In this letter, we investigate the cosmic expansion scenario of universe in framework f(R,Lm) gravity theory. We consider a non-linear model, specifically, f(R,Lm)=R2+Lmn+β, where n and β are free model parameters. Then derive motion equations for flat FLRW obtain exact solution corresponding field equations. estimate best fit ranges parameters by using updated H(z) datasets consisting 57 points Pantheon 1048 points. Further physical behavior density deceleration parameter. The evolution...

In this article, we attempt to describe the cosmic late-time acceleration of universe in framework f(R,Lm) gravity, by using an effective equation state, when bulk viscosity is taken into account. We presume a non-linear functional form, specifically, f(R,Lm)=R2+Lmα, where α free model parameter. obtain exact solution our viscous matter dominated model, and then utilize combined H(z) + Pantheon Analysis datasets estimate best fit values parameters model. Then, characterize behavior...

Abstract In this article, we investigate scalar field cosmology in the coincident f ( Q ) gravity formalism. We calculate motion equations of under flat Friedmann-Lemaître-Robertson-Walker background presence a field. consider non-linear model, particularly = − + α n , which is nothing but polynomial correction to Symmetric Teleparallel Equivalent General Relativity (STEGR) case. Further, assumed two well-known specific forms potential function, specifically exponential from V ϕ 0 e β and...

This article explores matter bounce non-singular cosmology in $f(R,L_m)$ gravity. We consider two non-linear functional forms, specifically, $f(R,L_m) = \frac{R}{2} + \lambda R^2 \alpha L_m$ and L_m ^\beta \gamma$ representing a minimal coupling case. derive the corresponding Friedmann-like equations for both assumed models FLRW background, then we present impact of model parameters along with parameter bouncing scale factor on equation state parameter, pressure, energy density. In addition,...

In the present paper we study a conformally flat generalized Ricci recurrent perfect fluid spacetime with constant scalar as solution of modified $F(R)$-gravity theory. We show that Robertson-Walker is Recurrent if and only it symmetric. The type matter shown to have EoS $\omega=-1$. Some energy conditions are analyzed couple popular toy models $F(R)$-gravity, like $F(R)= R+\alpha R^m $ where $\alpha, m$ constants F(R)=R+\beta RlnR $\beta constant. harmony recent observational studies...

Abstract Statefinder diagnostics is a convenient method that can differentiate between the various dark energy models. In this article, statefinder parameters in symmetric teleparallel cosmology are analyzed. The gravity theory an alternative to general relativity where gravitational interactions attribute non‐metricity scalar Q . present work, two models considered which contains linear and non‐linear form of scalar, specifically, , α β free then evaluated. trajectory plane plotted....

Abstract In this article, we present a dynamical system analysis of Dirac-Born-Infeld scalar field in modified gravity context. We considered polynomial form gravity, used two different types potential, and exponential, found closed autonomous equations. analyzed the fixed points such evaluated conditions under which deceleration to late-time acceleration occurs model. note similarity models show that our result is consistent with previous study on Einstein's gravity. also investigated...

In the last century, theoretical and experimental developments have established General Relativity theory as most successful for describing gravitational phenomenon. On other hand, in two decades, multiple observational probes strongly favored discovery of acceleration cosmic expansion. The enhancement development precision cosmology indicate a requirement to go beyond search an alternate description that can resolve persistent issues. Chapter 1, we highlight some important elements...

In the present article we analyze matter-geometry coupled $f(Q,T)$ theory of gravity. We offer fully covariant formulation theory, with which construct correct energy balance equation and employ it to conduct a dynamical system analysis in spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker spacetime. consider three different functional forms function, specifically, $f(Q,T)=\alpha Q+ \beta T$, T^2$, $f(Q,T)=Q+ \alpha Q^2+ T$ . attempt investigate physical capabilities these models...

Abstract In this article, we investigate the observed cosmic acceleration in framework of a cosmological f ( R , L m ) model dominated by bulk viscous matter an anisotropic background. We consider locally rotationally symmetric Bianchi type I metric and derive Friedmann equations that drive gravitational interactions gravity. Further, assume functional form <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>f</mml:mi> <mml:mo stretchy="false">(</mml:mo>...

Abstract In this article, the viscous fluid cosmological model is analyzed in framework of recently proposed gravity by assuming three different forms bulk viscosity coefficients, specifically, , and a linear model, particularly, where free parameter. The coefficients parameter values using combined H(z)+Pantheon+BAO data set are estimated. asymptotic behavior our studied utilizing phase space method. It found that corresponding to all cases, depicts evolution universe from matter dominated...

This article explores the impact of bulk viscosity on understanding universe's accelerated expansion within context modified $f(T,\mathcal{T})$ gravity, which is an extension $f(T)$ gravitational theory, allowing a broad coupling between energy-momentum scalar $\mathcal{T}$ and torsion $T$. We consider two functions, specifically $f(T,\mathcal{T})=\alpha T + \beta \mathcal{T}$ \sqrt{-T} \mathcal{T}$, where $\alpha$ $\beta$ are arbitrary constants, along with fluid part incorporating...

The standard formulation of General Relativity Theory, in the absence a cosmological constant, is unable to explain responsible mechanism for observed late-time cosmic acceleration. On other hand, by inserting constant Einstein’s field equations, it possible describe acceleration, but suffers from an unprecedented fine-tuning problem. This motivates one modify spacetime geometry Relativity. f(Q) modified theory gravity alternative Relativity, where non-metricity scalar Q candidate...

First and foremost, we show that a 4-dimensional conformally flat generalized Ricci recurrent spacetime $(GR)_4$ is an Einstein manifold. We examine such as solution of $f(R, G)$-gravity theory it shown the additional terms from modification gravitational sector can be expressed perfect fluid. Several energy conditions are investigated with G) = R +\sqrt{G}$ R^2+GlnG$. For both models, weak, null dominant satisfied while strong condition violated, which good agreement recent observational...

Abstract In this paper, a non‐interacting scalar field cosmology with an arbitrary potential using the f ‐deviser method that relies on differentiability properties of is investigated. Using alternative mathematical approach, unified dynamical system analysis at field's background and perturbation levels potentials presented. For illustration, monomial double exponential considered. These two classes comprise asymptotic behavior several potentials, and, therefore, they provide skeleton for...