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arXiv · 1609.00282

A 2D Stress Tensor for 4D Gravity

Daniel Kapec·Prahar Mitra·Ana-Maria Raclariu·Andrew Strominger
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Abstract

We use the subleading soft-graviton theorem to construct an operator $T_{zz}$ whose insertion in the four-dimensional tree-level quantum gravity $\mathcal{S}$-matrix obeys the Virasoro-Ward identities of the energy momentum tensor of a two-dimensional conformal field theory (CFT$_2$). The celestial sphere at Minkowskian null infinity plays the role of the Euclidean sphere of the CFT$_2$, with the Lorentz group acting as the unbroken $SL(2,\mathbb{C})$ subgroup.

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Daniel Kapec, Prahar Mitra, Ana-Maria Raclariu, Andrew Strominger. 2016-09-28. A 2D Stress Tensor for 4D Gravity. https://doi.org/10.1103/physrevlett.119.121601

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