https://doi.org/10.1140/epjs/s11734-023-01001-5
Regular Article
The smeared-horizon observer of a black hole
Institute for Theoretical Physics, University of Amsterdam, Science Park 904, 1090 GL, Amsterdam, The Netherlands
Received:
24
April
2023
Accepted:
3
October
2023
Published online:
23
October
2023
A class of observers is introduced that interpolate smoothly between the Schwarzschild observer, stable at spatial infinity, and the Kerr–Schild observer, who falls into a black hole. For these observers, the passing of the event and inner horizon takes a finite time, which diverges logarithmically when the interpolation parameter 
goes to zero. In the field theoretic approach to gravitation, the behavior at the horizons becomes regular, making the mass of the metric well defined.
Work dedicated to Igor V. Volovich.
© The Author(s) 2023
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