%I AMER PHYSICAL SOC
%L discovery1467847
%J Physical Review Letters
%T Gravitational Wave Consistency Relations for Multifield Inflation
%A LC Price
%A HV Peiris
%A J Frazer
%A R Easther
%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
|
Ï•
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.
%K Science & Technology, Physical Sciences, Physics, Multidisciplinary, Physics, FLUX COMPACTIFICATIONS
%O This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
%D 2015
%V 114