https://doi.org/10.1140/epjc/s10052-018-6222-1
Regular Article - Theoretical Physics
Quasinormal modes as a distinguisher between general relativity and f(R) gravity: charged black-holes
1
School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram (IISER-TVM), Trivandrum, 695551, India
2
Department of Physics, Indian Institute of Technology Bombay, Mumbai, 400076, India
* e-mail: xeonese13@iisertvm.ac.in
Received:
2
August
2018
Accepted:
4
September
2018
Published online:
15
September
2018
The ring-down phase of black-hole perturbations is governed by the quasi-normal modes (QNM) and offer valuable insight into the nature of the objects emitting them, raising an interesting question: whether QNMs can be used to distinguish between theories of gravity? We construct a consistency test of general relativity (GR) which enables one to distinguish between general relativity and a specific class of modified theories of gravity: f(R). We show that an energetic inequality between scalar (polar) and vector (axial) type gravitational perturbations will exist for Reissner–Nördstrom solutions of GR - using which we find a novel method of determining the charge of a non-spinning black hole in GR. We then show that there will be a further energetic difference for charged black holes in f(R). Finally, we utilize this extra difference to construct a parameter to quantify deviation from GR.
© The Author(s), 2018
