Quasinormal modes of the Dirac field in the novel 4D Einstein-Gauss-Bonnet gravity

TL;DR

This paper calculates the quasinormal modes of the Dirac field around black holes in a new 4D Einstein-Gauss-Bonnet gravity, revealing how these modes change with the coupling constant.

Contribution

It provides the first analysis of fermionic quasinormal modes in this novel 4D Einstein-Gauss-Bonnet gravity theory.

Findings

Real part of quasinormal modes increases with coupling constant.

Damping rate generally decreases as the coupling constant grows.

Results obtained using 6th order WKB method with Padé approximants and time-domain analysis.

Abstract

While quasinormal modes of bosonic fields for the non-trivial $4$-dimensional Einstein-Gauss-Bonnet theory of gravity suggested in [D.~Glavan and C.~Lin, Phys.\ Rev.\ Lett.\ {\bf 124}, 081301 (2020)] have been recently studied, there is no such study for fermionic fields. Here we calculate quasinormal modes of the Dirac field for spherically symmetric asymptotically flat black hole in this novel $4D$ Einstein-Gauss-Bonnet theory. The values of the quasinormal frequencies, calculated by the 6th order WKB method with Pad\'{e} approximants and the time-domain integration, show that the real part of the quasinormal modes is considerably increased, while the damping rate is usually decreasing when the coupling constant is growing.