K-mouflage Cosmology: Formation of Large-Scale Structures - Archive ouverte HAL Access content directly
Journal Articles Physical Review D Year : 2014

## K-mouflage Cosmology: Formation of Large-Scale Structures

(1) , (1)
1
Philippe Brax
• Function : Author
Patrick Valageas
• Function : Author

#### Abstract

We study structure formation in K-mouflage cosmology whose main feature is the absence of screening effect on quasi-linear scales. We show that the growth of structure at the linear level is both affected by a new time dependent Newton constant and a friction term which depend on the background evolution. These combine with the modified background evolution to change the growth rate by up to ten percent since $z\sim 2$. At the one loop level, we find that the non-linearities of the K-mouflage models are mostly due to the matter dynamics and that the scalar perturbations can be treated at tree level. We also study the spherical collapse in K-mouflage models and show that the critical density contrast deviates from its $\Lambda$-CDM value and that, as a result, the halo mass function is modified for large masses by an order one factor. Finally we consider the deviation of the matter spectrum from $\Lambda$-CDM on non-linear scales where a halo model is utilised. We find that the discrepancy peaks around $1\ h{\rm Mpc}^{-1}$ with a relative difference which can reach fifty percent. Importantly, these features are still true at larger redshifts, contrary to models of the chameleon-$f(R)$ and Galileon types.

### Dates and versions

cea-02929292 , version 1 (07-09-2020)

### Identifiers

• HAL Id : cea-02929292 , version 1
• ARXIV :
• DOI :

### Cite

Philippe Brax, Patrick Valageas. K-mouflage Cosmology: Formation of Large-Scale Structures. Physical Review D, 2014, 90, pp.023508. ⟨10.1103/PhysRevD.90.023508⟩. ⟨cea-02929292⟩

### Export

BibTeX TEI Dublin Core DC Terms EndNote Datacite

34 View