Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Flow Around a Cosmic String, Part I: Hydrodynamic Solution   Cosmic strings are linear topological defects which are hypothesized to be
produced during inflation. Most searches for strings have been relying on the
string's lensing of background galaxies or CMB. In this paper I obtained the
solution for the supersonic flow of the collisional gas past the cosmic string
which has two planar shocks with shock compression ratio that depend on the
angle defect of the string and its speed. The shocks result in compression and
heating of the gas and, given favorable condition, particle acceleration. The
gas heating and overdensity in an unusual wedge shape can be detected by
observing HI line at high redshifts. The particle acceleration can occur in
present-day Universe when the string crosses the hot gas contained in galaxy
clusters and, since the consequences of such collision persist for cosmological
timescales, could be located by looking at the unusual large-scale radio
sources situated on a single spatial plane.

16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas