“…We refer to book by Cowen and MacCluer [3] for basic theory of multiplication and composition operators. The study of these operators has been lifted from the Lebesgue spaces to other function spaces, for instance to Lorentz space, Orlicz space, Lorentz-Zygmund space, to name a few, over the years (see [1,4,10] and the references therein). Their theory touches various branches of mathematics and physics such as entropy theory, ergodic theory and classical mechanics.…”