Estimating the Role of Bag Constant and Modified Theory on Anisotropic Stellar Models

TL;DR

This paper investigates anisotropic stellar models within modified gravity theories, analyzing their physical viability and stability, and fitting model parameters to observed compact star data.

Contribution

It introduces solutions for anisotropic stars in specific $f( ext{R}, ext{T}, ext{Q})$ gravity models using Finch-Skea metric and MIT bag model, fitting parameters to observational data.

Findings

Models are physically viable and stable.

Model parameters fit observed star data.

Solutions agree with conditions for realistic stellar interiors.

Abstract

In this article, we are devoted to discuss different compact stars admitting anisotropic interiors in a particular modified theory of gravity. For this purpose, a spherically symmetric metric is adopted to formulate the field equations corresponding to two different $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ models, where $\mathcal{Q}=\mathcal{R}_{\alpha\gamma}\mathcal{T}^{\alpha\gamma}$. Since the field equations contain extra degrees of freedom, we choose Finch-Skea metric and MIT bag model equation of state to make them solvable. We also use matching conditions to calculate a constant triplet in the chosen ansatz. The resulting solutions are then graphically analyzed for particular values of the bag constant and model parameter in the interior of 4U 1820-30 compact star. The viability and stability of the modified models are also checked through certain tests. Further, we calculate the values of model parameter through the vanishing radial pressure constraint that correspond to the observed data (radii and masses) of eight different star candidates. Finally, we conclude that our models I and II are in well-agreement with the conditions needed for physically relevant interiors to exist.