Borsanyi, Sz. and Dierigl, M. and Fodor, Z. and Katz, S. D. and Mages, S. W. and Nogradi, D. and Redondo, J. and Ringwald, A. and Szabo, K. K. (2016) Axion cosmology, lattice QCD and the dilute instanton gas. PHYSICS LETTERS B, 752. pp. 175-181. ISSN 0370-2693, 1873-2445
Full text not available from this repository. (Request a copy)Abstract
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 chi(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 chi(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. (C) 2015 The Authors. Published by Elsevier B.V.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | TOPOLOGICAL SUSCEPTIBILITY; FINITE-TEMPERATURE; PHASE-TRANSITION; INVISIBLE AXION; DENSITY; ORDER; MODEL; ZERO; MASS; Axion dark matter; QCD on the lattice; Instantons |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 18 Mar 2019 12:23 |
| Last Modified: | 18 Mar 2019 12:23 |
| URI: | https://pred.uni-regensburg.de/id/eprint/2548 |
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