Abstract Details
| Name: DEBADRI BHATTACHARJEE Affiliation: Cooch Behar Panchanan Barma University Conference ID: ASI2025_118 Title : Structure and stability of dark energy stars in Rastall theory of gravity Authors and Co-Authors : Debadri Bhattacharjee 1 & Pradip Kumar Chattopadhyay 1 Abstract Type : Poster Abstract Category : High Energy Phenomena, Fundamental Physics and Astronomy Abstract : The concept of dark energy offers a promising approach to preventing the gravitational collapse of compact objects, thereby avoiding the formation of singularities. In this article, we focus on developing a novel, singularity-free relativistic solution to the Einstein field equations for dark energy stars, framed within the Rastall theory of gravity. To examine this model, we consider the Low-Mass X-ray Binary (LMXB) 4U 1608-52, with a mass of $1.74~M_{\odot}$ and a radius of 9.3 km (T. G"uver et al., Astrophys. J. {\bf 712}, 964 (2010)), as a potential candidate for a dark energy star. The analysis begins with the dark energy equation of state, in which dark energy density is linked to an isotropic perfect fluid distribution through a coupling parameter, $\alpha$. We derive the induced metric and extrinsic curvature tensors at the star's surface to determine the unknown constants within the model. A detailed analysis is carried out to explore how the physical behaviour of the system depends on the Rastall parameter, $\xi$. Notably, we identify a possible phase transition from dark energy to baryonic matter, sensitive to both $\alpha$ and $\xi$. Additionally, we compute the proportion of dark energy in the model by varying $\xi$, while for a fixed $\xi$, the variation of dark energy percentage with stellar mass reveals a dependence on both mass and radius. The model satisfies causality and energy conditions, affirming its physical plausibility. Stability of the stellar structure is confirmed through a comprehensive stability analysis. The graphical representation of physical parameters and the results of the theoretical study demonstrate that the proposed model is free of singularities and represents a stable, realistic stellar configuration that incorporates both dark energy and baryonic matter. |