Normalized solutions to the Chern-Simons-Schrödinger system: the supercritical case
Liejun Shen, Marco Squassina
TL;DR
The paper addresses the existence of normalized (mass-constrained) solutions to a generalized Chern-Simons-Schrödinger system in two dimensions with nonlinearities exhibiting subcritical, critical, and supercritical exponential growth. It develops a robust variational framework on the mass constraint $S(a)$, leveraging gauge-field estimates, the Trudinger-Moser inequality, and a natural constraint $\mathcal{M}(a)$ to obtain ground states via constrained minimization and Palais-Smale sequences; a homotopy stable family further guarantees the existence of a minimax level. In the supercritical regime, the authors introduce truncated nonlinearities $f^{R,\bar{\delta}}$ and $f^{R,2}$ to regain $C^1$-regularity and apply both constrained minimization (5.1) and mountain-pass (5.2) approaches to produce normalized solutions for small $a$, with uniform $L^{\infty}$ bounds. The work extends the theory of normalized CSS solutions in 2D without imposing radial symmetry or compact embeddings and provides several new mechanisms, including Moser-type compactness controls and cutoff strategies, to handle supercritical exponential growth.
Abstract
We are concerned with the existence of normalized solutions for a class of generalized Chern-Simons-Schrödinger type problems with supercritical exponential growth $$ -Δu +λu+A_0 u+\sum\limits_{j=1}^2A_j^2 u=f(u),\quad \partial_1A_2-\partial_2A_1=-\frac{1}{2}|u|^2,\quad \partial_1A_1+\partial_2A_2=0,\quad \partial_1A_0=A_2|u|^2,\quad \partial_2A_0=-A_1|u|^2,\quad \int_{\mathbb{R}^2}|u|^2dx=a^2, $$ where $a\neq0$, $λ\in \mathbb{R}$ is known as the Lagrange multiplier and $f\in C^1(\mathbb{R})$ denotes the nonlinearity that fulfills the supercritical exponential growth in the Trudinger-Moser sense at infinity. Under suitable assumptions, combining the constrained minimization approach together with the homotopy stable family and elliptic regularity theory, we obtain that the problem has at least a ground state solution.
