Cubic Galileon Gravity in the CMB

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Ye, Gen, Silvestri, Alessandra
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866914856189296640
author Ye, Gen
Silvestri, Alessandra
author_facet Ye, Gen
Silvestri, Alessandra
contents Among the models addressing the Hubble tension, those introducing a dynamical dark component around recombination have been the most promising thus far. Their study has highlighted that, in fact, cosmic microwave background (CMB) and baryon acoustic oscillation (BAO) observations can allow for such components before and near recombination. The new dynamical degree of freedom can be early dark energy (EDE) or early modified gravity depending on its coupling to gravity. We study a new model, $\mathcal{G}$EDE, featuring the cubic Galileon operator $X\Boxϕ$ and test it against the most recent Planck PR4 CMB and Cepheid calibrated Pantheon+ type Ia Supernovae data. Thanks to the kinetic braiding effects, $\mathcal{G}$EDE gives a better fit to the data, with a higher $H_0$, and is preferred over the canonical EDE with a Bayes factor $\ln B=0.9$, despite introducing one more parameter. This calls for further explorations of modified gravity near and before last scattering. To facilitate these, we introduce a substantial extension of the cosmological code \texttt{EFTCAMB} that allows to fully evolve the background and linear dynamics of any covariant theory, oscillatory or not, belonging to the Horndeski class.
format Preprint
id arxiv_https___arxiv_org_abs_2407_02471
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Cubic Galileon Gravity in the CMB
Ye, Gen
Silvestri, Alessandra
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
Among the models addressing the Hubble tension, those introducing a dynamical dark component around recombination have been the most promising thus far. Their study has highlighted that, in fact, cosmic microwave background (CMB) and baryon acoustic oscillation (BAO) observations can allow for such components before and near recombination. The new dynamical degree of freedom can be early dark energy (EDE) or early modified gravity depending on its coupling to gravity. We study a new model, $\mathcal{G}$EDE, featuring the cubic Galileon operator $X\Boxϕ$ and test it against the most recent Planck PR4 CMB and Cepheid calibrated Pantheon+ type Ia Supernovae data. Thanks to the kinetic braiding effects, $\mathcal{G}$EDE gives a better fit to the data, with a higher $H_0$, and is preferred over the canonical EDE with a Bayes factor $\ln B=0.9$, despite introducing one more parameter. This calls for further explorations of modified gravity near and before last scattering. To facilitate these, we introduce a substantial extension of the cosmological code \texttt{EFTCAMB} that allows to fully evolve the background and linear dynamics of any covariant theory, oscillatory or not, belonging to the Horndeski class.
title Cubic Galileon Gravity in the CMB
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2407.02471