Testing the Gaussianity and Statistical Isotropy of the Universe

Understand

The last few years have seen a surge in excitement about measurements of statistics of the primordial fluctuations beyond the power spectrum.

• New ideas for precision tests of Gaussianity and statistical isotropy in the data are developing simultaneously with proposals for a wide range of new theoretical possibilities.
• From both the observations and theory, it has become clear that there is a huge discovery potential from upcoming measurements.
• In this Special Issue of Advances in Astronomy we have collected articles that summarize the theoretical predictions for departures from Gaussianity or statistical isotropy from a variety of potential sources, together with the observational approaches to test these properties using the CMB or large-scale structure.