Positive definite functions on spheres: some statistical and mathematical issues

Abstract
Positive definite functions are a key mathematical tool in geostatistics. If the study region is geographically extensive, the space which needs to be considered is the spherical surface equipped with the geodesic distance. After reviewing some general results about positive definite functions on spheres, this talk will present a Bayesian nonparametric model for isotropic spatial covariance functions for global data.  Then, it will review main known results about strict positive definiteness on spheres in the isotropic case and will present a new result about the axially symmetric case.

Organizzatore
Alberto Lanconelli