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We argue that the origin of unitarity violation and information loss paradox in our understanding of black holes (BH) lies in the standard way of doing quantum field theory in curved space-time (QFTCS), which is heavily biased on intuition…

High Energy Physics - Theory · Physics 2024-12-23 K. Sravan Kumar , João Marto

A non-perturbative quantum field theory of General Relativity is presented which leads to a new realization of the theory of Covariant Quantum-Gravity (CQG-theory). The treatment is founded on the recently-identified Hamiltonian structure…

General Relativity and Quantum Cosmology · Physics 2017-05-24 Claudio Cremaschini , Massimo Tessarotto

It is well-known that there exist infinitely-many inequivalent representations of the canonical (anti)-commutation relations of Quantum Field Theory (QFT). A way out, suggested by Algebraic QFT, is to instead define the quantum theory as…

High Energy Physics - Theory · Physics 2016-10-28 Suzanne Lanéry

This article sets out the framework of algebraic quantum field theory in curved spacetimes, based on the idea of local covariance. In this framework, a quantum field theory is modelled by a functor from a category of spacetimes to a…

Mathematical Physics · Physics 2015-04-03 Christopher J. Fewster , Rainer Verch

In this article and a companion paper we address the question of how one might obtain the semiclassical limit of ordinary matter quantum fields (QFT) propagating on curved spacetimes (CST) from full fledged Quantum General Relativity (QGR),…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Hanno Sahlmann , Thomas Thiemann

The holographic principle and the thermodynamics of de Sitter space suggest that the total number of fundamental degrees of freedom associated with any finite-volume region of space may be finite. The naive picture of a short distance…

High Energy Physics - Theory · Physics 2009-11-11 Federico Piazza

A realistic measurement-free theory for the quantum physics of multiple qubits is proposed. This theory is based on a symbolic representation of a fractal state-space geometry which is invariant under the action of deterministic and locally…

Quantum Physics · Physics 2013-05-21 T. N. Palmer

This paper elaborates on an intrinsically quantum approach to gravity, which begins with a general framework for quantum mechanics and then seeks to identify additional mathematical structure on Hilbert space that is responsible for gravity…

High Energy Physics - Theory · Physics 2019-03-27 Steven B. Giddings

In this paper we will analyze the the status of gauge freedom in quantum mechanics (QM) and quantum field theory (QFT). Along with this analysis comparison with ordinary QFT will be given. We will show how the gauge freedom problem is…

Quantum Physics · Physics 2007-05-23 Jaroslaw Wawrzycki

We formulate semi-classical field theory as an approximate decoherence-free-subspace of a finite-dimensional quantum-gravity hilbert space. A complementarity construction can be realized as a unitary transformation which changes the…

High Energy Physics - Theory · Physics 2014-05-09 Jaime Varela

The paper shows how the Bohmian approach to quantum physics can be applied to develop a clear and coherent ontology of non-perturbative quantum gravity. We suggest retaining discrete objects as the primitive ontology also when it comes to a…

History and Philosophy of Physics · Physics 2015-06-17 Antonio Vassallo , Michael Esfeld

The question about the appearance of time in the semiclassical limit of quantum gravity continues to be discussed in the literature. It is believed that a temporal Schrodinger equation for matter fields on the background of a classical…

General Relativity and Quantum Cosmology · Physics 2025-07-24 R. I. Ayala Oña , M. B. Kalmykov , D. P. Kislyakova , T. P. Shestakova

The mutual conceptual incompatibility between GR and QM/QFT is generally seen as the most essential motivation for the development of a theory of Quantum Gravity (QG). It leads to the insight that, if gravity is a fundamental interaction…

General Relativity and Quantum Cosmology · Physics 2011-03-04 Reiner Hedrich

The Koslowski-Sahlmann (KS) representation is a generalization of the representation underlying the discrete spatial geometry of Loop Quantum Gravity (LQG), to accommodate states labelled by smooth spatial geometries. As shown recently, the…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Miguel Campiglia , Madhavan Varadarajan

This is a nontechnical introduction to recent work on quantum gravity using ideas from higher-dimensional algebra. We argue that reconciling general relativity with the Standard Model requires a `background-free quantum theory with local…

General Relativity and Quantum Cosmology · Physics 2015-02-13 John C. Baez

We elaborate the recently introduced asymptotically exact semiclassical quantum gravity derived from the Wheeler-DeWitt equation by finding a particular coherent state representation of a quantum scalar field in which the back-reaction of…

General Relativity and Quantum Cosmology · Physics 2011-08-17 Sang Pyo Kim

Based upon the holographic principle, Jacobson demonstrated that the spacetime can be viewed as a gas of atoms with a related entropy given by the Bekenstein-Hawking formula. Following this argument, Friedmann equations can be derived by…

General Relativity and Quantum Cosmology · Physics 2015-10-13 C. A. S. Silva

Explicit realizations of quantum field theory (QFT) are admitted by a revision to the Wightman axioms for the vacuum expectation values (VEV) of fields. The technical development of QFT is expanded beyond positive functionals on *-algebras…

Mathematical Physics · Physics 2014-10-02 Glenn Eric Johnson

Quantum gravity is fundamentally different from the non-gravitational quantum field theories in the sense that most of the techniques derived for the latter cannot be easily extended to the former. For example, correlation functions in…

High Energy Physics - Theory · Physics 2024-12-02 Keshav Dasgupta , Fang-Yi Guo , Bohdan Kulinich

We investigate gravity as a gauge theory in the language of fiber bundles with tools from algebraic geometry. Compelled by the construction of the Eilenberg-MacLane classifying space via Fox derivations in an integral group ring, the origin…

General Physics · Physics 2016-01-22 Rafael A. Araya-Gochez