aim of this paper is to show the existence and give an explicit description of a pseudo-Riemannian metric and a symplectic form on the $\mathrm{S}\mathrm{L}(3,\mathbb{R})$-Hitchin component, both compatible with Labourie and Loftin's complex structure. In particular, they give rise to a mapping class group invariant pseudo-K\"ahler structure on a neighborhood of the Fuchsian locus, which restricts to a multiple of the Weil-Petersson metric on Teichm\"uller space. By comparing our symplectic form with Goldman's $\boldsymbol{\omega}_G$, we prove that the pair $(\boldsymbol{\omega}_G, \mathbf{I})$ cannot define a K\"ahler structure on the Hitchin component.