Semi-flat metrics of the moduli spaces of Higgs bundles in the non-zero degree case

We study horizontal deformations of a Higgs bundle whose spectral curve is smooth. It allows us to define a natural integrable connection of the Hitchin fibration on the locus where the spectral curves are smooth. Then, in the non-zero degree case, we introduce the semi-flat metric, and compare the asymptotic behaviour of the semi-flat metric and the Hitchin metric along the ray $(E,t\theta )$ $(t\to \mathrm{\infty })$.