2018/10/10 by Morawiec, Janusz, Zürcher, Thomas
#39B12 #47A50 #47B38 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Primary 37A30 #Secondary 28A80
paper · doi:10.48550/arxiv.1810.04530
Let (X,\mathcal A,μ) be a probability space and let S\colon X→ X be a measurable transformation. Motivated by the paper of K. Nikodem [Czechoslovak Math. J. 41(116) (4) (1991) 565--569], we concentrate on a functional equation generating measures that are absolutely continuous with respect to μ and ε-invariant under S. As a consequence of the investigation, we obtain a result on the existence and uniqueness of solutions φ∈ L1([0,1]) of the functional equation φ(x)=∑n=1N|fn'(x)|φ(fn(x))+g(x), where g∈ L1([0,1]) and f1,…,fN\colon[0,1]→[0,1] are functions satisfying some extra conditions.