Isotropization of locally rotationally symmetric Bianchi-I universe in f(Q)-gravity

Abstract

Despite having the somewhat successful description of accelerated cosmology, the early evolution of the universe always challenges mankind. Our promising approach lies in a new class of symmetric teleparallel theory of gravity named f(Q), where the non-metricity scalar Q is responsible for the gravitational interaction, which may resolve some of the issues. To study the early evolution of the universe, we presume an anisotropic locally rotationally symmetric (LRS) Bianchi-I spacetime and derive the motion equations. We discuss the profiles of energy density, equation of state and skewness parameter and observe that our models archive anisotropic spatial geometry in the early phase of the universe with a possible presence of anisotropic fluid and as time goes on, even in the presence of an anisotropic fluid, the universe could approach isotropy due to inflation and the anisotropy of the fluid fades away at the same time.

Anisotropic f(Q) gravity model with bulk viscosity

“…At current, the Universe is filled with non-relativistic matter (dust), and thus we get p v = −3ζH. For bulk viscous fluid as matter contents, the corresponding field equations for Bianchi type-I Universe are derived as [32]…”

“…In this work, we will examine a cosmological model in order to explain the cosmic acceleration in the framework of f (Q) symmetric teleparallel gravity proposed by Jiménez et al [23], where the non-metricity scalar Q is responsible for the gravitational interaction in this theory. Energy conditions [24], cosmography [25], spherically symmetric configuration [26], signature of f (Q) gravity [27], growth index of matter perturbations [28], coupling matter [29], quantum cosmology for a f (Q) polynomial model [30], geodesic deviation equation [31], isotropization of LRS Bianchi-I Universe [32], etc, all these topics have been discussed in the framework of f (Q) gravity by several researchers and also the reader can see our work in this context [33][34][35][36][37].…”

“…The physical justification for this presumption is imposed on the basis of the observations of the velocity redshift relation for extragalactic sources which propose that the Hubble expansion of the Universe may achieve isotropy when σ θ is constant [48]. This condition has been used in many works [32,36,37]. Using Eq.…”

FLRW solutions in $f(Q)$ theory: the effect of using different connections

“…A recent work on the properties of the effective fluid, owed to the non-metricity, can be found in [19]. Some anisotropic spacetimes were studied in [20][21][22][23][24][25]. The Hamiltonian analysis for the theory was performed in [26], while the quantization process in the case of cosmology was presented in [27].…”

Flat LRW Universe in logarithmic symmetric teleparallel gravity with observational constraints

“…S. H. Shekh [14] discusses the idea of holographic dark energy (HDE) in f (Q) gravity. Also, several works have been discussed in the framework of f (Q) gravity, see [15][16][17][18][19][20]. This manuscript is organized as follows: In Sec.…”