Results 41 to 50 of about 39,130 (174)

INFLATIONARY COSMOLOGY AND OSCILLATING UNIVERSES IN LOOP QUANTUM COSMOLOGY [PDF]

open access: yesInternational Journal of Modern Physics A, 2005
We study oscillatory universes within the context of Loop Quantum Cosmology. We make a comparative study of flat and positively curved universes sourced by scalar fields with either positive or negative potentials. We investigate how oscillating universes can set the initial conditions for successful slow-roll inflation, while ensuring that the semi ...
Mulryne, David J.   +3 more
openaire   +3 more sources

Loop quantum gravity and cosmological constant

open access: yesPhysics Letters B, 2021
A one-parameter regularization freedom of the Hamiltonian constraint for loop quantum gravity is analyzed. The corresponding spatially flat, homogenous and isotropic model includes the two well-known models of loop quantum cosmology as special cases. The
Xiangdong Zhang, Gaoping Long, Yongge Ma
doaj   +1 more source

Mimetic gravity: mimicking the dynamics of the primeval universe in the context of loop quantum cosmology

open access: yesEuropean Physical Journal C: Particles and Fields, 2019
Mimetic gravity can be described as a formulation capable of mimicking different evolutionary scenarios regarding the universe dynamics. Notwithstanding its initial aim of producing a similar evolution to the one expected from the dark components of the ...
Eunice Bezerra, Oswaldo D. Miranda
doaj   +1 more source

The perturbed universe in the deformed algebra approach of Loop Quantum Cosmology

open access: yes, 2016
Loop quantum cosmology is a tentative approach to model the universe down to the Planck era where quantum gravity settings are needed. The quantization of the universe as a dynamical space-time is inspired by Loop Quantum Gravity ideas. In addition, loop
Grain, J.
core   +3 more sources

Inflationary Cosmology and Quantization Ambiguities in Semi-Classical Loop Quantum Gravity [PDF]

open access: yes, 2004
In loop quantum gravity, modifications to the geometrical density cause a self-interacting scalar field to accelerate away from a minimum of its potential.
A. Ashtekar   +30 more
core   +3 more sources

ON THE SEMICLASSICAL LIMIT OF LOOP QUANTUM COSMOLOGY

open access: yesInternational Journal of Modern Physics D, 2012
We consider a k = 0 Friedman–Robertson–Walker (FRW) model within loop quantum cosmology (LQC) and explore the issue of its semiclassical limit. The model is exactly solvable and allows us to construct analytical (Gaussian) coherent-state solutions for each point on the space of classical states.
Corichi, Alejandro, Montoya, Edison
openaire   +3 more sources

Quantum reduced loop gravity and the foundation of loop quantum cosmology [PDF]

open access: yesInternational Journal of Modern Physics D, 2016
Quantum reduced loop gravity is a promising framework for linking loop quantum gravity and the effective semiclassical dynamics of loop quantum cosmology. We review its basic achievements and its main perspectives, outlining how it provides a quantum description of the Universe in terms of a cuboidal graph which constitutes the proper framework for ...
Emanuele Alesci, Francesco Cianfrani
openaire   +3 more sources

Generic absence of strong singularities and geodesic completeness in modified loop quantum cosmologies [PDF]

open access: yes, 2019
Different regularizations of the Hamiltonian constraint in loop quantum cosmology yield modified loop quantum cosmologies, namely mLQC-I and mLQC-II, which lead to qualitatively different Planck scale physics.
Saini, Sahil, Singh, Parampreet
core   +3 more sources

Probability of inflation in loop quantum cosmology [PDF]

open access: yesGeneral Relativity and Gravitation, 2011
34 pages, 3 ...
Ashtekar, Abhay, Sloan, David
openaire   +3 more sources

Effective Field Theory of Loop Quantum Cosmology

open access: yesUniverse, 2019
Quantum cosmology is traditionally formulated in a minisuperspace setting, implicitly averaging fields over space to obtain homogeneous models. For universal reasons related to the uncertainty principle, quantum corrections then depend on the size of the
Martin Bojowald
doaj   +1 more source

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