Revisiting the Concentration Problem of Vector Fields within a Spherical Cap: A Commuting Differential Operator Solution

Kornél Jahn, Nándor Bokor

Research output: Contribution to journalArticle

8 Citations (Scopus)


We propose a novel basis of vector functions, the mixed vector spherical harmonics that are closely related to the functions of Sheppard and Török and help us reduce the concentration problem of tangential vector fields within a spherical cap to an equivalent scalar problem. Exploiting an analogy with previous results published by Grünbaum, Longhi and Perlstadt, we construct a differential operator that commutes with the concentration operator of this scalar problem and propose a stable and convenient method to obtain its eigenfunctions. Having obtained the scalar eigenfunctions, the calculation of tangential vector Slepian functions is straightforward.

Original languageEnglish
Pages (from-to)421-451
Number of pages31
JournalJournal of Fourier Analysis and Applications
Issue number2
Publication statusPublished - Apr 2014



  • Bandlimited function
  • Commuting differential operator
  • Concentration problem
  • Eigenvalue problem
  • Spherical cap
  • Vector spherical harmonics

ASJC Scopus subject areas

  • Analysis
  • Mathematics(all)
  • Applied Mathematics

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