2018/09/01 by Bringmann, Bjoern · 2 citations
#35L05 #35L15 #35L71 #Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.1809.00220
We study the derivative nonlinear wave equation \( - ∂tt u + Δu = |∇ u|2 \) on \( ℝ1+3 \). The deterministic theory is determined by the Lorentz-critical regularity \( sL = 2 \), and both local well-posedness above \( sL \) as well as ill-posedness below \( sL \) are known. In this paper, we show the local existence of solutions for randomized initial data at the super-critical regularities \( s≥ 1.984\). In comparison to the previous literature in random dispersive equations, the main difficulty is the absence of a (probabilistic) nonlinear smoothing effect. To overcome this, we introduce an adaptive and iterative decomposition of approximate solutions into rough and smooth components. In addition, our argument relies on refined Strichartz estimates, a paraproduct decomposition, and the truncation method of de Bouard and Debussche.