## Differential and Integral Equations

- Differential Integral Equations
- Volume 14, Number 1 (2001), 59-74.

### Global existence and gradient estimates for a quasilinear parabolic equation of the mean curvature type with a strong perturbation

Caisheng Chen, Mitsuhiro Nakao, and Yasuhiro Ohara

#### Abstract

We prove a global existence and gradient estimates of solutions to the initial-boundary problem of the quasilinear parabolic equation \[ u_t - \mbox{div}\{\sigma(|\nabla u|)^2 \nabla u\} + g(\nabla u) =0 \mbox{ in } \Omega \times (0,\infty),\] with the initial and boundary conditions $ u(0,x)=u_0(x), u|_{\partial\Omega}=0$, where $ \Omega $ is a bounded domain in $ R^N , \sigma(v)$ is a function like $ \sigma(v)=1/\!\sqrt{1+v}$ and $g(\nabla u)$ is a nonlinear perturbation like $ g(\nabla u)\!=\pm|\nabla u|^{\alpha +1}\!,$ $ \alpha >0$. In particular, we derive the estimate \[ ||\nabla u(t)||_{\infty} \leq C(||\nabla u_0||_{p_0})t^{-N/(2p_0-3N)}e^{-\lambda t}, t >0\] for a certain $\lambda > 0 $, under the assumptions that $||\nabla u_0||_{p_0}, p_0 >3(N+\alpha) \quad ( p_0 > 2\alpha+5 \mbox{ if } N=1) $, is small and the mean curvature of the boundary $ \partial \Omega $ is nonpositive.

#### Article information

**Source**

Differential Integral Equations, Volume 14, Number 1 (2001), 59-74.

**Dates**

First available in Project Euclid: 21 December 2012

**Permanent link to this document**

https://projecteuclid.org/euclid.die/1356123375

**Mathematical Reviews number (MathSciNet)**

MR1797932

**Zentralblatt MATH identifier**

1161.35316

**Subjects**

Primary: 35K55: Nonlinear parabolic equations

Secondary: 35B15: Almost and pseudo-almost periodic solutions 35D05 35K20: Initial-boundary value problems for second-order parabolic equations 35K60: Nonlinear initial value problems for linear parabolic equations

#### Citation

Chen, Caisheng; Nakao, Mitsuhiro; Ohara, Yasuhiro. Global existence and gradient estimates for a quasilinear parabolic equation of the mean curvature type with a strong perturbation. Differential Integral Equations 14 (2001), no. 1, 59--74. https://projecteuclid.org/euclid.die/1356123375