Li-Yorke chaotic weighted composition operators

[EN] We establish complete characterizations of the notion of Li-Yorke chaos for weighted composition operators on C-0(X) spaces and on L-p(mu) spaces. As a consequence, we obtain simple characterizations of the Li-Yorke chaotic weighted shifts on c(0) and on l(p) (1 <= p < infinity) that complement previously known results. We also investigate the notion of Li-Yorke chaos for weighted shifts on Frechet sequence spaces. As applications, we obtain characterizations of the Li-Yorke chaotic weighted shifts on K & ouml;the sequence spaces depending only on the entries of the Kothe matrix and the weights of the shift.