3 papers
gr-qc2026
Horizon-Evanescent Scalar Clouds from Coupled Rotation and Magnetic Fields around Black Holes
Hengyu Xu, Haowei Chen, Shao-Jun Zhang
We show that black-hole rotation and an external magnetic field can jointly generate a qualitatively new class of scalar cloud. Using the Kerr-Bertotti-Robinson geometry as a separ…
gr-qc2026
Electric Penrose process in spherically symmetric regular black holes with and without a cosmological constant
Haowei Chen, Hengyu Xu, Yizhi Zhan +1
We investigate the electric Penrose process in Ayón-Beato-García (ABG) black holes, both in the presence and absence of a cosmological constant, presenting, to the best of our know…
gr-qc2026
Charged Superradiant Instability of Spherically Symmetric Regular Black Holes in de Sitter Spacetime: Time- and Frequency-Domain Analysis
Yizhi Zhan, Hengyu Xu, Haowei Chen +1
We investigate the superradiant instability of Ayón-Beato-GarcÃa-de Sitter (ABG-dS) black holes under massless charged scalar perturbations using both time-domain evolutions and…