2018/09/04 by Nicola Garofalo, Garofalo, Nicola · 1 citation
Computer Science · Mathematics · #Advanced Mathematical Modeling in Engineering #Analysis of PDEs (math.AP) #FOS: Mathematics #Nonlinear Partial Differential Equations #Numerical methods in inverse problems
paper · pdf · doi:10.48550/arxiv.1809.01242
openalex publication_date 2018/09/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this note I present some properties of sub-Laplaceans associated with a collection of smooth vector fields satisfying Hörmander's finite rank assumption. One notable aspect of the paper is the development of the fractional powers of sub-Laplaceans as Dirichlet-to-Neumann maps of an extension problem inspired to the famous 2007 work of Caffarelli and Silvestre for the standard Laplacean. A key tool is an extension problem for the fractional heat equation for which I compute the relevant Poisson kernel. I then use the latter to: 1) find the Poisson kernel for the time-independent case; and 2) solve the extension problem.