Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Karatsuba's Problem Concerning the Divisor Function $\tau(n)$   We study an asymptotic behavior of the sum $\sum\limits_{n\le x}\frac{\D
\tau(n)}{\D \tau(n+a)}$. Here $\tau(n)$ denotes the number of divisors of $n$
and $a\ge 1$ is a fixed integer.

37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org