Bifurcations for a Coupled Schr\"odinger System with Multiple Components
  In this paper, we study local bifurcations of an indefinite elliptic system with multiple components: \begin{equation*}   \left\{\begin{array}{ll}   -\Delta u_j + au_j = \mu_ju_j^3+\beta\sum_{k\ne j}u_k^2u_j,   u_j>0\ \ \hbox{in}\ \Omega, u_j=0 \ \ \hbox{on}\ \partial\Omega,\ j=1,\dots,n.   \end{array}   \right. \end{equation*} Here $\Omega\subset{\mathbb{R}}^N$ is a smooth and bounded domain, $n\ge3$, $a<-\Lambda_1$ where $\Lambda_1$ is the principal eigenvalue of $(-\Delta, H_0^1(\Omega))$; $\mu_j$ and $\beta$ are real constants. Using the positive and non-degenerate solution of the scalar equation $-\Delta\omega-\omega=-\omega^3$, $\omega\in H_0^1(\Omega)$, we construct a synchronized solution branch $\mathcal{T}_\omega$. Then we find a sequence of local bifurcations with respect to $\mathcal{T}_\omega$, and we find global bifurcation branches of partially synchronized solutions. 
Thomas Bartsch, Rushun Tian, Zhi-Qiang Wang
math.AP