A correlation detector for very high frequency gravitational waves

Several processes active in the very early universe are thought capable of generating gravitational waves at frequencies above 1 MHz. These include parametric amplification of quantum fluctuations during inflation and bubble cavitation during first-order phase changes. Predictions of the likely spectra of such radiation often show peaks in the MHz to GHz region, far beyond the range of either bar detectors or interferometers and so other detection methods must be developed. A correlation detector based on these principles is being commissioned at Birmingham.