We study the existence of analytic solutions of a functional differential equation which comes from traffic flow model. By reducing the equation with the Schröder transformation to an auxiliary equation, the author discusses not only that the constant at resonance, that is, at a root of the unity, but also those near resonance under the Brjuno condition.
"Analytic Solutions for a Functional Differential Equation Related to a Traffic Flow Model." Abstr. Appl. Anal. 2012 1 - 13, 2012. https://doi.org/10.1155/2012/180595