Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Population of Fast Radio Bursts at Cosmological Distances   Searches for transient astrophysical sources often reveal unexpected classes
of objects that are useful physical laboratories. In a recent survey for
pulsars and fast transients we have uncovered four millisecond-duration radio
transients all more than 40{\deg} from the Galactic plane. The bursts'
properties indicate that they are of celestial rather than terrestrial origin.
Host galaxy and intergalactic medium models suggest that they have cosmological
redshifts of 0.5 to 1, and distances of up to 3 gigaparsecs. No temporally
coincident x- or gamma-ray signature was identified in association with the
bursts. Characterization of the source population and identification of host
galaxies offers an opportunity to determine the baryonic content of the
Universe.

13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org