Dynamical scalarization in Schwarzschild binary inspirals

We show that Schwarzschild black hole binaries can undergo dynamical scalarization (DS) in the inspiral phase, in a subclass of $\mathbb{Z}_2$-symmetric Einstein-scalar-Gauss-Bonnet (ESGB) theories of gravity. The mechanism is analogous to neutron star DS in scalar-tensor gravity, and it differs from the late merger and ringdown black hole (de)scalarization found in recent ESGB studies. To our knowledge, the new parameter space we highlight was unexplored in numerical relativity simulations. We also estimate the orbital separation at the DS onset, and characterize the subsequent scalar hair growth at the adiabatic approximation.