# Critical points of the Moser-Trudinger functional on a disk

created by martinazz on 06 Mar 2012
modified on 25 Feb 2013

[BibTeX]

Accepted Paper

Inserted: 6 mar 2012
Last Updated: 25 feb 2013

Journal: J. Eur. Math. Soc. (JEMS)
Year: 2012
Notes:

16 pages

Abstract:

On the unit disk $B_1\subset \mathbb{R}^2$ we study the Moser-Trudinger functional

$E(u)=\int_{B_1}(e^{u^2}-1)dx,\quad u\in H^1_0(B_1)$

and its restrictions to $M_\Lambda$, where $M_{\Lambda}:=\{u\in H^1_0(B_1):| u| ^2_{H^1_0}=\Lambda\}$ for $\Lambda>0$. We prove that if a sequence $u_k$ of positive critical points of $E|_{M_{\Lambda_k}}$ (for some $\Lambda_k>0$) blows up as $k\to\infty$, then $\Lambda_k\to 4\pi$, and $u_k\to 0$ weakly in $H^1_0(B_1)$ and strongly in $C^1_{loc}(\overline B_1\setminus\{0\})$.

Using this we also prove that when $\Lambda$ is large enough, then $E|_{M_\Lambda}$ has no positive critical point, complementing previous existence results by Carleson-Chang, M. Struwe and Lamm-Robert-Struwe.