Kinematically Blocked Curvaton

In this paper, we investigate the idea that the decay of a curvaton is kinematically blocked and show that the coupling constant for curvaton decay can be as large as $\mathcal{O}(1)$. We also find in this case the lower bound of the Hubble parameter at horizon exit from big bang nucleosynthesis (BBN) is H* ≳ 7.2 × 10-9MP ~ 1010GeV. Similar to conventional curvaton scenario, the nonlinear parameter can be as large as fNL = 100.