An exact model for enhancing/suppressing primordial fluctuations

verfasst von: Guillem Domènech, Gerson Vargas, Teófilo Vargas
Abstract: Enhancements of primordial curvature fluctuations in single field inflation often involve departures from attractor trajectories in the phase space. We study enhancement/suppression of primordial fluctuations in one of the simplest models with exact background solutions for arbitrary initial conditions: a single field inflationary model with a piecewise exponential potential. We then present close to exact analytical solutions for primordial fluctuations in a general transition between two slow-roll attractors, valid whether the first slow parameter increases or decreases. The main features in the primordial spectrum are determined by the ratio of exponents of the potential. We also discuss the imprint of such features in the induced GW spectrum. Lastly, we apply the δN formalism to discuss non-Gaussianities and the tail of the probability distribution. We find that while non-Gaussianities are at most o(1) in the case of enhancement, they can be very large in the case of suppression. Our work can be easily generalized to multiple piecewise exponential potentials.
Organisationseinheit(en): Institut für Theoretische Physik
Externe Organisation(en): Universidad Nacional Mayor de San Marcos
Typ: Artikel
Journal: Journal of Cosmology and Astroparticle Physics
Band: 2024
Anzahl der Seiten: 41
ISSN: 1475-7516
Publikationsdatum: 05.03.2024
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Astronomie und Astrophysik
Elektronische Version(en): https://doi.org/10.48550/arXiv.2309.05750 (Zugang: Offen)
https://doi.org/10.1088/1475-7516/2024/03/002 (Zugang: Offen)

BibTeX

@article{31c81345f7d74d84bb74684c33136f18,
title = "An exact model for enhancing/suppressing primordial fluctuations",
abstract = "Enhancements of primordial curvature fluctuations in single field inflation often involve departures from attractor trajectories in the phase space. We study enhancement/suppression of primordial fluctuations in one of the simplest models with exact background solutions for arbitrary initial conditions: a single field inflationary model with a piecewise exponential potential. We then present close to exact analytical solutions for primordial fluctuations in a general transition between two slow-roll attractors, valid whether the first slow parameter increases or decreases. The main features in the primordial spectrum are determined by the ratio of exponents of the potential. We also discuss the imprint of such features in the induced GW spectrum. Lastly, we apply the δN formalism to discuss non-Gaussianities and the tail of the probability distribution. We find that while non-Gaussianities are at most o(1) in the case of enhancement, they can be very large in the case of suppression. Our work can be easily generalized to multiple piecewise exponential potentials.",
keywords = "cosmological perturbation theory, inflation, primordial black holes, primordial gravitational waves (theory)",
author = "Guillem Dom{\`e}nech and Gerson Vargas and Te{\'o}filo Vargas",
note = "Funding Information: G.D. is supported by the DFG under the Emmy-Noether program grant no. DO 2574/1-1, project number 496592360. T.V. is supported by the Vice-rectorate for Research and Postgraduate B20131101 and CONCYTEC through the Research Academic grant.",
year = "2024",
month = mar,
day = "5",
doi = "10.48550/arXiv.2309.05750",
language = "English",
volume = "2024",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing Ltd.",
number = "3",
}