GEMS Embeddings of Schwarzschild and RN Black Holes in Painlevé-Gullstrand Spacetimes

Round 1

Reviewer 1 Report

Report:  GEMS embeddings of Schwarzschild and RN black holes in Painlevé-Gullstrand spacetimes.

Using Painlevé-Gullstrand coordinates, the authors have globally embedded the (3+1)-dimensional Schwarzschild and RN black holes into (5+1) and (5+2) dimensional flat spacetimes. The novel approach of the authors using GP coordinates has shown that freely falling temperatures in these spacetimes are well defined beyond the event horizons, while preserving the usual meaning for static observers.

The paper is well written and the problem at hand is interesting and the results are clearly presented, thus I consider the paper is suitable to be published in its present form in Universe.

 

Author Response

We would like to thank the referee very much.

Reviewer 2 Report

This ms suggests the embedding of four-dimensional BHs to higher-dimensional flat spacetime. It is totally unclear the motivation for such study. What physical problem maybe solved in this way? Surely, same 4d BH maybe embedded to different higher-dimensional spacetime. What for this procedure is good? At least, if it is related with superstring compactification it may have some sense. It does not look also that this embedding may give any novel science, while perhaps it may simplify some calculations which may still be done without knowing of any higher-dimensional embedding. In summary, this is technical ms which does not add much to our knowledge of BHs.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

sufficient revision