The study of the spectral properties of operator polynomials is reduced to the study of the spectral properties of the operator specified by the operator matrix. The results obtained are applied to higher-order difference operators. Conditions for their invertibility and for them to be Fredholm, as well as the asymptotic representation for bounded solutions of homogeneous difference equations are obtained.
This paper studies the topological properties of the automorphisms of the 4-torus R4/Z4 that are generated by integer symplectic transformations of R4. Such transformations are customarily called the symplectic automorphisms of the torus. The purpose is a classification of the possible types of behavior of the trajectories of symplectic automorphisms of T4.
A problem of complexity of Boolean functions realization over infinite complete bases of special type is studied. These bases contain all monotone functions with zero weight and finite number of non-monotone functions with unit weight. Exhaustive description of Boolean realization over basis that consists of all monotone functions and one non-monotone function negation has been obtained by Markov. The minimal sufficient number of negations for arbitrary Boolean function f realization (i.e. inversion complexity of the function f) equals ⌈log2(d(f)+1)⌉, where d(f) is the maximal number of function value changes from 1 to 0 over all increasing chains of tuples of variables values. In this paper the result above is generalized to the arbitrary basis of this type. It is shown that the minimal sucient for arbitrary Boolean function f realization number of non-monotone functions equals ⌈log2(d(f)/D(B) + 1)⌉. Here D(B) is the maximum d(ω) over all non-monotone functions ω from the basis B.
For gradient-like flows without heteroclinic intersections of the stable and unstable manifolds of saddle periodic points all
of whose saddle equilibrium states have Morse index 1 or n − 1, the notion of consistent equivalence of energy functions
is introduced. It is shown that the consistent equivalence of energy functions is necessary and sufficient for topological