The galaxy-halo connection in modified gravity cosmologies: environment dependence of galaxy luminosity function
Abstract
We investigate the dependence of the galaxy-halo connection and galaxy density field in modified gravity models using the N-body simulations for f(R) and nDGP models at z = 0. Because of the screening mechanisms employed by these models, chameleon and Vainshtein, haloes are clustered differently in the non-linear regime of structure formation. We quantify their deviations in the galaxy density field from the standard Λ cold dark matter (ΛCDM) model under different environments. We populate galaxies in haloes via the (sub)halo abundance matching. Our main results are as follows: (1) The galaxy-halo connection strongly depends on the gravity model; a maximum variation of {∼ }40{{ per cent}} is observed between halo occupational distribution (HOD) parameters; (2) f(R) gravity models predict an excess of galaxies in low-density environments of {∼ }10{{ per cent}} but predict a deficit of {∼ }10{{ per cent}} at high-density environments for |fR0| = 10-4 and 10-6 while |fR0| = 10-5 predicts more high-density structures; nDGP models are consistent with ΛCDM; (3) different gravity models predict different dependences of the galaxy luminosity function (GLF) with the environment, especially in void-like regions we find differences around {∼ }10{{ per cent}} for the f(R) models while nDPG models remain closer to ΛCDM for low-luminosity galaxies but there is a deficit of {∼ }11{{ per cent}} for high-luminosity galaxies in all environments. We conclude that the dependence of the GLF with environment might provide a test to distinguish between gravity models and their screening mechanisms from the ΛCDM. We provide HOD parameters for the gravity models analysed in this paper.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2019
- DOI:
- 10.1093/mnras/stz1664
- arXiv:
- arXiv:1901.02121
- Bibcode:
- 2019MNRAS.488..782D
- Keywords:
-
- galaxies: haloes;
- dark energy;
- dark matter;
- large-scale structure of Universe;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 22 pages, 14 figures, 4 tables