Abstract
We study the following Kirchhoff type equation:
−
a
+
b
∫
R
N
|
∇
u
|
2
d
x
Δ
u
+
u
=
k
(
x
)
|
u
|
p
−
2
u
+
m
(
x
)
|
u
|
q
−
2
u
in
R
N
,
$$\begin{equation*}\begin{array}{ll} -\left(a+b\int\limits_{\mathbb{R}^{N}}|\nabla u|^{2}\mathrm{d}x\right)\Delta u+u =k(x)|u|^{p-2}u+m(x)|u|^{q-2}u~~\text{in}~~\mathbb{R}^{N}, \end{array}
\end{equation*}$$
where N=3,
a
,
b
>
0
$ a,b \gt 0 $
,
1
<
q
<
2
<
p
<
min
{
4
,
2
∗
}
$ 1 \lt q \lt 2 \lt p \lt \min\{4, 2^{*}\} $
, 2≤=2N/(N − 2), k ∈ C (ℝ
N
) is bounded and m ∈ L
p/(p−q)(ℝ
N
). By imposing some suitable conditions on functions k(x) and m(x), we firstly introduce some novel techniques to recover the compactness of the Sobolev embedding
H
1
(
R
N
)
↪
L
r
(
R
N
)
(
2
≤
r
<
2
∗
)
$ H^{1}(\mathbb{R}^{N})\hookrightarrow L^{r}(\mathbb{R}^{N}) (2\leq r \lt 2^{*}) $
; then the Ekeland variational principle and an innovative constraint method of the Nehari manifold are adopted to get three positive solutions for the above problem.