English

New differential Harnack inequalities for nonlinear heat equations

Differential Geometry 2018-03-29 v1 Analysis of PDEs

Abstract

We prove constrained trace, matrix and constrained matrix Harnack inequalities for the nonlinear heat equation ωt=Δω+aωlnω\omega_t=\Delta\omega+a\omega\ln \omega on closed manifolds. We also derive a new interpolated Harnack inequality for the equation ωt=Δωωlnω+εRω\omega_t=\Delta\omega-\omega\ln\omega+\varepsilon R\omega on closed surfaces under the ε\varepsilon-Ricci flow. Finally we prove a new differential Harnack inequality for the equation ωt=Δωωlnω\omega_t=\Delta\omega-\omega\ln\omega under the Ricci flow without any curvature condition. Among these Harnack inequalities, the correction terms are all time-exponential functions, which are superior to time-polynomial functions.

Keywords

Cite

@article{arxiv.1803.10622,
  title  = {New differential Harnack inequalities for nonlinear heat equations},
  author = {Jia-Yong Wu},
  journal= {arXiv preprint arXiv:1803.10622},
  year   = {2018}
}

Comments

19 pages, to appear in Chin. Ann. Math. Ser. B