Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comment on ``Can Black Holes be Torn Up by a Phantom in Cyclic
  Cosmology?" by X. Zhang. arXiv:0708.1408 [gr-qc]   In a recently archived paper by Zhang\cite{Zhang}, it is claimed that before
turnaround in a cyclic model two unexpected events happen: (1) black holes
cease to contract and begin to expand; (2) separated causal patches start to
reconnect. We show that both conclusions are erroneous and result from the
author's choice of variables.

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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: cond-mat
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The categories of this paper are: eess
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The categories of this paper are: cmp-lg
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The categories of this paper are: astro-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: cs
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The categories of this paper are: math
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The categories of this paper are: physics