Related papers: An Accelerating Flat FLRW Model with Observation C…
In this paper, we propose a modified scale factor (MSF) that allows us to explore the accelerating expansion of the universe without invoking the traditional dark-energy model, as described in the Lambda cold dark matter ($\Lambda$CDM)…
One of the most challenging problems in cosmology is the Hubble tension, a discrepancy in the predicted expansion rate of the Universe. We leverage the sensitivity of the Dispersion Measure (DM) from Fast Radio Bursts (FRBs) with the Hubble…
We study an isotropic flat FLRW-model in Scale-covariant theory of gravity $ f_{\gamma \delta}(\phi) $ \cite{Canuto:1977zz} which is explained in terms of ordinary and covariant differentiation of scalar field $ \phi $. As we know the…
The $f(R)$ theory of gravitation developed perturbatively around the general theory of relativity with cosmological constant (the \text{$\Lambda$}CDM model) in a flat FLWR geometry is considered. As a result, a general explicit cosmological…
We study the m-z relation for Type Ia supernovae data and the \theta-z relation for the updated compact radio sources data in 4 variable \Lambda- models: \Lambda \sim S^{-2}, \Lambda \sim H^2, \Lambda \sim \rho and \Lambda \sim t^{-2}. It…
This paper investigates the flat Friedmann-Lema$\hat{\imath}$tre-Robertson-Walker (FLRW) cosmological model using a suitable parameterization represented as a differential equation concerning the energy density of the scalar field,…
The data of type Ia supernovae observed by the High-z SN Search Team and Supernova Cosmology Project are analyzed in inhomogeneous cosmological models with a local void on scales of about 200 Mpc, to derive the best-fit values of model…
Model-independent bounds on the Hubble constant $H_0$ are important to shed light on cosmological tensions. We work out a model-independent analysis based on the sum rule, which is applied to late- and early-time data catalogs to determine…
In this paper, we study the power-law $f(T)$ model using Hubble diagrams of type Ia supernovae (SNIa), quasars (QSOs), Gamma Ray Bursts (GRBs) and the measurements from baryonic acoustic oscillations (BAO) in the framework of the…
We examine the running vacuum model with $\Lambda (H) = 3 \nu H^2 + \Lambda_0$, where $\nu$ is the model parameter and $\Lambda_0$ is the cosmological constant. From the data of the cosmic microwave background radiation, weak lensing and…
The horizon of a flat Friedmann--Robertson--Walker (FRW) universe is considered to be dynamic when the Hubble parameter $H$ and the Hubble radius $r_{H}$ vary with time, unlike for de Sitter universes. To clarify the thermodynamics on a…
In this study, we use late-time probes, such as well-localized fast radio bursts (FRBs), baryon acoustic oscillations (BAO), supernovae (SNe), and cosmic chronometers (CC) to constrain cosmological parameters through a model-independent…
Parameters that quantify the acceleration of cosmic expansion are conventionally determined within the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) model, which fixes spatial curvature to be homogeneous. Generic averages of…
We perform a model independent reconstruction of the cosmic expansion rate based on type Ia supernova data. Using the Union 2.1 data set, we show that the Hubble parameter behaviour allowed by the data without making any hypothesis about…
Discrepancies between distance measurements and $\Lambda$CDM predictions reveal notable features in the distance-redshift relation, possibly suggesting the presence of an evolving dark energy component. Given the central role of the…
In this paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…
This study investigates the accelerated cosmic expansion within the Ho\v{r}ava-Lifshitz Model. To constrain the cosmological parameters of this model, we incorporate 17 Baryon Acoustic Oscillation points, 31 Cosmic Chronometer points, 40…
In this paper, we investigate the stability of the flat FLRW metric in $f(T)$ gravity. This is achieved by analysing the small perturbations, $\delta$ about the Hubble parameter and the matter energy density, $\delta_\text{m}$. We find that…
This paper examines the late-time accelerating Universe and the formation of large-scale structures within the modified symmetric teleparallel gravity framework, specifically using the $f(Q)$-gravity model, in light of recent cosmological…
In this study, we consider three dark energy models in which $\Lambda$ is not constant, but has a dynamic nature that depends on the Hubble parameter $H$ and/or its time derivative $\dot{H}$. We analyze the generalized running vacuum model,…