Tidal Deformability of Neutron Stars in Unimodular Gravity

Round 1

Reviewer 1 Report

review of "Tidal Deformability of Neutron Stars in Unimodular Gravity"

 

reviewers comments:

i) please explain the subscripts and superscripts on P and Q in equation 29

ii) line 116: It would help to recall that k is defined in equation 15.

 

minor changes:

line 31 "vacuum"

line 45 "stellar"

lines 101-102 plugging -> substituting

line 104 since -> because

Author Response

Thanks a lot for your kind recommendation and constructive comments.

Please see the attachment for the detailed response to your comments.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments for author File: Comments.pdf

Author Response

Thanks a lot for your helpful and constructive comments.

Please see the attachment for the detailed response to your comments.

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper is an interesting study of neutron stars deformation using unimodular gravity, allowing to implement external forces in terms of a non-conservation of the energy-momentum tensor. Theoretical approach and its background are well described. As an application, numerical studies of the tidal deformability of neutron stars are presented where a simple polytrope model is used. A central result is that within the chosen approach the recent observations of neutron stars seem to favor negative divergencies of the energy-momentum tensor. The tidal Love numbers of electric- and magnetic-type tidal modes are studied and found to behave significantly different from former results, obtained under different theoretical conditions. The authors point out correctly that these results impose interesting demands for the next generation of gravitational wave detectors. The paper qualifies for publication.

Supplementary:

The paper is an interesting study of neutron stars deformation using unimodular gravity, allowing to implement external forces in terms of a non-conservation of the energy-momentum tensor. The theoretical approach and its background are well described. As an application, numerical studies of the tidal deformability of neutron stars are presented where a simple polytrope  model is used. A central result is that within the chosen approach the recent observations of neutron stars seem to favor negative divergencies of the energy-momentum tensor. The tidal Love numbers of electric- and magnetic-type tidal modes are studied and found to behave significantly different from former results, obtained under different theoretical conditions. The authors point out correctly that these results impose interesting demands for the next generation of gravitational wave detectors.

The paper qualifies for publication. 

 

Author Response

Thank you very much for the kindly recommendation.

Round 2

Reviewer 2 Report

The value of parameter k is described in line 125 on page 6, but the validity is still questionable, because it is exactly zero  in the Einstein gravity.