%0 Journal Article
%@ 1079-7114
%A Price, LC
%A Peiris, HV
%A Frazer, J
%A Easther, R
%D 2015
%F discovery:1467847
%I AMER PHYSICAL SOC
%J Physical Review Letters
%K Science & Technology, Physical Sciences, Physics, Multidisciplinary, Physics, FLUX COMPACTIFICATIONS
%T Gravitational Wave Consistency Relations for Multifield Inflation
%U https://discovery.ucl.ac.uk/id/eprint/1467847/
%V 114
%X We study the tensor spectral index   n  t   and the tensor-to-scalar ratio   r   in the simplest multifield extension to single-field, slow-roll inflation models. We show that multifield models with potentials   V  ∼  ∑  i  λ  i  |  ϕ  i  |  p   have different predictions for   n  t  /  r   than single-field models, even when all the couplings are equal   λ  i  =  λ  j  , due to the probabilistic nature of the fields’ initial values. We analyze well-motivated prior probabilities for the   λ  i   and initial conditions to make detailed predictions for the marginalized probability distribution of   n  t  /  r  . With   O  (  100  )   fields and   p  >  3  /  4  , we find that   n  t  /  r   differs from the single-field result of   n  t  /  r  =  −  1  /  8   at the   5  σ   level. This gives a novel and testable prediction for the simplest multifield inflation models.
%Z This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.