本文首先简要介绍了最近新兴的天球全息(celestial holography)，这是一种平坦全息框架．然后将天球全息框架应用到二维Bullough-Dodd可解模型中去，其散射振幅的共形场论对偶为特殊的共形关联函数，称为微扰延迟（超前）振幅，我们计算了微扰延迟（超前）振幅的一阶项并验证其满足幺正性．

 In this paper, we firstly review the celestial holographic. Then we apply celestial holography to the 2d Bullough-Dodd model. We compute the conformal correlator dual to the 2d scattering amplitude of the Bullough-Dodd model at the leading order, and verify its unitarity.