ON THE UPPER AND LOWER RESOLVING FUNCTIONS IN GAME PROBLEMS OF DYNAMICS

The quasi-linear conflict-controlled processes of general form are studied. The theme for investigation is the problem of the trajectories approaching a given cylindrical set. The research is based on the method of upper and lower resolving functions. The main attention is paid to the case when Pontryagin’s condition does not hold, moreover, the bodily part of the terminal set is non-convex. A scheme of the method is proposed, which allows, in the case of non-convexity of the body part, to fix some point in it, namely the aiming point, and to realize the process of approach. Sufficient conditions are obtained for solving the problem of approach for different classes of strategies. In so doing, the Hayek stroboscopic strategies that prescribe control by N.N. Krasovskii are applied. The process of approach goes on in two stages — active and passive. On the active stage the upper resolving function of second type is accumulated and after the moment of switching the lower resolving function of second type is used. These functions allow constructing a measurable control of second player on the basis of the theorems on measurable choice, in particular, the Filippov-Castaing theorem. The obtained results for generalized quasi-linear processes make it possible to encompass a wide range of functional-differential systems as well as the systems with fractional and partial derivatives. Possibilities for development of the offered technique are specified.

Eigenvalues of Elliptic Functional Differential Systems via a Birkhoff–Kellogg Type Theorem

Motivated by recent interest on Kirchhoff-type equations, in this short note we utilize a classical, yet very powerful, tool of nonlinear functional analysis in order to investigate the existence of positive eigenvalues of systems of elliptic functional differential equations subject to functional boundary conditions. We obtain a localization of the corresponding non-negative eigenfunctions in terms of their norm. Under additional growth conditions, we also prove the existence of an unbounded set of eigenfunctions for these systems. The class of equations that we study is fairly general and our approach covers some systems of nonlocal elliptic differential equations subject to nonlocal boundary conditions. An example is presented to illustrate the theory.

On a class of linear continuous-discrete systems with discrete memory

A class of linear functional differential systems with continuous and discrete times and discrete memory is considered. An explicit representation of the principal components to the general solution representation such as the fundamental matrix and the Cauchy operator is derived. The obtained representation is given in terms of the system parameters and opens a way towards efficient studying general linear boundary value problems and control problems with respect to a fixed collection of linear on-target functionals. In the study of the problems mentioned above outside the class under consideration, the systems with discrete memory can be employed as model or approximating ones. This can be useful as applied to systems with aftereffect under studying rough properties that hold under small perturbations of the parameters.