English
Related papers

Related papers: Spacetime-Free Approach to Quantum Theory and Effe…

200 papers

We show that a non-commutative structure arises naturally from perturbative quantum gravity in a de Sitter background metric. Our work builds on recent advances in the construction of observables in highly symmetric background spacetimes…

General Relativity and Quantum Cosmology · Physics 2023-10-10 Markus Fröb , William C. C. Lima , Albert Much , Kyriakos Papadopoulos

We apply the new quantization scheme outlined in Phys. Rev. D102 (2020) 125001 to explore the influence which quantum vacuum fluctuations of the spacetime metric exert on the universes of Quantum Einstein Gravity, which is regarded an…

High Energy Physics - Theory · Physics 2021-12-22 Maximilian Becker , Martin Reuter

In any attempt to build a quantum theory of gravity, a central issue is to unravel the structure of space-time at the smallest scale. Of particular relevance is the possible definition of coordinate functions within the theory and the study…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alejandro Corichi , Jose A. Zapata

General relativity successfully describes space-times at scales that we can observe and probe today, but it cannot be complete as a consequence of singularity theorems. For a long time there have been indications that quantum gravity will…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald

This is a self-contained introduction to quantum Riemannian geometry based on quantum groups as frame groups, and its proposed role in quantum gravity. Much of the article is about the generalisation of classical Riemannian geometry that…

High Energy Physics - Theory · Physics 2007-05-23 S. Majid

We propose uncertainty relations for the different coordinates of spacetime events, motivated by Heisenberg's principle and by Einstein's theory of classical gravity. A model of Quantum Spacetime is then discussed where the commutation…

High Energy Physics - Theory · Physics 2015-06-26 Sergio Doplicher , Klaus Fredenhagen , John E. Roberts

We develop a detector-based framework in which quantum theory and spacetime geometry arise within a common inferential structure. Detector states and a detector kernel assign amplitudes to measurement events, allowing quantum theory to be…

Quantum Physics · Physics 2026-04-14 Marcello Rotondo

There has been a body of works deriving the complex Hilbert space structure of quantum theory from axioms/principles/postulates to deepen our understanding about quantum theory and to reveal ways to go beyond it to resolve foundational…

Quantum Physics · Physics 2018-09-26 Ding Jia

In this paper, we address a foundational challenge in quantum field theory on curved spacetime by developing a consistent framework within loop quantum gravity. We introduce a methodology for defining meaningful superpositions of quantum…

General Relativity and Quantum Cosmology · Physics 2026-02-17 Gaoping Long , Cong Zhang

This thesis is situated within the context of quantum gravity, broadly understood as any effort to explore the interplay between gravitation and the quantum realm, without necessarily requiring the quantization of the gravitational field…

General Relativity and Quantum Cosmology · Physics 2025-10-22 Gerardo García-Moreno

We argue that space and space-time emerge as a consequence of dynamical collapse of the wave function of macroscopic objects. Locality and separability are properties of our approximate, emergent universe. At the fundamental level,…

Quantum Physics · Physics 2018-10-31 Tejinder P. Singh

We review the investigations on the quantum structure of spactime, to be found at the Planck scale if one takes into account the operational limitations to localization of events which result from the concurrence of Quantum Mechanics and…

High Energy Physics - Theory · Physics 2015-10-15 Dorothea Bahns , Sergio Doplicher , Gerardo Morsella , Gherardo Piacitelli

It is now widely believed that if the gravitational field is (perturbatively) quantum, it would entangle two massive objects (in spatial superpositions) which were otherwise unentangled to begin with. Recently, actual table-top experiments…

General Relativity and Quantum Cosmology · Physics 2023-10-27 Suddhasattwa Brahma , Abhinove Nagarajan Seenivasan

We propose an algebra of operators along an observer's worldline as a background-independent algebra in quantum gravity. In that context, it is natural to think of the Hartle-Hawking no boundary state as a universal state of maximum…

High Energy Physics - Theory · Physics 2023-09-26 Edward Witten

In an attempt to re-establish space-time as an essential frame for formulating quantum gravity - rather than an "emergent" one -, we find that exact invariance under scale transformations is an essential new ingredient for such a theory.…

General Relativity and Quantum Cosmology · Physics 2009-09-21 Gerard 't Hooft

The theory of quantum fields propagating on an isotropic cosmological quantum spacetime is reexamined by generalizing the scalar test field to an electromagnetic (EM) vector field. For any given polarization of the EM field on the classical…

General Relativity and Quantum Cosmology · Physics 2017-11-15 Jerzy Lewandowski , Mohammad Nouri-Zonoz , Ali Parvizi , Yaser Tavakoli

In this note, we attempt to provide some insights into the structure of non-perturbative descriptions of quantum gravity using known examples of gauge-theory / gravity duality. We argue that in familiar examples, a quantum description of…

High Energy Physics - Theory · Physics 2010-03-24 Mark Van Raamsdonk

We describe a non-perturbative approach to studying the gravitational collapse of a scalar field in spherical symmetry with quantum gravity corrections. Quantum effects are described by a phase space function that modifies the constraints…

General Relativity and Quantum Cosmology · Physics 2011-09-15 Andreas Kreienbuehl , Viqar Husain , Sanjeev S. Seahra

We provide a mechanism by which, from a background independent model with no quantum mechanics, quantum theory arises in the same limit in which spatial properties appear. Starting with an arbitrary abstract graph as the microscopic model…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Fotini Markopoulou , Lee Smolin

We present a relational framework in which temporal structure is not fundamental but emerges from correlations within a globally stationary quantum state. Each subsystem includes an internal clock, and conditional states evolve effectively…

Quantum Physics · Physics 2025-12-19 Amir Hossein Ghasemi