Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solutions of First Order Linear Partial Differential Equations Related
  to Urn Models and Central Limit Theorems   We study first order linear partial differential equations that appear, for
example, in the analysis of dimishing urn models with the help of the method of
characteristics and formulate sufficient conditions for a central limit
theorem.

12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin