Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Evolution of the Chemical elements of the Universe   Spectroscopic observations of distant cosmological sources continue to
exhibit a surprising result; that the chemical abundance of the universe seems
to be approximately solar for the observed sources at redshifts of 5, 6, and
even 7, even though very few galaxies should have existed at these epochs and
the principal star formation and heavy element production event should have
been at the more local z = 1 - 2.

37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics