Accelerated black holes in (2 + 1) dimensions: quasinormal modes and stability

Abstract

We investigate the propagation of a scalar field in a (2 + 1)-dimensional accelerated black hole, recently revisited in Arenas-Henriquez et al. (J High Energy Phys https://doi.org/10.1007/jhep05(2022)063, 2022). We briefly describe how the conformal configuration renders a trivial scalar perturbation with a rescaling of the field mass. On the contrary, the free scalar field propagation presents an intricate dynamic, whose equation may be reduced through the use of Israel junction conditions and a non-trivial ansatz. In this case, using two different methods we calculate the quasinormal modes of the solution also obtaining unstable field profiles delivered by the linear scalar perturbation to the background geometry. We examine the parameter space of angular eigenvalues of the field and accelerations under which such instabilities occur.A. R. acknowledges financial support from the Generalitat Valenciana through PROMETEO PROJECT CIPROM/2022/13. A. R. is funded by the Universidad de Alicante (María Zambrano contract ZAMBRANO 21-25 (Spain)) (with funding from NextGenerationEU). R. D. B. Fontana thanks the hospitality of DMAT-University of Aveiro/CIDMA and the support of the Center for Research and Development in Mathematics and Applications (CIDMA) through the Portuguese Foundation for Science and Technology (FCT-Fundação para a Ciência e a Tecnologia), references https://doi.org/10.54499/UIDB/04106/2020 and https://doi.org/10.54499/UIDP/04106/2020