Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Naked singularity and black hole formation in self-similar
  Einstein-scalar fields with exponential potentials   Motivated by cosmic censorship in general relativity and string theory, we
extend Christodoulou's celebrated examples of naked singularity formation in
the Einstein-massless scalar field system to include a positive or negative
scalar potential of exponential forms, i.e., $V(\phi)=\pm\exp(2\phi/\kappa)$
with a parameter $\kappa$. Under spherical symmetry and a self-similar ansatz
depending on $\kappa$, we derive a 3-dimensional autonomous system of
first-order ordinary differential equations, which incorporates the equations
for massless scalar fields as a special case. Local behavior of the phase space
is studied analytically with global solutions constructed numerically. Within
the 3-dimensional solution manifold, we observe, for the negative potentials,
naked singularity formation from nonsingular initial data for $\kappa^2<1$.
Meanwhile, transitions between solutions containing naked singularities and
black holes are also identified. However, when the potential is taken positive,
numerical evolutions result in formation of black holes, but not naked
singularities.

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The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
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The categories of this paper are: eess
4
The categories of this paper are: cond-mat
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The categories of this paper are: dg-ga