Muhammad Shakeeb Sharif

Spherically symmetric anisotropic solutions that describe compact stellar objects within the framework of modified Rastall f ( Q , T ) $f(\mathbb {Q},\mathcal {T})$ gravity are explored in this manuscript, where the non-metricity scalar represented by Q $\mathbb {Q}$ and the trace of the energy-momentum tensor is denoted by T $\mathcal {T}$ . To achieve this, the Karmarkar condition is applied and a relationship between the metric functions to solve the resulting field equations is established.

1 INTRODUCTION Antiphospholipid syndrome (APS) is a systemic autoimmune condition marked by thrombosis in both veins and arteries, recurrent miscarriages, and consistently high levels of antiphospholipid (aPL) antibodies like lupus anticoagulant (LAC), anti-β2-glycoprotein I (anti-β2GPI), and anticardiolipin (aCL) antibodies. This syndrome can manifest independently (primary APS [PAPS]) or alongside other autoimmune disorders (secondary APS [SAPS]).

In this study, the features of a charged gravastar are investigated within the framework of gravity ( represents nonmetricity) using the Finch–Skea metric. This metric is applied to both the interior and shell regions of the charged gravastar and the field equations are derived accordingly. For the exterior regions, various black holes are considered, i.e., Reissner–Nordström, Bardeen, and Hayward regular black holes.