2023/11/14 by Chapouto, Andreia, Forlano, Justin, Li, Guopeng +2 · 3 citations
#35Q35 #37K10 #76B55 #Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.2311.08142
We study the intermediate long wave equation (ILW) in negative Sobolev spaces. In particular, despite the lack of scaling invariance, we identify the regularity s = -\frac 12 as the critical regularity for ILW with any depth parameter, by establishing the following two results. (i) By viewing ILW as a perturbation of the Benjamin-Ono equation (BO) and exploiting the complete integrability of BO, we establish a global-in-time a priori bound on the Hs-norm of a solution to ILW for - \frac 12 < s < 0. (ii) By making use of explicit solutions, we prove that ILW is ill-posed in Hs for s < - \frac 12. Our results apply to both the real line case and the periodic case.