Modeling anisotropic compact objects in the vanishing complexity regime through gravitational decoupling

Abstract In this work, we model static spherically symmetric compact stars within the framework of classical general relativity. In order to obtain exact solutions of the Einstein field equations with non-singular density profile we adopt the generalised Mak–Harko ansatz (Mak and Harko in Chin. J. Astron. Astrophys. 2:248, 2002) and demand that the complexity factor as defined by Herrera for static relativistic spheres (Herrera, Phys. Rev. D 97:044010, 2018) vanishes everywhere inside the self-gravitating object. Exact solutions of the Einstein field equations describing anisotropic fluid spheres are obtained via the gravitational decoupling method. We show that the decoupling constant, central and surface density values play a crucial role in dictating the stability of the stellar structure. The interplay between these factors accounts for mass–radius profiles associated with gravitational wave events such as GW190814 and further predicts stellar masses in the range 2.9 $$M_\odot $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⊙</mml:mo> </mml:msub> </mml:math> and 3.4 $$M_\odot $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⊙</mml:mo> </mml:msub> </mml:math> . Our models are excellent candidates for predicting compact objects such as neutron stars residing in the so-called mass gap associated with binary mergers without invoking exotic matter and modified gravity theories.