We investigate stability of a gravitationally collapsing iron core against non-spherical perturbation. The gravitationally collapsing iron core is approximated by a similarity solution for dynamically collapsing polytropic gas sphere. We find that the similarity solution is unstable against non-spherical perturbations. The perturbation grows in proportion to (t − t0) −σ while the the central de...

Abstract In this paper a simple (i.e. free of fine-tuning, etc.) new mechanism for primordial black hole formation based on the collapse large antimatter systems in early Universe is introduced. A peculiarity process that, compared to their material counterparts, takes much less time due reversed thermodynamics antimatter, an idea which has been proposed our earlier Etesi (2021). This model sev...