Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-uniqueness, Counterrotation, and Negative Horizon Mass of
  Einstein-Maxwell-Chern-Simons Black Holes   Stationary black holes in 5-dimensional Einstein-Maxwell-Chern-Simons theory
possess surprising properties. When considering the Chern-Simons coefficient
$\lambda$ as a parameter, two critical values of $\lambda$ appear: the
supergravity value $\lambda_{\rm SG}=1$, and the value $\lambda=2$. At
$\lambda=1$, supersymmetric black holes with vanishing horizon angular
velocity, but finite angular momentum exist. As $\lambda$ increases beyond
$\lambda_{\rm SG}$ a rotational instability arises, and counterrotating black
holes appear, whose horizon rotates in the opposite sense to the angular
momentum. Thus supersymmetry is associated with the borderline between
stability and instability. At $\lambda=2$ rotating black holes with vanishing
angular momentum emerge. Beyond $\lambda=2$ black holes may possess a negative
horizon mass, while their total mass is positive. Charged rotating black holes
with vanishing gyromagnetic ratio appear, and black holes are no longer
uniquely characterized by their global charges.

30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom