2025/09/28 by Myung, Yun Soo
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2509.24113
We study scalarization of quantum Oppenheimer-Snyder (qOS)-extremal black hole in the Einstein-Gauss-Bonnet-scalar theory. This black hole is described by mass (M=4√α/3√(3)) with α quantum parameter. From studying onset of scalarization, we find the appearance of the single branch of scalarized qOS-extremal black holes. To obtain the tachyonic scalar cloud being a seed to generate the single branch of scalarized qOS-extremal black holes, we consider the near-horizon geometry of the Bertotti-Bobinson (BR) spacetime. In this case, we find that the appearance of a large scalar cloud at the horizon (ρ=0) is a new feature to represent onset scalarization of extremal black holes for tachyon with negative mass, but it is not related to the Aretakis instability of a propagating scalar with standard mass around the BR spacetime, showing polynomial instability of the ingoing time v. The Aretakis instability is connected to the scalar cloud with standard mass, indicating the blow-up at the horizon.