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We describe a simple gauge-fixing that leads to a construction of a quantum Hilbert space for quantum gravity in an asymptotically Anti de Sitter spacetime, valid to all orders of perturbation theory. The construction is motivated by a…

High Energy Physics - Theory · Physics 2023-06-28 Edward Witten

We present a new geometry of spacetime where events may be positive dimensional. This geometry is obtained by applying the identity of indiscernibles, which is a fundamental principle of quantum statistics, to time. Quantum nonlocality…

Quantum Physics · Physics 2015-11-18 Charlie Beil

Gravitational waves are considered as metric perturbations about a curved background metric, rather than the flat Minkowski metric since several situations of physical interest can be discussed by this generalization. In this case, when the…

General Relativity and Quantum Cosmology · Physics 2008-12-21 Donato Bini , Salvatore Capozziello , Giampiero Esposito

In this expository note, I present some basic geometric and twistor theoretic facts about de Sitter space leading up to a discussion of Penrose's quasi-local mass construction for linear gravity theory in the de Sitter background. The…

General Relativity and Quantum Cosmology · Physics 2015-05-25 Paul Tod

We investigate a relation of the contravariant geometry to the emergent gravity from noncommutative gauge theories. We give a refined formulation of the contravariant gravity and provide solutions to the contravariant Einstein equation. We…

High Energy Physics - Theory · Physics 2018-02-09 Yukio Kaneko , Hisayoshi Muraki , Satoshi Watamura

In a recent paper we have suggested that a formulation of quantum mechanics should exist, which does not require the concept of time, and that the appropriate mathematical language for such a formulation is noncommutative differential…

General Relativity and Quantum Cosmology · Physics 2015-06-25 T. P. Singh

Quantum mechanics in its presently known formulation requires an external classical time for its description. A classical spacetime manifold and a classical spacetime metric are produced by classical matter fields. In the absence of such…

General Relativity and Quantum Cosmology · Physics 2008-11-26 T. P. Singh

Extending earlier work(*), we examine the deformation of the canonical symplectic structure in a cotangent bundle $T^\star(\Q)$ by additional terms implying the Poisson non-commutativity of both configuration and momentum variables. In this…

Mathematical Physics · Physics 2008-11-26 F. J. Vanhecke , C. Sigaud , A. R. da Silva

We consider scalar field theory in de Sitter space with a general vacuum invariant under the continuously connected symmetries of the de Sitter group. We begin by reviewing approaches to define this as a perturbative quantum field theory.…

High Energy Physics - Theory · Physics 2009-11-10 Kevin Goldstein , David A. Lowe

In this paper we present a cosmological model arising from a non-conservative gravitational theory proposed in [PRD 95, 101501(R) (2017)]. The novel feature where comparing with previous implementations of dissipative effects in gravity is…

General Relativity and Quantum Cosmology · Physics 2018-05-28 Júlio C. Fabris , Hermano Velten , Thiago R. P. Caramês , Matheus J. Lazo , Gastão S. F. Frederico

Close to the Planck energy scale, the quantum nature of space-time reveals itself and all forces, including gravity, should be unified so that all interactions correspond to just one underlying symmetry. In the absence of a full quantum…

High Energy Physics - Theory · Physics 2015-03-17 Mairi Sakellariadou

We illustrate an isomorphic representation of the observable algebra for quantum mechanics in terms of the functions on the projective Hilbert space, and its Hilbert space analog, with a noncommutative product in terms of explicit…

Quantum Physics · Physics 2022-02-09 Otto C. W. Kong , Wei-Yin Liu

Using an approach similar to arXiv:2409.15460, we give a new proof of the nonlinear stability of de Sitter space as a solution to the Einstein vacuum equations with positive cosmological constant in $n+1$ dimensions, with $n\geq3$. Using…

Analysis of PDEs · Mathematics 2026-05-06 Maurus Leimbacher

Several versions of fuzzy four-dimensional de Sitter space are constructed using the noncommutative frame formalism. Although all noncommutative spacetimes which are found have commutative de Sitter metric as a classical limit, the algebras…

High Energy Physics - Theory · Physics 2015-08-26 Maja Buric , John Madore

In this short note, we verify explicitly in static coordinates that the non trivial asymptotic Killing vectors at spatial infinity for anti-de Sitter space-times correspond one to one to the conformal Killing vectors of the conformally flat…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Glenn Barnich , Friedemann Brandt , Kim Claes

In recent years the idea that not only the configuration space of particles, i.e. spacetime, but also the corresponding momentum space may have nontrivial geometry has attracted significant attention, especially in the context of quantum…

High Energy Physics - Theory · Physics 2016-06-28 Jakub Mielczarek , Tomasz Trzesniewski

We show that if a discrete quantum gravity is not classical, then it cannot be generated by an isometric dynamics. In particular, we show that if the quantum measure {\mu} (or equivalently the decoherence functional) is generated by an…

General Relativity and Quantum Cosmology · Physics 2011-12-06 Stan Gudder

We find a new, non-commutative geometry inspired, solution of the coupled Einstein-Maxwell field equations describing a variety of charged, self-gravitating objects, including extremal and non-extremal black holes. The metric smoothly…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Stefano Ansoldi , Piero Nicolini , Anais Smailagic , Euro Spallucci

We present the first detailed study of the kinematics of free relativistic particles whose symmetries are described by a quantum deformation of the de Sitter algebra, known as $q$-de Sitter Hopf algebra. The quantum deformation parameter is…

General Relativity and Quantum Cosmology · Physics 2016-06-29 Leonardo Barcaroli , Giulia Gubitosi

One of the longstanding problems of modern gravitational physics is the detection of gravitational waves, for which the standard theoretical analysis relies upon the split of the space-time metric into a background metric plus perturbation.…

General Relativity and Quantum Cosmology · Physics 2010-04-19 Roberto Valentino Montaquila
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