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Related papers: Cosmological footprints of loop quantum gravity

200 papers

I present a streamlined review of how the separate universe approach to cosmological perturbation theory can be used to study the dynamics of long-wavelength scalar perturbations in loop quantum cosmology, and then use it to calculate how…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Edward Wilson-Ewing

We review several related investigations of the effects of the quantum stress tensor of a conformal field in inflationary cosmology. Particular attention will be paid to the effects of quantum stress tensor fluctuations as a source of…

General Relativity and Quantum Cosmology · Physics 2011-12-15 Jen-Tsung Hsiang , Chun-Hsien Wu , L. H. Ford , Kin-Wang Ng

We discuss the effects of cosmic phase transition on the spectrum of primordial gravitational waves generated during inflation. The energy density of the scalar condensation responsible for the phase transition may become sizable at the…

High Energy Physics - Phenomenology · Physics 2015-06-03 Ryusuke Jinno , Takeo Moroi , Kazunori Nakayama

In the context of Quantum Cosmology and the Wheeler-DeWitt equation we investigate the possible effects of a non semiclassical wave-function of the universe on the evolution of the inflationary perturbations. These are associated with the…

General Relativity and Quantum Cosmology · Physics 2018-06-20 A. Y. Kamenshchik , A. Tronconi , T. Vardanyan , G. Venturi

The particle production process is reviewed, through which cosmic inflation can produce a scale invariant superhorizon spectrum of perturbations of suitable fields starting from their quantum fluctuations. Afterwards, in the context of the…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-28 Konstantinos Dimopoulos

We consider the effects of entanglement in the initial quantum state of scalar and tensor fluctuations during inflation. We allow the gauge-invariant scalar and tensor fluctuations to be entangled in the initial state and compute…

High Energy Physics - Theory · Physics 2017-01-13 Nadia Bolis , Andreas Albrecht , R. Holman

An assessment is made of recent attempts to evaluate how quantum gravity may affect the anisotropy spectrum of the cosmic microwave background. A perturbative scheme for the solution of the Wheeler-DeWitt equation has been found to allow…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Donato Bini , Giampiero Esposito

Multi-messenger astronomy provides us with the possibility of discovering phenomenological signatures of quantum-gravity effects. This should be of paramount importance in the pursuit of an elusive quantum theory for the gravitational…

General Relativity and Quantum Cosmology · Physics 2023-12-25 Gabriel Menezes

Positively-curved, oscillatory universes are studied within the context of Loop Quantum Cosmology subject to a consistent semi-classical treatment. The semi-classical effects are reformulated in terms of an effective phantom fluid with a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 James E. Lidsey , David J. Mulryne , N. J. Nunes , Reza Tavakol

After a brief introduction to classical and quantum gravity we discuss applications of loop quantum gravity in the cosmological realm. This includes the basic formalism and recent results of loop quantum cosmology, and a computation of…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Martin Bojowald , Hugo A. Morales-Tecotl

In the early universe it is important to take into account quantum effect of the gravity to explain the feature of the inflation. In this paper, we consider the M-theory effective action which consists of 11 dimensional supergravity and…

High Energy Physics - Theory · Physics 2021-04-20 Kazuho Hiraga , Yoshifumi Hyakutake

We study in detail the power spectra of scalar and tensor perturbations generated during inflation in loop quantum cosmology (LQC). After clarifying in a novel quantitative way how inverse-volume corrections arise in inhomogeneous settings,…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Martin Bojowald , Gianluca Calcagni , Shinji Tsujikawa

Primordial gravitational waves are a crucial prediction of inflation theory, and their detection through their imprints on the cosmic microwave background is actively being pursued. However, these attempts have not yet been successful. In…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-06 Yan-Heng Yu , Sai Wang

This paper is the third in a series of theorems which state how cosmological observations can provide evidence for an early phase of acceleration in the universe. Previous theorems demonstrated that the observed power spectrum for scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-19 Ghazal Geshnizjani , William H. Kinney

This introductory review is addressed to beginning researchers. Some of the distinguishing features of loop quantum gravity are illustrated through loop quantum cosmology of FRW models. In particular, these examples illustrate: i) how…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Abhay Ashtekar

Quantum gravity has long been thought to be completely decoupled from experiments or observations. Although it is true that smoking guns are still missing, there are now serious hopes that quantum gravity phenomena might be tested. We…

General Relativity and Quantum Cosmology · Physics 2015-10-29 A. Barrau , J. Grain

We examine the quantum loop effects on the single-field inflationary models in a spatially flat Friedmann-Robertson-Walker (FRW) cosmological space-time with a general self-interacting scalar field potential, which is modeled in terms of…

General Relativity and Quantum Cosmology · Physics 2020-02-05 Wei-Can Syu , Da-Shin Lee , Kin-Wang Ng

Quantum effects play an essential role in modern cosmology. Perhaps the most striking example comes from large-scale structures, generally assumed to originate from vacuum quantum fluctuations and stretched by an expansion phase. Inflation…

General Relativity and Quantum Cosmology · Physics 2020-10-08 Emmanuel Frion

We derive the power spectrum of primordial quantum fluctuations in an inflationary universe for curvature parameter ${\mathcal K}=1$. This is achieved through a Born--Oppenheimer type of approximation scheme from the Wheeler--DeWitt…

General Relativity and Quantum Cosmology · Physics 2022-04-05 Claus Kiefer , Tatevik Vardanyan

Research during the last decade demonstrates that effects originating on the Planck scale are currently being tested in multiple observational contexts. In this review we discuss quantum gravity phenomenological models and their possible…

General Relativity and Quantum Cosmology · Physics 2012-12-14 Florian Girelli , Franz Hinterleitner , Seth A. Major