Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bulk QCD Thermodynamics and Sterile Neutrino Dark Matter   We point out that the relic densities of singlet (sterile) neutrinos of
interest in viable warm and cold dark matter scenarios, depend on the
characteristics of the QCD transition in the early universe. In the most
promising of these dark matter scenarios the production of the singlets occurs
at or near the QCD transition. Since production of the singlets, their
dilution, and the disappearance of weak scatterers occur simultaneously, we
calculate these processes contemporaneously to obtain accurate predictions of
relic sterile neutrino mass density. Therefore, a determination of the mass and
superweak mixing of the singlet neutrino through, for example, its radiative
decay, along with a determination of its contribution to the critical density,
can provide insight into the finite-temperature QCD transition.

25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin