In the description of the AdS5/CFT4 duality by an integrable system the scattering matrix for bound states plays a crucial role: it was initially constructed for the evaluation of finite size corrections to the planar spectrum of energy levels/anomalous dimensions by the thermodynamic Bethe ansatz, and more recently it re-appeared in the context of the glueing prescription of the hexagon approach to higher-point functions. In this work we present a simplified form of this scattering matrix and we make its pole structure manifest. We find some new relations between its matrix elements and also present an explicit form for its inverse. We finally discuss some of its properties including crossing symmetry. Our results will hopefully be useful for computing finite-size effects such as the ones given by the complicated sum-integrals arising from the glueing of hexagons, as well as help towards understanding universal features of the AdS5/CFT4 scattering matrix.

中文翻译：

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简化的束缚态散射

在可积系统对 AdS5/CFT4 对偶性的描述中，束缚态的散射矩阵起着至关重要的作用：它最初是为了评估热力学 Bethe ansatz 对平面能级/异常维度谱的有限尺寸校正而构建的，最近它重新出现在六边形方法对高点函数的粘合处方的背景下。在这项工作中，我们展示了这个散射矩阵的简化形式，并展示了它的极点结构。我们发现了它的矩阵元素之间的一些新关系，并且还给出了它的逆的显式形式。我们最后讨论了它的一些性质，包括交叉对称性。