What is the fine-grained topic of the following text: In this talk I will discuss the dependence of PBH formation from the initial shape of the curvature profile showing the relation between the threshold amplitude and the steepness of the perturbation which is linked to the amplitude of the pressure gradients that are developing during the collapse. Only return the topic.
PBH (Primordial Black Holes) Formation and Curvature Profile Dependence