A new mechanism for primordial black hole formation during reheating

Understand

The Reheating process at the end of inflation is often modeled by an oscillating scalar field which shows a background dust-like behaviour, prompting the analysis of gravitational collapse and black hole formation in this era to be approached by the spherical collapse of standard structure formation.

• In the scalar field dark matter structure formation process virialized halos halt the direct collapse, resulting in halos with condensed central cores at the de Broglie scale of the dominant scalar field.
• We show that a similar process can take place during reheating, leading to the formation of primordial black holes (PBHs).
• We study the formation of PBHs through the gravitational further collapse of structures virialized during reheating, looking at the collapse of either the whole structure, or that of the central core within these configurations.