Averaging matter before solving the Klein-Gordon equation mis-estimates the coarse-grained scalar-field energy density and pressure, by factors up to about 10^5 for a Yukawa model and with mean-field deviations exceeding 10^5 for screened chameleons.
Averaging in Cosmology
1 Pith paper cite this work. Polarity classification is still indexing.
1
Pith paper citing it
abstract
In this paper we discuss the effect of local inhomogeneities on the global expansion of nearly FLRW universes, in a perturbative setting. We derive a generic linearized averaging operation for metric perturbations from basic assumptions, and we explicify the issue of gauge invariance. We derive a gauge invariant expression for the back-reaction of density inhomogeneities on the global expansion of perturbed FLRW spacetimes, in terms of observable quantities, and we calculate the effect quantitatively. Since we do not adopt a comoving gauge, our result incorporates the back-reaction on the metric due to scalar velocity and vorticity perturbations. The results are compared with the results by other authors in this field.
fields
gr-qc 1years
2025 1verdicts
CONDITIONAL 1representative citing papers
citing papers explorer
-
Scalar-tensor theories at different scales: averaging the scalar sector
Averaging matter before solving the Klein-Gordon equation mis-estimates the coarse-grained scalar-field energy density and pressure, by factors up to about 10^5 for a Yukawa model and with mean-field deviations exceeding 10^5 for screened chameleons.