arXiv subjects

Sanjeeda Sultana

Publications and source records attributed to Sanjeeda Sultana.

4 recordsLinked to original sources

arXiv2026

Reconstruction of Tsallis Holographic Dark Energy via Modified Non-Metric Gravity: An $f(Q,C)$ Approach

In the current research, we have reported the Tsallis Holographic Dark Energy (THDE) (\textit{JCAP}, 2018(12), p.012.) model reconstructed within the framework of $f(Q, C)$ gravity (\textit{JCAP}, 2024(03), p.050.), combining entropy-based dark energy models with geometrically motivated modified gravity to explain late-time cosmic acceleration. The reconstructed model is found to exhibit significant sensitivity to the parameter space $(H_0, a_0, n, δ, ζ,r_d)$ and the initial conditions. The evolution of the equation of state and deceleration parameters is found to be highly dependent on these parameters. A comprehensive Markov Chain Monte Carlo analysis using observational datasets comprising {CC+Pantheon$^{+}$+DESI DR2} was performed, yielding best-fit values that demonstrate strong consistency with observational data, which is further validated for its consistency through the computation of the age of the Universe. The evolution of the jerk and snap parameters is examined and compared with the $Λ$CDM prediction. Statefinder diagnostics, through the evolutionary trajectories of the pairs $(r, s)$ and $(r, q)$ are derived and indicate that the model passes through the $Λ$CDM fixed point and the physical viability of the model is further consolidated through analysis of the four energy conditions.

gr-qc↗

arXiv2026

Cosmology of the interacting Tsallis holographic dark energy in $f(R,T)$ gravity framework

In this work, we have analyzed the cosmology of the Tsallis holographic dark energy (THDE), a particular case of Nojiri-Odintsov HDE proposed in [S. Nojiri and S. D. Odintsov, \textit{Gen. Relativ. Gravit.} \textbf{38} (2006), 1285; \textit{Eur. Phys. J. C} \textbf{77} (2017) 528], using Hubble's horizon cutoff in $f(R,T)=μR+νT$ model considering pressureless dark matter. We have examined the equation of state (EoS) parameters in this scenario. The deceleration parameter has been evaluated for this interacting model to justify the late-time acceleration of the expanding universe. We have also studied the cosmological consequences of Statefinder pair, $O_{m}(z)$ diagnostics, $r-q$ plane, and $w_{DE}-w^{'}_{DE}$ pair for interacting THDE in $f(R,T)=μR+νT$ model. We have also illustrated the cosmology of the interacting THDE using Hubble's horizon cutoff in $f(R,T)=R+γR^2+ξT$ model. The EoS parameter, deceleration parameter and Statefinder pair are studied in this interacting scenario. Attainment of $Λ$CDM fixed point has been observed for both models. We have also constrained model parameters based on observational data sets through the formalism of $χ^{2}$ minimum test.

gr-qc↗

arXiv2026

Cosmological Dynamics of Exponential Quintessence Constrained by BAO, Cosmic Chronometers, and DES-SN5YR/Pantheon+ Data

We perform a comprehensive observational test of a canonical quintessence model driven by an exponential potential, motivated by its emergence in higher-dimensional theories, string-inspired scenarios, and modified gravity. Using a Markov Chain Monte Carlo framework, we constrain the model with the latest high-precision observational datasets including Cosmic Chronometers, Baryon Acoustic Oscillation, Pantheon+, and DES-SN5YR Type Ia Supernovae. The combined data significantly tighten the parameter bounds on (H0, Omega_m0, eta0, gamma) and yield predictions for the Hubble parameter H(z), the distance modulus mu(z), and the scaled comoving angular diameter distance that remain in excellent agreement with observations and closely follow the LCDM baseline. An information-theoretic model comparison using the Akaike Information Criterion shows that the exponential quintessence model remains statistically comparable with LCDM despite having additional parameters. The model successfully reproduces the transition from matter domination to late-time acceleration, maintains w_tot > -1, and provides an age of the universe consistent with Planck 2018. Statefinder diagnostics indicate trajectories approaching the LCDM fixed point with small deviations, and energy condition analysis confirms physical viability, with only the Strong Energy Condition violated at late times as required for acceleration.

astro-ph.CO↗

arXiv2025

A comprehensive analysis of Barrow holographic Chaplygin gas model reconstruction and its cosmological consequences

In the current study, we have reconstructed variable modified Chaplygin gas in the Barrow holographic dark energy framework motivated by many recent studies. We have validated the generalized second law of thermodynamics for the reconstructed model. The permissible values of the reconstructed model have been determined by the recent astrophysical and cosmological observational data. The Hubble parameter is presented in terms of the observable parameters and redshift $z$ and other model parameters. From the Stern data set and joint data set of Stern with BAO and CMB observations, the bounds of the model parameters $(B_{0}, Ω_{bhd0})$ are obtained by the $χ^{2}$ minimization procedure. The best-fit value of the distance modulus $μ(z)$ against redshift $z$ is obtained for the reconstructed model and it is consistent with the SNe Ia union2 sample data.

gr-qc↗