Exploring physical properties of spherically symmetric anisotropic stellar models with string clouds and quintessence field

In this study, we investigate the implications of modified matter sources within General Relativity, aiming to establish a physically sound and stable configuration for neutron stars such as PSR J1614−2230, PSR J1903+327, and SMC X−1. Employing an anisotropic fluid, alongside a cloud of strings and a quintessence field, we adopt a linear relationship between radial pressure and energy density as the equation of state. Notably, our findings reveal that the modified matter source’s stellar model is free of geometric singularities, with positive and finite metric potentials at the center. Moreover, we observe a switch-over behavior in the energy density influenced by metric potentials, whereas the density of quintessence meets physical criteria. The stellar configuration displays no singularities, with positive and finite central values of density and pressure. Anisotropy, along with hydrostatic forces, maintains stable equilibrium, and the sound speed criteria support the stability of the stars. Furthermore, the use of modified matter sources for constructing stellar systems is deemed physically acceptable, meeting energy conditions and maintaining a valid mass function. Importantly, the inclusion of string clouds and quintessence does not lead to excessive compactness or surface redshift, remaining within the Buchdahl limits.