We consider probability measures, dμ=w(θ)\fdθ2π+dμ\s, on the unit circle, ∂\bbD, with Verblunsky coefficients, {αj}j=0∞. We prove for θ1=θ2 in [0,2π) and (δβ)j=βj+1 that ∫[1−cos(θ−θ1)][1−cos(θ−θ2)]logw(θ)\fdθ2π>−∞ if and only if j=0∑∞{(δ−e−iθ2)(δ−e−iθ1)α}j2+\absαj4<∞ We also prove that ∫(1−cosθ)2logw(θ)\fdθ2π>−∞ if and only if j=0∑∞\absαj+2−2αj+1+αj2+\absαj6<∞
引用
@article{arxiv.math-ph/0409065,
title = {Higher-Order Szego Theorems With Two Singular Points},
author = {Barry Simon and Andrej Zlatos},
journal= {arXiv preprint arXiv:math-ph/0409065},
year = {2007}
}