English

Interaction between fast diffusion and geometry of domain

Analysis of PDEs 2014-05-28 v2

Abstract

Let Ω\Omega be a domain in RN\mathbb R^N, where N2N \ge 2 and Ω\partial\Omega is not necessarily bounded. We consider two fast diffusion equations tu=\mboxdiv(up2u)\partial_t u= \mbox{div}(|\nabla u|^{p-2}{\nabla u}) and tu=Δum\partial_t u= \Delta u^{m}, where 1<p<21<p<2 and 0<m<10<m<1. Let u=u(x,t)u=u(x,t) be the solution of either the initial-boundary value problem over Ω\Omega, where the initial value equals zero and the boundary value is a positive continuous function, or the Cauchy problem where the initial datum equals a nonnegative continuous function multiplied by the characteristic function of the set RNΩ\mathbb R^N\setminus \Omega. Choose an open ball BB in Ω\Omega whose closure intersects Ω\partial\Omega only at one point, and let α>(N+1)(2p)2p\alpha > \frac {(N+1)(2-p)}{2p} or α>(N+1)(1m)4\alpha > \frac {(N+1)(1-m)}{4}. Then, we derive asymptotic estimates for the integral of uαu^\alpha over BB for short times in terms of principal curvatures of Ω\partial\Omega at the point, which tells us about the interaction between fast diffusion and geometry of domain.

Keywords

Cite

@article{arxiv.1404.4915,
  title  = {Interaction between fast diffusion and geometry of domain},
  author = {Shigeru Sakaguchi},
  journal= {arXiv preprint arXiv:1404.4915},
  year   = {2014}
}

Comments

23 pages, to appear in Kodai Math. J

R2 v1 2026-06-22T03:54:04.726Z