This article presents main results of investigations of the authors which were obtained
during the last five years by the partially support on the Shota Rustaveli National
Science Foundation (Grant no. 31–24). These results are Liouville-type theorems
and describe the behavior of various phase motions in terms of ordinary and
standard “Lebesgue measures” in R∞. In this context, the following three problems
are discussed in this paper:
Problem 1. An existence and uniqueness of partial analogs of the Lebesgue measure
in various function spaces;
Problem 2. A construction of various dynamical systems with domain in function
spaces defined by various partial differential equations;
Problem 3. To establish the validity of Liouville-type theorems for various dynamical
systems with domains in function spaces in terms of partial analogs of the
Lebesgue measure.