Non-Gaussian signatures of multi-field inflation from string theory

点击翻译按钮获取中文摘要

Multi-field inflationary models are natural in string theory, yet their predictions are degenerate. If non-Gaussianities are observed in fluctuations of the cosmic microwave background radiation (CMBR) by the Planck satellite, simple single-field models are ruled out. Lifting this degeneracy is thus a most pressing task. Multi-field scenarios often include additional effects during inflation, such as the decay of fields or particle production and the associated backreaction. These effects can lead to unique, non-Gaussian signatures in higher order correlation functions of fluctuations in the CMBR. We propose to use non-Gaussianities, especially the shape function of the bi- and trispectrum, to identify those models that are most likely responsible for inflation. We plan to use and improve upon a recently proposed mode decomposition retaining information of the full shape function and investigate the efficiency of the mode decomposition for constructing initial conditions for cosmological simulations.