Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Static forms of the Robertson-Walker spacetimes   It is shown that only the maximally-symmetric spacetimes can be expressed in
both the Robertson-Walker form and in static form - there are no other static
forms of the Robertson-Walker spacetimes. All possible static forms of the
metric of the maximally-symmetric spacetimes are presented as a table. The
findings are generalized to apply to functionally more general spacetimes: it
is shown that the maximally symmetric spacetimes are also the only spacetimes
that can be written in both orthogonal-time isotropic form and in static form.

10
The categories of this paper are: q-bio
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The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas