A quantum gravitational inflationary scenario in Bianchi-I spacetime

Abstract

We investigate the ${\varphi }^2$ inflationary model in the Bianchi-I spacetime using effective spacetime description of loop quantum cosmology to understand the issues of the resolution of initial singularity, isotropization, effect of anisotropies on amount of inflation, and the phase space attractors in the presence of non-perturbative quantum gravitational modifications. A comparative analysis with the classical theory by including more general initial conditions than the ones previously considered in the latter is also performed. We show that, in general, the classical singularity is replaced by a bounce of the mean scale factor in loop quantum cosmology. Due to the underlying quantum geometric effects, the energy density of the inflaton and the anisotropic shear remain bounded throughout the non-singular evolution. Starting from arbitrary anisotropic initial conditions, a loop quantum universe isotropizes either before or soon after the onset of slow-roll inflation. We find a double attractor behavior in the phase space dynamics of loop quantum cosmology, similar to the one in classical theory, but with some additional subtle features. Quantum modifications to the dynamical equations are such that, unlike the classical theory, the amount of inflation does not monotonically depend on the initial anisotropy in loop quantum cosmology. Our results suggest that a viable non-singular inflationary model can be constructed from highly anisotropic initial conditions in the Planck regime.

35 pages, 19 figures. References added. Minor changes to match published version. To appear in CQG

References in corpus (20)

• Quantum Nature of the Big Bang: Improved dynamics
• Quantum Nature of the Big Bang
• Quantum Nature of the Big Bang: An Analytical and Numerical Investigation
• Inflationary Universe with Anisotropic Hair
• Corrections to the Friedmann Equations from LQG for a Universe with a Free Scalar Field
• Non-Singular Bouncing Universes in Loop Quantum Cosmology
• Loop quantum cosmology and the k = - 1 RW model
• Closed FRW model in Loop Quantum Cosmology
• A geometric perspective on singularity resolution and uniqueness in loop quantum cosmology
• Loop Quantization of Vacuum Bianchi I Cosmology
• Physical evolution in Loop Quantum Cosmology: The example of vacuum Bianchi I
• Loop Quantum Cosmology in Bianchi Type I Models: Analytical Investigation
• The behavior of non-linear anisotropies in bouncing Bianchi I models of loop quantum cosmology
• A Model of Universe Anisotropization
• On the measure problem in slow roll inflation and loop quantum cosmology
• Quantum gravitational Kasner transitions in Bianchi-I spacetime
• Open FRW model in Loop Quantum Cosmology
• Loop Quantum Cosmology of Diagonal Bianchi Type I model: simplifications and scaling problems
• Gravity Waves Signatures from Anisotropic pre-Inflation
• Non-singular Power-law and Assisted inflation in Loop Quantum Cosmology

Cited by in corpus (26)

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• Quantum Reduced Loop Gravity and the foundation of Loop Quantum Cosmology
• General dissipative coefficient in warm intermediate inflation in loop quantum cosmology in light of Planck and BICEP2
• Primordial power spectrum from the dressed metric approach in loop cosmologies
• Phenomenological implications of modified loop cosmologies: an overview
• Anomalies in the CMB from a cosmic bounce
• Is classical flat Kasner spacetime flat in quantum gravity?
• Some conceptual issues in loop quantum cosmology
• Exhaustive investigation of the duration of inflation in effective anisotropic loop quantum cosmology
• Einstein-Cartan gravitational collapse of a homogeneous Weyssenhoff fluid
• Predictions for the CMB from an anisotropic quantum bounce
• Observational consequences of Bianchi I spacetimes in loop quantum cosmology
• Singularity avoidance in the hybrid quantization of the Gowdy model
• Quantum gravitational onset of Starobinsky inflation in a closed universe
• Hamiltonian theory of classical and quantum gauge invariant perturbations in Bianchi I spacetimes
• Loop quantum cosmology: relation between theory and observations
• Quantum gravity might restrict a cyclic evolution
• Phenomenology analysis of duration inflation for Tachyon field in loop quantum cosmology
• Loop Quantum Cosmology: Physics of Singularity Resolution and its Implications
• Alternative effective mass functions in the modified Mukhanov-Sasaki equation of loop quantum cosmology
• $w=-1$ as an Attractor
• Ekpyrosis in Quantum Gravitational Anisotropic Bouncing Models
• 2+1 dimensional loop quantum cosmology of Bianchi I models