Positive Equilibrium Solutions for Age- and Spatially-Structured Population Models

Positive Equilibrium Solutions for Age- and Spatially-Structured Population Models

The existence of positive equilibrium solutions to age-dependent population equations with nonlinear diffusion is studied in an abstract setting. By introducing a bifurcation parameter measuring the intensity of the fertility it is shown that a branch of (positive) equilibria bifurcates from the trivial equilibrium. In some cases the direction of bifurcation is analyzed.

A Note on the Convergence of the Homotopy Analysis Method for Nonlinear Age-Structured Population Models

In this paper, a theorem is proved which presents the series solution obtained from the homotopy analysis method is convergent to the exact solution of nonlinear age-structured population models.

Population Viability Analyses with Demographically and Spatially Structured Models

This paper presents a review of demographically structured (or, frequency-based) models, in which the individuals in a population are grouped into distinct classes. Structured models are used when vital rates (survival, reproduction, dispersal) of individuals depend on their age or physiological/morphological stage. Variation in these rates (environmental stochasticity) and the effect of abunda...

Weak Solutions and Differentiability for Size - Structured Population Models

Variational iteration method for nonlinear age-structured population models

In this paper, we apply He’s variational iteration method (VIM) coupled with an auxiliary parameter which proves very effective to control the convergence region of an approximate solution. Moreover, a convenient way is considered for choosing a suitable auxiliary parameter via a residual function. The proposed algorithm is tested on some nonlinear age-structured population models, and numerica...