Stochastic background of relic gravitons in a bouncing quantum   cosmological model
  The spectrum and amplitude of the stochastic background of relic gravitons produced in a bouncing universe is calculated. The matter content of the model consists of dust and radiation fluids, and the bounce occurs due to quantum cosmological effects when the universe approaches the classical singularity in the contracting phase. The resulting amplitude is very small and it cannot be observed by any present and near future gravitational wave detector. Hence, as in the ekpyrotic model, any observation of these relic gravitons will rule out this type of quantum cosmological bouncing model. 
Dennis Bessada, Nelson Pinto-Neto, Beatriz B. Siffert, Oswaldo D.   Miranda
gr-qc astro-ph.CO