Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modifying Gravity in the Infra-Red by imposing an "Ultra-Strong"
  Equivalence Principle   The equivalence principle suggests to consider gravity as an infra-red
phenomenon, whose effects are visible only outside Einstein's free-falling
elevator. By curving spacetime, General Relativity leaves the smallest systems
free of classical gravitational effects. However, according to the standard
semi-classical treatment, indirect effects of gravity can be experienced inside
the elevator through the well-known mechanism of quantum particle production.
Here we try a different path than the one historically followed: rather than
imposing field quantization on top of a curved manifold, we attempt to upgrade
the equivalence principle and extend it to the quantum phenomena. Therefore, we
consider, and try to realize in a theoretical framework, a stronger version of
the equivalence principle, in which all the effects of gravity are definitely
banned from the elevator and confined to the infra-red. For this purpose, we
introduce infra-red modified commutation relations for the global field
operators (Fourier modes) that allow to reabsorb the time-dependent quadratic
divergence of the vacuum expectation value of the stress-energy tensor. The
proposed modification is effective on length scales comparable to the inverse
curvature and, therefore, does no add any dimensional parameter to the theory.

19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
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The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: quant-ph
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The categories of this paper are: cmp-lg