### Abstract

We show that the addition of a topological Gauss-Bonnet term to the gravitational action can greatly increase the instability of four-dimensional de Sitter space by favoring the nucleation of black holes. The pair-production rate given by the Euclidean action for the instanton takes the form exp(ΔS) where S is the entropy in Einstein-Gauss-Bonnet theory. The coefficient of the Gauss-Bonnet term in the action sets a stability bound on the curvature of empty de Sitter space. For that coefficient in the low-energy effective action of heterotic string theory, the maximal curvature of de Sitter space is, in general, much lower than the Planck scale.

Original language | English (US) |
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Article number | 044048 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 84 |

Issue number | 4 |

DOIs | |

State | Published - Aug 18 2011 |

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### ASJC Scopus subject areas

- Nuclear and High Energy Physics

### Cite this

**Enhanced instability of de Sitter space in Einstein-Gauss-Bonnet gravity.** / Parikh, Maulik.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - Enhanced instability of de Sitter space in Einstein-Gauss-Bonnet gravity

AU - Parikh, Maulik

PY - 2011/8/18

Y1 - 2011/8/18

N2 - We show that the addition of a topological Gauss-Bonnet term to the gravitational action can greatly increase the instability of four-dimensional de Sitter space by favoring the nucleation of black holes. The pair-production rate given by the Euclidean action for the instanton takes the form exp(ΔS) where S is the entropy in Einstein-Gauss-Bonnet theory. The coefficient of the Gauss-Bonnet term in the action sets a stability bound on the curvature of empty de Sitter space. For that coefficient in the low-energy effective action of heterotic string theory, the maximal curvature of de Sitter space is, in general, much lower than the Planck scale.

AB - We show that the addition of a topological Gauss-Bonnet term to the gravitational action can greatly increase the instability of four-dimensional de Sitter space by favoring the nucleation of black holes. The pair-production rate given by the Euclidean action for the instanton takes the form exp(ΔS) where S is the entropy in Einstein-Gauss-Bonnet theory. The coefficient of the Gauss-Bonnet term in the action sets a stability bound on the curvature of empty de Sitter space. For that coefficient in the low-energy effective action of heterotic string theory, the maximal curvature of de Sitter space is, in general, much lower than the Planck scale.

UR - http://www.scopus.com/inward/record.url?scp=80052853315&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80052853315&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.84.044048

DO - 10.1103/PhysRevD.84.044048

M3 - Article

AN - SCOPUS:80052853315

VL - 84

JO - Physical review D: Particles and fields

JF - Physical review D: Particles and fields

SN - 1550-7998

IS - 4

M1 - 044048

ER -