Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Brief Remark on Energy Conditions and the Geroch-Jang Theorem   The status of the geodesic principle in General Relativity has been a topic
of some interest in the recent literature on the foundations of spacetime
theories. Part of this discussion has focused on the role that a certain energy
condition plays in the proof of a theorem due to Bob Geroch and Pong-Soo Jang
["Motion of a Body in General Relativity." Journal of Mathematical Physics
16(1), (1975)] that can be taken to make precise the claim that the geodesic
principle is a theorem, rather than a postulate, of General Relativity. In this
brief note, I show, by explicit counterexample, that not only is a weaker
energy condition than the one Geroch and Jang state insufficient to prove the
theorem, but in fact a condition still stronger than the one that they assume
is necessary.

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The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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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: acc-phys
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: econ
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The categories of this paper are: hep-ex