Vacuum Effects Induced by a Plate in de Sitter Spacetime in the Presence of a Cosmic String

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Universe-2757178

Vacuum effects induced by a plate in de Sitter spacetime in the presence of a cosmic string

Wagner O. Dos Santos, Eugênio R. R. Bezerra de Mello

 

 

The authors find the vacuum expectation value of the scalar field squared and the energy-momentum tensor induced by a flat boundary perpendicular to the infinitely thin cosmic string in de Sitter spacetime. Although general boundary conditions can be formulated, the closed form can be found for Dirichlet and Neumann boundary conditions. They calculate the above quantum expectation value from the two-point Wightman function, and it is explicitly shown that it can be separated into a divergent part and a finite part, such as de Sitter spacetime only, no cosmic string, etc. The parameter dependence is studied for the expectation values of both the field square and the energy-momentum tensor.

Although there is no urgency to this research in terms of a realistic physical setting, the formulations of authors who are experts in this field (as can be seen from numerous past publications) are accurate, and the calculation method and the formulations mentioned above may be useful somewhere. Therefore, I am happy to recommend this paper for publication. However, although it is not essential to the content, I was concerned about the following. If, after consideration, the authors feel that no corrections are necessary, they may do so.

1. (2.17), this defines a function, but since only k_z is used as an argument, there is no need to write it as a function of x.

2. (4.17) is also a function definition, but it is not used in (4.16) and is probably used for the first time in (5.18), so why not move that location later?

 

Author Response

See attached file

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The article shows that a conical defect of the space-time  enhances the vacuum polarization caused by the presence of a flat boundary. The research was carried out at a good level. However, I have some minor comments.

I think the introduction is missing an important quote, lines 57-58. As far as I know, the Casimir effect for a scalar field in spacetime with two parallel cosmic strings was first considered by M. Bordag  in  Ann. Phys. (Berlin) 47, 93 (1990). See also, J. M. Mu˜noz-Castaneda, M. Bordag, Phys. Rev. D. 89, 6, 065034, (2014).

In all figure captions, please, preplace “left panel” and "right panel" with "top panel" and "bottom panel".

 

 

Author Response

See attached file

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Please, see the report

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Some typos are found

Author Response

See attached file

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Two insignificant remarks. See PDF with report

Comments for author File: Comments.pdf

Comments on the Quality of English Language

There are few typos in the new text.

Author Response

See attached file

Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

Comments and Suggestions for Authors

everything is OK

Comments on the Quality of English Language

I know that MDPI Language Dept. will modify (and propose to modify) a lot. Check carefully their changes, some of them will be inappropriate, and some of them are not visible and not declared in the latex comments