## Advances in Differential Equations

- Adv. Differential Equations
- Volume 23, Number 1/2 (2018), 109-134.

### Sign-changing solutions for non-local elliptic equations involving the fractional Laplacain

Yinbin Deng and Wei Shuai

#### Abstract

In this paper, we consider the existence of sign-changing solutions for fractional elliptic equations of the form \begin{equation*} \left\{\begin{array}{ll} (-\Delta)^s u=f(x,u) & \text{in}\ \Omega , \\ u=0 & \text{in}\ \mathbb R^N\setminus \Omega, \end{array} \right. \end{equation*} where $s\in(0,1)$ and $\Omega\subset \mathbb R^N$ is a bounded smooth domain. Since the non-local operator $(-\Delta)^s$ is involved in the equation, the variational functional of the equation has totally different properties from the local cases. By introducing some new ideas, we prove, via variational method and the method of invariant sets of descending flow, that the problem has a positive solution, a negative solution and a sign-changing solution under suitable conditions. Moreover, if $f(x,u)$ satisfies a monotonicity condition, we show that the problem has a least energy sign-changing solution with its energy is strictly larger than that of the ground state solution of Nehari type. We also obtain an unbounded sequence of sign-changing solutions if $f(x,u)$ is odd in $u$.

#### Article information

**Source**

Adv. Differential Equations, Volume 23, Number 1/2 (2018), 109-134.

**Dates**

First available in Project Euclid: 26 October 2017

**Permanent link to this document**

https://projecteuclid.org/euclid.ade/1508983363

**Mathematical Reviews number (MathSciNet)**

MR3718170

**Zentralblatt MATH identifier**

06822195

**Subjects**

Primary: 35J60: Nonlinear elliptic equations 35R11: Fractional partial differential equations 58E05: Abstract critical point theory (Morse theory, Ljusternik-Schnirelman (Lyusternik-Shnirel m an) theory, etc.) 47J30: Variational methods [See also 58Exx]

#### Citation

Deng, Yinbin; Shuai, Wei. Sign-changing solutions for non-local elliptic equations involving the fractional Laplacain. Adv. Differential Equations 23 (2018), no. 1/2, 109--134. https://projecteuclid.org/euclid.ade/1508983363