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Virial expansion coefficients in the unitary Fermi gas
by Shimpei Endo
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Submission summary
| Authors (as registered SciPost users): | Shimpei Endo |
| Submission information | |
|---|---|
| Preprint Link: | scipost_201910_00037v1 (pdf) |
| Date submitted: | 2019-10-24 02:00 |
| Submitted by: | Endo, Shimpei |
| Submitted to: | SciPost Physics Proceedings |
| Proceedings issue: | 24th European Few Body Conference (EFB2019) |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approach: | Theoretical |
Abstract
Virial expansion is widely used in cold atoms to analyze high temperature strongly correlated many-body systems. As the n-th order virial expansion coefficient can be accurately obtained by exactly solving up to n-body problems, the virial expansion offers a few-body approach to study strongly correlated many-body problems. In particular, the virial expansion has successfully been applied to unitary Fermi gas. We review recent progress of the virial expansion studies in the unitary Fermi gas, in particular the fourth order virial coefficient.
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Reports on this Submission
Anonymous Report 1 on 2019-12-12 (Invited Report)
- Cite as: Anonymous, Report on arXiv:scipost_201910_00037v1, delivered 2019-12-12, doi: 10.21468/SciPost.Report.1389
Report
The author reviews the study of virial expansion in a unitary Fermi gas.
The general background of the virial expansion is clearly explained in the connection with few-body and many-body physics.
I recommend the publication of this article after addressing following issues.
1) In the introduction, the author mentions that a unitary Fermi gas is relevant for understanding neutron stars.
I think that more detailed explanation with some references is required because the system scales are quite different between these two systems.
While the scattering length in cold atoms is generally the order of nano(or micro)-meters, the neutron-neutron scattering length is -18.5 femto-meters.
2) Since the virial expansion itself cannot directly be applied to neutron star physics where the temperature is quite low, I suggest the author additionally refer to the supernova matter at finite temperature.
In Phys. Rev. C 96, 055804 (2017), a neutrino-nucleon scattering properties have been derived from the 4th virial expansion of a unitary Fermi gas.
3) I think that Eqs. (2)-(4) for the virial equation of state should explicitly involve the 4-th order coefficient b_4 since in the latter part the author reviews b_4.