The impact of $$f(R,\Sigma ,T)$$ gravity on strange star structure

Abstract This research paper explores the structure of hypothetical compact stars, known as strange stars, within the framework of a novel modified theory of gravity called $$f(R,\Sigma ,T)$$ f ( R , Σ , T ) gravity. This theory extends General Relativity by making gravity dependent not only on the Ricci curvature scalar R but also on a torsion scalar $$\Sigma $$ Σ and the trace of the matter energy–momentum tensor T . This introduces a richer coupling between geometry and matter. The study presents a highly exotic, multi-layered stellar model composed of five distinct regions, each with a unique equation of state and geometric properties. The model features a dark-energy-like core with powerful repulsive gravity (anti-gravity), surrounded by successive layers of dust, exotic radiation, and a stiff matter crust, all enveloped by a standard Schwarzschild vacuum exterior. A key finding is the prevalence of negative energy densities and pressures in several layers, a hallmark of exotic matter. These configurations, enabled by the $$f(R,\Sigma ,T)$$ f ( R , Σ , T ) framework, lead to repulsive gravitational effects that radically alter the star’s internal equilibrium. The analysis demonstrates how additional geometry-driven forces within this theory can support such exotic structures, potentially preventing gravitational collapse and resulting in a stable, non-singular object. This work demonstrates that $$f(R,\Sigma ,T)$$ f ( R , Σ , T ) gravity allows for new and complex classes of compact objects with stratified, exotic matter distributions, whose properties and observational signatures would differ significantly from those predicted by standard General Relativity.