Speaker
Description
The Gibbons-Maeda-Garfinkle-Horowitz-Strominger (GMGHS)
black hole is an influential solution of the low energy heterotic
string theory. As it is well known, it presents a singular extremal
limit. We construct a regular extension of the GMGHS extremal black
hole in a model with $\mathcal{O}(\alpha')$ corrections in the action,
by solving the fully non-linear equations of motion. The
de-singularization is supported by the $\mathcal{O}(\alpha')$-terms.
The regularised extremal GMGHS BHs are asymptotically flat, possess a
regular (non-zero size) horizon of spherical topology, with an
$AdS_2\times S^2$ near horizon geometry, and their entropy is
proportional to the electric charge. The near horizon solution is
obtained analytically and some illustrative bulk solutions are
constructed numerically.
