Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: "Gauge" freedom and relationship between the Einstein and Jordan
  conformal frames   The issue of the physical equivalence between the Einstein and Jordan
conformal frames in Jordan-Brans-Dicke (JBD) theory is revised. Scalar-tensor
theories equations are not invariant with respect to conformal transformations
if one uses the same "gauge" fixing in Jordan and Einstein frames. We hope to
have clarified some eventual obscure issues associated to the concept of
conformal invariance of relativistic theories appearing in the literature, in
particular the relationship between Jordan and Einstein frames.

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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ph
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The categories of this paper are: ao-sci
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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: econ
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The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-bio
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys