### Abstract

We show that the existence of semiclassical black holes of size as small as a minimal length scale l
_{UV} implies a bound on a gravitational analogue of 't-Hooft's coupling λ
_{G}(l)≡N(l)G
_{N}/l
^{2} at all scales l l
_{UV}. The proof is valid for any metric theory of gravity that consistently extends Einstein's gravity and is based on two assumptions about semiclassical black holes: i) that they emit as black bodies, and ii) that they are perfect quantum emitters. The examples of higher dimensional gravity and of weakly coupled string theory are used to explicitly check our assumptions and to verify that the proposed bound holds. Finally, we discuss some consequences of the bound for theories of quantum gravity in general and for string theory in particular.

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

Article number | 085 |

Journal | Journal of High Energy Physics |

Volume | 2009 |

Issue number | 10 |

DOIs | |

State | Published - 2009 |

### Fingerprint

### Keywords

- Black Holes
- Black Holes in String Theory
- Models of Quantum Gravity

### ASJC Scopus subject areas

- Nuclear and High Energy Physics

### Cite this

*Journal of High Energy Physics*,

*2009*(10), [085]. https://doi.org/10.1088/1126-6708/2009/10/085

**A bound on the effective gravitational coupling from semiclassical black holes.** / Brustein, R.; Dvali, G.; Veneziano, G.

Research output: Contribution to journal › Article

*Journal of High Energy Physics*, vol. 2009, no. 10, 085. https://doi.org/10.1088/1126-6708/2009/10/085

}

TY - JOUR

T1 - A bound on the effective gravitational coupling from semiclassical black holes

AU - Brustein, R.

AU - Dvali, G.

AU - Veneziano, G.

PY - 2009

Y1 - 2009

N2 - We show that the existence of semiclassical black holes of size as small as a minimal length scale l UV implies a bound on a gravitational analogue of 't-Hooft's coupling λ G(l)≡N(l)G N/l 2 at all scales l l UV. The proof is valid for any metric theory of gravity that consistently extends Einstein's gravity and is based on two assumptions about semiclassical black holes: i) that they emit as black bodies, and ii) that they are perfect quantum emitters. The examples of higher dimensional gravity and of weakly coupled string theory are used to explicitly check our assumptions and to verify that the proposed bound holds. Finally, we discuss some consequences of the bound for theories of quantum gravity in general and for string theory in particular.

AB - We show that the existence of semiclassical black holes of size as small as a minimal length scale l UV implies a bound on a gravitational analogue of 't-Hooft's coupling λ G(l)≡N(l)G N/l 2 at all scales l l UV. The proof is valid for any metric theory of gravity that consistently extends Einstein's gravity and is based on two assumptions about semiclassical black holes: i) that they emit as black bodies, and ii) that they are perfect quantum emitters. The examples of higher dimensional gravity and of weakly coupled string theory are used to explicitly check our assumptions and to verify that the proposed bound holds. Finally, we discuss some consequences of the bound for theories of quantum gravity in general and for string theory in particular.

KW - Black Holes

KW - Black Holes in String Theory

KW - Models of Quantum Gravity

UR - http://www.scopus.com/inward/record.url?scp=70350749576&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70350749576&partnerID=8YFLogxK

U2 - 10.1088/1126-6708/2009/10/085

DO - 10.1088/1126-6708/2009/10/085

M3 - Article

VL - 2009

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1126-6708

IS - 10

M1 - 085

ER -