Livermore, PW (2012) The Spherical Harmonic Spectrum of a Function with Algebraic Singularities. Journal of Fourier Analysis and Applications, 18 (6). 1146 - 1166. ISSN 1069-5869
Abstract
The asymptotic behaviour of the spectral coefficients of a function provides a useful diagnostic of its smoothness. On a spherical surface, we consider the coefficients al m of fully normalised spherical harmonics of a function that is smooth except either at a point or on a line of colatitude, at which it has an algebraic singularity taking the form θp or {pipe}θ-θ0{pipe}p respectively, where θ is the co-latitude and p>-1. It is proven that each type of singularity has a signature on the rotationally invariant energy spectrum, E(l) = √Σm(al m)2 where l and m are the spherical harmonic degree and order, of l-(p+3/2) or l-(p+1) respectively. This result is extended to any collection of finitely many point or (possibly intersecting) line singularities of arbitrary orientation: in such a case, it is shown that the overall behaviour of E(l) is controlled by the gravest singularity. Several numerical examples are presented to illustrate the results. We discuss the generalisation of singularities on lines of colatitude to those on any closed curve on a spherical surface.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2013, Springer-Verlag. This is an author produced version of a paper published in the Journal of Fourier Analysis and Applications. Uploaded in accordance with the publisher's self-archiving policy. The final publication is available at link.springer.com |
Keywords: | Algebraic decay; Darboux's principle; Singularity; Spectrum; Spherical harmonics |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 18 Sep 2013 11:20 |
Last Modified: | 15 Sep 2014 03:03 |
Published Version: | http://dx.doi.org/10.1007/s00041-012-9236-3 |
Status: | Published |
Publisher: | Springer Verlag |
Identification Number: | 10.1007/s00041-012-9236-3 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:76449 |