Reaction-diffusionequations for population dynamics with forced speed II -cylindrical-type domains

By Henri Berestycki, Luca Rossi. 2009

94 citations recorded by the source corpus.

This work is the continuation of our previous paper [6]. There, we dealt with the reaction-diffusion equation $\partial_t u=\Delta u+f(x-cte,u),\qquad t>0,\quad x\in\R^N,$ where $e\in S^{N-1}$ and $c>0$ are given and $f(x,s)$ satisfies some usual assumptions in population dynamics, together with $f_s(x,0)<0$ for $|x|$ large. The interest for such equation comes from an ecological model introduced in [1] describing the effects of global warming on biological species. In [6],we proved that existence and uniqueness of travelling wave solutions of the type $u(x,t)=U(x-cte)$ and the large time behaviour of solutions with arbitrary nonnegative bounded initial datum depend on the sign of the generalized principal in $\R^N$ of an associated linear operator. Here, we establish analogous results for the Neumann problem in domains which are asymptotically cylindrical, as well as for the problem in the whole space with $f$ periodic in some space variables, orthogonal to the direction of the shift $e$. The $L^1$ convergence of solution $u(t,x)$ as $t\to\infty$ is established next. In this paper, we also show that a bifurcation from the zero solution takes place as the principal crosses $0$. We are able to describe the shape of solutions close to extinction thus answering a question raised by M.~Mimura. These two results are new even in the framework considered in [6]. Another type of problem is obtained by adding to the previous one a term $g(x-c'te,u)$ periodic in $x$ in the direction $e$. Such a model arises when considering environmental change on two different scales. Lastly, we also solve the case of an equation $\partial_t u=\Delta u+f(t,x-cte,u),$ when $f(t,x,s)$ is periodic in $t$. This for instance represents the seasonal dependence of $f$. In both cases, we obtain a necessary and sufficient condition for the existence, uniqueness and stability of pulsating travelling waves, which are solutions with a profile which is periodic in time.

Subfields: Genetics, Modeling and Simulation, Public Health, Environmental and Occupational Health

View Paper: https://www.semanticscholar.org/paper/874fdecd2f1e58fa1b8ae6140644d8583cbd06d1

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Genetics

In Modeling and Simulation

In Public Health, Environmental and Occupational Health

Citations in the corpus

Generalizations and Properties of the Principal Eigenvalue of Elliptic Operators in Unbounded Domains (2010, methodology): “Statement (ii) was announced and used in our previous paper [13].”
Asymptotic spreading in heterogeneous diffusive excitable media (2008, background): “On the other hand, there may be propagation along an unbounded path but not persistence in the stationary frame (see [12, 13]).”