Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fine-structure constant variability, equivalence principle and cosmology   It has been widely believed that variability of the fine-structure constant
alpha would imply detectable violations of the weak equivalence principle. This
belief is not justified in general. It is put to rest here in the context of
the general framework for alpha variability [J. D. Bekenstein, Phys. Rev. D 25,
1527 (1982)] in which the exponent of a scalar field plays the role of the
permittivity and inverse permeability of the vacuum. The coupling of particles
to the scalar field is necessarily such that the anomalous force acting on a
charged particle by virtue of its mass's dependence on the scalar field is
cancelled by terms modifying the usual Coulomb force. As a consequence a
particle's acceleration in external fields depends only on its charge to mass
ratio, in accordance with the principle. And the center of mass acceleration of
a composite object can be proved to be independent of the object's internal
constitution, as the weak equivalence principle requires. Likewise the widely
employed assumption that the Coulomb energy of matter is the principal source
of the scalar field proves wrong; Coulomb energy effectively cancels out in the
continuum description of the scalar field's dynamics. This cancellation
resolves a cosmological conundrum: with Coulomb energy as source of the scalar
field, the framework would predict a decrease of alpha with cosmological
expansion, whereas an increase is claimed to be observed. Because of the said
cancellation, magnetic energy of cosmological baryonic matter is the main
source of the scalar field. Consequently the expansion is accompanied by an
increase in alpha; for reasonable values of the framework's sole parameter,
this occurs at a rate consistent with the observers' claims.

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The categories of this paper are: math
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
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The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
30
The categories of this paper are: q-alg