Kinematically Blocked Curvaton

Abstract

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 ${\cal O}(1)$. We also find in this case the lower bound of the Hubble parameter at horizon exit from big bang nucleosynthesis (BBN) is H_\ast \gae 7.2 \times 10^{-9}M_P \sim 10^{10} {GeV}. Similar to conventional curvaton scenario, the nonlinear parameter can be as large as $f_{NL}=100$.Comment: 6 pages, 2 figures, 2 tables; typos corrected, accepted for publication in MPL