Results 31 to 40 of about 155 (123)

Flow invariance for perturbed nonlinear evolution equations

open access: yesAbstract and Applied Analysis, Volume 1, Issue 4, Page 417-433, 1996., 2000
Let X be a real Banach space, J = [0, a] ⊂ R, A : D(A) ⊂ X → 2X\ϕ an m‐accretive operator and f : J × X → X continuous. In this paper we obtain necessary and sufficient conditions for weak positive invariance (also called viability) of closed sets K ⊂ X for the evolution system u′ + Au∍f(t, u) on J = [0, a].
Dieter Bothe
wiley   +1 more source

Drift perturbation’s influence on traveling wave speed in KPP-Fisher system

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016
This paper dressed the drift perturbation effects on the traveling wave speed in a reaction-diffusion system. We prove the existence of a traveling front solution of a KPP-Fisher equation and we show an asymptotic expansion of her speed.
Dkhil Fathi, Mannoubi Bechir
doaj   +1 more source

Explicit solutions of Fisher′s equation with three zeros

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 13, Issue 3, Page 617-620, 1990., 1990
Explicit traveling wave solutions of Fisher′s equation with three simple zeros ut = uxx + u(1 − u)(u − a), a ∈ (0, 1), are obtained for the wave speeds suggested by pure analytic considerations. Two types of solutions are obtained: one type is of a permanent wave form whereas the other is not.
M. F. K. Abur-Robb
wiley   +1 more source

On the existence of the solution of Burgers′ equation for n ≤ 4

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 13, Issue 4, Page 645-650, 1990., 1990
In this paper a proof of the existence of the solution of Burgers′ equation for n ≤ 4 is presented. The technique used is shown to be valid for equations with more general types of nonlinearities than is present in Burgers′ equation.
Adel N. Boules
wiley   +1 more source

On the solution of reaction‐diffusion equations with double diffusivity

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 10, Issue 1, Page 163-172, 1987., 1986
In this paper, solution of a pair of Coupled Partial Differential equations is derived. These equations arise in the solution of problems of flow of homogeneous liquids in fissured rocks and heat conduction involving two temperatures. These equations have been considered by Hill and Aifantis, but the technique we use appears to be simpler and more ...
B. D. Aggarwala, C. Nasim
wiley   +1 more source

Unstable periodic wave solutions of Nerve Axion diffusion equations

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 10, Issue 4, Page 787-796, 1987., 1987
Unstable periodic solutions of systems of parabolic equations are studied. Special attention is given to the existence and stability of solutions.
Rina Ling
wiley   +1 more source

Blow-up for an evolution p-laplace system with nonlocal sources and inner absorptions [PDF]

open access: yes, 2011
This paper investigates the blow-up properties of positive solutions to the following system of evolution p-Laplace equations with nonlocal sources and inner absorptions
Dengming Liu   +3 more
core   +1 more source

Qualitative analysis of a reaction-diffusion SIRS epidemic model with nonlinear incidence rate and partial immunity

open access: yesInfectious Disease Modelling, 2023
In this paper, a reaction-diffusion SIRS epidemic model with nonlinear incidence rate and partial immunity in a spatially heterogeneous environment is proposed. The well-posedness of the solution is firstly established. Then the basic reproduction number
Jianpeng Wang   +2 more
doaj   +1 more source

Analysis of the Diffusion SIR Epidemic Model With Networked Delay and Nonlinear Incidence Rate

open access: yesJournal of Mathematics, Volume 2024, Issue 1, 2024.
This paper is concerned with the qualitative analysis of a diffusion SIR epidemic model with networked delay and nonlinear incidence rate. First, we prove the existence and uniqueness of the model by using the method of upper and lower solutions. Then, we prove that the trivial equilibrium (0, 0) is unstable; the disease‐free equilibrium (N, 0) is ...
Xiangyu Tang, Yujuan Chen, Mengxin Chen
wiley   +1 more source

Critical Exponents of Semilinear Equations via the Feynman-Kac Formula [PDF]

open access: yes, 2007
2000 Mathematics Subject Classification: 60H30, 35K55, 35K57 ...
T. Kolkovska, Ekaterina   +1 more
core  

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