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arXiv · 2412.19880

Accidental Symmetry Near Extreme Spinning Black Holes

Avik Banerjee·Achilleas P. Porfyriadis·Grant N. Remmen
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Abstract

Near the horizon of extremal charged black holes, an accidental symmetry is known to act on zero-temperature perturbations, transforming them into finite-temperature ones. In this paper, we uncover the corresponding accidental symmetry of the vacuum Einstein equation near the horizon of extremal spinning black holes. To do so, we first devise a new method of deriving the symmetry near the ${\rm AdS}_2 \times S^2$ near-horizon geometry of extreme Reissner-Nordstr\"om, using a new scaling coordinate transformation that unifies the near-horizon limits of extremal and near-extremal black holes in a way that is regular at zero temperature. We use our new method to obtain the accidental symmetry in the near-horizon of extreme Kerr (NHEK). We show that accidental symmetries combine neatly with the near-horizon isometries inside a Virasoro algebra.

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Avik Banerjee, Achilleas P. Porfyriadis, Grant N. Remmen. 2024-12-27. Accidental Symmetry Near Extreme Spinning Black Holes. https://doi.org/10.1007/jhep04(2025)149

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