https://doi.org/10.1140/epjc/s10052-012-2098-7
Regular Article - Theoretical Physics
Nonsingular black holes in quadratic Palatini gravity
1
Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Universidad de Valencia, Burjassot, 46100, Valencia, Spain
2
Departamento de Física, Universidad de Oviedo, Avenida Calvo Sotelo 18, 33007, Oviedo, Asturias, Spain
* e-mail: rubieradiego@gmail.com
Received:
18
May
2012
Revised:
24
June
2012
Published online:
7
August
2012
We find that if general relativity is modified at the Planck scale by a Ricci-squared term, electrically charged black holes may be nonsingular. These objects concentrate their mass in a microscopic sphere of radius 
, where l
P is the Planck length and N
q
is the number of electric charges. The singularity is avoided if the mass of the object satisfies the condition 
, where m
P is the Planck mass and α
em is the fine-structure constant. For astrophysical black holes this amount of charge is so small that their external horizon almost coincides with their Schwarzschild radius. We work within a first-order (Palatini) approach.
© Springer-Verlag / Società Italiana di Fisica, 2012
