We study persistence properties of the solution of the Benjamin-Ono equation in weighted Sobolev spaces. Roughly, we show that for <7/2, the solution u (x, t) of the BO remains in the space L² (|x|^2 dx) if and only if its data u (x, 0) belongs to this space and it is regular enough, i. e. u₀ H^ (R).
Linares et al. (2026) studied this question.