Gravitational wave backgrounds and the cosmic transition from Population
  III to Population II stars
  Using the results of a numerical simulation which follows the evolution,
metal enrichment and energy deposition of both Population III and Population II
stars, we predict the redshift dependence of the formation rate of black hole
remnants of Population III stars with masses 100- 500Msun and of neutron
stars(black holes) remnants of Population II stars with masses 8-20Msun
(20-40Msun). We describe the gravitational wave spectrum produced by Population
III and Population II sources adopting the most appropriate signals available
in the literature and we compute the stochastic backgrounds resulting from the
cumulative emission of these sources throughout the history of the Universe.
With the aim of assessing whether these backgrounds might act as foregrounds
for signals generated in the Inflationary epoch, we compare their amplitudes
with the sensitivity of currently planned and future ground/space-based
interferometers.
