Alaa Jamal Eddine | Searcharxiv

arXiv2015

An overview of harmonic analysis and the shifted wave equation on symmetric graphs

Let X be a symmetric graph of type k and order r, where k,r $\ge$ 2 are integers. In this paper we give explicite expressions of the horocyclic Abel transform and its dual, as well as their inverses X. We then derive the Plancherel measure for the Helgason-Fourier transform on G and give a version of the Kunze-Stein phenomenon thereon. Finally, we compute the solution to the shifted wave equation on X, using {À}sgeirsson's mean value theorem and the inverse dual Abel transform.

math.GR↗

arXiv2013

Schrodinger Equation on homogeneous trees

Let T be a homogeneous tree and L the Laplace operator on T. We consider the semilinear Schrodinger equation associated to L with a power-like nonlinearity F of degree d. We first obtain dispersive estimates and Strichartz estimates with no admissibility conditions. We next deduce global well-posedness for small L2 data with no gauge invariance assumption on the nonlinearity F. On the other hand if F is gauge invariant, L2 conservation leads to global well-posedness for arbitrary L2 data. Notice that, in contrast with the Euclidean case, these global well-posedness results hold with no restriction on d > 1. We finally prove scattering for small L2 data, with no gauge invariance assumption.

math.AP↗