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Pattern and Waves for a Model in Population Dynamics with Nonlocal Consumption of Resources

S. Genieys, V. Volpert, P. Auger (2010)

Mathematical Modelling of Natural Phenomena

We study a reaction-diffusion equation with an integral term describing nonlocal consumption of resources in population dynamics. We show that a homogeneous equilibrium can lose its stability resulting in appearance of stationary spatial structures. They can be related to the emergence of biological species due to the intra-specific competition and random mutations. Various types of travelling waves are observed.

Periodic and Almost Periodic Solutions of Integral Inclusions

Radosław Pietkun (2010)

Bulletin of the Polish Academy of Sciences. Mathematics

The existence of a continuous periodic and almost periodic solutions of the nonlinear integral inclusion is established by means of the generalized Schauder fixed point theorem.

Periodic solutions for nonlinear Volterra integrodifferential equations in Banach spaces

Dimitrios A. Kandilakis, Nikolaos S. Papageorgiou (1997)

Commentationes Mathematicae Universitatis Carolinae

In this paper we examine periodic integrodifferential equations in Banach spaces. When the cone is regular, we prove two existence theorems for the extremal solutions in the order interval determined by an upper and a lower solution. Both theorems use only the order structure of the problem and no compactness condition is assumed. In the last section we ask the cone to be only normal but we impose a compactness condition using the ball measure of noncompactness. We obtain the extremal solutions...

Periodic solutions for second order integro-differential equations with infinite delay in Banach spaces

Shangquan Bu, Yi Fang (2008)

Studia Mathematica

We study the maximal regularity on different function spaces of the second order integro-differential equations with infinite delay ( P ) u ' ' ( t ) + α u ' ( t ) + d / d t ( - t b ( t - s ) u ( s ) d s ) = A u ( t ) - - t a ( t - s ) A u ( s ) d s + f ( t ) (0 ≤ t ≤ 2π) with periodic boundary conditions u(0) = u(2π), u’(0) = u’(2π), where A is a closed operator in a Banach space X, α ∈ ℂ, and a,b ∈ L¹(ℝ₊). We use Fourier multipliers to characterize maximal regularity for (P). Using known results on Fourier multipliers, we find suitable conditions on the kernels a and b under which necessary and sufficient conditions...

Perturbed Hammerstein integral inclusions with solutions that change sign

Gennaro Infante, Paolamaria Pietramala (2009)

Commentationes Mathematicae Universitatis Carolinae

We establish new existence results for nontrivial solutions of some integral inclusions of Hammerstein type, that are perturbed with an affine functional. In order to use a theory of fixed point index for multivalued mappings, we work in a cone of continuous functions that are positive on a suitable subinterval of [ 0 , 1 ] . We also discuss the optimality of some constants that occur in our theory. We improve, complement and extend previous results in the literature.

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