Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relativistic MHD jets and the GRBs   High velocity highly collimated beams of plasma -- the jets -- are known as a
general phenomenon among astrophysical sources of different energy and spatial
scale. The common MHD scenario of astrophysical jet formation allows to
describe the different jet sources by a scaling of the jet magnetization. In
this paper we apply the MHD jet theory for GRB parameters and find indeed that
main features as ultra-relativistic motion and strong collimation can be
explained. Others, like GRB time-variability and the bi-modal GRB duration are
(yet) beyond a MHD description.

15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
16
The categories of this paper are: stat
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg