arXiv subjects

Banadipa Chakraborty

Publications and source records attributed to Banadipa Chakraborty.

4 recordsLinked to original sources

arXiv2025

Reconstructions of Einstein-Aether Gravity from Barrow Agegraphic and New Barrow Agegraphic Dark Energy models: Examinations and Observational Limits

We present a comprehensive investigation exploring the theoretical framework of Einstein-Aether gravity theory when combined with two modified cosmological paradigms: the Barrow Agegraphic Dark Energy (BADE) and its newer variant, the New Barrow Agegraphic Dark Energy (NBADE). Our study focuses on reconstructing the functional form of the Einstein-Aether Lagrangian component $F(K)$ from these phenomenological dark energy models. Model parameters are constrained using a Markov Chain Monte Carlo (MCMC) approach based on multiple datasets, including cosmic chronometers (CC), Baryon Acoustic Oscillations (BAO), and the Pantheon+SH0ES compilation. Using best-fit parameters, we analyze various cosmological diagnostics: Hubble and deceleration parameter evolution, dark energy equation of state $ω_{DE}$, density parameter trajectories, $ω'_{DE}$--$ω_{DE}$ phase space behavior, statefinder diagnostics $(r,s^*)$ and $(r,q)$, and Om(z) trajectories. Both models exhibit late-time acceleration, with the dark energy sector showing a quintessence-like nature in the current epoch and evolving toward a phantom regime in the future. Stability analysis based on the squared sound speed $v_s^2$ highlights partial epoch-dependent stability. While our results demonstrate reasonable agreement with observational data and reveal physically plausible dynamics, the models do not yet offer a fundamentally superior alternative to other dark energy reconstructions. Nonetheless, their behavior under modified entropy assumptions and their flexibility in dynamical diagnostics provide a useful framework for probing non-standard extensions of Einstein-Aether gravity and dark energy phenomenology.

gr-qc↗

arXiv2025

On the Field Theoretical Description of an Alternative Model to Generalized Chaplygin Gas and its Thermodynamic Behaviour

This paper investigates a newly proposed fluid description of dark energy within the framework of the late-time accelerated expansion of the universe. Our primary objective is to explore the theoretical foundation of the proposed equation of state by establishing its correspondence with well-known scalar field models such as quintessence, k-essence, and DBI-essence. Through this correspondence, we reconstruct key field parameters, including the scalar field $ϕ$ and scalar potential $V(ϕ)$, and analyze their evolutionary behavior across cosmic time. The study also evaluates the model's physical consistency and cosmological implications by examining fundamental energy conditions - Null Energy Condition (NEC), Dominant Energy Condition (DEC), and Strong Energy Condition (SEC). Furthermore, we conduct a comprehensive stability analysis to ensure the robustness of the model and investigate its thermodynamic properties, including possible phase transitions using entropy and Gibbs free energy. To assess the observational viability of the model, we compare its predictions against recent datasets, including Cosmic Chronometers (CC), Baryon Acoustic Oscillation (BAO), and Supernova Type Ia from the Pantheon+SH0ES compilation and Union 2.1, as well as recent DESI and DESY5 data. Our analysis demonstrates that the proposed fluid model aligns well with observational constraints, reproduces the late-time acceleration of the universe, and offers a compelling alternative to the standard $Λ$-CDM model while maintaining consistency with current data.

gr-qc↗

arXiv2024

Thermodynamics of Modified Chaplygin-Jacobi Gas and Modified Chaplygin-Abel Gas: Stability Analysis and Observational Constraints

This paper explores the thermodynamic properties and stability of two newly introduced gas models, namely the Modified Chaplygin-Jacobi gas and the Modified Chaplygin-Abel gas. To achieve this, we examine the behavior of relevant physical parameters to gain in depth information about the evolution of the universe. The specific heat formalism is employed to verify the applicability of the third law of thermodynamics. Furthermore, the equation of state for the thermal system is obtained by applying thermodynamic variables. The stability of the gas models is investigated within the framework of classical thermodynamics, focusing on adiabatic processes, specific heat capacities, and isothermal conditions. It is inferred that the proposed fluid configurations exhibit thermodynamic stability and undergo adiabatic expansion for suitable parameter choices. We then perform observational analysis using CC+BAO and Pantheon+SH0ES datasets to impose constraints on our model parameters using the Markov Chain Monte Carlo (MCMC) process.

gr-qc↗

arXiv2024

Reconstructions of $f(\mathcal{P})$ and $f(\mathcal{Q})$ gravity models from $(m,n)$-type Barrow Holographic Dark Energy: Analysis and Observational Constraints

In this research, we have reconstructed the extended $f(\mathcal{P})$ cubic gravity and symmetric $f(\mathcal{Q})$ teleparallel gravity from the $(m,n)$-type Barrow Holographic Dark Energy (BHDE) model. We have derived the unknown functions $f(\mathcal{P})$ and $f(\mathcal{Q})$ in terms of $\mathcal{P}$ and $\mathcal{Q}$, assuming a flat, homogeneous, and isotropic universe. To constrain our model parameters, we employed cosmic chronometer datasets and Baryon Acoustic Oscillation datasets, utilizing Markov Chain Monte Carlo (MCMC) method. We analysed the behaviour and stability of each model throughout the universe's evolution by studying crucial parameters such as the deceleration parameter, equation of state (EoS) parameter $ω_{DE}$, density parameter $Ω(z)$ and the square of the speed of sound $v_s^2$. Additionally, we explored the cosmographic behaviour by plotting the jerk parameter, snap parameter, and lerk parameter against the redshift. Furthermore, we examined the $ω'_{DE}-ω_{DE}$ phase plane, the $(r,s^*)$, $(r,q)$ statefinder parameters, and the $Om(z)$ parameter offers profound revelations about the dynamics of the universe and the distinctive features of dark energy. Our analyses indicated that our model could produce a universe undergoing accelerated expansion with quintessence-type dark energy. These findings contribute to our understanding of the nature of dark energy and the evolution of the cosmos.

gr-qc↗