Symmetron scalar fields: Modified gravity, dark matter, or both?
Autor: | Peter Millington, Christian Käding, Clare Burrage, Edmund J. Copeland |
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Rok vydání: | 2019 |
Předmět: |
Physics
Gravity (chemistry) Cosmology and Nongalactic Astrophysics (astro-ph.CO) Field (physics) 010308 nuclear & particles physics Scalar (mathematics) Dark matter Fifth force FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Galaxy High Energy Physics - Phenomenology Gravitational potential Theoretical physics High Energy Physics - Phenomenology (hep-ph) Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences 010306 general physics Scalar field Astrophysics - Cosmology and Nongalactic Astrophysics |
Zdroj: | Physical Review D. 99 |
ISSN: | 2470-0029 2470-0010 |
DOI: | 10.1103/physrevd.99.043539 |
Popis: | Scalar fields coupled to gravity through the Ricci scalar have been considered both as dark matter candidates and as a possible modified gravity explanation for galactic dynamics. It has recently been demonstrated that the dynamics of baryonic matter in disk galaxies may be explained, in the absence of particle dark matter, by a symmetron scalar field that mediates a fifth force. The symmetron provides a concrete and archetypal field theory within which to explore how large a role modifications of gravity can play on galactic scales. In this article, we extend these previous works by asking whether the same symmetron field can explain the difference between the baryonic and lens masses of galaxies through a modification of gravity. We consider the possibilities for minimal modifications of the model and find that this difference cannot be explained entirely by the symmetron fifth force without extending the field content of the model. Instead, we are pushed towards a regime of parameter space where one scalar field both mediates a fifth force and stores enough energy density that it also contributes to the galaxy's gravitational potential as a dark matter component, a regime which remains to be fully explored. 27 pages, 4 figures. v2: Minor changes to agree with published version |
Databáze: | OpenAIRE |
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