  We analyze the spectrum of gravitational waves generated by the induced
spectrum of tensor fluctuation during warm natural inflation. In our previous
work it has been demonstrated that an epoch of warm natural inflation can lead
to cosmologically relevant dark matter production in the form of primordial
black holes. Here we show that models which solve the dark-matter production
also produce a contribution to the cosmic gravitational wave background that
satisfies current constraints from pulsar timing and big bang nucleosynthesis.
More importantly, this gravitational wave background may be observable in the
next generation of space-based and ground-based gravitational wave
interferometers.
