## Advances in Differential Equations

- Adv. Differential Equations
- Volume 21, Number 7/8 (2016), 699-734.

### Existence and blow-up rate of large solutions of $p(x)$-Laplacian equations with large perturbation and gradient terms

Dumitru Motreanu and Qihu Zhang

#### Abstract

In this paper, we investigate boundary blow-up solutions of the problem \begin{equation*} \quad \left\{ \begin{array}{l} -\Delta _{p(x)}u+f(x,u)=\rho (x,u)+K(x)|\nabla u|^{m(x)}\mbox{ in }\Omega , \\[2mm] u(x)\rightarrow +\infty \mbox{ as }d(x,\partial \Omega )\rightarrow 0, \end{array} \right. \end{equation*} where $\Delta _{p(x)}u=\mathrm{div}\,(|\nabla u|^{p(x)-2}\nabla u)$ is called $p(x)$-Laplacian. Our results extend the previous work of J. García-Melián, A. Suárez [23] from the case where $p(\cdot )\equiv 2 $, without gradient term, to the case where $p(\cdot )$ is a function, with gradient term. It also extends the previous work of Y. Liang, Q.H. Zhang and C.S. Zhao [38] from the radial case in the problem to the non-radial case. The existence of boundary blow-up solutions is established and the singularity of boundary blow-up solution is also studied for several cases including when $\frac{\rho (x,u(x))}{f(x,u(x))}\rightarrow 1$ as $x\rightarrow \partial \Omega $, which means that $\rho (x,u)$ is a large perturbation. We provide an exact estimate of the pointwise different behavior of the solutions near the boundary in terms of $d(x,\partial \Omega )$. Hence, the results of this paper are new even in the canonical case $p(\cdot )\equiv 2$. In particular, we do not have the comparison principle, because we don't make the monotone assumption of nonlinear term.

#### Article information

**Source**

Adv. Differential Equations Volume 21, Number 7/8 (2016), 699-734.

**Dates**

First available in Project Euclid: 3 May 2016

**Permanent link to this document**

https://projecteuclid.org/euclid.ade/1462298655

**Mathematical Reviews number (MathSciNet)**

MR3493932

**Zentralblatt MATH identifier**

1375.35144

**Subjects**

Primary: 35J25: Boundary value problems for second-order elliptic equations 35B40: Asymptotic behavior of solutions 35J60: Nonlinear elliptic equations

#### Citation

Zhang, Qihu; Motreanu, Dumitru. Existence and blow-up rate of large solutions of $p(x)$-Laplacian equations with large perturbation and gradient terms. Adv. Differential Equations 21 (2016), no. 7/8, 699--734. https://projecteuclid.org/euclid.ade/1462298655