Symmetron Cosmology
read the original abstract
The symmetron is a scalar field associated with the dark sector whose coupling to matter depends on the ambient matter density. The symmetron is decoupled and screened in regions of high density, thereby satisfying local constraints from tests of gravity, but couples with gravitational strength in regions of low density, such as the cosmos. In this paper we derive the cosmological expansion history in the presence of a symmetron field, tracking the evolution through the inflationary, radiation- and matter-dominated epochs, using a combination of analytical approximations and numerical integration. For a broad range of initial conditions at the onset of inflation, the scalar field reaches its symmetry-breaking vacuum by the present epoch, as assumed in the local analysis of spherically-symmetric solutions and tests of gravity. For the simplest form of the potential, the energy scale is too small for the symmetron to act as dark energy, hence we must add a cosmological constant to drive late-time cosmic acceleration. We briefly discuss a class of generalized, non-renormalizable potentials that can have a greater impact on the late-time cosmology, though cosmic acceleration requires a delicate tuning of parameters in this case.
This paper has not been read by Pith yet.
Forward citations
Cited by 5 Pith papers
-
Quantum corrections to symmetron fifth forces for planar sources
Quantum corrections suppress the symmetron fifth force by order 10% within a Compton wavelength of a thick planar source and enhance it at larger distances.
-
Mass-Varying Dark Matter Induced Scalarization and Scalar Clouds around Black Holes
Scalar clouds around black holes in mass-varying dark matter halos exist only for quantized scalar-dark matter couplings set by halo parameters such as compactness.
-
Mass-Varying Neutrinos from an Inverse Symmetron
An inverse symmetron model for mass-varying neutrinos tames linear instabilities, suppresses matter power spectrum, and may address the Hubble tension via early dark energy around recombination.
-
Mass Varying Neutrino Oscillation in Teleparallel Gravity
Torsion-coupled scalar in teleparallel gravity induces density-dependent neutrino masses that alter MSW resonance and yield constraints on coupling parameters from Super-Kamiokande, Borexino and SNO data.
-
Galaxy formation in modified gravity -- II. galaxy halo connection and assembly bias
Simulations in f(R) gravity show that environment density in the HOD model reduces assembly bias effects to 2-3% at z≲0.5 in both ΛCDM and modified gravity.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.