Blow-up Solutions for General Toda Systems on Riemann Surfaces
Zhengni Hu, Miaomiao Zhu
TL;DR
This work analyzes the $N$-component Toda system with homogeneous Neumann boundary on a compact Riemann surface under a $k$-symmetry constraint. It develops a singular perturbation framework augmented by Lyapunov–Schmidt reduction, leveraging isothermal coordinates and Green’s functions to pull back planar bubbling profiles and control inter-component interactions through the Cartan matrix. The main result proves the existence of bubbling solutions concentrating at $m$ interior $k$-symmetric centers, with mass parameters satisfying $\rho_i^{\varepsilon} \to 2\alpha_i\pi m$ and the associated measures converging to Dirac masses at the blow-up points; for the $SU(3)$ case this yields asymmetric blow-up configurations. The method, which yields interior blow-up on models like $\mathbb{S}^2$ and $\mathbb{S}^2_+$, advances the bubbling theory for Toda systems on curved manifolds with boundary and identifies the $k$-symmetric centers as the natural blow-up sites; boundary blow-up remains an open question for future work.
Abstract
In this paper, we study general Toda systems with homogeneous Neumann boundary conditions on Riemann surfaces. Assuming the surface satisfies the ``$k$-symmetric'' condition, we construct a family of bubbling solutions using singular perturbation methods, where the concentration rates of different components occur in distinct orders. In particular, we establish the existence of asymmetric blow-up solutions for the $SU(3)$ Toda system. Furthermore, the blow-up points are precisely located at the ``$k$-symmetric'' centers of the surface. Keywords: Toda system, Neumann boundary condition, Blow-up solutions, $k$-symmetry, Finite-dimensional reduction
