Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Abundance of local actions for the vacuum Einstein equations   We exhibit large classes of local actions for the vacuum Einstein equations.
In presence of fermions, or more generally of matter which couple to the
connection, these actions lead to inequivalent equations revealing an arbitrary
number of parameters. Even in the pure gravitational sector, any corresponding
quantum theory would depend on these parameters.

35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
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The categories of this paper are: chao-dyn
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The categories of this paper are: eess
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom