Stable initial conditions and analytical investigations of cosmological perturbations in a modified loop quantum cosmology

Fuente: arXiv
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Main Authors: Pan, Rui, Saeed, Jamal, Wang, Anzhong
Format: Preprint
Published: 2025
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author Pan, Rui
Saeed, Jamal
Wang, Anzhong
author_facet Pan, Rui
Saeed, Jamal
Wang, Anzhong
contents In this paper, we study cosmological perturbations in a modified theory of loop quantum cosmologies, the so-called mLQC-I model. Our purposes are two-fold: First, using a method developed by Birrell and Davies, we identify an initial state in the remote contracting phase, which turns out to be stable, minimize particle creations and diagonalize the Hamiltonian, despite the fact that at this time some modes may be still outside of the Hubble horizon and not in their adiabatic states. Second, using the uniform asymptotic approximation method, we obtain the first-order approximate solutions of the mode function in terms of either the Airy functions, or the first or second kind of cylindrical functions, depending on the values of the wavenumber. In each case, the mode function contains two integration constants, which are uniquely determined by the initial state.
format Preprint
id arxiv_https___arxiv_org_abs_2505_14813
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Stable initial conditions and analytical investigations of cosmological perturbations in a modified loop quantum cosmology
Pan, Rui
Saeed, Jamal
Wang, Anzhong
General Relativity and Quantum Cosmology
In this paper, we study cosmological perturbations in a modified theory of loop quantum cosmologies, the so-called mLQC-I model. Our purposes are two-fold: First, using a method developed by Birrell and Davies, we identify an initial state in the remote contracting phase, which turns out to be stable, minimize particle creations and diagonalize the Hamiltonian, despite the fact that at this time some modes may be still outside of the Hubble horizon and not in their adiabatic states. Second, using the uniform asymptotic approximation method, we obtain the first-order approximate solutions of the mode function in terms of either the Airy functions, or the first or second kind of cylindrical functions, depending on the values of the wavenumber. In each case, the mode function contains two integration constants, which are uniquely determined by the initial state.
title Stable initial conditions and analytical investigations of cosmological perturbations in a modified loop quantum cosmology
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2505.14813