Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the black hole from merging binary neutron stars: how fast can it
  spin?   The merger of two neutron stars will in general lead to the formation of a
torus surrounding a black hole whose rotational energy can be tapped to
potentially power a short gamma-ray burst. We have studied the merger of
equal-mass binaries with spins aligned with the orbital angular momentum to
determine the maximum spin the black hole can reach. Our initial data consists
of irrotational binaries to which we add various amounts of rotation to
increase the total angular momentum. Although the initial data violates the
constraint equations, the use of the constraint-damping CCZ4 formulation yields
evolutions with violations smaller than those with irrotational initial data
and standard formulations. Interestingly, we find that a limit of $J/M^2 \simeq
0.89$ exists for the dimensionless spin and that any additional angular
momentum given to the binary ends up in the torus rather than in the black
hole, thus providing another nontrivial example supporting the cosmic
censorship hypothesis.

37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg