Damour–Solodukhin Wormhole as a Black Hole Mimicker: The Role of Observers’ Location

Round 1

Reviewer 1 Report

Dear Authors,

 

I have carefully read your paper “Damour-Solodukhin wormhole as black hole mimicker: The role of observers’ location”. The work deals with the Damour-Solodukhin (DS) wormhole (WH) metric, containing a parameter \lambda\neq0, which is responsible to detect deviations from the Schwarzschild black hole (BH) geometry. The mean idea is in proposing a strategy to disentangle between a BH and WH through the detection of photon motion. The method relies upon the Tangherlini formalism, where a probabilistic approach is employed. Quantitatively, this analysis is carried out via the Fresnel reflection and transmission coefficients calculated by asymptotical and local observers.

 

The work is interesting and contains some potential new ideas, however the presentation of the contents, the methodology, and the outcomes of your analysis necessitates of a major revision, because in my opinion there are some important points that there are not clearly explained. In addition, I would recommend the authors to review the English style. Please also define the acronyms and substitute everywhere in the text. Below I report my comments.

 

1. Introduction

1. I would introduce more clearly the DS WH spacetime, since it represents the main focus of the article;
2. It is not described what is a WH. I would suggest to write just one/two sentences on this class of exotic objects;
3. WHs, as well as BHs, are not only solutions of Einstein equations, because they could be potential solutions of Extended and Alternative Theories of gravity. In the text, it is barely mentioned. This is also a crucial point, that should be explained.
4. The concept of BH mimicker is fundamental and should be defined when it is mentioned for the first time.
5. Tangherlini’s idea of non-quantum indeterminacy in the ordinary optical medium is not clearly explained. The main ideas are confusingly sketched.

 

2. Tangherlini’s formulation of R and T

6. I would better explain the hypotheses behind the Tangherlini’s formalism.
7. The introduction of the refractive index n(r) should be better motivated, because it is not clear from the text.
8. The concept of asymptotic and local observers should be motivated from a physical point of view. I can understand that asymptotic observers coincide with our instrumentations and observations; instead observers close to the WH throat or BH event horizon, who plays the role of such observers?

 

3. Application to Damour-Solodukhin wormhole

9. Can this experiment be realized from a physical point of view? In other words, how can one detect the coefficients R and T? This is very useful to validate the theory and making the method more appealing and interesting.
10. I would make a plot of the coefficients R and T with respect the two observers letting the \lambda parameter varying. This will allow to understand for which range of \lambda the analysis will give a BH or a WH.

 

4. Conclusions

11. In the conclusions it is missing that this analysis is biased by the fact that we are assuming a model for a WH, which we do not know whether it is valid, because observationally it has been not proved, at the contrary of the BH Schwarzschild spacetime. I would comment on possible extensions of the method to other more general frameworks.
12. I would discuss also the possibility in how to make this strategy astrophysically feasible. What are the criticalities and challenges of such an approach?

Author Response

The responses to the questions of the reviewer are in the attached file

Author Response File: Author Response.pdf

Reviewer 2 Report

The main question posed in the article is to what extend Damour wormhole object resembles the black hole. The authors used the interesting tool (Fresnel reflection and transition coefficient derived by Tangherlini in 1975) to investigate the problem. They obtained that the coefficients had no dependence on the mass of the object and that for the same value of the parameter \lambda it could be seen like a wormhole or black hole by different observers. The results are interesting and in my opinion they deserve publishing.

But in order to give a more complete view of the problem considering distinguishing between black hole and wormhole, the author should consider to mention in the introduction:

1.the works concerning with Kerr-like Damour wormholes (e.g., S.Kasuyua et al.Phys.Rev.D 103,104050 (2021), B.Kiczek et al., Eur.Phys.J.C 82, 586 (2022),M. Amir et al. Class.Quantum Grav.36, 215007 (2019). )

They also propose to distinguish between these objects by different methods.

 

 

 

Author Response

We thank the referee for his/her appreciative comments and for pointing out recent useful works relevant to the Kerr-like Damour WHs that have now been included.

Round 2

Reviewer 1 Report

Dear Authors,

I have read the new version of  your paper. I am very satisfied about the reply you have provided and the improvements you have introduced in your article. Therefore, I accept your paper for publication.