PUB - Publikationen an der Universität Bielefeld

A new and powerful probe of the origin and evolution of structures in theUniverse has emerged and been actively developed over the last decade. In thecoming decade, non-Gaussianity, i.e., the study of non-Gaussian contributionsto the correlations of cosmological fluctuations, will become an importantprobe of both the early and the late Universe. Specifically, it will play aleading role in furthering our understanding of two fundamental aspects ofcosmology and astrophysics: (i) the physics of the very early universe thatcreated the primordial seeds for large-scale structures, and (ii) thesubsequent growth of structures via gravitational instability and gas physicsat later times. To date, observations of fluctuations in the Cosmic MicrowaveBackground (CMB) and the Large-Scale Structure of the Universe (LSS) havefocused largely on the Gaussian contribution as measured by the two-pointcorrelations (or the power spectrum) of density fluctuations. However, an evengreater amount of information is contained in non-Gaussianity and a largediscovery space therefore still remains to be explored. Many observationalprobes can be used to measure non-Gaussianity, including CMB, LSS,gravitational lensing, Lyman-alpha forest, 21-cm fluctuations, and theabundance of rare objects such as clusters of galaxies and high-redshiftgalaxies. Not only does the study of non-Gaussianity maximize the sciencereturn from a plethora of present and future cosmological experiments andobservations, but it also carries great potential for important discoveries inthe coming decade.