Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: GUT-Scale Primordial Black Holes: Consequences and Constraints   A population of very light primordial black holes which evaporate before
nucleosynthesis begins is unconstrained unless the decaying black holes leave
stable relics. We show that gravitons Hawking radiated from these black holes
would source a substantial stochastic background of high frequency
gravititational waves ($10^{12}$ Hz or more) in the present universe. These
black holes may lead to a transient period of matter dominated expansion. In
this case the primordial universe could be temporarily dominated by large
clusters of "Hawking stars" and the resulting gravitational wave spectrum is
independent of the initial number density of primordial black holes.

12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex