https://doi.org/10.1140/epjp/i2015-15230-2
Regular Article
Rindler approximation to Kerr-Newman black hole
1
Facultad de Ciencias, Universidad Nacional Autónoma de México Circuito Exterior, Ciudad Universitaria, 04510, México D.F., Mexico
2
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México Circuito Exterior, Ciudad Universitaria, 04510, México D.F., Mexico
* e-mail: socolovs@nucleares.unam.mx
Received:
30
August
2015
Accepted:
15
October
2015
Published online:
19
November
2015
We show that the Rindler approximation to the time-radial part of the Kerr and Kerr-Newman metrics near their external 
and internal 
horizons only holds outside
and inside
, so respectively inside and outside the external and internal ergospheres, regions where, in Boyer-Lindquist coordinates, both 
and 
are negative, but preserving the Lorentzian character of the metric, and 
i.e. outside the region 
where closed timelike curves exist. At each point, the choice of Rindler coordinates is not trivial, but depends on the polar angle 
. The approximation, as is known, automatically gives the absolute values of the surface gravities 
as the corresponding proper accelerations, and therefore the Hawking temperatures 
at 
.
© Società Italiana di Fisica and Springer-Verlag Berlin Heidelberg, 2015
