Results 1 to 10 of about 2,706,843 (321)
Quantum gravity and the standard model [PDF]
Classical and Quantum Gravity, 2007 12 pages, 21 figures, improved presentation, results ...
Sundance Bilson-Thompson +2 more
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Testing A (Stringy) Model of Quantum Gravity [PDF]
, 2000 I discuss a specific model of space-time foam, inspired by the modern non-perturbative approach to string theory (D-branes). The model views our world as a three brane, intersecting with D-particles that represent stringy quantum gravity effects, which can be real or virtual.
Nick E. Mavromatos
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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 ...
Aleksandar Miković
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Contextual extensions of quantum gravity models [PDF]
International Journal of Geometric Methods in Modern Physics Vol.
18, No. 6 (2021) 2150085, 2020 We present a simple way of incorporating the structure of contextual extensions into quantum gravity models. The contextual extensions of $C^*$-algebras, originally proposed for contextual hidden variables, are generalized to the cones indexed by the contexts and their limit in a category. By abstracting the quantum gravity models as functors, we study
arxiv +5 more sources
State sum models for quantum gravity [PDF]
, 2000 amslatex, 7 pages, ICMP conference ...
John W. Barrett
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Diffeomorphism symmetry in quantum gravity models [PDF]
Advanced Science Letters, 2008 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.
Bianca Dittrich
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Analogue model for quantum gravity phenomenology [PDF]
Journal of Physics A: Mathematical and General, 2006 So called "analogue models" use condensed matter systems (typically hydrodynamic) to set up an "effective metric" and to model curved-space quantum field theory in a physical system where all the microscopic degrees of freedom are well understood. Known analogue models typically lead to massless minimally coupled scalar fields.
Silke Weinfurtner +2 more
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SPIN-CUBE MODELS OF QUANTUM GRAVITY [PDF]
Reviews in Mathematical Physics, 2013 We study the state-sum models of quantum gravity based on a representation 2-category of the Poincaré 2-group. We call them spin-cube models, since they are categorical generalizations of spin-foam models. A spin-cube state sum can be considered as a path integral for a constrained 2-BF theory, and depending on how the constraints are imposed, a spin ...
Aleksandar Miković
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Inequivalence of mimetic gravity with models of loop quantum gravity [PDF]
Phys. Rev. D 109 (2024) 084044Certain versions of mimetic gravity have recently been claimed to present potential covariant theories of canonically modified spherically symmetric gravity, motivated by ingredients from loop quantum gravity. If such an equivalence were to hold, it would demonstrate general covariance of a large class of models considered in loop quantum gravity ...
Martin Bojowald, Erick I. Duque
arxiv +3 more sources
MINISUPERSPACE MODEL FOR REVISED CANONICAL QUANTUM GRAVITY [PDF]
International Journal of Modern Physics D, 2004 We present a reformulation of the canonical quantization of gravity, as referred to the minisuperspace; the new approach is based on fixing a Gaussian (or synchronous) reference frame and then quantizing the system via the reconstruction of a suitable constraint; then the quantum dynamics is re-stated in a generic coordinates system and it becomes ...
Giovanni Montani
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