@article{Yadav2025, 
author = {Sunil Kumar Yadav and Sameh Shenawy and Nasser Bin Turki and Yanlin Li},
title = {Investigating string cloud spacetimes with energy-momentum tensor constraints in general relativity},
year = {2025},
journal = {AIMS Mathematics},
volume = {10},
number = {9},
pages = {21492-21511},
keywords = {Lorentzian spacetime manifold, string cloud spacetimes, generalized T-recurrent, semi-generalized T-recurrent tensor, Codazzi-type energy-momentum tensor, geometric strings},
url = {https://www.sciopen.com/article/10.3934/math.2025955},
doi = {10.3934/math.2025955},
abstract = {The objective of this study was to investigate the behavior of relativistic G(QE)                 n       string cloud spacetime endowed with various forms of the string cloud energy-momentum tensor        T  , which includes the string cloud fluid density    α and string tension    β. A G(QE)                 n       string cloud spacetime with a covariantly constant energy-momentum tensor satisfies the equation of state        α    β    =  −  1, and represents either a massive string cloud spacetime or a bulk viscous fluid spacetime. Moreover, when a string cloud spacetime is coupled with a covariantly constant energy-momentum tensor, the equation of state        α    β    =  −  1 coincides with the state equation for a cloud of geometric strings or represents the quintessence era. G(QE)                 n       string cloud spacetimes with Codazzi-type and pseudo-symmetric energy-momentum tensors were investigated. Furthermore, we characterized        T  -recurrent, weakly        T  -symmetric, specially weakly        T  -symmetric, generalized        T  -recurrent, semi-generalized        T  -recurrent, and quadratic Killing-type energy-momentum tensors on a string cloud spacetime with a Killing velocity vector field, and concluded that the string cloud spacetime either represents a massive string cloud spacetime or corresponds to the quintessence era.}
}