## Advances in Differential Equations

- Adv. Differential Equations
- Volume 2, Number 3 (1997), 361-382.

### Existence of multiple positive solutions for a semilinear elliptic equation

Yinbing Deng and Yi Li

#### Abstract

In this paper, we consider the semilinear elliptic problem $$ -\triangle u+ u=|u|^{p-2}u+ \mu f(x), \quad u \in H^1(\Bbb R^N), \quad N>2. \tag"$(*)_\mu$" $$ For $p> 2$, we show that there exists a positive constant $\mu ^*>0$ such that $(*)_\mu$ possesses a minimal positive solution if $\mu \in (0, \mu ^*)$ and no positive solutions if $\mu > \mu^*$. Furthermore, if $p< \frac{2N}{N-2}$, then $(*)_\mu$ possesses at least two positive solutions for $\mu \in (0, \mu^{*})$, a unique positive solution if $\mu =\mu^*$ and there exists a constant $\mu _{*} >0 $ such that when $ \mu\in (0, \mu_{*})$, problem $(*)_\mu$ possesses at least three solutions. We also obtain some bifurcation results of the solutions at $\mu =0$ and $\mu=\mu^*$.

#### Article information

**Source**

Adv. Differential Equations, Volume 2, Number 3 (1997), 361-382.

**Dates**

First available in Project Euclid: 23 April 2013

**Permanent link to this document**

https://projecteuclid.org/euclid.ade/1366742248

**Mathematical Reviews number (MathSciNet)**

MR1441848

**Zentralblatt MATH identifier**

1023.35503

**Subjects**

Primary: 35J60: Nonlinear elliptic equations

Secondary: 35B05: Oscillation, zeros of solutions, mean value theorems, etc. 35B32: Bifurcation [See also 37Gxx, 37K50]

#### Citation

Deng, Yinbing; Li, Yi. Existence of multiple positive solutions for a semilinear elliptic equation. Adv. Differential Equations 2 (1997), no. 3, 361--382. https://projecteuclid.org/euclid.ade/1366742248