Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Little Rip   We examine models in which the dark energy density increases with time (so
that the equation-of-state parameter w satisfies w < -1), but w approaches -1
asymptotically, such that there is no future singularity. We refine previous
calculations to determine the conditions necessary to produce this evolution.
Such models can display arbitrarily rapid expansion in the near future, leading
to the destruction of all bound structures (a "little rip"). We determine
observational constraints on these models and calculate the point at which the
disintegration of bound structures occurs. For the same present-day value of w,
a big rip with constant w disintegrates bound structures earlier than a little
rip.

18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int