Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The Plancherel decomposition for a reductive symmetric space I.
  Spherical functions
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph