Magnetic fields from QCD phase transitions
2012 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 759, no 1, 54- p.Article in journal (Refereed) Published
We study the evolution of QCD phase transition-generated magnetic fields (MFs) in freely decaying MHD turbulence of the expanding universe. We consider an MF generation model that starts from basic non-perturbative QCD theory and predicts stochastic MFs with an amplitude of the order of 0.02μG and small magnetic helicity. We employ direct numerical simulations to model the MHD turbulence decay and identify two different regimes: a "weakly helical" turbulence regime, when magnetic helicity increases during decay, and "fully helical" turbulence, when maximal magnetic helicity is reached and an inverse cascade develops. The results of our analysis show that in the most optimistic scenario the magnetic correlation length in the comoving frame can reach 10kpc with the amplitude of the effective MF being 0.007nG. We demonstrate that the considered model of magnetogenesis can provide the seed MF for galaxies and clusters.
Place, publisher, year, edition, pages
2012. Vol. 759, no 1, 54- p.
early universe, magnetic fields
IdentifiersURN: urn:nbn:se:kth:diva-107252DOI: 10.1088/0004-637X/759/1/54ISI: 000310566900054ScopusID: 2-s2.0-84868132817OAI: oai:DiVA.org:kth-107252DiVA: diva2:576866
FunderEU, European Research Council, 227952Swedish Research Council, 621-2007-4064
QC 201212142012-12-142012-12-102013-08-28Bibliographically approved