Weak almost periodic and optimal mild solutions of fractional evolution equations.
In this paper we prove a theorem for the existence of pseudo-solutions to the Cauchy problem, x' = f(t,x), x(0) = x₀ in Banach spaces. The function f will be assumed Pettis-integrable, but this assumption is not sufficient for the existence of solutions. We impose a weak compactness type condition expressed in terms of measures of weak noncompactness. We show that under some additionally assumptions our solutions are, in fact, weak solutions or even strong solutions. Thus, our theorem is an essential...
It is a basic fact in infinite-dimensional Lie theory that the unit group of a continuous inverse algebra A is a Lie group. We describe criteria ensuring that the Lie group is regular in Milnor’s sense. Notably, is regular if A is Mackey-complete and locally m-convex.