Our goal is to define exponentials of linear operators. We will try to construct etA as a linear operator, where A : D(A)→ X is a general linear operator, not necessarily bounded. Notationally, it seems like we are looking for a solution to μ̇(t) = Aμ(t), μ(0) = μ0, and we would like to write μ(t) = eμ0. It turns out that this will hold once we make sense of the terms. How can we construct etA w...

the main result of this article is that for collections of entry-wise non-negative matrices the property of possessing a standard triangularization is stable under approximation. the methodology introduced to prove this result allows us to offer quick proofs of the corresponding results of [b. r. yahaghi, near triangularizability implies triangularizability, canad. math. bull. 47, (2004), no. 2...

in this note some useful properties of strongly continuous two-parameter semigroups of operators are studied, an exponential formula for two-parameter semigroups of operators on banach spaces is obtained and some applied examples of two-parameter dynamical systems are discussed

This paper is concerned with the behavior of semigroups of nonlinear contractions on closed convex subsets of a Hilbert space H. Recently, many results, known for semigroups of linear operators, were extended to semigroups of nonlinear contractions. The first results in this direction by Neuberger [25] and oharu [26] dealt mainly with the representation of such semigroups by means of exponentia...

In this paper, we prove existence and controllability results for first and second order semilinear neutral functional differential inclusions with finite or infinite delay in Banach spaces, with nonlocal conditions. Our theory makes use of analytic semigroups and fractional powers of closed operators, integrated semigroups and cosine families.

In this paper we prove existence results for first and second order semilinear neutral functional differential inclusions with finite or infinite delay in Banach spaces and nonlocal conditions, via a Nonlinear Alternative for condensing maps. Our theory makes use of analytic semigroups and fractional powers of closed operators, integrated semigroups and cosine families. Mathematics subject clas...