In this paper we are investigating the long time behaviour of the solution of a mutation competition model of Lotka-Volterra's type. Our main motivation comes from the analysis of the Lotka-Volterra's competition system with mutation which simulates the demo-genetic dynamics of diverse virus in their host : $$ \frac{dv_{i}(t)}{dt}=v_i\[r_i-\frac{1}{K}Ψ_i(v)\]+\sum_{j=1}^{N} μ_{ij}(v_j-v_i). $$ In a first part we analyse the case where the competition terms $Ψ_i$ are independent of the virus type $i$. In this situation and under some rather general assumptions on the functions $Ψ_i$, the coefficients $r_i$ and the mutation matrix $μ_{ij}$ we prove the existence of a unique positive globally stable stationary solution i.e. the solution attracts the trajectory initiated from any nonnegative initial datum. Moreover the unique steady state $\bar v$ is strictly positive in the sense that $\bar v_i>0$ for all $i$. These results are in sharp contrast with the behaviour of Lotka-Volterra without mutation term where it is known that multiple non negative stationary solutions exist and an exclusion principle occurs (i.e For all $i\neq i_0, \bar v_{i}=0$ and $\bar v_{i_0}>0$). Then we explore a typical example that has been proposed to explain some experimental data. For such particular models we characterise the speed of convergence to the equilibrium. In a second part, under some additional assumption, we prove the existence of a positive steady state for the full system and we analyse the long term dynamics. The proofs mainly rely on the construction of a relative entropy which plays the role of a Lyapunov functional.
Lotka-Volterra competition models on finite graphs
本文研究了有限连通图上三个两种群竞争的Lotka-Volterra竞争模型,分别具有Dirichlet、Neumann和无边界条件.在Neumann边界条件和无边界条件下,当时间趋于无穷大时,种群中的一个种群灭绝而另一个种群生存,或者两个竞争种群共存,这主要取决于种群竞争力的强弱和种群初始规模.我们的一个结果部分回答了斯拉夫·勒克在[SIAM J. Appl. Dyn.系统:19(2020)]。证明主要结果的关键技术是上、下解方法,本文针对有限图上的弱耦合抛物型方程组发展了上、下解方法。
Traveling Wave Solutions for Delayed Reaction-Diffusion Systems and Applications to Lotka-Volterra Competition-Diffusion Models with Distributed Delays
Propagation Direction of Bistable Traveling Fronts in the Lotka--Volterra Competition--Diffusion System
School of Mathematical Sciences, Shanghai Jiao Tong University(上海交通大学数学科学学院);Institute of Natural Sciences, Shanghai Jiao Tong University(上海交通大学自然科学研究院);Chern Institute of Mathematics, Nankai University(南开大学陈省身数学研究所)
Sharp Thresholds for Linear Determinacy and Zero Wave Speed in Lotka-Volterra Competition-Diffusion Systems
School of Mathematical Sciences, Shanghai Jiao Tong University(上海交通大学数学科学学院);Institute of Natural Sciences, Shanghai Jiao Tong University(上海交通大学自然博物馆);Chern Institute of Mathematics, Nankai University(南开大学陈省身数学研究所)