Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A unified formulation of Gaussian vs. sparse stochastic processes - Part
  I: Continuous-domain theory
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn