Results 41 to 50 of about 9,570 (308)
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 ...
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Quantum gravity and the standard model [PDF]
Classical and Quantum Gravity, 2007 12 pages, 21 figures, improved presentation, results ...
Bilson-Thompson, Sundance O. +2 more
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Solving puzzles in deformed JT gravity: phase transitions and non-perturbative effects
Journal of High Energy Physics, 2021 Recent work has shown that certain deformations of the scalar potential in Jackiw-Teitelboim gravity can be written as double-scaled matrix models. However, some of the deformations exhibit an apparent breakdown of unitarity in the form of a negative ...
Clifford V. Johnson, Felipe Rosso
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Spin foam models for quantum gravity [PDF]
Classical and Quantum Gravity, 2003 In this article we review the present status of the spin foam formulation of non-perturbative (background independent) quantum gravity. The article is divided in two parts. In the first part we present a general introduction to the main ideas emphasizing their motivations from various perspectives.
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Renormalizable and Unitary Model of Quantum Gravity [PDF]
Symmetry, 2019 We consider R + R 2 relativistic quantum gravity with the action where all possible terms quadratic in the curvature tensor are added to the Einstein-Hilbert term. This model was shown to be renormalizable in the work by K.S. Stelle. In this paper, we demonstrate that the R + R 2 model is also unitary contrary to the statements made
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An effective matrix model for dynamical end of the world branes in Jackiw-Teitelboim gravity
Journal of High Energy Physics, 2022 We study Jackiw-Teitelboim gravity with dynamical end of the world branes in asymptotically nearly AdS2 spacetimes. We quantize this theory in Lorentz signature, and compute the Euclidean path integral summing over topologies including dynamical branes ...
Ping Gao +2 more
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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 ...
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Space–Time Physics in Background-Independent Theories of Quantum Gravity
, 2021 Background independence is often emphasized as an important property of a quantum theory of gravity that takes seriously the geometrical nature of general relativity.
Martin Bojowald
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Journal of High Energy Physics, 2021 We study the genus expansion on compact Riemann surfaces of the gravitational path integral Z grav m $$ {\mathcal{Z}}_{\mathrm{grav}}^{(m)} $$ in two spacetime dimensions with cosmological constant Λ > 0 coupled to one of the non-unitary minimal models ...
Dionysios Anninos, Beatrix Mühlmann
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Diffeomorphism Symmetry in Quantum Gravity Models [PDF]
Advanced Science Letters, 2009 We review and discuss the role of diffeomorphism symmetry in quantum gravity models. Such models often involve a discretization of the space-time manifold as a regularization method. Generically this leads to a breaking of the symmetries to approximate ones, however there are incidences in which the symmetries are exactly preserved.
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