This title appears in the Scientific Report :
2016
Please use the identifier:
http://dx.doi.org/10.1016/j.physletb.2015.11.020 in citations.
Please use the identifier: http://hdl.handle.net/2128/9743 in citations.
Axion cosmology, lattice QCD and the dilute instanton gas
Axion cosmology, lattice QCD and the dilute instanton gas
Axions are one of the most attractive dark matter candidates. The evolution of their number density in the early universe can be determined by calculating the topological susceptibility χ(T)χ(T) of QCD as a function of the temperature. Lattice QCD provides an ab initio technique to carry out such...
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Personal Name(s): | Borsanyi, Sz. |
---|---|
Dierigl, M. / Fodor, Z. / Katz, S. D. (Corresponding author) / Mages, Simon / Nogradi, D. / Redondo, J. / Ringwald, A. / Szabo, Kalman | |
Contributing Institute: |
John von Neumann - Institut für Computing; NIC Jülich Supercomputing Center; JSC |
Published in: | Physics letters / B, 752 (2016) S. 175 - 181 |
Imprint: |
Amsterdam
North-Holland Publ.
2016
|
DOI: |
10.1016/j.physletb.2015.11.020 |
Document Type: |
Journal Article |
Research Program: |
Axion cosmology and the topological susceptibility at finite temperature Computational Science and Mathematical Methods |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/9743 in citations.
Axions are one of the most attractive dark matter candidates. The evolution of their number density in the early universe can be determined by calculating the topological susceptibility χ(T)χ(T) of QCD as a function of the temperature. Lattice QCD provides an ab initio technique to carry out such a calculation. A full result needs two ingredients: physical quark masses and a controlled continuum extrapolation from non-vanishing to zero lattice spacings. We determine χ(T)χ(T) in the quenched framework (infinitely large quark masses) and extrapolate its values to the continuum limit. The results are compared with the prediction of the dilute instanton gas approximation (DIGA). A nice agreement is found for the temperature dependence, whereas the overall normalization of the DIGA result still differs from the non-perturbative continuum extrapolated lattice results by a factor of order ten. We discuss the consequences of our findings for the prediction of the amount of axion dark matter. |