Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Double fermionic contributions to the heavy-quark vacuum polarization   We compute the virtual O(\alpha_s^3 n_f^2) corrections to the heavy quark
vector current correlator in terms of expansions in the external momentum and
as an exact numerical solution. As a byproduct, the available high-energy
expansion at the three-loop level is extended.

17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph