Direct detection of inflationary gravitational waves

Beyond the B-modes of cosmic microwave background polarization, space-based laser interferometers can also be used to probe the inflationary gravitational wave background at frequencies below 0.001 Hz. There is a significant confusion with such observations related to the removal of merging neutron star binaries at cosmological distances. Given the low merger rate and the rapid evolution of the gravitational wave frequency across this band, reliable removal techniques can be constructed. We discuss the science case and the results related to inflation obtainable with direct detection experiments using space-based interferometers such as the Big Bang Observer.