English
Related papers

Related papers: Does Cosmology require Hermiticity in Quantum Mech…

200 papers

It is shown that several prescriptions for the effective continuum limit of the flat Friedmann-Lemaitre-Robertson-Walker loop quantum cosmology can be understood as the exact classical limit of the Wheeler-DeWitt quantization of certain…

General Relativity and Quantum Cosmology · Physics 2025-04-23 Abraham Espinoza-García

We review recent literature on the connection between quantum entanglement and cosmology, with an emphasis on the context of expanding universes. We discuss recent theoretical results reporting on the production of entanglement in quantum…

General Relativity and Quantum Cosmology · Physics 2015-03-20 Eduardo Martin-Martinez , Nicolas C. Menicucci

For decades, Hermiticity was considered an immutable axiom of quantum mechanics, essential for ensuring real energies and unitary evolution. This perspective has shifted radically, driven by the realization that non-Hermitian Hamiltonians…

Quantum Physics · Physics 2026-03-17 Federico Roccati , Federico Balducci

In this review, we focus on whether a canonical quantization of general relativity can produce testable predictions for cosmology. In particular, we examine how this approach can be used to model the evolution of primordial perturbations.…

General Relativity and Quantum Cosmology · Physics 2023-10-20 Leonardo Chataignier , Claus Kiefer , Paulo Moniz

We contrast the initial condition requirements of various contemporary cosmological models, including inflationary and bouncing cosmologies. Various proposals such as Hartle-Hawking's no boundary, or Tunnelling boundary conditions are…

General Relativity and Quantum Cosmology · Physics 2014-11-17 D. H. Coule

We exploit the hidden symmetry structure of a recently proposed non-Hermitian Hamiltonian and of its Hermitian equivalent one. This sheds new light on the pseudo-Hermitian character of the former and allows access to a generalized quantum…

Quantum Physics · Physics 2009-11-11 B. Bagchi , C. Quesne , R. Roychoudhury

The implications of an Evolutionary Quantum Gravity are addressed in view of formulating a new dark matter candidate. We consider a Schr\"odinger dynamics for the gravitational field associated to a generic cosmological model and then we…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Marco Valerio Battisti , Giovanni Montani

Recently, Wang with Stankiewicz (Phys. Lett. B 800 (2020) 135106) opposed the widespread belief that due to quantization, the Big Bang singularity {\em must} necessarily get smeared and replaced by a non-singular "Big Bounce" process. Their…

General Relativity and Quantum Cosmology · Physics 2022-12-21 Miloslav Znojil

The operational approach to time is a cornerstone of relativistic theories, as evidenced by the notion of proper time. In standard quantum mechanics, however, time is an external parameter. Recently, many attempts have been made to extend…

Quantum Physics · Physics 2022-11-24 Ismael L. Paiva , Amit Te'eni , Bar Y. Peled , Eliahu Cohen , Yakir Aharonov

In this paper we investigate to which extent noncommutativity, a intrinsically quantum property, may influence the Friedmann-Robertson-Walker cosmological dynamics at late times/large scales. To our purpose it will be enough to explore the…

General Relativity and Quantum Cosmology · Physics 2011-08-10 Octavio Obregon , Israel Quiros

In order to study quantum dynamics of the FRW-universe of closed type, definitions of velocity, Hubble function and duration of the evolved universe are introduced into cosmology. The proposed definitions are characterized by high stability…

General Relativity and Quantum Cosmology · Physics 2014-05-23 Sergei P. Maydanyuk

Closed, singularity-free, inflationary cosmological models have recently been studied in the context of general relativity. Despite their appeal, these so called emergent models suffer from a number of limitations. These include the fact…

Astrophysics · Physics 2009-11-10 David J. Mulryne , Reza Tavakol , James E. Lidsey , George F. R. Ellis

For a FRW-spacetime coupled to an arbitrary real scalar field, we endow the solution space of the associated Wheeler-DeWitt equation with a Hilbert-space structure, construct the observables, and introduce the physical wave functions of the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Ali Mostafazadeh

The origin of cosmic structure is widely regarded as quantum, yet the Universe today appears classical. Standard lore attributes this to a "quantum-to-classical" transition on super-horizon scales during inflation. Gravity plays a central…

General Relativity and Quantum Cosmology · Physics 2026-04-03 Aurora Ireland

Selection of physically meaningful solutions of the Wheeler-DeWitt equation for the wavefunction in quantum cosmology, can be attained by a reduction of the theory to the sector of true physical degrees of freedom and their canonical…

General Relativity and Quantum Cosmology · Physics 2014-05-06 A. O. Barvinsky , A. Yu. Kamenshchik

Within the framework of symmetric teleparallel $f\left( Q\right) $-gravity for a connection defined in the non-coincidence gauge we derive the Wheeler-DeWitt equation of quantum cosmology. Because the gravitational field equation in…

General Relativity and Quantum Cosmology · Physics 2024-09-13 Andronikos Paliathanasis

In this paper, a new Hamiltonian constraint operator for loop quantum cosmology is constructed by using the Chern-Simons action. The quantum dynamics of the $k=0$ cosmological model with respect to a massless scalar field as an emergent…

General Relativity and Quantum Cosmology · Physics 2019-09-23 Jinsong Yang , Cong Zhang , Yongge Ma

In loop quantum gravity, modifications to the geometrical density cause a self-interacting scalar field to accelerate away from a minimum of its potential. In principle, this mechanism can generate the conditions that subsequently lead to…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Martin Bojowald , James E. Lidsey , David J. Mulryne , Parampreet Singh , Reza Tavakol

A diagonalizable non-Hermitian Hamiltonian having a real spectrum may be used to define a unitary quantum system, if one modifies the inner product of the Hilbert space properly. We give a comprehensive and essentially self-contained review…

Quantum Physics · Physics 2015-05-13 Ali Mostafazadeh

Wheeler-DeWitt equation is applied to $k > 0$ Friedmann Robertson Walker metric with various types of matter. It is shown that if the Universe ends in the matter dominated era (e.g., radiation or pressureless gas) with zero cosmological…

High Energy Physics - Theory · Physics 2010-11-01 Jong Hyun Kung