The spectrum of primordial gravitational waves is one of the most robust
inflationary observables, often thought of as a direct probe of the energy
scale of inflation. We present a simple model, where the dynamics controlling
this observable is very different than in the standard paradigm of inflation.
The model is based on a peculiar finite density phase---the magnetic
gaugid---which stems from a highly non-linear effective theory of a triplet of
abelian gauge fields. The gaugid extends the notion of homogeneous isotropic
solid, in that its spectrum of fluctuations includes helicity-2 phonons. We
show how, upon implementing the gaugid to drive inflation, the helicity-2
phonon mixes with the graviton, significantly affecting the size of the
primordial tensor spectrum. The rest of the features of the theory, in
particular the vector and scalar perturbations, closely resemble those of solid
inflation.Comment: 35+8 page
