DeWitt Boundary Condition in One-Loop Quantum Cosmology
Round 1
Reviewer 1 Report
The paper provides a detailed overview of various approaches developed in the literature on quantum gravity and quantum cosmology to study the possible quantum origin of spacetime geometry, particularly in relation to one-loop effects in the early universe. The authors explore the relevance of these approaches for the singularity issue in cosmology, including the behavior of the wave function of the universe in correspondence with classical big-bang singularity. The paper also reviews various concepts of singularity that have been conceived over many years. The paper is also well-written and provides a comprehensive review of existing research on quantum cosmology and singularity issues. I recommend this paper for publication in Universe.
Author Response
I am glad my paper has been appreciated.
Reviewer 2 Report
I think this work of interest. Unfortunately, at present time the only one-loop quantum gravity is possible to employ to investigate the de Witt's idea which leaves many questions unanswered. However, in the frame of one-loop this work is of iterest, definitely.
Author Response
I am glad my work is of interest.
Reviewer 3 Report
The paper is devoted to analysis of De Witt's suggestion that the universe wave function vanishes at the big bang singularity. This assumption is considered in the framework of the one loop quantum gravity with the use of the dzeta function formalism. The main and distinguished result of the paper is that in the one loop approximation the wave function approaches zero when the 3 sphere boundary tends to zero. This property means that the resulting one-loop wave function fulfills De Witt's assumption.
This is a very nice and inspiring paper and it certainly should be published in the Universe as it is now.
Author Response
I am glad my paper has been recommended for publication.
Reviewer 4 Report
See attached file
Comments for author File: 
Comments.pdf
Author Response
this is what I have done in order to improve my paper: (i) The concept of zeta(0) is now clearly defined in Section 2 and in the Appendix. The Appendix was missing in my original submission, and it helps also in reaching the desired length. (ii) The magnetic curvature has been defined before Eq. (2.6) (iii) My reply: the position of indices in Eq. (2.2) was and is correct. (iv) The origin of relation (2.8) has been sketched immediately after (2.8). (v) Two references, after references to Witten's papers, have been added. In section 2, the text added occurs on the line before (2.5), on the line after (2.5), on the line before (2.6), and on the line after (2.8).