关键词: radial solution, quasilinear elliptic equations, variational methods, Orlicz-Sobolev spaces

Abstract: We investigate the following elliptic equations: $$ \begin{cases} -M\Bigl(\int_{\mathbb{R}^N}\phi(|\nabla u|^2){\rm d}x\Bigr)\text{div}(\phi^{\prime}(|\nabla u|^2)\nabla u) +|u|^{\alpha-2}u=\lambda h(x,u), \\[2mm] u(x) \rightarrow 0, \quad \text{as} \ |x| \rightarrow \infty, \end{cases} \quad \text{ in } \ \ \mathbb{R}^N, $$ where $N \geq 2$, $1 < p < q < N$, $\alpha < q$, $1 < \alpha \leq p^*q^{\prime}/p^{\prime}$ with $p^*=\frac{Np}{N-p}$, $\phi(t)$ behaves like $t^{q/2}$ for small $t$ and $t^{p/2}$ for large $t$, and $p^{\prime}$ and $q^{\prime}$ are the conjugate exponents of $p$ and $q$, respectively. We study the existence of nontrivial radially symmetric solutions for the problem above by applying the mountain pass theorem and the fountain theorem. Moreover, taking into account the dual fountain theorem, we show that the problem admits a sequence of small-energy, radially symmetric solutions.

Key words: radial solution, quasilinear elliptic equations, variational methods, Orlicz-Sobolev spaces