Synchronised gravitational atoms from mergers of bosonic stars

Understand

If ultralight bosonic fields exist in Nature as dark matter, superradiance spins down rotating black holes (BHs), dynamically endowing them with equilibrium bosonic clouds, here dubbed synchronised gravitational atoms (SGAs).

• The self-gravity of these same fields, on the other hand, can lump them into (scalar or vector) horizonless solitons known as bosonic stars (BSs).
• We show that the dynamics of BSs yields a new channel forming SGAs.
• We study BS binaries that merge to form spinning BHs.