论文标题
超支模式的有效作用
The Effective Action of Superrotation Modes
论文作者
论文摘要
从以一阶公式对四维渐近性重力进行分析开始，我们表明，超值重复模式由Alekseev-shatashvili对天体球体的作用控制。这个二维的共形理论描述了Virasoro超端的自发对称性破坏，以及更通用的diff $（\ nathcal {s}^2）$ seartrotations的显式对称性破坏。我们通过首先根据Chern-Simons理论在Null Infinity的理论上重新阐明了辐射真空部门的渐近场方程和对称性，从而得出了这一结果。
Starting from an analysis of four-dimensional asymptotically flat gravity in first order formulation, we show that superrotation reparametrization modes are governed by an Alekseev--Shatashvili action on the celestial sphere. This two-dimensional conformal theory describes spontaneous symmetry breaking of Virasoro superrotations together with the explicit symmetry breaking of more general Diff$(\mathcal{S}^2)$ superrotations. We arrive at this result by first reformulating the asymptotic field equations and symmetries of the radiative vacuum sector in terms of a Chern--Simons theory at null infinity, and subsequently performing a Hamiltonian reduction of this theory onto the celestial sphere.
