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Related papers: A view on the problems of Quantum Gravity

200 papers

We study a class of theories in which space-time is treated classically, while interacting with quantum fields. These circumvent various no-go theorems and the pathologies of semi-classical gravity, by being linear in the density matrix and…

High Energy Physics - Theory · Physics 2022-02-15 Jonathan Oppenheim , Zachary Weller-Davies

Commutator anomalies obstruct solving the Wheeler-DeWitt constraint equation in Dirac quantization of quantum gravity-matter theory. When the obstruction is removed, there result quantal modifications to the constraints. The same classical…

General Relativity and Quantum Cosmology · Physics 2007-05-23 R. Jackiw

A brief review of main features of the new approach named ``quantum geometrodynamics in extended phase space'' is given and its possible prospects are discussed. Gauge degrees of freedom are treated as a subsystem of the Universe which…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. P. Shestakova

Loop Quantum Gravity heavily relies on a connection formulation of General Relativity such that 1. the connection Poisson commutes with itself and 2. the corresponding gauge group is compact. This can be achieved starting from the Palatini…

General Relativity and Quantum Cosmology · Physics 2013-02-13 Norbert Bodendorfer , Thomas Thiemann , Andreas Thurn

An approach to quantization of fields and gravity based on the De Donder-Weyl covariant Hamiltonian formalism is outlined. It leads to a hypercomplex extension of quantum mechanics in which the algebra of complex numbers is replaced by the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 I. V. Kanatchikov

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected to project quantum states of the geometry…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Federico Mattei , Carlo Rovelli , Simone Speziale , Massimo Testa

We do not yet know how to quantize gravity in 3+1 dimensions, but in lower dimensions we face the opposite problem: many of the approaches originally developed for (3+1)-dimensional gravity can be successfully implemented in 2+1 dimensions,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Carlip

These notes summarise a talk surveying the combinatorial or Hamiltonian quantisation of three dimensional gravity in the Chern-Simons formulation, with an emphasis on the role of quantum groups and on the way the various physical constants…

General Relativity and Quantum Cosmology · Physics 2011-05-20 Bernd J Schroers

The prerequisites of the extended phase space approach to quantization of gravity, which is alternative to the Wheeler-DeWitt one and other existing approaches, are presented. The features of the proposed approach and conclusions from its…

General Physics · Physics 2026-03-23 T. P. Shestakova

In this paper, I emphasize those features of the extended phase space approach to quantization of gravity that distinguish it among other approaches. First of all, it is the conjecture about non-trivial topology of the Universe which was…

General Relativity and Quantum Cosmology · Physics 2025-07-24 T. P. Shestakova

The degree of freedom of the scalar field in scalar-tensor gravity is employed as "time" to deparametrize the Hamiltonian constraint of the theory. The deparametrized system is then nonperturbatively quantized by the approach of loop…

General Relativity and Quantum Cosmology · Physics 2026-03-02 Faqiang Yuan , Haida Li , Shengzhi Li , Yongge Ma

General relativity in three spacetime dimensions is used to explore three approaches to the ``problem of time'' in quantum gravity: the internal Schr\"odinger approach with mean extrinsic curvature as a time variable, the Wheeler-DeWitt…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Carlip

It is shown that introducing the quantum effects using deBroglie--Bohm theory in the canonical formulation of gravity would change the constraints algebra. The new algebra is derived and shown that it is the clear projection of general…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Ali Shojai , Fatimah Shojai

We consider non-relativistic point-particles coupled to Einstein gravity and their canonical quantization. From the resulting Wheeler-DeWitt wave equation we determine a quantum version of geometrodynamics, where the coupled evolution of…

General Relativity and Quantum Cosmology · Physics 2021-08-19 Christian Maes , Kasper Meerts , Ward Struyve

One of the hardest problems to tackle in the dynamics of canonical approaches to quantum gravity is that of the Hamiltonian constraint. We investigate said problem in the context of formal geometric quantization. We study the implications…

General Relativity and Quantum Cosmology · Physics 2013-04-19 Vasudev Shyam

A generalized quantization principle is considered, which incorporates nontrivial commutation relations of the components of the variables of the quantized theory with the components of the corresponding canonical conjugated momenta…

General Physics · Physics 2016-09-02 Martin Kober

Most approaches towards a quantum theory of gravitation indicate the existence of a minimal length scale of the order of the Planck length. Quantum mechanical models incorporating such an intrinsic length scale call for a deformation of…

General Relativity and Quantum Cosmology · Physics 2025-05-21 Won Sang Chung , Georg Junker , Hassan Hassanabadi

This chapter focuses on the status of the implementation of the dynamics in the canonical version of Loop Quantum Gravity (LQG). Concretely this means to provide a mathematical meaning of the quantum Einstein equations, sometimes called…

General Relativity and Quantum Cosmology · Physics 2023-04-03 Thomas Thiemann , Kristina Giesel

General Theory of Relativity and Quantum theory gives two different description of the same mother nature in the big and small scale respectively. Mathematical languages of these two theories are entirely different, one is geometric while…

General Physics · Physics 2020-05-11 Sijo K. Joseph

The quantum gauge general relativity is proposed in the framework of quantum gauge theory of gravity. It is formulated based on gauge principle which states that the correct symmetry for gravitational interactions should be gravitational…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ning Wu