Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sterile Neutrino Dark Matter from Generalized $CPT$-Symmetric
  Early-Universe Cosmologies   We generalize gravitational particle production in a radiation-dominated
$CPT$-symmetric universe to non-standard, but also $CPT$-symmetric early
universe cosmologies. We calculate the mass of a right-handed "sterile"
neutrino needed for it to be the cosmological dark matter. Since generically
sterile neutrinos mix with the Standard Model active neutrinos, we use
state-of-the-art tools to compute the expected spectrum of gamma rays and
high-energy active neutrinos from ultra-heavy sterile neutrino dark matter
decay. We demonstrate that the sterile neutrinos are never in thermal
equilibrium in the early universe. We show that very high-energy Cherenkov
telescopes might detect a signal for sterile neutrino lifetimes up to around
10$^{27}$ s, while a signal in high-energy neutrino telescopes such as IceCube
could be detectable for lifetimes up to 10$^{30}$ s, offering a better chance
of detection across a vast landscape of possible masses.

22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph