### Abstract

Canonical quantization is often used to suggest new effects in quantum gravity, in the dynamics as well as the structure of space-time. Usually, possible phenomena are first seen in a modified version of the classical dynamics, for instance in an effective Friedmann equation, but there should also be implications for a modified space-time structure. Quantum space-time effects, however, are often ignored in this setting because they are not obvious: they require a careful analysis of gauge transformations and the anomaly problem. It is shown here how modified space-time structures and effective line elements can be derived unambiguously, provided an off-shell anomaly-free system of modified constraints exists. The resulting effective line elements reveal signature change as an inescapable consequence of nonclassical gauge transformations in the presence of holonomy modifications. The general framework is then specialized to black-hole models in loop quantum gravity. In contrast to previous studies, a self-consistent space-time structure is taken into account, leading to a new picture of black-hole interiors.

Original language | English (US) |
---|---|

Article number | 046015 |

Journal | Physical Review D |

Volume | 98 |

Issue number | 4 |

DOIs | |

State | Published - Aug 15 2018 |

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### All Science Journal Classification (ASJC) codes

- Physics and Astronomy (miscellaneous)

### Cite this

*Physical Review D*,

*98*(4), [046015]. https://doi.org/10.1103/PhysRevD.98.046015

}

*Physical Review D*, vol. 98, no. 4, 046015. https://doi.org/10.1103/PhysRevD.98.046015

**Effective line elements and black-hole models in canonical loop quantum gravity.** / Bojowald, Martin; Brahma, Suddhasattwa; Yeom, Dong Han.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Effective line elements and black-hole models in canonical loop quantum gravity

AU - Bojowald, Martin

AU - Brahma, Suddhasattwa

AU - Yeom, Dong Han

PY - 2018/8/15

Y1 - 2018/8/15

N2 - Canonical quantization is often used to suggest new effects in quantum gravity, in the dynamics as well as the structure of space-time. Usually, possible phenomena are first seen in a modified version of the classical dynamics, for instance in an effective Friedmann equation, but there should also be implications for a modified space-time structure. Quantum space-time effects, however, are often ignored in this setting because they are not obvious: they require a careful analysis of gauge transformations and the anomaly problem. It is shown here how modified space-time structures and effective line elements can be derived unambiguously, provided an off-shell anomaly-free system of modified constraints exists. The resulting effective line elements reveal signature change as an inescapable consequence of nonclassical gauge transformations in the presence of holonomy modifications. The general framework is then specialized to black-hole models in loop quantum gravity. In contrast to previous studies, a self-consistent space-time structure is taken into account, leading to a new picture of black-hole interiors.

AB - Canonical quantization is often used to suggest new effects in quantum gravity, in the dynamics as well as the structure of space-time. Usually, possible phenomena are first seen in a modified version of the classical dynamics, for instance in an effective Friedmann equation, but there should also be implications for a modified space-time structure. Quantum space-time effects, however, are often ignored in this setting because they are not obvious: they require a careful analysis of gauge transformations and the anomaly problem. It is shown here how modified space-time structures and effective line elements can be derived unambiguously, provided an off-shell anomaly-free system of modified constraints exists. The resulting effective line elements reveal signature change as an inescapable consequence of nonclassical gauge transformations in the presence of holonomy modifications. The general framework is then specialized to black-hole models in loop quantum gravity. In contrast to previous studies, a self-consistent space-time structure is taken into account, leading to a new picture of black-hole interiors.

UR - http://www.scopus.com/inward/record.url?scp=85052611134&partnerID=8YFLogxK

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U2 - 10.1103/PhysRevD.98.046015

DO - 10.1103/PhysRevD.98.046015

M3 - Article

AN - SCOPUS:85052611134

VL - 98

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 4

M1 - 046015

ER -