English

Can $\Lambda$CDM model reproduce MOND-like behavior?

General Relativity and Quantum Cosmology 2018-01-17 v1 Astrophysics of Galaxies High Energy Physics - Theory

Abstract

It is usually believed that MOND can describe the galactic rotational curves with only baryonic matter and without any dark matter very well, while the Λ\LambdaCDM model is expected to have difficulty in reproducing MOND-like behavior. Here, we use EAGLE's data to learn whether the Λ\LambdaCDM model can reproduce MOND-like behavior. EAGLE's simulation result clearly reproduces the MOND-like behavior for ab1012m/s2a_b\gtrapprox 10^{-12}\text{m/s}^2 at z=0z=0, although the acceleration constant, a0a_0, is a little larger than the observational data indicate. We find that a0a_0 increases with the redshift in a way different from what Milgrom proposed (a0Ha_0\propto H). Therefore, while galaxy rotation curves can be fitted by MOND's empirical function in the Λ\LambdaCDM model, there is no clear connection between a0a_0 and the Hubble constant. We also find that a0a_0 at z1z\gtrapprox 1 is well separated from a0a_0 at z=0z=0. Once we have enough galaxies observed at high redshifts, we will be able to rule out the modified gravity model based on MOND-like empirical function with a z-independent a0a_0.

Keywords

Cite

@article{arxiv.1712.01654,
  title  = {Can $\Lambda$CDM model reproduce MOND-like behavior?},
  author = {De-Chang Dai and Chunyu Lu},
  journal= {arXiv preprint arXiv:1712.01654},
  year   = {2018}
}

Comments

9 figures, accepted by Phys. Rev. D

R2 v1 2026-06-22T23:07:21.999Z