Global boundedness and Allee effect for a nonlocal time fractional reaction-diffusion equation

TL;DR

This paper studies the global boundedness and long-term behavior of solutions to a nonlocal time fractional reaction-diffusion equation, revealing conditions for bounded solutions and demonstrating an Allee effect under certain parameters.

Contribution

It establishes new conditions for global boundedness of solutions to a nonlocal time fractional reaction-diffusion equation and explores the Allee effect in this fractional context.

Findings

Solutions are globally bounded under specific parameter conditions.

For small growth rates, solutions decay exponentially or locally uniformly to zero.

The model exhibits an Allee effect in the fractional derivative setting.

Abstract

The global boundedness and asymptotic behavior are investigated for the solutions of a nonlocal time fractional reaction-diffusion equation (NTFRDE) $$ \frac{\partial^{\alpha }u}{\partial t^{\alpha }}=\Delta u+\mu u^{2}(1-kJ*u)-\gamma u, \qquad(x,t)\in\mathbb{R}^{N}\times(0,+\infty)$$ with $0<\alpha <1,\beta, \mu ,k>0,N\leq 2$ and $u(x,0)=u_{0}(x)$. Under appropriate assumptions on $J$ and the property of time fractional derivative, it is proved that for any nonnegative and bounded initial conditions, the problem has a global bounded classical solution if $k^{*}=0$ for $N=1$ or $k^{*}=(\mu C^{2}_{GN}+1)\eta^{-1}$ for $N=2$, where $C_{GN}$ is the constant in Gagliardo-Nirenberg inequality. With further assumptions on the initial datum, for small $\mu$ values, the solution is shown to converge to $0$ exponentially or locally uniformly as $t \rightarrow \infty$, which is referred as the Allee effect in sense of Caputo derivative. Moreover, under the condition of $J \equiv 1$, it is proved that the nonlinear NTFRDE has a global bounded solution in any dimensional space with the nonlinear diffusion terms $\Delta u^{m}\, (2-\frac{2}{N}< m\leq 3)$.