### Abstract

Due to quantum fluctuations, a black hole of mass M represents an average over an ensemble of black hole geometries with angular momentum. This observation is apparently at odds with the fact that the curvature singularity inside a rotating black hole is timelike, while the one inside a non-rotating black hole is spacelike. Is the average of timelike singularities really spacelike? We use the Bekenstein-Hawking entropy formula to introduce a microcanonical ensemble for spin fluctuations and show that the onset of quantum gravity is always spacelike. We discuss the impact of this result on singularity resolution in quantum gravity and hint at the possibility of an observational test.

Original language | English (US) |
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Article number | 103028 |

Journal | New Journal of Physics |

Volume | 20 |

Issue number | 10 |

DOIs | |

State | Published - Oct 23 2018 |

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### All Science Journal Classification (ASJC) codes

- Physics and Astronomy(all)

### Cite this

*New Journal of Physics*,

*20*(10), [103028]. https://doi.org/10.1088/1367-2630/aae71d

}

*New Journal of Physics*, vol. 20, no. 10, 103028. https://doi.org/10.1088/1367-2630/aae71d

**Spin fluctuations and black hole singularities : The onset of quantum gravity is spacelike.** / Bianchi, Eugenio; Haggard, Hal M.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Spin fluctuations and black hole singularities

T2 - The onset of quantum gravity is spacelike

AU - Bianchi, Eugenio

AU - Haggard, Hal M.

PY - 2018/10/23

Y1 - 2018/10/23

N2 - Due to quantum fluctuations, a black hole of mass M represents an average over an ensemble of black hole geometries with angular momentum. This observation is apparently at odds with the fact that the curvature singularity inside a rotating black hole is timelike, while the one inside a non-rotating black hole is spacelike. Is the average of timelike singularities really spacelike? We use the Bekenstein-Hawking entropy formula to introduce a microcanonical ensemble for spin fluctuations and show that the onset of quantum gravity is always spacelike. We discuss the impact of this result on singularity resolution in quantum gravity and hint at the possibility of an observational test.

AB - Due to quantum fluctuations, a black hole of mass M represents an average over an ensemble of black hole geometries with angular momentum. This observation is apparently at odds with the fact that the curvature singularity inside a rotating black hole is timelike, while the one inside a non-rotating black hole is spacelike. Is the average of timelike singularities really spacelike? We use the Bekenstein-Hawking entropy formula to introduce a microcanonical ensemble for spin fluctuations and show that the onset of quantum gravity is always spacelike. We discuss the impact of this result on singularity resolution in quantum gravity and hint at the possibility of an observational test.

UR - http://www.scopus.com/inward/record.url?scp=85056095397&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85056095397&partnerID=8YFLogxK

U2 - 10.1088/1367-2630/aae71d

DO - 10.1088/1367-2630/aae71d

M3 - Article

AN - SCOPUS:85056095397

VL - 20

JO - New Journal of Physics

JF - New Journal of Physics

SN - 1367-2630

IS - 10

M1 - 103028

ER -