Final State of Spherical Gravitational Collapse and Likely Source of Gamma Ray Bursts

Abstract

Following our result that for the final state of continued spherical gravitational collapse, the gravitational mass of the fluid, $M_f\to 0$, we show that for a physical fluid the eventual value of $2GM_f/R_f\to 1$ rather than $2GM_f/R_f <1$, indicating approach to a zero-mass black hole. We also indicate that as the final state would be approached, the curvature components tend to blow up, and the proper radial distance $l$ and the proper time $τ\to \infty$. This indicates that actually the singularity is never attained for the collapse of an isolated body. We also identify that, the final state may correspond to the local 3-speed $v\to c$, eventhough the circumference speed $U\to 0$. However, at a finite observation epoch, such Eternally Collapsing Objects (ECOs) may have a modest local speed of collapse $v \ll c$, and the lab frame speed of collapse should practically be zero because of their extremely high surface gravitational red-shifts.