Analysis of PDEs (math.AP)

Abstract: We study a class of Schr\"{o}dinger-Kirchhoff system involving critical exponent. We aim to find suitable conditions to assure the existence of a positive ground state solution of Nehari-Poho\u{z}aev type $u_{\varepsilon}$ with exponential decay at infinity for $\varepsilon$ and $ u_{\varepsilon}$ concentrates around a global minimum point of $ V$ as $ \varepsilon\rightarrow0^{+}.$ The nonlinear term includes the nonlinearity $f(u)\sim|u|^{p-1}u$ for the well-studied case $ p\in[3,5)$, and the less-studied case $p\in(2,3)$.

Abstract: In this article, we study the existence of normalized ground state solutions for the following biharmonic nonlinear Schr\"{o}dinger equation with combined nonlinearities \begin{equation*} \Delta^2u=\lambda u+\mu|u|^{q-2}u+|u|^{p-2}u,\quad \text {in $\mathbb{R}^N$} \end{equation*} having prescribed mass \begin{equation*} \int_{\mathbb{R}^N}|u|^2dx=a^2, \end{equation*} where $N\geq2$, $\mu\in \mathbb{R}$, $a>0$, $2<q<p<\infty$ if $2\leq N\leq 4$, $2<q<p\leq 4^*$ if $N\geq 5$, and $4^*=\frac{2N}{N-4}$ is the Sobolev critical exponent and $\lambda\in \mathbb{R}$ appears as a Lagrange multiplier. By using the Sobolev subcritical approximation method, we prove the second critical point of mountain pass type for the case $N\geq5$, $\mu>0$, $p=4^*$, and $2<q<2+\frac{8}{N}$. Moreover, we also consider the case $\mu=0$ and $\mu<0$.