2024/12/04 by Gérard, Patrick, Lenzmann, Enno · 3 citations
#Analysis of PDEs (math.AP) #Exactly Solvable and Integrable Systems (nlin.SI) #FOS: Mathematics #FOS: Physical sciences #Mathematical Physics (math-ph)
paper · doi:10.48550/arxiv.2412.03351
We study the energy-critical half-wave maps equation: ∂t u = u × |D| u for u : [0, T) × ℝ → \mathbbS2. Our main result establishes the global existence and uniqueness of solutions for all rational initial data u0 : ℝ → \mathbbS2. This demonstrates global well-posedness for a dense subset within the scaling-critical energy space H1/2(ℝ; \mathbbS2). Furthermore, we prove soliton resolution for a dense subset of initial data in the energy space, with uniform bounds for all higher Sobolev norms Hs for s > 0. Our analysis utilizes the Lax pair structure of the half-wave maps equation on Hardy spaces in combination with an explicit flow formula. Extending these results, we establish global well-posedness for rational initial data (along with a soliton resolution result) for a generalized class of matrix-valued half-wave maps equations with target spaces in the complex Grassmannians Grk(ℂd). Notably, this includes the complex projective spaces \mathbbCPd-1 ≅ Gr1(ℂd) thereby extending the classical case of the target \mathbbS2 ≅ \mathbbCP1.