Speaker
Description
I will discuss aspects of the Husain-Kelly-Santacruz-Wilson-Ewing dust collapse model in effective loop quantum gravity. I will focus on rigorous causal structure analysis, in particular, I will present numerically computed Penrose-Carter diagrams for both homogeneous Oppenheimer-Snyder collapse scenario and nonhomogeneous one with a Gaussian initial dust profile. I will argue that a significant region of spacetime remains inaccessible to the model's dynamics due to the formation of the shell-crossing singularities. The question of whether a timelike singularity, similar to that one in the homogeneous collapse scenario, arises in the nonhomogeneous case remains unresolved. Furthermore, I will prove that phenomena such as black hole explosions or gravitational shock waves cannot be witnessed by an external observer who does not cross any horizon. Indeed, the collapse cannot take place within single asymptotic region.
