Pre-Inflationary Relics in the CMB?

Gruppuso, A.; Kitazawa, N.; Natoli, P.; Sagnotti, A.; Mandolesi, N.

doi:10.1016/j.dark.2015.12.001

Article
Report number	CERN-PH-TH-2015-181 ; arXiv:1508.00411
Title	Pre-Inflationary Relics in the CMB?
Related title	Pre-Inflationary Relics in the CMB?
Author(s)	Gruppuso, A. (IASF, Bologna ; INFN, Bologna) ; Kitazawa, N. (Tokyo Metropolitan U.) ; Mandolesi, N. (Ferrara U. ; INFN, Ferrara ; IASF, Bologna) ; Natoli, P. (Ferrara U. ; INFN, Ferrara) ; Sagnotti, A. (CERN ; Pisa, Scuola Normale Superiore ; INFN, Pisa)
Publication	2016-03
Imprint	03 Aug 2015
Number of pages	6
Note	Comments: 5 pages, 5 figures 16 pages, 6 figures, 1 table. Final version to appear in Physics of the Dark Universe. Contains: more detailed discussion of galactic masking, improved estimate
In:	Phys. Dark Universe 11 (2016) 68-73
DOI	10.1016/j.dark.2015.12.001
Subject category	Astrophysics and Astronomy
Abstract	String Theory and Supergravity allow, in principle, to follow the transition of the inflaton from pre-inflationary fast roll to slow roll. This introduces an infrared depression in the primordial power spectrum that might have left an imprint in the CMB anisotropy, if it occurred at accessible wavelengths. We model the effect extending $\Lambda$CDM with a scale $\Delta$ related to the infrared depression and explore the constraints allowed by {\sc Planck} data, employing also more conservative, wider Galactic masks in the low resolution CMB likelihood. In an extended mask with $f_{sky}=39\%$, we thus find $\Delta = (0.351 \pm 0.114) \times 10^{-3} \, \mbox{Mpc}^{-1}$, at $99.4\%$ confidence level, to be compared with a nearby value at $88.5\%$ with the standard $f_{sky}=94\%$ mask. With about 64 $e$--folds of inflation, these values for $\Delta$ would translate into primordial energy scales ${\cal O}(10^{14})$ GeV.
Copyright/License	arXiv nonexclusive-distrib. 1.0 Preprint: © 2015-2025 CERN (License: CC-BY-4.0)

$\small Some power spectra in arbitrary units \emph{vs} $x=\log_{10}(k/k_0)$, compared with the light dotted curves obtained from eq.~(\ref{tilt}). \emph{Left:} analytic power spectra from eq.~(\ref{coulomb_power}) for $\gamma=-1$ (dotted), $0$ (continuous), $0.2$ (dashed), $0.4$ (dashed-dotted). \emph{Right:} four types of spectra from BSB, where the scalar bounces against a steep exponential potential before attaining slow--roll. An initial condition, $\varphi_0$, gauges the bounce, and mild bounces (continuous) recover the spectra of \cite{destri}.$ $\small Some power spectra in arbitrary units \emph{vs} $x=\log_{10}(k/k_0)$, compared with the light dotted curves obtained from eq.~(\ref{tilt}). \emph{Left:} analytic power spectra from eq.~(\ref{coulomb_power}) for $\gamma=-1$ (dotted), $0$ (continuous), $0.2$ (dashed), $0.4$ (dashed-dotted). \emph{Right:} four types of spectra from BSB, where the scalar bounces against a steep exponential potential before attaining slow--roll. An initial condition, $\varphi_0$, gauges the bounce, and mild bounces (continuous) recover the spectra of \cite{destri}.$ $\small Posteriors for the six standard $\Lambda$CDM cosmological parameters. The black and gray curves are determined by the $\Lambda$CDM power law (\ref{tilt}). They refer to the standard 94\% mask released by the {\sc Planck} team (black) and to a $+30^\circ$ extended mask (gray). All other curves are determined by the modified power law of eq.~(\ref{power_cutoff}): solid blue for the 94\% mask, thick red for a $+30^\circ$ extension, dotted blue for the intermediate masks $+6^\circ$, $+12^\circ$, $+18^\circ$, $+24^\circ$, and dotted red for $+36^\circ$. The $\Lambda$CDM parameters are substantially stable for all these choices, except possibly for the gray curves in $\Lambda$CDM. Notice how, with the model of eq.~(\ref{power_cutoff}), all $\Lambda$CDM parameters become more stable, even for very large masks.$ Show more plots

Corresponding record in: Inspire

Back to search

Rekord stworzony 2015-08-05, ostatnia modyfikacja 2021-05-03

Podobne rekordy

Preprint:

PDF

Link zewnętrzny:

Preprint

Dodaj do koszyka osobistego
Wyeksportuj jako BibTeX, MARC, MARCXML, DC, EndNote, NLM, RefWorks

CERN Document Server

Access articles, reports and multimedia content in HEP

Main menu

CERN Accelerating science