Session 38. Variational Methods in Nonlinear Analysis

Minimal energy solutions for repulsive nonlinear Schrödinger systems

Rainer Mandel, Karlsruhe Institute of Technology, Germany
We establish existence and nonexistence results concerning fully nontrivial minimal energy solutions of the nonlinear Schrödinger system \begin{align*} \begin{aligned} -\Delta u + \; u &= |u|^{2q-2}u + b|u|^{q-2}u|v|^q \quad\text{in }\mathbb{R}^n, \\ -\Delta v + \omega^2 v &= |v|^{2q-2}v + b|u|^q|v|^{q-2}v\quad $\,$ \text{in }\mathbb{R}^n. \end{aligned} \end{align*} We consider the repulsive case \(b<0\) and assume that the exponent \(q\) satisfies \(1<q<\frac{n}{n-2}\) in case \(n\geq 3\) and \(1<q<\infty\) in case \(n=1\) or \(n=2\). For space dimensions \(n\geq 2\) and arbitrary \(b<0\) we prove the existence of fully nontrivial nonnegative solutions which converge to a solution of some optimal partition problem as \(b\to -\infty\). In case \(n=1\) we prove that minimal energy solutions exist provided the coupling parameter \(b\) has small absolute value whereas fully nontrivial solutions do not exist if \(1<q\leq 2\) and \(b\) has large absolute value. This generalizes the existence results found in [1].
References
  1. B. Sirakov: Least energy solitary waves for a system of nonlinear Schrödinger equations in \(R^n\), Comm. Math. Phys. 271 (2007), 199-221.
  2. R. Mandel: Minimal energy solutions for repulsive nonlinear Schrödinger systems, http://arxiv.org/abs/1303.4521
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