Speaker
Description
In string theory, a natural low energy effective action is the Einstein-Gauss-
Bonnet gravity, in which a Gauss-Bonnet term accompanies the usual Einstein-
Hilbert action. Born-Infeld electrodynamics arises when considering an Abelian
gauge field coupled to the open bosonic string or open superstring. In this talk,
we analyze the superradiant behavior of a massive, charged scalar field coupled to
a spherically symmetric, charged black hole solution within this modified theory
of gravity, and compare it with the classical Reisnner-Nordström solution. We show
how this setup gives rise to a different phenomenology than in the classical case. In
particular, the absorption cross section of a charged scalar field can be unbounded
from below for certain parameter ranges, a phenomenon only studied previously
for the Ayón-Beato-García regular black hole. Lastly, we will determine the presence of superradiant instabilities of the solution, by determining the spectrum of quasi-bound states.