LAUSR

We report a new black hole (BH) scalarization mechanism and disclose novel dynamical critical phenomena in the process of the nonlinear accretion of the scalar field into BHs. The accretion process can transform a seed BH into a final scalarized or bald BH, depending on the initial parameter of the scalar field p . There is a critical parameter p ∗ and near it all intermediate solutions are attracted to a critical solution (CS) and stay there for a time scaling as T ∝ − γ ln | p − p ∗ | . At late times, the solutions evolve into scalarized black holes (BHs) if p > p ∗ , or bald BHs if p < p ∗ . The final masses of the resulting scalarized/bald BHs satisfy power-laws M p − M ± ∝ | p − p ∗ | γ ± where M ± are the masses of the scalarized/bald BHs when p → p ∗ from above/below, and γ ± the corresponding exponents.