Black Hole Formation from Collapsing Quark Binding String Fluid in \(\boldsymbol{f(R,T)}\) Theory

Abstract

We consider the gravitational collapse of a quark binding string fluid in \(f(R,T)\) theory of gravity. A quark binding string state of a fluid is expected to occur as a combination of quark matter and strings in the initial phases of the Universe. Assuming the collapse of this quark fluid, the junction conditions are derived, taking famous FRW and Schwarzschild space-times as the interior and exterior regions, respectively. We have assumed that \(f(R,T)=\alpha R+\beta T\), (\(\alpha\), \(\beta\) are positive constants). The collapsing gravitational mass is calculated under the conditions of a trace of the energy momentum tensor and a constant scalar curvature. It is calculated how long and how far the apparent horizons form. The constant term \(f(R_{0},T_{0})\) is a factor which delays the collapse. The event horizon formation is followed by creation of an apparent horizon, which results in a black hole. Additionally, the existence of the string tension lengthens the period before the horizon forms. As a result, it is anticipated that the Universe’s black holes are expected to originate during the quark binding string phase.