Non-oscillating power spectra in loop quantum cosmology

Elizaga de Navascués B, Mena Marugán GA, Prado S (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Classical and Quantum Gravity Institute of Physics: Hybrid Open Access

Book Volume: 38

Article Number: 035001

Journal Issue: 3

DOI: 10.1088/1361-6382/abc6bb

Abstract

We characterize in an analytical way the general conditions that a choice of vacuum state for the cosmological perturbations must satisfy to lead to a power spectrum with no scale-dependent oscillations over time. In particular, we pay special attention to the case of cosmological backgrounds governed by effective loop quantum cosmology and in which the Einsteinian branch after the bounce suffers a pre-inflationary period of decelerated expansion. This is the case more often studied in the literature because of the physical interest of the resulting predictions. In this context, we argue that non-oscillating power spectra are optimal to gain observational access to those regimes near the bounce where loop quantum cosmology effects are non-negligible. In addition, we show that non-oscillatory spectra can indeed be consistently obtained when the evolution of the perturbations is ruled by the hyperbolic equations derived in the hybrid loop quantization approach. Moreover, in the ultraviolet regime of short wavelength scales we prove that there exists a unique asymptotic expansion of the power spectrum that displays no scale-dependent oscillations over time. This expansion would pick out the natural Poincaré and Bunch-Davies vacua in Minkowski and de Sitter spacetimes, respectively, and provides an appealing candidate for the choice of a vacuum for the perturbations in loop quantum cosmology based on physical motivations.

Authors with CRIS profile

Beatriz Elizaga de Navascués Chair for Theoretical Physics III (Quantum Gravity)

Involved external institutions

Institute for the Structure of Matter / Instituto de Estructura de la Materia (IEM) ES Spain (ES)

How to cite

APA:

Elizaga de Navascués, B., Mena Marugán, G.A., & Prado, S. (2021). Non-oscillating power spectra in loop quantum cosmology. Classical and Quantum Gravity, 38(3). https://dx.doi.org/10.1088/1361-6382/abc6bb

MLA:

Elizaga de Navascués, Beatriz, Guillermo A. Mena Marugán, and Santiago Prado. "Non-oscillating power spectra in loop quantum cosmology." Classical and Quantum Gravity 38.3 (2021).

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