Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spherical Harmonics   This is Chapter 1 of the book {\it Approximation Theory and Harmonic Analysis
on Spheres and Balls} by the authors. It provides a self-contained introduction
to spherical harmonics. The book will be published as a title in {\it Springer
Monographs in Mathematics} by Springer in 2013. The table of contents of the
book is attached at the end of this file.

15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol