Introducing the Random Phase Approximation Theory

Round 1

Reviewer 1 Report

This manuscript reviews the three main methods to derive the Random Phase Approximation (RPA), namely the Equation of Motion, the Green’s function and the time-dependent Hartree–Fock theory. Each approach emphasizes specific aspects of the theory overlooked by the other methods.
Extensions of the RPA secular equations to treat the continuum part of the excitation spectrum and also the pairing interaction are presented.
Theoretical approaches which extend the standard approximations of the RPA, like 2p-2h approach and correlated RPA, are outlined.
The paper is a good introduction to this many-body approach, giving all technical details of the derivations. It is clearly written and therefore I recommend its publication as a review paper, after the Author will take care on
the following remarks:
1) The main extension connected to Pauli principle is given by the so-called
renormalized RPA, where the commutation relations between RPA generators are satisfied as mean values on the RPA vacuum. The corresponding RPA system is similar to (274), where M is the normalization matrix. A special chapter on this important issue should be added.
2) Recently a review paper on this subject was published in Physics Reports 929 (2021) 1 and it should also be mentioned.

Author Response

I corrected the paper following the remarks. Thank you for pointing out issues and reference which I overlooked

Reviewer 2 Report

In this article, the author does an excellent review of the random phase approximation theory in Nuclear Physics. I highly recommend its publication, after the minor revision indicated in the document attached.

Comments for author File: Comments.pdf

Author Response

I corrected the manuscript following the indication. Thank you for pointing out issues and details which I overlooked.

Round 2

Reviewer 1 Report

The Author properly answered my remarks and therefore

I recommend the manuscript for publication.