Properties of Quantum Fields in de Sitter

分析了欧几里得共形对称性对加速膨胀时空理论关联函数的影响。我们考虑了固定de Sitter(DS)背景下场论中量子力态的谱，以及渐近De Sitter中引力涨落的可能推广和联系。通过对怀特曼传播子的分析，我们用嵌入空间的方法阐明了任意维DS中大质量费米子场的构造。然后，我们分析了包含希尔伯特空间中离散级数表示的态变换的场论模型。这是由于观察到这些表示在DS中是酉且不可约的。我们考虑了约束对这些模型的动力学结果的影响，以及它们的接触项在后期引力可观测量中出现的影响。我们主要在2个维度上工作，希望将我们的分析扩展到更高维度DS中的类似系列表示。这种对De Sitter态光谱的分析有望进一步阐明可能呈现DS/CFT对应的模型的性质。

We analyse the consequences of euclidean conformal symmetry on correlation functions of theories in spacetimes undergoing accelerated expansion. We consider the spectra of quantum mechanical states in field theories on a fixed de Sitter (dS) background, as well as possible extensions and connections to gravitational fluctuations in asymptotic de Sitter. We elucidate the construction of massive Fermionic fields in dS in any dimension using embedding space methods, with analysis of the Wightman propagator. We then analyse field theoretic models which include states transforming in discrete series representations in their Hilbert space. Led by the observation that these representations are unitary and irreducible in dS. We consider the consequences of constraints to dynamical results for these models, as well as the impact of their contact terms appearing in late time gravitational observables. We work primarily in 2 dimensions and hope to extend our analysis to analogous series of representations in higher dimensional dS. This analysis of the spectra of de Sitter states is hoped to further clarify the properties of models which might exhibit the dS/CFT correspondence.