Lower bounds for Lyapunov exponents of flat bundles on curves
Abstract
Consider a flat bundle over a complex curve. We prove a conjecture of Fei Yu that the sum of the top k Lyapunov exponents of the flat bundle is always greater or equal to the degree of any rank k holomorphic subbundle. We generalize the original context from Teichmueller curves to any local system over a curve with non-expanding cusp monodromies. As an application we obtain the large genus limits of individual Lyapunov exponents in hyperelliptic strata of Abelian differentials. Understanding the case of equality with the degrees of subbundle coming from the Hodge filtration seems challenging, e.g. for Calabi-Yau type families. We conjecture that equality of the sum of Lyapunov exponents and the degree is related to the monodromy group being a thin subgroup of its Zariski closure.
Keywords
Cite
@article{arxiv.1609.01170,
title = {Lower bounds for Lyapunov exponents of flat bundles on curves},
author = {Alex Eskin and Maxim Kontsevich and Martin Moeller and Anton Zorich},
journal= {arXiv preprint arXiv:1609.01170},
year = {2020}
}
Comments
minor changes, formulation of the conjecture updated, to appear in Geometry and Topology