Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Uniqueness of the static spacetimes with a photon sphere in
  Einstein-scalar field theory   In the present paper we prove a uniqueness theorem for the static and
asymptotically flat solutions to the Einstein-scalar field equations which
possess a photon sphere. We show that such solutions are uniquely specified by
their mass $M$ and scalar charge $q$ and that they are isometric to the
Janis-Newman-Winicour solution with the same mass and scalar charge subject to
the inequality $\frac{q^2}{M^2}<3$.

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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: econ
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: acc-phys