Nonabelian Hodge isomorphisms for cohomological Hall algebras

Nonabelian Hodge theory relates three different kinds of objects on smooth, projective, algebraic varieties: Higgs bundles, local systems, and connections. The corresponding moduli spaces are diffeomorphic but not isomorphic. Nevertheless, this suffices to compare their cohomologies. When considering the moduli stacks, the situation is less favourable: it is not known how to compare the topologies of the Dolbeault and de Rham moduli stacks. I will explain how cohomological Hall algebras give us the right tool to study these stacks for a smooth projective curve. In addition, it is even possible to compare the cohomological Hall algebra structures through the nonabelian Hodge isomorphisms we obtain.