Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phantom Friedmann Cosmologies and Higher-Order Characteristics of
  Expansion   We discuss a more general class of phantom ($p < -\varrho$) cosmologies with
various forms of both phantom ($w < -1$), and standard ($w > -1$) matter. We
show that many types of evolution which include both Big-Bang and Big-Rip
singularities are admitted and give explicit examples. Among some interesting
models, there exist non-singular oscillating (or "bounce") cosmologies, which
appear due to a competition between positive and negative pressure of variety
of matter content. From the point of view of the current observations the most
interesting cosmologies are the ones which start with a Big-Bang and terminate
at a Big-Rip. A related consequence of having a possibility of two types of
singularities is that there exists an unstable static universe approached by
the two asymptotic models - one of them reaches Big-Bang, and another reaches
Big-Rip. We also give explicit relations between density parameters $\Omega$
and the dynamical characteristics for these generalized phantom models,
including higher-order observational characteristics such as jerk and "kerk".
Finally, we discuss the observational quantities such as luminosity distance,
angular diameter, and source counts, both in series expansion and explicitly,
for phantom models. Our series expansion formulas for the luminosity distance
and the apparent magnitude go as far as to the fourth-order in redshift $z$
term, which includes explicitly not only the jerk, but also the "kerk" (or
"snap") which may serve as an indicator of the curvature of the universe.

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The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
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The categories of this paper are: bayes-an
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: q-bio
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The categories of this paper are: quant-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph