A cosmic degeneracy story: structure formation with warm dark matter and scale-dependent primordial non-Gaussianities

Document detail

ID

oai:arXiv.org:2501.03672

Topic

Astrophysics - Cosmology and Nonga...

Author

Stahl, Clément Famaey, Benoit Ibata, Rodrigo Kraljic, Katarina Castillo, Fabien

Year

2025

listing date

1/15/2025

Keywords

models dark spng wdm

Metrics

Abstract

It has been recently shown that cosmological models with scale-dependent primordial non-Gaussianities (sPNG) could provide a possible path to solve current cosmic tensions.

Moreover, it has been pointed out that some of these models might mimic the effects of Warm Dark Matter (WDM) for several observables at low redshift.

Here, we confirm the qualitative similarity of the matter power spectrum for sPNG and WDM models, but also point out differences in the halo mass function and void size function.

We then jointly simulate WDM and sPNG together.

Such simulations allow us to demonstrate that the joint impact of WDM and sPNG is close to the linear superposition of their respective effects at low redshift, at the percent level.

We finally propose a model with mixed hot and cold dark matter together with sPNG, that reproduces the $\Lambda$CDM power spectrum at redshifts $z \leq 3$ but is still distinct in terms of halo statistics.

;Comment: 13 pages, 7 figures, comments welcome :)

Stahl, Clément,Famaey, Benoit,Ibata, Rodrigo,Kraljic, Katarina,Castillo, Fabien, 2025, A cosmic degeneracy story: structure formation with warm dark matter and scale-dependent primordial non-Gaussianities