{ "id": "1609.01441", "version": "v1", "published": "2016-09-06T08:58:53.000Z", "updated": "2016-09-06T08:58:53.000Z", "title": "How does the spreading speed associated with the Fisher-KPP equation depend on random stationary diffusion and reaction terms?", "authors": [ "Grégoire Nadin" ], "doi": "10.3934/dcdsb.2015.20.1785", "categories": [ "math.AP", "math.OC" ], "abstract": "We consider one-dimensional reaction-diffusion equations of Fisher-KPP type with random stationary ergodic coefficients. A classical result of Freidlin and Gartner [16] yields that the solutions of the initial value problems associated with compactly supported initial data admit a linear spreading speed almost surely. We use in this paper a new characterization of this spreading speed recently proved in [8] in order to investigate the dependence of this speed with respect to the heterogeneity of the diffusion and reaction terms. We prove in particular that adding a reaction term with null average or rescaling the coefficients by the change of variables x $\\rightarrow$ x/L, with L \\textgreater{} 1, speeds up the propagation. From a modelling point of view, these results mean that adding some heterogeneity in the medium gives a higher invasion speed, while fragmentation of the medium slows down the invasion.", "revisions": [ { "version": "v1", "updated": "2016-09-06T08:58:53.000Z" } ], "analyses": { "keywords": [ "random stationary diffusion", "reaction term", "fisher-kpp equation", "random stationary ergodic coefficients", "initial value problems" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }