CLOVER: Measuring gravitational waves from inflation.

The Cosmic Microwave Background (CMB) is a radiation emitted in the very early Universe. It tells us that the Universe has a beginning in Time. Measurements to date of the intensity of the CMB are consistent with the inflationary theory of the origin of the Universe, however there is much still to learn. Structures - galaxies, clusters and super-clusters of galaxies - that we see in the sky are generated by primordial quantum fluctuations of space-time during an exponential expansion phase during the first fraction of a second of the existance of the Universe. These primordial quantum fluctuations are the source of a background of gravitational waves, which in turn generates a signature on the polarisation of the CMB, known as B-modes. CLOVER, a UK-led experiment based in the Antarctic continent, will provide the first, high-sensitivity, measurement of the spectrum of this B-mode signature. To achieve this high-sensitivity, new world-class technologies are being developed in the UK.