Key points are not available for this paper at this time.
We study the generation of helical magnetic fields in a model of inflationary magnetogenesis which is free from the strong coupling and backreaction problems. To generate helical magnetic fields, we add an f^2{F}^F_ term to the Lagrangian of the Ratra model. The strong coupling and backreaction problems are avoided if we take a particular behavior of coupling function f, in which f increases during inflation and decreases postinflation to reheating. The generated magnetic field is fully helical and has a blue spectrum, d₁/dlnkk^4. This spectrum is obtained when coupling function fa^2 during inflation. The scale of reheating in our model has to be lower than 4000 GeV to avoid backreaction postinflation. The generated magnetic field spectrum satisfies the -ray bound for all the possible scales of reheating. The comoving magnetic field strength and its correlation length are 410^-11 G and 70 kpc respectively, if reheating takes place at 100 GeV. For reheating at the QCD scales of 150 MeV, the field strength increases to nano gauss, with coherence scale of 0. 6 Mpc.
Sharma et al. (Wed,) studied this question.