Blowup masses of Toda systems corresponding to the Weyl groups
Zhaohu Nie
TL;DR
The paper investigates blow-up phenomena for Toda systems associated with complex simple Lie algebras in the plane with a singular source. Leveraging Lie-theoretic tools (Phi maps, Iwasawa decomposition, highest-weight theory) and Kostant-type arguments, it derives a local mass formula that ties blow-up masses to Weyl-group data. Specifically, for $\tau$ in the Weyl group $W$ and $H$ in the cone $\tau C_0$, the local masses satisfy $\sigma_i = \langle \omega_i - \tau \omega_i, w_0\rangle$, illustrating a precise Weyl-group reflection rule in the blow-up regime. An explicit $A_2$ example demonstrates the predicted masses $(\sigma_1,\sigma_2) = (1,0)$ and confirms the connection between Lie-theoretic structure and nonlinear PDE blow-up behavior, highlighting the generalization of Liouville-type mass quantization to higher-rank Toda systems.
Abstract
Toda systems are generalizations of the Liouville equation to systems using simple Lie algebras. We study the blowup phenomena of their solutions by giving concrete examples demonstrating blowup masses corresponding to the Weyl groups.
