Abstract
Hodge correlators are
complex numbers given by certain integrals assigned to a smooth complex curve.
We show that they are correlators of a Feynman integral, and describe the real mixed Hodge structure
on the pronilpotent completion of the fundamental group of the curve. We introduce motivic correlators, which are elements of the motivic Lie algebra and whose periods are the Hodge correlators. They describe the motivic fundamental group of the curve.
We describe variations of real mixed Hodge structures on a variety by certain connections
on the product of the variety by twistor plane. We call them twistor connections.
In particular, we define the canonical period map on variations of real mixed
Hodge structures. We show that the obtained period functions satisfy a simple
Maurer–Cartan type non-linear differential equation.
Generalizing this, we suggest a DG-enhancement of the subcategory of Saito’s Hodge complexes with smooth cohomology. We show that when the curve varies,
the Hodge correlators are the coefficients of the twistor connection describing the corresponding variation of real MHS.
Examples of the Hodge correlators include classical and elliptic polylogarithms, and their generalizations.
The simplest Hodge correlators on the modular curves are the Rankin–Selberg integrals. Examples of the motivic
correlators include Beilinson’s elements in the motivic cohomology, e.g. the ones delivering
the Beilinson–Kato Euler system on modular curves.
Classifying spaces of degenerating mixed Hodge structures, III: Spaces of nilpotent orbits
