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Related papers: Quantum Breaking Bound on de Sitter and Swampland

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An overview is given of effective gravitational field theories with fixed background fields that break spacetime symmetry. The behavior of the background fields and the types of excitations that can occur depend on whether the symmetry…

General Relativity and Quantum Cosmology · Physics 2017-10-31 Robert Bluhm

We study perturbative unitarity bounds on the field-space curvature in de Sitter spacetime, using the momentum-space entanglement approach recently proposed by Duaso Pueyo, Goodhew, McCulloch, and Pajer. As an illustration, we perform a…

High Energy Physics - Theory · Physics 2026-03-17 Qianhang Cai , Tomoya Inada , Masataka Ishikawa , Kanji Nishii , Toshifumi Noumi

We study the effects of explicit spacetime-symmetry breaking on primordial tensor fluctuations using an effective-field theory for Lorentz/CPT violation. We find that the graviton is still massless, but that the propagation speed of tensor…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Nils A. Nilsson

Among Swampland conditions, the distance conjecture characterizes the geometry of scalar fields and the de Sitter conjecture constrains allowed potentials on it. We point out a connection between the distance conjecture and a refined…

High Energy Physics - Theory · Physics 2018-11-21 Hirosi Ooguri , Eran Palti , Gary Shiu , Cumrun Vafa

If entanglement builds spacetime, then conversely, disentanglement ought to destroy spacetime. From the quantum null energy condition and quantum focusing conjecture, we obtain disentanglement criteria which necessitate infinite energies…

High Energy Physics - Theory · Physics 2025-01-29 Hong Zhe Chen

A quantum theory of gravity is described in the case of a positive cosmological constant in 3+1 dimensions. Both old and new results are described, which support the case that loop quantum gravity provides a satisfactory quantum theory of…

High Energy Physics - Theory · Physics 2007-05-23 Lee Smolin

For certain terms in the action, supersymmetry can forbid an infinite number of possible contributions. We study whether such protection can occur in quantum gravity even without sufficient supersymmetry. We focus on whether the…

High Energy Physics - Theory · Physics 2020-07-15 Eran Palti , Cumrun Vafa , Timo Weigand

The density of mass levels \rho(m) and the critical temperature for strings in de Sitter space-time are found. QFT and string theory in de Sitter space are compared. A `Dual'-transform is introduced which relates classical to quantum string…

High Energy Physics - Theory · Physics 2009-10-31 M. Ram'on Medrano , N. S'anchez

The quantum nature of the Big Bang is reexamined in the framework of Loop Quantum Cosmology. The strict application of a regularization procedure to the Hamiltonian, originally developed for the Hamiltonian in loop quantum gravity, leads to…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Mehdi Assanioussi , Andrea Dapor , Klaus Liegener , Tomasz Pawłowski

We construct a model of the Cyclic Universe from a joint theory of General relativity, Thermodynamics and Quantum information theory. Friedmann equations and the thermodynamical Gibbs-Duhem relation determine a general form of the Hubble…

General Relativity and Quantum Cosmology · Physics 2018-11-21 Miloslav Svec

We formulate the information paradox in de Sitter space in terms of the no-cloning principle of quantum mechanics. We show that energy conservation puts an upper bound on the maximum entropy available to any de Sitter observer. Combined…

High Energy Physics - Theory · Physics 2008-11-26 Maulik K. Parikh , Jan Pieter van der Schaar

In this Letter, we study the implications of string Swampland criteria for dark energy in view of ongoing and future cosmological observations. If string theory should be the ultimate quantum gravity theory, there is evidence that exact de…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Lavinia Heisenberg , Matthias Bartelmann , Robert Brandenberger , Alexandre Refregier

We study the dynamics of quantum-memory-assisted entropic uncertainty for a hybrid qutrit-qubit system interacting with fluctuating quantum scalar field in the background of expanding de Sitter space. We firstly derive the master equation…

Quantum Physics · Physics 2019-05-06 Zhiming Huang

When it comes to performing thought experiments with black holes, Einstein-Bohr like discussions have to be re-opened. For instance one can ask what happens to the quantum state of a black hole when the wave function of a single ingoing…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. 't Hooft

The uncertainty principle restricts our ability to simultaneously predict the measurement outcomes of two incompatible observables of a quantum particle. However, this uncertainty could be reduced and quantified by a new Entropic…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Lijuan Jia , Zehua Tian , Jiliang Jing

The decay rate of the Bunch-Davies state of a massive scalar field in the expanding flat spatial sections of de Sitter space is determined by an analysis of the particle pair creation process in real time. The Feynman definition of particle…

General Relativity and Quantum Cosmology · Physics 2018-04-04 Paul R. Anderson , Emil Mottola , Dillon H. Sanders

Gravitational physics is arguably better understood in the presence of a negative cosmological constant than a positive one, yet there exist strong technical similarities between the two settings. These similarities can be exploited to…

High Energy Physics - Theory · Physics 2020-10-21 Alice Di Tucci , Michal P. Heller , Jean-Luc Lehners

Two spatial regions $B$ and $R$ are hyperentangled if the generalized entropy satisfies $S_{\text{gen}}^{B\cup R}<S_{\text{gen}}^R$. If in addition all future (or all past) directed inward null shape deformations of $B$ decrease…

High Energy Physics - Theory · Physics 2023-03-30 Raphael Bousso , Arvin Shahbazi-Moghaddam

We discuss some general properties of quantum gravity in De Sitter space. It has been argued that the Hilbert space is of finite dimension. This suggests a macroscopic argument that General Relativity cannot be quantized -- unless it is…

High Energy Physics - Theory · Physics 2007-05-23 Edward Witten

In a quantum theory of gravity spacetime behaves classically when quantum probabilities are high for histories of geometry and field that are correlated in time by the Einstein equation. Probabilities follow from the quantum state. This…

High Energy Physics - Theory · Physics 2015-09-16 James Hartle , Thomas Hertog
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