Quasinormal modes and gray-body factors of regular black holes in asymptotically safe gravity
Abstract
Recently, Bonanno et al. [Dust collapse in asymptotic safety: A path to regular black holes, Phys. Rev. Lett. 132, 031401 (2024)] presented an explicit metric describing the exterior of a collapsing dust ball within the framework of asymptotically safe gravity. Based on this metric, we investigate in detail the properties of the quasinormal mode (QNM) spectra for test massless scalar, vector, and Dirac fields. We find accurate values for the fundamental QNM frequency and the first overtones, demonstrating the appearance of a peculiar spiral-like behavior of the overtones compared to the fundamental modes. Additionally, we study black hole shadows and show that they align with Enstein Horizon Telescope observations. Finally, we study the gray-body factors and provide explicit lower bound estimates.