6 research outputs found
Probing the inflationary particle content: extra spin-2 field
We study how inflationary observables associated with primordial tensor modes
are affected by coupling the minimal field content with an extra spin-2
particle during inflation. We work with a model that is ghost-free at the fully
non-linear level and show how the new degrees of freedom modify standard
consistency relations for the tensor bispectrum. The extra interacting spin-2
field is necessarily massive and unitarity dictates its mass be in the range. Despite the fact that this bound selects a decaying solution
for the corresponding tensor mode, cosmological correlators still carry the
imprints of such "fossil" fields. Remarkably, fossil(s) of spin
generate distinctive anisotropies in observables such as the tensor power
spectrum. We show how this plays out in our set-up.Comment: 25 pages, 3 figure