1112.1581 (Ivan Agullo et al.)

Enhanced local-type inflationary trispectrum from a non-vacuum initial
state    [PDF]

Ivan Agullo, Jose Navarro-Salas, Leonard Parker

We compute the primordial trispectrum for curvature perturbations produced
during cosmic inflation in models with standard kinetic terms, when the initial
quantum state is not necessarily the vacuum state. The presence of initial
perturbations enhances the trispectrum amplitude for configuration in which one
of the momenta, say $k_3$, is much smaller than the others, $k_3 \ll
k_{1,2,4}$. For those squeezed configurations the trispectrum acquires the
so-called local form, with a scale dependent amplitude that can get values of
order $ \epsilon ({k_1}/{k_3})^2$. This amplitude can be larger than the
prediction of the so-called Maldacena consistency relation by a factor $10^6$,
and can reach the sensitivity of forthcoming observations, even for
single-field inflationary models.

View original: http://arxiv.org/abs/1112.1581