arrow
Return

Bouncing cosmology in VCDM

delete2023-04-24
delete4
delete
OA
AI
A
Alexander Ganz *
P
Paul Martens
S
Shinji Mukohyama
R
Ryo Namba
DOI:10.1088/1475-7516/2023/04/060delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
We construct an asymmetric bouncing scenario within the VCDM model - also known as type-II minimally modified gravity, - a modified gravity theory with two local physical degrees of freedom. The scenario is exempt of any ghost or gradient instability, ad -hoc matching conditions or anisotropic stress issue (BKL instability). It moreover succeeds in generating the cosmological perturbations compatible with the observations. The scalar spectral index can be adapted by the choice of the equation of state of the matter sector and the form of the VCDM potential leading to an almost scale-invariant power spectrum. Satisfying the CMB bounds on the tensor-to-scalar ratio leads to a blue tensor spectrum.
Keywords:
alternatives to inflation
modified gravity
cosmological perturbation theory
Cosmological perturbation theory in GR and beyond

Journal

Journal of Cosmology and Astroparticle Physics cover
Journal of Cosmology and Astroparticle Physics
IF:
5.9
Papers:
1.3W
Citations:
4.7W

Organization

K
Kyoto University
Scholars:
5.1W
Papers: 4.6W
Citations: 6.1W
J
jagiellonian university
Scholars:
2.2W
Papers: 1.8W
Citations: 11