Three-Dimensional Quantum Black Holes: A Primer

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript attempts to overview the current research on the three-dimensional "Quantum" black holes arising from the holographic braneworld by considering the higher-derivative theory of gravity coupled with quantum field theory to include all semi-classical backreations. The second goal of the manuscript is to review the applications of holographic quantum black holes, such as the study of semi-classical horizon thermodynamics, holographic entanglement entropy, complexity, and probing the black hole singularities.

The topic studies the holographic braneworld and is very relevant to the Gravity Section. It tries to overview the current understanding of 3-D "quantum" black holes and highlight its possible applications to advance the understanding the semi-classical/quantum gravity.

Moreover, firstly, it overviews a wide range of research on three-dimensional quantum black holes, especially those arising from holographic braneworlds. Secondly, it delves deep into the unique quantum effects and singularities associated with 3-D black holes, offering new perspectives on how these quantum aspects influence black hole behavior and potentially probe classical singularities. It also points out future research directions and open questions, encouraging further exploration and development in the field.

The current draft is good. The paper is well-written and the conclusions are solidly driven. I don't find any inappropriate citations.

Fig A.1 on page 93, Both figures are missing the labels for the horizontal and vertical axis. So it is unclear what does it mean.

Overall I found this manuscript is well organized and written in a clear manner to review a wide range of many advanced topics covering gravity, black hole theory, and holograph braneworld.

Author Response

We thank the referee for their feedback and helpful comments. Below we respond to their single comment.

Comment 1: "Fig A.1 on page 93, Both figures are missing the labels for the horizontal and vertical axis. So it is unclear what does it mean."

It is convention to have no axes for either of the left and right figures on Fig A.1. However, to clarify the figure further, in the caption we have added additional description concerning the left figure. Specifically, we now write: "Bulk AdS with a `horosphere' (red curve), and horizon at $y=\infty$ (diagonal lines). Vertical lines represent timelike infinity." This indicates to the reader (as with many Penrose diagrams) that time runs vertically whilst the radial coordinate (in this case y) runs horizontally. Meanwhile, the right figure in Fig. A.1 is akin to previous figures concerning braneworld constructions, e.g., the two-branes in Fig. 16.

 

We thank the referee again for their positive and useful feedback.

Reviewer 2 Report

Comments and Suggestions for Authors

This an excellent review of three-dimensional "quantum black holes", classical solutions of braneworld models that correspond to backreacted semiclassical solutions in the context of holography. The authors have done an excellent job in presenting a comprehensive, accessible, and clear introduction to the subject. I recommend publication of the manuscript as is.

Author Response

We thank the referee for their positive feedback.

Reviewer 3 Report

Comments and Suggestions for Authors

Comments for author File: Comments.pdf

Author Response

We thank the referee for their positive feedback and helpful comments. Let us now respond to their few comments.

Comment 1:  "Equation (297) and (298), it is better to add the brace {…} between `min` and
`ext` on page 77."

We agree, and have since added an additional brace {...} between the min and ext for both equations.

Comment 2: "Typo: In the Author Contributions on page 81, `tis` should be `this`."

We have since corrected this typo.

Comment 3: "Since this review is rather long, it is better to list the contents in the front of the
paper."

We agree. On our end, the table of contents do appear at the front of the submittted manuscript. We will check with the editorial staff prior to completion that indeed the table of contents appear at the beginning of the document.

We thank the referee again for their helpful feedback.