A simple proof of the Uniqueness of blow-up solutions of mean field equations
Lina Wu, Wenming Zou
TL;DR
This work establishes a simple proof of the uniqueness of blow-up solutions for mean field equations on compact Riemann surfaces, including singular cases with negative poles ($\alpha_M\le 0$). It leverages a Green's function reformulation and refined local asymptotics to extend prior results and to derive a concise contradiction-argument that forces all relevant vanishing parameters to be zero, hence uniqueness. The analysis combines improved regular-point expansions, negative-source bubbling, and careful energy balance near multiple blow-up points, offering a more accessible route than previous technical proofs. The results have implications for related Dirichlet problems and broaden the scope of uniqueness in mean field-type equations with singular inputs.
Abstract
For a regular mean field equation defined on a compact Riemann surface, an important work of Bartolucci-Jevnikar-Lee-Yang \cite{bart-4} proved a uniqueness theorem for blow-up solutions under non-degeneracy assumptions. However, the proof is highly nontrivial and challenging to read. In this article, we not only provide a simple proof for the regular equation but also extend our proof to the case of singular equations with negative singular poles. Our proof supplements what is not written in a recent outstanding work by Bartolucci-Yang-Zhang \cite{byz-1}.
