Searching for a cosmological preferred axis in complicated class of cosmological models: case study f (R, T) model

Abstract

Recent astronomical observations show that the universe may be anisotropic on large scales. The Union2 SnIa data hint that the universe has a preferred direction. If such a cosmological privileged axis indeed exists, one has to consider an anisotropic expanding Universe instead of the isotropic cosmological model. In this paper, we present a detailed analysis of the dark energy dipole in f (R, T) = f1(R) + f2(T) Cosmological Model using three types of dipole fit (DF) method which are (I) dipole + monopole fitting for distance modulus (DMFDM), (II) dipole + monopole fitting for luminosity distance (DMFLD) and (III) general dipole fitting for luminosity distance (GDFLD). We have found the maximum anisotropic deviation direction for (DMFDM) method as (l, b) = (315− 25+ 25, − 23− 15+ 14), for (DMFLD) as (l, b) = (l, b) = (315− 37+ 35, − 23− 18+ 18), and for (GDFLD) method as (l, b) = (317− 32+ 32, − 23− 18+ 18) which are located very close to each other. We compare our model with the CPL, ΛCDM and ωCDM models. Constraints on (l, b) in f (R, T) model are not much different from the cases of the CPL, ΛCDM and ωCDM models. Moreover, the results are consistent with other studies.