Relativistic anisotropic models for the existence of ghost stellar star in modified gravity

In this paper, we examine how ghost stars appear in [Formula: see text] gravitational theory, where [Formula: see text] refers to the Ricci scalar. We adhere to Zeldovich and Novikov’s theory, according to which the presence of negative energy density in a certain region of the geometry determines the existence of such objects. To comprehend stellar structure, we construct relativistic models for such objects and first derive the field equations in [Formula: see text] gravity with an anisotropic source for a static spherical configuration. We then reconstructed modified field equations in terms of the star mass and the chosen metric variables. Next, we utilize geometric conditions like conformally flatness, in conjunction with the considered generating functions, to develop the first two relativistic models. The restrictions of null active mass, minimal complexity, and conservation equation are used to construct two additional models. Graphically, we determined that the fluid mass density of all constructed anisotropic models is negative for a specific range of star radius, and distinct values of the parameter [Formula: see text]. Our results strongly corroborated the ghost star appearance in the framework of [Formula: see text] gravity.