E- and T-model hybrid inflation

Abstract

AbstractWe consider the impact of a kinetic pole of order one or two on the non-supersymmetric model of hybrid inflation. These poles arise due to logarithmic Kähler potentials which control the kinetic mixing of the inflaton field and parameterize hyperbolic manifolds with scalar curvature related to the coefficient $$(-N)<0$$ ( - N ) < 0 of the logarithm. Inflation is associated with the breaking of a local $$SU(2)\times U(1)$$ S U ( 2 ) × U ( 1 ) symmetry, which does not produce any cosmological defects after it, and remains largely immune from the minimal possible radiative corrections to the inflationary potential. For $$N=1$$ N = 1 and equal values of the relevant coupling constants, $$\lambda $$ λ and $$\kappa $$ κ , the achievement of the observationally central value for the scalar spectral index, $$n_{\textrm{s}}$$ n s , requires the mass parameter, m, and the symmetry breaking scale, M, to be of the order of $$10^{12}~{\textrm{GeV}}$$ 10 12 GeV and $$10^{17}~{\textrm{GeV}}$$ 10 17 GeV respectively. Increasing N above unity the tensor-to-scalar ratio r increases above 0.002 and reaches its maximal allowed value for $$N\simeq 10{-}20$$ N ≃ 10 - 20 .