Results 21 to 30 of about 165,231 (345)

Midisuperspace Models of Canonical Quantum Gravity [PDF]

International Journal of Theoretical Physics, 1999
29 pages, RevTex, contribution to "Quantum Gravity in the Southern Cone II", Bariloche, Argentina, January 6-10 ...
openaire   +5 more sources

Matrix model formulation of four dimensional gravity [PDF]

, 2000
The attempt of extending to higher dimensions the matrix model formulation of two-dimensional quantum gravity leads to the consideration of higher rank tensor models.
Ambjorn, Barrett, Boulatov, Boulatov, De Pietri, De Pietri, Ooguri, Ponzano, Roberto De Pietri   +8 more
core   +3 more sources

Gravity as an ensemble and the moment problem

Journal of High Energy Physics, 2021
If a bulk gravitational path integral can be identified with an average of partition functions over an ensemble of boundary quantum theories, then a corresponding moment problem can be solved. We review existence and uniqueness criteria for the Stieltjes
Oliver Janssen, Mehrdad Mirbabayi, Peter Zograf   +2 more
doaj   +1 more source

SPIN FOAM MODELS OF QUANTUM GRAVITY [PDF]

Mathematical, Theoretical and Phenomenological Challenges Beyond the Standard Model, 2005
We give a short review of the spin foam models of quantum gravity, with an emphasis on the Barret-Crane model. After explaining the shortcomings of the Barret-Crane model, we briefly discuss two new approaches, one based on the 3d spin foam state sum invariants for the embedded spin networks, and the other based on representing the string scattering ...
openaire   +2 more sources

Discrete structures in gravity [PDF]

, 2000
Discrete approaches to gravity, both classical and quantum, are reviewed briefly, with emphasis on the method using piecewise-linear spaces. Models of 3-dimensional quantum gravity involving 6j-symbols are then described, and progress in generalising ...
Ambjørn J., Archer F. J., Baez J., Baez J., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Barrett J. W., Birmingham D., Birmingham D., Brewin L., Brewin L., Carfora M., Caselle M., Correia da Silva C. L. B., Correia da Silva C. L. B., Franzosi R., Franzosi R., Freidel L., Freidel L., Gott J. R., Hamber H. W., Hamber H. W., Hartle J. B., Hasslacher B., Hollmann H. R., Immirzi G., Ionicioiu R., Ionicioiu R., Iwasaki J., Kauffman L. H., Mannion C. L., Markopoulou F., Markopoulou F., Menotti P., Ooguri H., Reisenberger M., Reisenberger M., Reisenberger M., Riedler J., Roberts J. D., Roček M., Ruth M. Williams, Schleich K., Schleich K., Tullio Regge, Turaev V. G., Waelbroeck H., Welling M., Williams R. M., ’t Hooft G., ’t Hooft G.   +54 more
core   +2 more sources

Bra-ket wormholes in gravitationally prepared states

Journal of High Energy Physics, 2021
We consider two dimensional CFT states that are produced by a gravitational path integral. As a first case, we consider a state produced by Euclidean AdS2 evolution followed by flat space evolution.
Yiming Chen, Victor Gorbenko, Juan Maldacena   +2 more
doaj   +1 more source

No Page curves for the de Sitter horizon

Journal of High Energy Physics, 2022
We investigate the fine-grained entropy of the de Sitter cosmological horizon. Starting from three-dimensional pure de Sitter space, we consider a partial reduction approach, which supplies an auxiliary system acting as a heat bath both at I $$ \mathcal ...
Joshua Kames-King, Evita M. H. Verheijden, Erik P. Verlinde   +2 more
doaj   +1 more source

NEW SPIN FOAM MODELS OF QUANTUM GRAVITY [PDF]

Modern Physics Letters A, 2005
We give a brief and a critical review of the Barret-Crane spin foam models of quantum gravity. Then we describe two new spin foam models which are obtained by direct quantization of General Relativity and do not have some of the drawbacks of the Barret-Crane models.
openaire   +3 more sources

Renormalizable and Unitary Lorentz Invariant Model of Quantum Gravity [PDF]

Universe, 2021
We analyze the R+R2 model of quantum gravity where terms quadratic in the curvature tensor are added to the General Relativity action. This model was recently proved to be a self-consistent quantum theory of gravitation, being both renormalizable and unitary.
openaire   +4 more sources

Discrete Lorentzian Quantum Gravity [PDF]

, 2000
Just as for non-abelian gauge theories at strong coupling, discrete lattice methods are a natural tool in the study of non-perturbative quantum gravity. They have to reflect the fact that the geometric degrees of freedom are dynamical, and that therefore
Loll, R.
core   +4 more sources