Permanence of a discrete model of mutualism with infinite deviating arguments.
Permanence of a discrete -species Schoener competition system with time delays and feedback controls.
Permanence of a discrete nonlinear prey-competition system with delays.
Permanence of a discrete periodic Volterra model with mutual interference.
Permanence of a discrete predator-prey system with Beddington-DeAngelis functional response and feedback controls.
Perron-type criterion for linear difference equations with distributed delay.
Perturbation method for linear difference equations with small parameters.
Pexider functional equations -- their fuzzy analogs.
Pexider type operators and their norms in spaces
In this paper, we introduce Pexiderized generalized operators on certain special spaces introduced by Bielecki-Czerwik and investigate their norms.
Pexider's equation and aggregation of allocations.
Phases of linear difference equations and symplectic systems
The second order linear difference equation where and , is considered as a special type of symplectic systems. The concept of the phase for symplectic systems is introduced as the discrete analogy of the Borůvka concept of the phase for second order linear differential equations. Oscillation and nonoscillation of (1) and of symplectic systems are investigated in connection with phases and trigonometric systems. Some applications to summation of number series are given, too.
Plus-operators in Krein spaces and dichotomous behavior of irreversible dynamical systems with discrete time
We study dichotomous behavior of solutions to a non-autonomous linear difference equation in a Hilbert space. The evolution operator of this equation is not continuously invertible and the corresponding unstable subspace is of infinite dimension in general. We formulate a condition ensuring the dichotomy in terms of a sequence of indefinite metrics in the Hilbert space. We also construct an example of a difference equation in which dichotomous behavior of solutions is not compatible with the signature...
PM functions, their characteristic intervals and iterative roots
The concept of characteristic interval for piecewise monotone functions is introduced and used in the study of their iterative roots on a closed interval.
Poincaré inequalities and hitting times
Equivalence of the spectral gap, exponential integrability of hitting times and Lyapunov conditions is well known. We give here the correspondence (with quantitative results) for reversible diffusion processes. As a consequence, we generalize results of Bobkov in the one dimensional case on the value of the Poincaré constant for log-concave measures to superlinear potentials. Finally, we study various functional inequalities under different hitting times integrability conditions (polynomial,…)....
Pointwise and global sums and negatives of translation relations.
Pointwise transformations of linear differential equations
Poisson kernels of drifted Laplace operators on trees and on the half-plane
Starting with the computation of the appropriate Poisson kernels, we review, complement, and compare results on drifted Laplace operators in two different contexts: homogeneous trees and the hyperbolic half-plane.
Polylogarithmic functional equations: A new category of results developed with the help of computer algebra (MACSYMA).
Polylogarithms in the field of omega (a root of given cubic): Functional equations and ladders.
Polynomial selections and separation by polynomials
K. Nikodem and the present author proved in [3] a theorem concerning separation by affine functions. Our purpose is to generalize that result for polynomials. As a consequence we obtain two theorems on separation of an n-convex function from an n-concave function by a polynomial of degree at most n and a stability result of Hyers-Ulam type for polynomials.