Nonlinear Harmonic Bundles
Mao Sheng
TL;DR
The paper introduces nonlinear harmonic bundles as a nonlinear analogue of harmonic bundles in nonabelian Hodge theory by replacing linear fibers with complex manifolds and equipping differentiable bundles with two integrable complex structures connected by a beta-automorphism. It develops a generalized Simpson mechanism, Chern connection theory, and curvature-based harmonicity conditions, anchored in almost connections and almost Higgs fields. It then connects these ideas to relative nonabelian Hodge moduli spaces, proving a rank-one case that ties Gauss-Manin data to Kodaira-Spencer Higgs fields and suggesting a nonlinear Hodge structure on the base. Finally, it establishes a Torelli-type result for abelian varieties, showing that nonlinear Higgs data on moduli spaces captures the isomorphism class of polarized families under strong monodromy, thereby enriching the classical VHS/Torelli framework with nonlinear Higgs dynamics.
Abstract
We generalize the notion of harmonic bundles in nonabelian Hodge theory to the nonlinear setting.
