home > programme

Magnetogenesis from Rotating Cosmic String Loops

Thorsten Battefeld (DAMTP Cambridge University)
03 July 2007, 14:30 - 16:15

Primordial magnetic seed fields are needed in order to explain the presence of large scale magnetic fields in galaxies and clusters today. However, it is difficult to generate them in simple models of inflation. In this talk, we investigate a cosmic string network in the matter era, more precisely the loops in the network. Given a rotating loop of suitable large size, we show that part of its angular momentum can be transfered to the surrounding plasma by gravitational dragging. The resulting vortex can cause suitable magnetic seed fields via the Harrison/Rees mechanism, improving upon models based on turbulent effects in the wake of strings.
Battefeld.pdf [557 KBytes]