J. R. L. Webb

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We investigate positive steady states of a diffusive predator–prey model in spatially heterogeneous environment. In comparison with the spatially homogeneous environment, the dynamics of the predator–prey model of spatial heterogeneity is more complicated. Our studies show that if dispersal rate of the prey is treated as a bifurcation parameter, for some(More)
The paper deals with the existence and multiplicity of positive solutions for a system of higher-order singular nonlinear fractional differential equations with nonlocal boundary conditions. The main tool used in the proof is fixed point index theory in cone. Some limit type conditions for ensuring the existence of positive solutions are given.
We are interested in the asymptotic analysis of singular solutions with blowup boundary for a class of quasilinear logistic equations with indefinite potential. Under natural assumptions, we study the competition between the growth of the variable weight and the behaviour of the nonlinear term, in order to establish the blow-up rate of the positive(More)
  • Constantin BuşeB, Olivia Saierli, Afshan Tabassum, J. R. L. Webb, A. Tabassum
  • 2014
First we prove that an n× n complex linear system is Hyers–Ulam stable if and only if it is dichotomic (i.e. its associated matrix has no eigenvalues on the imaginary axis iR). Also we show that the scalar differential equation of order n, x(n)(t) = a1x(t) + · · ·+ an−1x(t) + anx(t), t ∈ R+ := [0, ∞), is Hyers–Ulam stable if and only if the algebraic(More)