The Very Early Universe
Inflation is a period of accelerated expansion believed to have occurred at very early times when the universe we observe today was much smaller than at present – maybe only a few centimetres in size. This rapid expansion can explain why the universe looks so uniform at very large scales, but also provides the seeds for the present day cosmic structures. Microscopic quantum fluctuations about an initial vacuum state would be stretched by inflation to cosmological scales.

CMB detail from ESA/Planck.

Figure from http://arxiv.org/abs/arXiv:1303.3975
Recent research highlights include:
– scale dependence of non-linear fluctuations from inflation
Scale dependence of local fNL, JCAP 02(2010)034, Christian T. Byrnes, Sami Nurmi, Gianmassimo Tasinato, David Wands
– general relativistic effects and non-linearity in the galaxy distribution
Disentangling non-Gaussianity, bias and GR effects in the galaxy distribution, Phys.Rev. D85 (2012) 041301, Marco Bruni, Robert Crittenden, Kazuya Koyama, Roy Maartens, Cyril Pitrou, David Wands
– precision calculation of CMB fluctuations from non-linear evolution of primordial perturbations
The intrinsic bispectrum of the Cosmic Microwave Background, JCAP 1304(2013)003, Guido W. Pettinari, Christian Fidler, Robert Crittenden, Kazuya Koyama, David Wands