TY - JOUR
T1 - Intergalactic magnetic fields from first-order phase transitions
AU - Ellis, John
AU - Fairbairn, Malcolm
AU - Lewicki, Marek
AU - Vaskonen, Ville
AU - Wickens, Alastair
PY - 2019/9/11
Y1 - 2019/9/11
N2 - We study the generation of intergalactic magnetic fields in two models for first-order phase transitions in the early Universe that have been studied previously in connection with the generation of gravitational waves (GWs): the Standard Model supplemented by an |H|6 operator (SM+H6) and a classically scale-invariant model with an extra gauged U(1) B - L symmetry (SMB-L). We consider contributions to magnetic fields generated by bubble collisions and by turbulence in the primordial plasma, and we consider the hypotheses that helicity is seeded in the gauge field or kinetically. We study the conditions under which the intergalactic magnetic fields generated may be larger than the lower bounds from blazar observations, and correlate them with the observability of GWs and possible collider signatures. In the SM+H6 model bubble collisions alone cannot yield large enough magnetic fields, whereas turbulence may do so. In the SMB-L model bubble collisions and turbulence may both yield magnetic fields above the blazar bound unless the B-L gauge boson is very heavy. In both models there may be observable GW and collider signatures if sufficiently large magnetic fields are generated.
AB - We study the generation of intergalactic magnetic fields in two models for first-order phase transitions in the early Universe that have been studied previously in connection with the generation of gravitational waves (GWs): the Standard Model supplemented by an |H|6 operator (SM+H6) and a classically scale-invariant model with an extra gauged U(1) B - L symmetry (SMB-L). We consider contributions to magnetic fields generated by bubble collisions and by turbulence in the primordial plasma, and we consider the hypotheses that helicity is seeded in the gauge field or kinetically. We study the conditions under which the intergalactic magnetic fields generated may be larger than the lower bounds from blazar observations, and correlate them with the observability of GWs and possible collider signatures. In the SM+H6 model bubble collisions alone cannot yield large enough magnetic fields, whereas turbulence may do so. In the SMB-L model bubble collisions and turbulence may both yield magnetic fields above the blazar bound unless the B-L gauge boson is very heavy. In both models there may be observable GW and collider signatures if sufficiently large magnetic fields are generated.
KW - cosmological phase transitions
KW - cosmology of theories beyond the SM
KW - primordial magnetic fields
UR - http://www.scopus.com/inward/record.url?scp=85074365369&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2019/09/019
DO - 10.1088/1475-7516/2019/09/019
M3 - Article
AN - SCOPUS:85074365369
SN - 1475-7516
VL - 2019
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
IS - 9
M1 - 019
ER -