Testing Viable f(T) Models with Current Observations

Abstract

We perform observational tests on the f ( T ) gravity with the BAO data (including the BOSS DR 12 galaxy sample, the DR12 Ly α -Forests measurement, the new eBOSS DR14 quasar sample, the 6dFGS, and the SDSS), the CMB distance priors from the Planck 2015, the SNIa data from the joint light-curve analysis, the latest H ( z ) data, and the local value of the Hubble constant. Six different f ( T ) models are investigated. Furthermore, the ΛCDM is also considered. All models are compared by using the Akaike information criteria (AIC) and the Bayesian information criteria (BIC). Our results show that the ΛCDM remains to be the most favored model by current observations. However, there are also the Hubble constant tension between the Planck measurements and the local Universe observations and the tension between the CMB data and the H ( z ) data in the ΛCDM. For f ( T ) models considered in this paper, half, which can reduce to the ΛCDM, have values of smaller than that of the ΛCDM and can relieve the tensions existing in the ΛCDM. However, they are punished slightly by the BIC due to one extra parameter. Two of six f ( T ) models, in which the crossing of the phantom divide line can be realized for the equation of state of the effective dark energy and this crossing is shown in this paper to be favored by current observations, are punished by the information criteria. In addition, we find that the logarithmic f ( T ) model is excluded by cosmological observations.