论文标题
从广告到DS交换：光谱表示，梅林振幅和交叉
From AdS to dS Exchanges: Spectral Representation, Mellin Amplitudes and Crossing
论文作者
论文摘要
我们在广告和DS中的树级交换之间提出了一个简单的一般关系。这种关系允许在位置和动量空间中直接导入Witten图的ADS的技术和结果，以将其引入DS中的边界相关函数。在这项工作中，我们将此关系应用于定义梅林振幅和ds中交换的光谱表示。我们还从其广告中得出了直接和交叉通道中DS交换的共形块分解。 ADS和DS交换本身之间的关系是使用最近引入的Mellin-Barnes表示在动量空间中边界相关器的表示，其中（a）DS交换是通过分解，组合对称性和边界条件的组合来直接固定的。
We present a simple general relation between tree-level exchanges in AdS and dS. This relation allows to directly import techniques and results for AdS Witten diagrams, both in position and momentum space, to boundary correlation functions in dS. In this work we apply this relation to define Mellin amplitudes and a spectral representation for exchanges in dS. We also derive the conformal block decomposition of a dS exchange, both in the direct and crossed channels, from their AdS counterparts. The relation between AdS and dS exchanges itself is derived using a recently introduced Mellin-Barnes representation for boundary correlators in momentum space, where (A)dS exchanges are straightforwardly fixed by a combination of factorisation, conformal symmetry and boundary conditions.
