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

多场通胀模型在弦理论中是自然的，但它们的预测是退化的。如果普朗克卫星在宇宙微波背景辐射(CMBR)的涨落中观察到非高斯性，简单的单场模型将被排除。因此，消除这种退化是一项最紧迫的任务。多场场景通常包括充气过程中的附加效应，例如场的衰变或粒子的产生以及相关的反作用。这些效应可以导致CMBR中涨落的高阶相关函数中的唯一非高斯签名。我们建议使用非高斯性，特别是双谱和三谱的形函数来识别那些最有可能导致通货膨胀的模型。我们计划使用并改进最近提出的模分解，它保留了全形函数的信息，并研究了模分解在构造宇宙学模拟初始条件方面的效率。

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.