2021/12/29 by Lindenstrauss, Elon, Mohammadi, Amir
#Dynamical Systems (math.DS) #FOS: Mathematics #Geometric Topology (math.GT) #Metric Geometry (math.MG)
paper · doi:10.48550/arxiv.2112.14562
We prove effective density theorems, with a polynomial error rate, for orbits of the upper triangular subgroup of SL2(\mathbb R) in arithmetic quotients of SL2(\mathbb C) and SL2(\mathbb R)\timesSL2(\mathbb R). The proof is based on the use of a Margulis function, tools from incidence geometry, and the spectral gap of the ambient space.