2021/11/08 by Joseph P. Davies, Gabriel S. Koch, Davies, Joseph P. +1
Engineering · Mathematics · #Advanced Mathematical Physics Problems #Analysis of PDEs (math.AP) #FOS: Mathematics #Navier-Stokes equation solutions #Stability and Controllability of Differential Equations
paper · pdf · doi:10.48550/arxiv.2111.04350
openalex publication_date 2021/11/08 · openalex created_date 2022/08/01 · openalex updated_date 2026/07/28
For initial data f∈ L2(ℝn) (n≥ 2), we prove that if p∈(n,∞], any solution u∈ Lt∞Lx2∩ Lt2Hx1∩ Lt(2p)/(p-n)Lxp,∞ to the Navier-Stokes equations satisfies the energy equality, and that such a solution u is unique among all solutions v∈ Lt∞Lx2∩ Lt2Hx1 satisfying the energy inequality. This extends well-known results due to G. Prodi (1959) and J. Serrin (1963), which treated the Lebesgue space Lxp rather than the larger Lorentz (and `weak Lebesgue') space Lxp,∞. In doing so, we also prove the equivalence of various notions of solutions in Lxp,∞, generalizing in particular a result proved for the Lebesgue setting in Fabes-Jones-Riviere (1972).