Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Casimir effect in a weak gravitational field and the spacetime index of
  refraction   In a recent paper [arXiv:0904.2904] using a conjecture it is shown how one
can calculate the effect of a weak stationary gravitational field on vacuum
energy in the context of Casimir effect in an external gravitational field
treated in 1+3 formulation of spacetime decomposition.. In this article,
employing quntum field theory in curved spacetime, we explicitly calculate the
effect of a weak static gravitational field on virtual massless scalar
particles in a Casimir apparatus. It is shown that, as expected from the
proposed conjecture, both the frequency and renormalized energy of the virtual
scalar field are affected by the gravitational field through its index of
refraction. This could be taken as a strong evidence in favour of the proposed
conjecture. Generalizations to weak {\it stationary} spacetimes and virtual
photons are also discussed.

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The categories of this paper are: acc-phys
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The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th
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The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph