Bianchi type-V Research Articles

Cosmic Evolution in a Bianchi type-V Universe with Barrow Holographic Dark Energy with Granda-Oliveros Length Scale as IR Cutoff

In this work, we construct a spatially homogeneous and anisotropic Bianchi type-V cosmological model with a hybrid expansion law by considering the universe to be filled with cold dark matter and non-interacting Barrow holographic dark energy with Granda-Oliveros length scale as IR cutoff. The physical and kinematical characteristics of the resulting model are discussed by studying the evolution of various parameters of cosmological importance such as the Hubble parameter, the deceleration parameter, the anisotropic parameter, the equation of state parameter, jerk parameter etc. We also examine whether the energy conditions are satisfied or violated. Our analysis reveals that the Null,Weak, and Dominant energy conditions are fullfilled, while the Strong Energy Condition is violated, which supports the accelerated expansion of the universe. Statefinder diagnostics have also been performed based on recent cosmological observations in order to compare our model with different dark energy cosmological scenario. Additionally, we establish the correspondence between the quintessence scalar field and the Barrow holographic dark energy model, supporting our description of the universe’s accelerated expansion.

Observational constraints on FLRW, Bianchi type I and V brane models

This study explores the compatibility of Covariant Extrinsic Gravity (CEG), a braneworld scenario with an arbitrary number of non-compact extra dimensions, with current cosmological observations. We employ the chi-square statistic and Markov Chain Monte Carlo (MCMC) methods to fit the Friedmann–Lemaître–Robertson–Walker (FLRW) and Bianchi type-I and V brane models to the latest datasets, including Hubble, Pantheon+ Supernova samples, Big Bang Nucleosynthesis (BBN), Baryon Acoustic Oscillations (BAO), and the structure growth rate, fσ8(z). Parameters for FLRW universe consist Ω0(b),Ω0(cd),Ω0(k),H0,γ,σ8, while for the Bianchi model are Ω0(b),Ω0(cd),Ω0(β),H0,γ,Ω0(θ),σ8. By comparing our models to observational data, we determine the best values for cosmological parameters. For the FLRW model, these values depend on the sign of γ (which gives the time variation of gravitational constant in Hubble time unit): γ>0 yields γ=0.00008−0.00011+0.00015, and Ω0(k)=0.014−0.022+0.024 and γ<0 leads to γ=−0.0226−0.0062+0.0054, and Ω0(k)=0.023−0.041+0.039. It should be noted that in both cases Ω0(k)>0, which represents a closed universe. Similarly, for the Bianchi type-V brane model, the parameter values vary with the sign of γ, resulting in γ=0.00084−0.00021+0.00019, Ω0(β)=0.0258−0.0063+0.0052, and Ω0θ(×10−5)=4.19−0.75+0.67 (as with the density parameter of stiff matter) for γ>0, and γ=−0.00107−0.00020+0.00019, Ω0(β)=0.0259−0.0062+0.0050, and Ω0θ(×10−5)=4.17−0.98+0.91 for γ<0. In both cases Ω0(β)>0, which represents the Bianchi type-V, because in the Bianchi type-I, β=0. Subsequently, utilizing these obtained best values, we analyze the behavior of key cosmological parameters such as the Hubble parameter, deceleration parameter, distance modulus, equation of state, and density parameters that characterize both matter and the geometric component of dark energy, as functions of redshift. Our results notably show that the FLRW model with γ<0 is more compatible with observational data than the Bianchi model, based on various statistical criteria.

Late time acceleration in Bianchi type-V dark energy cosmological models with linear deceleration parameter

We present a Bianchi type-V cosmological model with deceleration parameter as a simple linear function of the Hubble parameter interacting with a perfect fluid in the general theory of relativity. For Bianchi type-V space-time, the available solutions of Einstein field equations have been procure under the assumption of linear deceleration parameter, q = A + BH, where H is the Hubble parameter. Also,during the evolution of the Bianchi-V universe, dark energy(DE) with a variable EoS parameters has been studied in detail and w slowly varies around w = –0.33 for a 10 GYr. lapse, which involves an accelerated expansion, through an expansion not compatible with current. In this article, we discuss the physical and geometrical facets of the cosmological parameter of the model. Several elements of the model universe are explained by the jerk parameter and energy conditions, including the recent cosmological expansion and singularity theories. We also deliberated state-finder parameters, which forecast that the Universe created from Einstein’s static era rallies towards ΛCDM model (r = 1, s = 0).

Cosmic Aspects of Sharma-Mittal Holographic Dark Energy Model in Brans-Dicke Theory of Gravity

We investigate the cosmological scenario involving spatially homogeneous and anisotropic Bianchi type-V I0 space-time in the context of the Sharma-Mittal holographic dark energy model within the framework of Brans-Dicke’s theory of gravitation. In order to achieve this objective, the Hubble, deceleration, equation-of-state parameters have been discussed. The deceleration parameter (q) is used to measure the pace at which the expansion of the universe is accelerating. The equation-of-state parameter (ωsmhde) characterizes the quintessence and vacuum areas of the universe. All the parameters demonstrate consistent behaviour following the Planck 2018 data. We assess the dynamical stability by defining the squared speed of sound and examining its behaviour. In addition, the energy conditions and the variation of ωsmhde and ω′smhde in the model indicate the present accelerating expansion of the universe.

Dynamics of Anisotropic Universes in LRS Bianchi Type-V Cosmological Model with Perfect Fluid in Generic Viable Non-Minimally Coupled f(R, T) Gravity

Dynamics of Anisotropic Universes in LRS Bianchi Type-V Cosmological Model with Perfect Fluid in Generic Viable Non-Minimally Coupled f(R, T) Gravity

MATHEMATICAL ANALYSIS OF COSMOLOGICAL MODELS WITH LINEARLY VARYING DECELERATION PARAMETER

Bianchi type-V is investigated using a decaying cosmological constant with perfect fluid. The study solves Einstein field equations by assuming that the deceleration parameter q is functionally connected to the Hubble parameter H, which yields the scale factor a. As cosmic time t increases, the cosmological model experiences exponential inflation. The physical characteristics and behavior of the cosmological model are also covered.

Energy model in Bianchi type-V spacetime via RIF integration techniques

This paper investigates the Noether versus Killing symmetries and their associated conservation laws of Bianchi type-V spacetimes. The study is carried out using the Maple RIFSIMP package, which converts a set of nonlinear differential equations into the reduced involutive form (RIF). This technique generates an RIF tree, where each branch is solved to obtain the explicit forms of Noether symmetries. Separate RIF trees are used to represent each group. We derive a general expression for the Noether symmetry connected to homothety, and then we investigate this Noether symmetry in each separate group. To explore whether dark energy is associated with Bianchi type-V spacetime, we examine the energy density of each spacetime obtained in association with the Ricci scalar. The symmetries of the larger groups, 11- and 17-dimensional, are presented separately in the tables.

Bianchi Type-V space time with Tsallis holographic dark energy

In this paper, using the framework of Saez–Ballester theory, Bianchi Type-V metric Tsallis holographic dark energy models with interacting and non-interacting elements have been constructed. To obtain solutions for the model, we used correlation between metric potentials and varying deceleration parameters. There is additional discussion of the models’ physical characteristics and behavior.

Higher Dimensional Bianchi V Models in f (R,T) Theory with Perfect Fluid Distribution

In this paper we have studied five-dimensional Bianchi type-V spacetime in the f (R,T) theory. To solve Einstein’s field equations, we have assumed that the Hubble parameter is inversely proportional toݎ ℎݐ power of the scale factor alpha i.e. H alpha 1/alphar. We have obtained a singular model for r &gt;0, non-singular model for r=0. The physical behavior of the models has also been discussed using some physical parameters.

Observational constraints in modified Chaplygin gas cosmological model

Bianchi type-V cosmological model with modified Chaplygin gas having the equation of state p=γρ−Cρα, where C is a positive constant and 0≤α,γ≤1, has been investigated. To find the deterministic solution, we have considered power-law and intermediate expansions which predicts the decelerating and accelerating phases of expansion of the Universe. Here, we have also constructed cosmographic parameters like H,j,l,s∗ and studied their evolution in the background of Bianchi type-V Universe with modified Chaplygin gas. The geometric diagnostics, the state-finder (r,s) in our cosmological model to discriminate from the ΛCDM model are studied. We have performed the statistical analysis and obtained best fit values of the parameters using MCMC technique for intermediate model. We have also compared our models with observed Hubble data for both scenarios. We have noted some new and interesting cosmological solutions which is relevant for the model building, including present accelerating phase of the Universe.

Two fluid cosmological models in f(R,T) theory of gravity

This work deals with the two fluid Bianchi type-V cosmological models consisting of matter and radiating source in the [Formula: see text] theory of gravity studied by Harko et al. [Phys. Rev. D 84, 024020 (2011)]. In this paper, we developed a new idea about [Formula: see text] gravity with the help of two fluids: one fluid is matter field modeling material content of the Universe and other fluid is radiation field modeling the cosmic microwave background (CMB). We have determined the solution of the two fluid gravitational field equations with the systematic structure in [Formula: see text] gravity. Here, we have deliberated four types of universe such as dust universe, radiation universe, hard universe and Zel’dovich universe and also extended our work to observe the big rip and big bang singularity. We have also tested the cosmological parameters.

Hyperbolic Scenario of Accelerating Universe in Modified Gravity

Throughout this study, locally rotationally symmetric (LRS) Bianchi type-V space-time is pondered with Tsallis holographic dark energy (THDE) with the Granda–Oliveros (GO) cut-off in the Sáez–Ballester (SB) theory of gravity. A parameterization of the deceleration parameter (q) has been suggested: q=α−βH2. The proposed deceleration parameterization demonstrates the Universe’s phase transition from early deceleration to current acceleration. Markov chain Monte Carlo (MCMC) was utilized to have the best-fit value for our model parameter and confirm that the model satisfies the recent observational data. Additional parameters such as deceleration parameter q with cosmographic parameters jerk, snap, and lerk have also been observed physically and graphically. The constructed model is differentiated from other dark energy models using statefinder pair analysis. Some important features of the model are discussed physically and geometrically.

Behaviour of Bianchi Type-V Dark Energy Model in f(R,T) Gravity with a Specific Form of Hubble Parameter

Abstract: In this paper, we have constructed a Bianchi type V cosmological model, in the presence of bulk viscous fluid and within the framework of f(R,T) theory of gravity with an appropriate choice of the functional f(R,T)in the form f(R,T )=R+2f(T), where R and T are respectively Ricci scalar and trace of energy momentum tensor. In order to obtain a deterministic solution, we have considered two general forms of hyperbolic scale factors. The different forms of scale factors considered here produce time-varying deceleration parameters in all the cases that simulate the cosmic transition. The state finder diagnostic pair is found to be in the acceptable range. The physical parameters are constrained from different representative values to build up a realistic cosmological model aligned with the observational behaviour. Keywords: Bianchi type V, Dark energy, f(R,T) gravity, Variable deceleration parameter.

Perturbations in Bianchi-V Spacetimes with Varying Λ, G and Viscous Fluids

As a follow-up of a recent article in which we investigated the cosmological background expansion history of the universe in Bianchi type-V cosmological models with bulk viscous fluid and evolving cosmological Λ and Newtonian G parameters, we study the evolution of the cosmological perturbations in the current work. In particular, we analyse the evolution of the viscous matter over-density that leads to formation of large-scale structures in the Bianchi-V model, and compare the results with standard ΛCDM solutions. Our results suggest that introducing viscous fluid in the background described by Bianchi-V geometry with evolving Λ and G amplifies the structure-growth rate.

Anisotropic massive scalar field model with domain walls in f(R, T) gravity

The Bianchi type-V universe with massive scalar fields and domain walls examined within f(R, T) theory of gravity described by Harko et al. (Phys. Rev. D. 84, 024020, 2011). Solving the field equations of the theory using a power law relation between the scalar field and average scale factor of the model we have presented an anisotropic massive scalar field model in this modified theory of gravity. In light of the recent scenario of the universe expanding at an accelerated rate and cosmological observations, we computed the cosmological parameters like energy density, pressure, deceleration parameter (q), statefinder parameters (r,s), and r-q plane of our model and discussed their physical significance.

COSMOLOGICAL BIANCHI TYPE – V MODEL WITH ZERO MASSIVE SCALAR FIELD

In this paper, we discussed cosmological model in the general theory of relativity considering Bianchi type-V metric where the matter is in the form of zero massive scalar field. Exact solutions to the field equations are derived when the metric potentials are functions of cosmic time only. Some physical and geometrical properties of the solutions are also discussed.

ACCELERATING COSMOLOGICAL MODELS WITH VARIABLE G AND Λ-TERM IN GENERAL RELATIVITY

In this paper, we have presented a new class of accelerating universe models with variable cosmological term Λ(t) and gravitational constant G(t) in the framework of general relativity. To get exact solution of Einstein’s field equations for homogeneous and anisotropic Bianchi type-V space-time, a time varying de- celeration parameters is considered as q = 1 + nα , where n, α are constants. The present model shows a point type singularity at origin. The results establish the quintessence like behavior of model initially, and approaches to ΛCDM model ultimately. Some geometrical and physical properties of the models have been evidenced, and conferred to derive the validity of models with respect to recent astrophysical observations. Stability of the model has been discussed through the means of Om(z) diagnostic and state-finder analysis.

Kaniadakis holographic dark energy with scalar field in Bianchi type-V universe

In this work, considering anisotropic and homogeneous Bianchi type-V universe we investigated Kaniadakis holographic dark energy (KHDE). It is demonstrated that the equation of state (EoS) parameter has a transition from the quintessence era to the phantom era for the chosen model. Additionally, in the late time of the universe, EoS parameter behaves like a cosmological constant ([Formula: see text]) with an IR (Infrared) cut-off apparent horizon in case of a particular form of deceleration parameter. We reconstructed correspondence between the KHDE and tachyon, quintessence and k-essence scalar fields. Also, our numerical solutions have been shown in graphs for EoS parameter and scalar fields.

COSMOLOGICAL BIANCHI TYPE – V MODEL WITH ZERO MASSIVE SCALAR FIELD

In this paper, we discussed cosmological model in the general theory of relativity considering Bianchi type-V metric where the matter is in the form of zero massive scalar field. Exact solutions to the field equations are derived when the metric potentials are functions of cosmic time only. Some physical and geometrical properties of the solutions are also discussed.

Bianchi type-V Dark Energy Modified f(R,T) Gravity Model in the Presence of Massive Scalar Field in Lyra Geometry

Here, we investigate Bianchi type-V modified f(R,T) gravity cosmological models in Lyra geometry. To acquire the deterministic solution of the field equations with f(R,T) gravity based on Lyra geometry, we consider f(R,T)= f_1 (R)+f_2 (T), R indicates Ricci Scalar, T indicates trace of the energy momentum tensor in Lagrangian matter. Presence of Massive scalar field and Displacement vector of Lyra played an important role. The physical as well as the geometrical nature of the f(R,T) model is also discussed. HIGHLIGHTS In this present model of universe, we obtained that the universe starts with zero volume As in present observational data like CMB, BAO, La Supernona, our model is accelerating It is observed that the scalar field and kinetic energy both are non singular CDM is not satisfied in this model of universe GRAPHICAL ABSTRACT