Character of the highest weight module of BMS algebra realized on codimensional-two boundary

作者：Bin Chen, Song He, Pujian Mao, Xin-Cheng Mao · 发表于：Journal of High Energy Physics · 年份：2026 · DOI：10.1007/jhep01(2026)051 · 被引用次数：1 · 研究领域：Advanced Topics in Algebra、Algebraic structures and combinatorial models、Commutative Algebra and Its Applications

A bstract In this paper, we investigate the highest weight representation (HWR) of the three and four-dimensional Bondi-Metzner-Sachs (BMS) algebra realized on the codimension-two boundary of asymptotic flat spacetime (AFS). In such a realization, the action of supertranslation shifts the conformal weight of the highest-weight states. As a result, there is no extra quantum number relating to the supertranslation. We construct the highest-weight BMS modules and compute their characters. We show that the BMS 3 highest-weight vacuum character with special value of central charges coincides with the 1-loop partition function of three-dimensional asymptotic flat gravity, up to an overall phase factor “ i ”. We expect the vacuum character of BMS 4 may shed light on the flat holography in four dimensions.