2024/07/14 by Stanley Snelson, Snelson, Stanley, Shelly Ann Taylor +1 · 1 citation
Mathematics · #Advanced Mathematical Physics Problems #Analysis of PDEs (math.AP) #FOS: Mathematics #Nonlinear Partial Differential Equations #Spectral Theory in Mathematical Physics
paper · pdf · doi:10.48550/arxiv.2407.10293
openalex publication_date 2024/07/14 · openalex created_date 2024/07/17 · openalex updated_date 2026/07/28
This paper addresses large-data local existence and uniqueness of classical solutions to the inhomogeneous Landau equation in the hard potentials case (including Maxwell molecules). Solutions have previously been constructed by Chaturvedi [SIAM J. Math. Anal., 55(5), 5345--5385, 2023] for initial data in an exponentially-weighted H10 space, but it is not a priori clear whether these solutions have more regularity than the initial data. We improve Chaturvedi's existence result in two ways: our solutions are C^∞ for positive times, and we allow initial data in a sub-exponentially-weighted L^∞ space, at the cost of requiring a mild positivity condition at time zero. To prove uniqueness, we require stronger assumptions on the initial data: Hölder continuity and the absence of vacuum regions. These are the same assumptions that are required for uniqueness in prior work on the soft potentials case. Along the way to proving existence and uniqueness, we establish some useful results that were previously only known in the case of soft potentials, including spreading of positivity and propagation of Hölder continuity. Many of the proof strategies from the soft potentials case do not apply here because of the more severe loss of velocity moments.