Results 21 to 30 of about 173,760 (383)
An integrable model of quantum gravity [PDF]
Physics Letters B, 1995 12 ...
Hermann Nicolai +2 more
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Effective spin foam models for Lorentzian quantum gravity [PDF]
, 2021 Making the Lorentzian path integral for quantum gravity well-defined and computable has been a long standing challenge. In this work we adopt the recently proposed effective spin foam models to the Lorentzian case.
Seth K. Asante +2 more
semanticscholar +1 more source
Lorentzian quantum gravity via Pachner moves: one-loop evaluation
Journal of High Energy Physics, 2023 Lorentzian quantum gravity is believed to cure the pathologies encountered in Euclidean quantum gravity, such as the conformal factor problem. We show that this is the case for the Lorentzian Regge path integral expanded around a flat background.
Johanna N. Borissova, Bianca Dittrich
doaj +1 more source
No-go result for covariance in models of loop quantum gravity [PDF]
, 2020 Based on the observation that the exterior space-times of Schwarzschild-type solutions allow two symmetric slicings, a static spherically symmetric one and a timelike homogeneous one, modifications of gravitational dynamics suggested by symmetry-reduced ...
M. Bojowald
semanticscholar +1 more source
A model of quantum gravity with emergent spacetime [PDF]
Journal of High Energy Physics, 2020 Abstract We construct a model of quantum gravity in which dimension, topology and geometry of spacetime are dynamical. The microscopic degree of freedom is a real rectangular matrix whose rows label internal flavours, and columns label spatial sites. In the limit that the size of the matrix is large, the sites can collectively form
Sung-Sik Lee, Sung-Sik Lee
openaire +4 more sources
Effective Spin Foam Models for Four-Dimensional Quantum Gravity. [PDF]
Physical Review Letters, 2020 A number of approaches to four-dimensional quantum gravity, such as loop quantum gravity and holography, situate areas as their fundamental variables. However, this choice of kinematics can easily lead to gravitational dynamics peaked on flat spacetimes.
Seth K. Asante +2 more
semanticscholar +1 more source
Journal of High Energy Physics, 2022 Combinatorial quantum gravity is governed by a discrete Einstein-Hilbert action formulated on an ensemble of random graphs. There is strong evidence for a second-order quantum phase transition separating a random phase at strong coupling from an ordered,
C. A. Trugenberger
doaj +1 more source
Solvable model for quantum gravity? [PDF]
Classical and Quantum Gravity, 2013 We study a type of geometric theory with a non-dynamical one-form field. Its dynamical variables are an $su(2)$ gauge field and a triad of $su(2)$ valued one-forms. Hamiltonian decomposition reveals that the theory has a true Hamiltonian, together with spatial diffeomorphism and Gauss law constraints, which generate the only local symmetries.
Viqar Husain, Jack Gegenberg
openaire +3 more sources
Effective de Sitter space, quantum behaviour and large-scale spectral dimension (3+1)
Journal of High Energy Physics, 2023 De Sitter space-time, essentially our own universe, is plagued by problems at the quantum level. Here we propose that Lorentzian de Sitter space-time is not fundamental but constitutes only an effective description of a more fundamental quantum gravity ...
C. A. Trugenberger
doaj +1 more source
Tests of Loop Quantum Gravity from the Event Horizon Telescope Results of Sgr A* [PDF]
Astrophysical Journal, 2022 The Event Horizon Telescope (EHT) collaboration’s image of the compact object at the Galactic center is the first direct evidence of the supermassive black hole (BH) Sgr A*. The shadow of Sgr A* has an angular diameter d sh = 48.7 ± 7 μas with fractional
Misba Afrin +2 more
semanticscholar +1 more source