Results 1 to 10 of about 116,432 (201)

Quantum String Cosmology [PDF]

open access: yesUniverse, 2021
We present a short review of possible applications of the Wheeler-De Witt equation to cosmological models based on the low-energy string effective action, and characterised by an initial regime of asymptotically flat, low energy, weak coupling evolution.
Maurizio Gasperini
doaj   +4 more sources

Is a loopy and noncommutative early Universe viable?

open access: yesPhysics Letters B, 2023
We conduct a (pre-)inflationary dynamics study of the chaotic quadratic potential within the framework of a simple noncommutative extension of effective loop quantum cosmology put forward recently.
Luis Rey Díaz-Barrón   +3 more
doaj   +1 more source

Bouncing Quantum Cosmology

open access: yesUniverse, 2021
The goal of this contribution is to present the properties of a class of quantum bouncing models in which the quantum bounce originates from the Dirac canonical quantization of a midi-superspace model composed of a homogeneous and isotropic background ...
Nelson Pinto-Neto
doaj   +1 more source

Quantum Nature of the Big Bang: Improved dynamics [PDF]

open access: yes, 2006
An improved Hamiltonian constraint operator is introduced in loop quantum cosmology. Quantum dynamics of the spatially flat, isotropic model with a massless scalar field is then studied in detail using analytical and numerical methods.
A. Ashtekar   +11 more
core   +3 more sources

Modern cosmology: 100 years of quantum science [PDF]

open access: yesKragujevac Journal of Science
In this article, we contribute to the special issue of the Kragujevac Journal of Science devoted to the International Year of Quantum Science and Technology (IYQ2025). We discuss several connections between Quantum Theory and Modern Cosmology.
Dimitrijević Dragoljub D.   +1 more
doaj   +1 more source

L'emergenza dello spazio-tempo nella gravità quantistica e nella cosmologia quantistica

open access: yesPhilosophy Kitchen, 2019
Our best description of spacetime is provided by general relativity – yet, this theory is not thought to be fundamental. Instead, it is expected to be replaced by a theory of quantum gravity, which may not feature spacetime fundamentally.
Karen Crowther
doaj   +1 more source

(b,v)-type variables for black to white hole transitions in effective loop quantum gravity

open access: yesPhysics Letters B, 2021
Quantum gravity effects in effective models of loop quantum gravity, such as loop quantum cosmology, are encoded in the choice of so-called polymerisation schemes.
Norbert Bodendorfer   +2 more
doaj   +1 more source

Loop Quantum Cosmology, Modified Gravity and Extra Dimensions

open access: yesUniverse, 2016
Loop quantum cosmology (LQC) is a framework of quantum cosmology based on the quantization of symmetry reduced models following the quantization techniques of loop quantum gravity (LQG).
Xiangdong Zhang
doaj   +1 more source

Tachyon field in loop cosmology

open access: yesPhysics Letters B, 2020
The evolutionary pictures of tachyon field in modified loop cosmology have been investigated. We present the dynamical behavior of the tachyon field associated with an exponential potential and find that the pre-inflation dynamics are very similar in ...
Kui Xiao
doaj   +1 more source

Quantum Gravity Effects in Cosmology

open access: yesEPJ Web of Conferences, 2018
Within the geometrodynamic approach to quantum cosmology, we studied the quantum gravity effects in cosmology. The Gibbons-Hawking temperature is corrected by quantum gravity due to spacetime fluctuations and the power spectrum as well as any probe field
Gu Je-An, Pyo Kim Sang, Shen Che-Min
doaj   +1 more source

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