Results 41 to 50 of about 59,677 (306)
A Covariant Polymerized Scalar Field in Semi-Classical Loop Quantum Gravity
Universe, 2022 We propose a new polymerization scheme for scalar fields coupled to gravity. It has the advantage of being a (non-bijective) canonical transformation of the fields, and therefore ensures the covariance of the theory.
Rodolfo Gambini +2 more
doaj +1 more source
Entropy of black holes with arbitrary shapes in loop quantum gravity [PDF]
Science China Physics Mechanics and Astronomy, 2020 The quasi-local notion of an isolated horizon is employed to study the entropy of black holes without any particular symmetry in loop quantum gravity. The idea of characterizing the shape of a horizon by a sequence of local areas is successfully applied ...
Shupeng Song +3 more
semanticscholar +1 more source
Extended loop quantum gravity [PDF]
Classical and Quantum Gravity, 2010 We discuss constraint structure of extended theories of gravitation (also known as f(R) theories) in the vacuum selfdual formulation introduced in ref. [1].
FATIBENE, Lorenzo +2 more
openaire +4 more sources
Loop quantum gravity and cosmological constant
Physics Letters B, 2021 A one-parameter regularization freedom of the Hamiltonian constraint for loop quantum gravity is analyzed. The corresponding spatially flat, homogenous and isotropic model includes the two well-known models of loop quantum cosmology as special cases. The
Xiangdong Zhang, Gaoping Long, Yongge Ma
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Quaternion-Loop Quantum Gravity [PDF]
Foundations of Physics, 2009 It is shown that the Riemannian curvature of the 3-dimensional hypersurfaces in space-time, described by the Wilson loop integral, can be represented by a quaternion quantum operator induced by the SU(2) gauge potential, thus providing a justification for quaternion quantum gravity at the Tev energy scale.
Maia, M. D. +2 more
openaire +3 more sources
Primordial regular black holes as all the dark matter. II. Non-time-radial-symmetric and loop quantum gravity-inspired metrics [PDF]
Physical Review DIt is a common belief that a theory of quantum gravity should ultimately cure curvature singularities which are inevitable within General Relativity, and plague for instance the Schwarzschild and Kerr metrics, usually considered as prototypes for ...
Marco Calzà +2 more
semanticscholar +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
General geometric operators in all dimensional loop quantum gravity [PDF]
Physical Review D, 2020 Two strategies for constructing general geometric operators in all dimensional loop quantum gravity are proposed. The different constructions mainly come from the two different regularization methods for the basic building blocks of the spatial geometry.
Gaoping Long, Yongge Ma
semanticscholar +1 more source
Loop-Quantum-Gravity Vertex Amplitude [PDF]
Physical Review Letters, 2007 Spinfoam theories are hoped to provide the dynamics of non-perturbative loop quantum gravity. But a number of their features remain elusive. The best studied one -the euclidean Barrett-Crane model- does not have the boundary state space needed for this, and there are recent indications that, consequently, it may fail to yield the correct low-energy $n$-
Engle, Jonathan +2 more
openaire +5 more sources
Twisted geometries coherent states for loop quantum gravity [PDF]
Classical and quantum gravity, 2020 We introduce a new family of coherent states for loop quantum gravity, inspired by the twisted geometry parametrization. We compute their peakedness properties and compare them with the heat-kernel coherent states. They show similar features for the area
Andrea Calcinari +3 more
semanticscholar +1 more source