2025/04/23 by Adachi, Masanori, Matsuda, Yoshifumi, Nozawa, Hiraku
#22D50 #31A15 #53C12 #57M60 #57R20 #58D19 #FOS: Mathematics #Geometric Topology (math.GT)
paper · doi:10.48550/arxiv.2504.16336
Thurston proposed, in part of an unfinished manuscript, to study surface group actions on S1 by using an S1-connection on the suspension bundle obtained from a harmonic measure. Following the approach and previous work of the authors, we study the actions of general lattices of PSU(1,1) on S1. We prove the Gauss--Bonnet formula for the S1-connection associated with a harmonic measure, and show that a harmonic measure on the suspension bundle of the action with maximal Euler number has rigidity, having a form closely related to the Poisson kernel. As an application, we prove a semiconjugacy rigidity for foliations with maximal Euler number, which is analogous to theorems due to Matsumoto, Minakawa and Burger--Iozzi--Wienhard.