Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Jeans theorem and the "Tolman-Oppenheimer-Volkov equation" in an
  exact wave solution of R^2 gravity   Corda, Mosquera Cuesta and Lorduy Gomez have shown that spherically symmetric
stationary states can be used as a model for galaxies in the framework of the
linearized R^2 gravity. Those states could represent a partial solution to the
Dark Matter Problem. Here we discuss an improvement of this work. In fact, as
the star density is a functional of the invariants of the associated Vlasov
equation, we show that any of these invariants is in its turn a functional of
the local energy and the angular momentum. As a consequence, the star density
depends only on these two integrals of the Vlasov system. This result is known
as the "Jeans theorem". In addition, we find an analogous of the historical
Tolman- Oppenheimer-Volkov equation for the system considered in this paper.
For the sake of completeness, in the final Section of the paper we consider two
additional models which argue that Dark Matter could not be an essential
element.

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The categories of this paper are: hep-lat
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: physics
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The categories of this paper are: math
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The categories of this paper are: hep-ex
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: econ
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The categories of this paper are: eess