Quantized slow blow-up dynamics for the energy-critical corotational wave maps problem
Uihyeon Jeong
TL;DR
This work advances the theory of energy-critical wave maps by constructing a family of finite-time blow-up solutions with quantized rates in the 1-corotational setting. Building on modulational techniques, the authors design an approximate blow-up profile $\boldsymbol{Q}_b$ with a high-dimensional modulation vector $b=(b_1,\dots,b_L)$, and derive a coupled system of ODEs for the modulations that selects slow, quantized decay modes. To overcome the lack of dissipation, they introduce radiation corrections and a higher-order Lyapunov functional $\mathcal{E}_{L+1}$ tied to a repulsive conjugated Hamiltonian, enabling monotonic control of the error through a bootstrap argument and a Brouwer fixed-point step. The main result shows the existence of smooth initial data yielding blow-up at time $T$ with rate $\lambda(t) \sim c (T-t)^{\ell} / |\log(T-t)|^{\ell/(\ell-1)}$, and with the radiative part gaining higher regularity, highlighting a robust mechanism for quantized rate blow-up in energy-critical dispersive equations. These methods connect dispersive wave maps to the quantized blow-up phenomena known in parabolic contexts and provide a framework for analyzing unstable directions via codimension-$\ell-1$ modulations and radiation corrections.
Abstract
We study the blow-up dynamics for the energy-critical 1-corotational wave maps problem with 2-sphere target. In arXiv:0911.0692, Raphaël and Rodnianski exhibited a stable finite time blow-up dynamics arising from smooth initial data. In this paper, we exhibit a sequence of new finite-time blow-up rates (quantized rates), which can still arise from well-localized smooth initial data. We closely follow the strategy of the paper arXiv:1301.1859 by Raphaël and Schweyer, who exhibited a similar construction of the quantized blow-up rates for the harmonic map heat flow. The main difficulty in our wave maps setting stems from the lack of dissipation and its critical nature, which we overcome by a systematic identification of correction terms in higher-order energy estimates.
