Coupling quintessence kinetics to electromagnetism
Abstract We propose a general model where quintessence couples to electromagnetism via its kinetic term. This novelty generalizes the linear dependence of the gauge kinetic function on ϕ , commonly adopted in the literature. The interaction naturally induces a time variation of the fine-structure co...
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Published in | Journal of cosmology and astroparticle physics Vol. 2023; no. 6; pp. 48 - 78 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Bristol
IOP Publishing
01.06.2023
|
Subjects | |
Online Access | Get full text |
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Summary: | Abstract
We propose a general model where quintessence couples to electromagnetism via its kinetic
term. This novelty generalizes the linear dependence of the gauge kinetic function on
ϕ
,
commonly adopted in the literature. The interaction naturally induces a time variation of the
fine-structure constant that can be formulated within a disformally coupled framework, akin to a
Gordon metric. Through a suitable parametrization of the scalar field and the coupling function,
we test the model against observations sensitive to the variation of
α
. We undertake a
Bayesian analysis to infer the free parameters with data from Earth based, astrophysical and early
Universe experiments. We find that the evolution of
α
is specific to each cosmological era
and slows down at late times when dark energy accelerates the Universe. While the most stringent
bound on the interaction is obtained from atomic clocks measurements, the quasars provide a
constraint consistent with weak equivalence principle tests. This promising model is to be further
tested with upcoming and more precise astrophysical measurements, such as those of the
ESPRESSO spectrograph. |
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ISSN: | 1475-7516 1475-7516 |
DOI: | 10.1088/1475-7516/2023/06/048 |