scholarly journals Faddeev-Popov-ghost propagators for Yang-Mills theories and perturbative quantum gravity in the covariant gauge in de Sitter spacetime

2008 ◽  
Vol 78 (6) ◽  
Author(s):  
Mir Faizal ◽  
Atsushi Higuchi
Keyword(s):  
Quantum Gravity ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Yang Mills ◽  
Sitter Spacetime ◽  
Covariant Gauge ◽  
Perturbative Quantum ◽  
Popov Ghost

scholarly journals Perturbative Quantum Gravity on de Sitter Spacetime

OALib ◽  
2015 ◽  
Vol 02 (04) ◽  
pp. 1-9
Author(s):  
Ashaq Hussain Sofi ◽  
Shabir Ahmad Akhoon ◽  
Asloob Ahmad Rather ◽  
Anil Maini
Keyword(s):  
Quantum Gravity ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Perturbative Quantum

scholarly journals Dark energy and quantum gravity

2019 ◽  
Vol 28 (14) ◽  
pp. 1944018 ◽  
Author(s):  
Per Berglund ◽  
Tristan Hübsch ◽  
Djordje Minić
Keyword(s):  
Dark Energy ◽  
String Theory ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Particle Physics ◽  
Dual Space ◽  
Planck Scale ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime

Realizing dark energy and the observed de Sitter spacetime in quantum gravity has proven to be obstructed in almost every usual approach. We argue that additional degrees of freedom of the left- and right-movers in string theory and a resulting doubled, noncommutatively generalized geometric formulation thereof can lead to an effective model of dark energy consistent with de Sitter spacetime. In this approach, the curvature of the canonically conjugate dual space provides for the dark energy inducing a positive cosmological constant in the observed spacetime, whereas the size of the above dual space is the gravitational constant in the same observed de Sitter spacetime. As a hallmark relation owing to a unique feature of string theory which relates short distances to long distances, the cosmological constant scale, the Planck scale and the effective TeV-sized particle physics scale must satisfy a see-saw-like formula — precisely the generic prediction of certain stringy cosmic brane type models.

scholarly journals Holographic de Sitter spacetime and quantum corrections to the cosmological constant

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Shuichi Yokoyama
Keyword(s):  
Quantum Gravity ◽  
Cosmological Constant ◽  
Conformal Symmetry ◽  
Flow Equation ◽  
Vector Model ◽  
Quantum Corrections ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Dynamical Aspect

Abstract A dynamical aspect of quantum gravity on de Sitter spacetime is investigated by holography and the de Sitter/conformal field theory correspondence. We show that de Sitter spacetime emerges from a free Sp($N$) vector model by complexifying the ghost fields and course-graining them by flow equation in parallel to the imaginary axis. We confirm that the emergence of de Sitter spacetime is ensured by conformal symmetry. We also compute the quantum corrections to the cosmological constant up to the next-to-leading order of the $1/N$ expansion in a proposed holographic approach. As a result the sub-leading corrections have the opposite sign to the classical value. This implies that a quantum gravity on de Sitter spacetime is perturbatively stable and quantum effects make the universe flatter and the cosmological constant smaller.

scholarly journals Supersymmetric localization on dS: sum over topologies

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Rudranil Basu ◽  
Augniva Ray
Keyword(s):  
Partition Function ◽  
Quantum Gravity ◽  
Higher Spin Gravity ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Higher Spin ◽  
3D Gravity ◽  
Chern Simons ◽  
Perturbative Result

AbstractWe find the exact quantum gravity partition function on the static patch of 3d de Sitter spacetime. We have worked in the Chern Simons formulation of 3d gravity. To obtain a non-perturbative result, we supersymmetrized the Chern Simons action and used the technique of supersymmetric localization. We have obtained an exact non-perturbative result for the spin-2 gravity case. We comment on the divergences present in the theory. We also comment on higher spin gravity theories and analyse the nature of divergences present in such theories.

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