Telescope in bright South Polar light with other telescopes in background

Pryke leads research effort that improves constraints on Physics of Big Bang

Professor Clem Pryke of the School of Physics and Astronomy is a co-leader of a collaboration that recently published a paper in Physics Review Letters that refines models of the early expansion of the Universe after the Big Bang.

At the start of the Big Bang, the rapid expansion of the Universe is predicted to have generated Primordial Gravitational Waves (PGW) that can only be seen as a faint pattern of Cosmic Microwave Background radiation. A study published in Physics Review Letters, has used data from the BICEP/Keck experiments at the South Pole to refine models of how this expansion of space may have taken place in the early Universe. The period covered by this analysis was using data taken up to and including 2018.

In recent years, researchers from the BICEP/Keck collaboration have used an array of increasingly powerful telescopes at the South Pole, operating at many different frequencies or colors of microwave light, to study the cosmos. In that ancient light they have distinguished the expected patterns caused by its bending as it traveled past massive clusters of galaxies, as predicted by Einstein, from the possible faint patterns of primordial gravitational waves.

While the latest results do not detect primordial gravitational waves, they set limits on them that narrow the range of models that can explain the early expansion of the Universe.

"Prospects for the future look bright," Pryke says, "as the most favored of the remaining class of models predict primordial gravitational waves should be detected or ruled out with coming data from telescopes at the South Pole within the next decade."