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Related papers: Projective Structures in Loop Quantum Cosmology

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Many homogeneous, four-dimensional space-time geometries can be considered within real projective geometry, which yields a mathematically well-defined framework for their deformations and limits without the appearance of singularities.…

High Energy Physics - Theory · Physics 2024-07-22 Daniel Spitz

Canonical quantum gravity provides insights into the quantum dynamics as well as quantum geometry of space-time by its implications for constraints. Loop quantum gravity in particular requires specific corrections due to its quantization…

General Relativity and Quantum Cosmology · Physics 2015-05-14 Martin Bojowald

The Gowdy cosmologies provide a suitable arena to further develop Loop Quantum Cosmology, allowing the presence of inhomogeneities. For the particular case of Gowdy spacetimes with the spatial topology of a three-torus and a content of…

General Relativity and Quantum Cosmology · Physics 2010-09-22 L. J. Garay , M. Martín-Benito , G. A. Mena Marugán

The Projection Postulate from Standard Quantum Mechanics relies fundamentally on measurements. But measurements implicitly suggest the existence of anthropocentric notions like measuring devices, which should rather emerge from the theory.…

Quantum Physics · Physics 2021-03-26 Ovidiu Cristinel Stoica

We show how Loop Quantum Cosmology can be derived as an effective semiclassical description of Loop Quantum Gravity. Using the tools of QRLG, a gauge fixed version of LQG, we take the coherent states of the fundamental microscopic theory…

General Relativity and Quantum Cosmology · Physics 2014-10-20 Emanuele Alesci , Francesco Cianfrani

A central challenge in quantum metrology is identifying optimal measurements that saturate the quantum Cramer-Rao bound under realistic constraints, e.g., local measurements. We show that symmetries of the probe state provide a general…

Quantum Physics · Physics 2026-03-10 Jia-Xuan Liu , Hai-Long Shi , Chunfeng Wu , Sixia Yu

In this work, it is demonstrated how the kinematical Hilbert space of Loop Quantum Gravity (LQG) can be inferred from the configuration space of BF theories via the imposition of the Hamiltonian constraints. In particular, it is outlined…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Francesco Cianfrani

Quantum gravity is sometimes considered as a kind of metaphysical speculation. In this review, we show that, although still extremely difficult to reach, observational signatures can in fact be expected. The early universe is an invaluable…

General Relativity and Quantum Cosmology · Physics 2015-06-17 A. Barrau , T. Cailleteau , J. Grain , J. Mielczarek

As part of a wider study of coherent states in (loop) quantum gravity, we introduce a modification to the standard construction, based on the recently introduced (non-commutative) flux representation. The resulting quantum states have some…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Daniele Oriti , Roberto Pereira , Lorenzo Sindoni

We propose an approach which, by combining insights from Loop Quantum Gravity (LQG), Topos theory, Non-commutative Geometry \`a la Connes, and spacetime relationalism, provides fertile ground for the search of an adequate spacetime picture…

General Relativity and Quantum Cosmology · Physics 2021-03-12 Alejandro Ascárate

After short historical overview we describe the difficulties with application of standard QFT methods in quantum gravity (QG). The incompatibility of QG with the use of classical continuous space-time required conceptually new approach. We…

High Energy Physics - Theory · Physics 2014-12-01 Jerzy Lukierski

If quantum gravity respects the principles of quantum mechanics, suitably generalized, it may be that a more viable approach to the theory is through identifying the relevant quantum structures rather than by quantizing classical spacetime.…

High Energy Physics - Theory · Physics 2016-01-27 Steven B. Giddings

Considering homogeneous four-dimensional space-time geometries within real projective geometry provides a mathematically well-defined framework to discuss their deformations and limits without the appearance of coordinate singularities. On…

Mathematical Physics · Physics 2025-05-22 Daniel Spitz

We perform a canonical, reduced phase space quantisation of General Relativity by Loop Quantum Gravity (LQG) methods. The explicit construction of the reduced phase space is made possible by the combination of 1. the Brown -- Kuchar…

General Relativity and Quantum Cosmology · Physics 2014-11-18 K. Giesel , T. Thiemann

Loop quantum cosmology in (b, v) variables, which is governed by a unit step size difference equation, is embedded into a full theory context based on similar variables. A full theory context here means a theory of quantum gravity arrived…

General Relativity and Quantum Cosmology · Physics 2016-05-20 Norbert Bodendorfer

We construct in this article a new realization of quantum geometry, which is obtained by quantizing the recently-introduced flux formulation of loop quantum gravity. In this framework, the vacuum is peaked on flat connections, and states…

General Relativity and Quantum Cosmology · Physics 2021-06-18 Benjamin Bahr , Bianca Dittrich , Marc Geiller

Loop quantum cosmology(LQC) is the symmetric model of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogenous cosmological…

General Relativity and Quantum Cosmology · Physics 2016-10-13 Xiangdong Zhang

Observables in a quantum system, represented by a Hilbert space, are given by the orthogonal bases of the aforementioned Hilbert space. Categorical Quantum Mechanics provides further abstraction of such observables, allowing for a…

Quantum Physics · Physics 2024-06-19 Aqilah Rasat

The minimal-length paradigm is a cornerstone of quantum gravity phenomenology. Recently, it has been demonstrated that minimal-length quantum mechanics can alternatively be described as an undeformed theory set on a nontrivial momentum…

General Relativity and Quantum Cosmology · Physics 2024-01-12 Fabian Wagner

The central idea of this work is the concept of prespace, a hypothetical structure that is postulated to underlie the fabric of space or space-time. I consider how such a structure could relate to space and space-time, and the implications…

Quantum Physics · Physics 2018-07-31 Martin Leckey