{ "id": "1706.06057", "version": "v1", "published": "2017-06-19T16:58:13.000Z", "updated": "2017-06-19T16:58:13.000Z", "title": "Life-span of smooth solutions to a PDE system with cubic nonlinearity", "authors": [ "Xiangsheng Xu" ], "categories": [ "math.AP" ], "abstract": "In this paper we study the life-span of classical solutions to the initial boundary value problem for the system $-\\mbox{div}\\left[(I+{\\bf m}\\otimes {\\bf m})\\nabla p\\right]=S(x),\\ \\ \\partial_t{\\bf m}-D^2\\Delta {\\bf m}-E^2({\\bf m}\\cdot\\nabla p)\\nabla p+|{\\bf m}|^{2(\\gamma-1)}{\\bf m}=0$, where $S(x)$ is a given function and $D, E, \\gamma$ are given numbers. This problem has been proposed as a PDE model for biological transportation networks. Our investigations reveal that local existence of a classical solution can always be achieved and the life-span of such a solution can be extended as far away as one wishes as long as the term $\\|{\\bf m}(x,0)\\|_{\\infty, \\Omega}+\\|S(x)\\|_{\\frac{2N}{3}, \\Omega}$ is made suitably small, where $N$ is the space dimension and $\\|\\cdot\\|_{q,\\Omega}$ denotes the norm in $L^q(\\Omega)$.", "revisions": [ { "version": "v1", "updated": "2017-06-19T16:58:13.000Z" } ], "analyses": { "keywords": [ "cubic nonlinearity", "pde system", "smooth solutions", "initial boundary value problem", "classical solution" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }