Spin-induced dynamical scalarization, de-scalarization and stealthness in scalar-Gauss-Bonnet gravity during black hole coalescence

Understand

Particular couplings between a scalar field and the Gauss-Bonnet invariant lead to spontaneous scalarization of black holes.

• Here we continue our work on simulating this phenomenon in the context of binary black hole systems.
• We consider a negative coupling for which the black-hole spin plays a major role in the scalarization process.
• We find two main phenomena: (i) dynamical descalarization, in which initially scalarized black holes form an unscalarized remnant, and (ii) dynamical scalarization, whereby the late merger of initially unscalarized black holes can cause scalar hair to grow.