Relativistic formulation and physical viability of anisotropic analytic gravastars

Abstract We develop a fully consistent anisotropic extension of the Imran class ICG (Isotropic Compact Gravastar) model within general relativity. A geometry-coupled anisotropy is introduced at the exact equation level, ensuring regularity at the center, smooth matching to the exterior Schwarzschild spacetime, and the absence of thin shells. A controlled option enforces vanishing anisotropy at both the center and the surface. The resulting equilibrium configurations satisfy energy conditions, ca