A Specific Case of Generalized Einstein-aether Theories

TL;DR

This paper investigates a specific case of generalized Einstein-aether theories, comparing its cosmological predictions with observational data and exploring its relation to other models like DGP and MOND.

Contribution

It introduces a particular Einstein-aether model with a Friedmann equation similar to DGP and constrains its parameters using multiple cosmological datasets.

Findings

Model fits observational data well

Relation between coupling constant and MOND acceleration scale

Comparison with standard $\\Lambda$CDM model

Abstract

With the dark energy phenomena explored over a decade, in this present work we discuss a specific case of the generalized Einstein-aether theories, in which the modified Friedmann Equation is similar to that in the Dvali-Gabadadze-Porrati (DGP) brane world model. We compute the joint statistic constraints on model parameters in this specific case by using the recent type Ia supernovae (SNe Ia) data, the Cosmic Microwave Background (CMB) shift parameter data, and the Baryonic Acoustic Oscillations (BAOs) data traced by the Sloan Digital Sky Survey (SDSS). Furthermore, we analyze other constrains from the observational Hubble parameter data (OHD). The comparison with the standard cosmological model (cosmological constant $\Lambda$ Cold Dark Matter ($\Lambda$CDM) model) is clearly shown; also we comment on the interesting relation between the coupling constant $M$ in this model and the special accelerate scale in the MOdified Newtonian Dynamics (MOND) model initially given by Milgrom with the hope for interpreting the galaxy rotation curves without introducing mysterious dark matter.