English

SPHARMA approximations for stationary functional time series on the sphere

Statistics Theory 2020-09-29 v1 Probability Statistics Theory

Abstract

In this paper, we focus on isotropic and stationary sphere-cross-time random fields. We first introduce the class of spherical functional autoregressive-moving average processes (SPHARMA), which extend in a natural way the spherical functional autoregressions (SPHAR) recently studied in [8, 7]; more importantly, we then show that SPHAR and SPHARMA processes of sufficiently large order can be exploited to approximate every isotropic and stationary sphere-cross-time random field, thus generalizing to this infinite-dimensional framework some classical results on real-valued stationary processes. Further characterizations in terms of functional spectral representation theorems and Wold-like decompositions are also established.

Keywords

Cite

@article{arxiv.2009.13189,
  title  = {SPHARMA approximations for stationary functional time series on the sphere},
  author = {Alessia Caponera},
  journal= {arXiv preprint arXiv:2009.13189},
  year   = {2020}
}
R2 v1 2026-06-23T18:50:28.489Z