{ "id": "1706.03403", "version": "v1", "published": "2017-06-11T20:24:39.000Z", "updated": "2017-06-11T20:24:39.000Z", "title": "Global continuation of monotone waves for a unimodal bistable reaction-diffusion equation with delay", "authors": [ "Sergei Trofimchuk", "Vitaly Volpert" ], "comment": "36 pages, 3 figures", "categories": [ "math.CA" ], "abstract": "We consider a delayed reaction-diffusion equation $u_t(t,x) = u_{xx}(t,x) + g(u(t,x), u(t-\\tau,x)) \\ (*)$ with bistable nonlinearity $g$. In difference with previous works, we do not assume the monotonicity of $g(u,v)$ with respect to $v$ that hinders application of the comparison techniques. For two different types of $v-$unimodal nonlinearity $g(u,v)$, we prove the existence of a maximal continuous family of bistable monotone wavefronts $u= \\phi(x+c(\\tau)t,\\tau)$. Our proof is based on a variant of the Hale-Lin functional-analytic approach to heteroclinic solutions where Lyapunov-Schmidt reduction is realised in appropriate weighted spaces of $C^2$-smooth functions. This method requires a detailed analysis of associated linear differential Fredholm operators and their formal adjoints. Depending on type of unimodality (equivalently, on the sign of $c(\\tau)$), two different scenarios can be observed for our wave solutions of $(*)$: i) independently on the size of delay $\\tau$, each bistable wavefront is monotone; ii) wavefronts are monotone for moderate values of $\\tau$ and can oscillate for large $\\tau$. Our results are illustrated by two biological models and one `toy' example.", "revisions": [ { "version": "v1", "updated": "2017-06-11T20:24:39.000Z" } ], "analyses": { "subjects": [ "34K12", "35K57", "92D25" ], "keywords": [ "unimodal bistable reaction-diffusion equation", "monotone waves", "global continuation", "associated linear differential fredholm operators" ], "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable" } } }