Semiprojectivity of the moduli of principal $G$-bundles with $λ$-connections
Sumit Roy, Anoop Singh
Abstract
Let $X$ be a compact connected Riemann surface of genus $g \geq 2$ and $G$ a connected reductive affine algebraic group over $\mathbb{C}$. We prove the semiprojectivity of the moduli spaces of semistable $G$-Higgs bundles and $G$-bundles with $λ$-connections of fixed topological type $d\in π_1(G)$. As an application, in the smooth case we describe the resulting Bialynicki - Birula decomposition and derive cohomological and motivic consequences.
