Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Issues in the Blandford-Znajek Process for GRB Inner Engine   Several issues regarding the Blandford-Znajek process are discussed to
demonstrate that it can be an effective mechanism for powering the gamma ray
bursts. Using a simple circuit analysis it is argued that the disk power
increases the effective power of the black hole-accretion disk system, although
a part of disk power can be dissipated into black hole entropy. Within the
framework of the force-free magnetosphere with the strong magnetic field, the
magnetically dominated MHD flow is found to support the Blandford-Znajek
process and it is demonstrated that the possible magnetic repulsion by the
rotating black hole will not affect the efficiency substantially.

14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph