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Related papers: On Spinfoams Near a Classical Curvature Singularit…

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We investigate the requirement of suppressing spacetime geometries with a curvature singularity via destructive interference in the Lorentzian gravitational path integral as a constraint on the microscopic action for gravity. Based on…

General Relativity and Quantum Cosmology · Physics 2024-05-07 Johanna Borissova

We study the "improved dynamics" for the treatment of spherically symmetric space-times in loop quantum gravity introduced by Chiou {\em et al.} in analogy with the one that has been constructed by Ashtekar, Pawlowski and Singh for the…

General Relativity and Quantum Cosmology · Physics 2020-10-28 R. Gambini , J. Olmedo , J. Pullin

In this paper, an open quantum system theory for spinfoams is developed. This new formalism aims at deriving an effective Lindblad equation to compute the reduced dynamics of a quantum gravitational field. The system parameters are…

Quantum Physics · Physics 2021-05-26 Quentin Ansel

The unification of general relativity and quantum theory is one of the fascinating problems of modern physics. One leading solution is Loop Quantum Gravity (LQG). Simulating LQG may be important for providing predictions which can then be…

Loop Quantum Cosmology (LQC), mainly due to Bojowald, is not the cosmological sector of Loop Quantum Gravity (LQG). Rather, LQC consists of a truncation of the phase space of classical General Relativity to spatially homogeneous situations…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Johannes Brunnemann , Thomas Thiemann

In this paper we summarize "loop quantum gravity" (LQG) and we show how ideas developed in LQG can solve the black hole singularity problem when applied to a minisuperspace model.

High Energy Physics - Theory · Physics 2007-05-23 Leonardo Modesto

Here, we present a review about the quantization of spherically-symmetric spacetimes adopting loop quantum gravity techniques. Several models that have been studied so far share similar properties: the resolution of the classical…

General Relativity and Quantum Cosmology · Physics 2016-06-22 Javier Olmedo

Based on modifications inspired from loop quantum gravity (LQG), spherically symmetric models have recently been explored to understand the resolution of classical singularities and the fate of the spacetime beyond. While such…

General Relativity and Quantum Cosmology · Physics 2023-08-23 Kristina Giesel , Hongguang Liu , Parampreet Singh , Stefan Andreas Weigl

We describe a refined version of a previous proposal for the exploration of quantum gravity phenomenology. Unlike the original scheme, the one presented here is free from sign ambiguities while it shares with the previous one the essential…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Yuri Bonder , Daniel Sudarsky

We extend the ideas introduced in the previous work to a more general space-time. In particular we consider the Kantowski-Sachs space time with space section with topology $R \times S^2$. In this way we want to study a general space time…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Leonardo Modesto

A decoherence mechanism caused by spacetime curvature is discussed. The spin state of a particle is shown to decohere if only the particle moves in a curved spacetime. In particular, when a particle is near the event horizon of a black…

Quantum Physics · Physics 2009-11-10 Hiroaki Terashima , Masahito Ueda

We apply the full theory of Loop Quantum Gravity (LQG) to cosmology and present a top-down derivation of gauge-invariant cosmological perturbation theory from quantum gravity. The derivation employs the reduced phase space formulation of…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Muxin Han , Haida Li , Hongguang Liu

We review aspects of loop quantum gravity in a pedagogical manner, with the aim of enabling a precise but critical assessment of its achievements so far. We emphasise that the off-shell (`strong') closure of the constraint algebra is a…

High Energy Physics - Theory · Physics 2009-11-11 Hermann Nicolai , Kasper Peeters , Marija Zamaklar

There are not many tools to quantitatively monitor the emergence of classical geometric features from a quantum spacetime, whose microscopic structure may be a highly quantum-fluctuating "spacetime foam". To improve this situation, we…

High Energy Physics - Theory · Physics 2023-05-10 R. Loll , A. Silva

This work explores the intersection of quantum mechanics and curved spacetime by employing the Wigner formalism to investigate quantum systems in the vicinity of black holes. Specifically, we study the quantum dynamics of a probe particle…

General Relativity and Quantum Cosmology · Physics 2026-05-21 David Garcia-Garcia , Jose A. R. Cembranos

EPR-type measurements on spatially separated entangled spin qubits allow one, in principle, to detect curvature. Also the entanglement of the vacuum state is affected by curvature. Here, we ask if the curvature of spacetime can be expressed…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Achim Kempf

We find a nontrivial regime of spinfoam quantum gravity that reproduces classical Einstein equations. This is the double scaling limit of small Immirzi parameter (gamma), large spins (j) with physical area (gamma times j) constant. In…

General Relativity and Quantum Cosmology · Physics 2013-04-30 Elena Magliaro , Claudio Perini

We study homogenous and isotropic quantum cosmology using the spinfoam formalism of Loop Quantum Gravity (LQG). We define a coupling of a scalar field to the 4-dimensional Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model. We…

General Relativity and Quantum Cosmology · Physics 2024-02-14 Muxin Han , Hongguang Liu , Dongxue Qu , Francesca Vidotto , Cong Zhang

In the absence of a fully-fledged theory of quantum gravity, we propose a "bottom-up" framework for exploring quantum-gravitational physics by pairing two of the most fundamental concepts of quantum theory and general relativity, namely…

General Relativity and Quantum Cosmology · Physics 2022-12-20 Joshua Foo , Robert B. Mann , Magdalena Zych

We give a brief review of the problem of quantum gravity. After the discussion of the nonrenormalizability of general relativity, we briefly mention the main research directions which aim to resolve this problem. Our attention then focuses…

General Relativity and Quantum Cosmology · Physics 2015-12-22 Aleksandar Mikovic , Marko Vojinovic