Cosmological Constant in SUGRA Models with Degenerate Vacua

Round 1

Reviewer 1 Report

 See the report file. No other specific comments. 

Comments for author File: Comments.pdf

Author Response

We would like to thank this referee for the careful reading our article and positive comments on our manuscript.

Reviewer 2 Report

I have read this manuscript on estimating the value of the cosmological constant in the physical phase of the SUGRA theory under consideration.

The authors mention that this is a kind of review, they say: "In this paper we review the results of the implementation of the MPP [Multiple Point Principle] in the (N = 1) SUGRA models and examine the dependence of the dark energy density".

In my opinion, as a review paper the contextualization of the work is low and the level of description is insufficient. The abstract is too short, for instance, for a paper purportedly revising a subject. In fact, the authors have written several other papers on these matters and they are reviewing the main results. However I cannot see a lot of effort in doing it. Moreover, it is not even clear to me if there is a single one new result in this new work on the subject or just a list of old results.  I cannot see that they clarify this point, if only to inform the reader in a more transparent way.  If this paper is to be part of an special issue devoted to the cosmological constant problem, I cannot see how a reader interested in looking at different points of view on this subject can find very useful this paper without a more comprehensive description of the framework of these investigations.  My main two questions are: does this paper contributes to help the reader on this task minimally, namely does it provide complementary information beyond the already existing works of the authors on these matters? And (as I said), is there any new result here?  From what I have seen, I would say that he answer to these two questions is probably negative in both cases.  Maybe the authors would like to add something to convince this referee that it is not the case. But in any case I think that the paper should be improved as a review paper.  The manuscript does not even contain a specific section for Conclusions. I think that this is not admissible for any serious research paper and much less for a review paper where at least a summary of the consolidated results must be provided.

I should also note that the estimation of the vacuum energy density based on these SUGRA models is based on assumed that the vacua are degenerate to extremely high accuracy (as the authors themselves recognize). It does not seem to me that this is a natural solution to the cosmological constant (CC) problem. In fact, it is nothing but the consuetudinary fine tuning problem existing in SUGRA theories trying to solve the CC problem since eons ago. I do not see that the authors improve at all the situation.  I am not saying that this is a reason for rejecting the paper, I am saying that it does not add anything new at all to what is already known on this subject since many years. Otherwise, please disprove me. If they cannot disprove me (or even if they can),  they should at least make some more significant effort to explain what is the framework and the situation of SUGRA with the CC problem.  It is probably as hopeless as ever.  Some more pedagogical effort is the minimum to be demanded for a review paper, isn't it? So, please, do some extra effort in the benefit of the readers.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

This is an interesting paper which proposes a way to understand the measured value of the cosmological constant. It develops previous work by the same authors and is based on the curious but intriguing idea that the values of the coupling constants in a physical theory are fixed such that two or more vacua are exactly degenerate for those values. This receives support from the observed Higgs and top masses. Here, this idea is used to "transmit" a non-perturbatively small value of the vacuum energy due to dynamical supersymmetry breaking in one vacuum in a SUGRA theory to our vacuum. The basic idea is worked through in great detail and the paper is very thorough. I recommend it should be published in its present form.

Author Response

We would like to thank this referee for the careful reading our article and positive comments on our manuscript.