Eur. Phys. J. C (2012) 72: 1978
https://doi.org/10.1140/epjc/s10052-012-1978-1

Regular Article - Theoretical Physics

Large-scale magnetic fields from inflation due to a CPT-even Chern–Simons-like term with Kalb–Ramond and scalar fields

¹ Department of Physics, National Tsing Hua University, Hsinchu, 300, Taiwan
² Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya, 464-8602, Japan
³ Eurasian International Center for Theoretical Physics, Eurasian National University, Astana, 010008, Kazakhstan
⁴ Physics Division, National Center for Theoretical Sciences, Hsinchu, 300, Taiwan
⁵ Institute of Physics, National Chiao Tung University, Hsinchu, 300, Taiwan
⁶ Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA

^* e-mail: bamba@kmi.nagoya-u.ac.jp

Received: 10 March 2012
Revised: 23 March 2012
Published online: 18 April 2012

Abstract

We investigate the generation of large-scale magnetic fields due to the breaking of the conformal invariance in the electromagnetic field through the CPT-even dimension-six Chern–Simons-like effective interaction with a fermion current by taking account of the dynamical Kalb–Ramond and scalar fields in inflationary cosmology. It is explicitly demonstrated that magnetic fields on 1 Mpc scale with the field strength of ∼10⁻⁹ G at the present time can be induced.