Renormalization-group flow of the effective action of cosmological large-scale structures

• Verfasst von: Flörchinger, Stefan [VerfasserIn]
• Titel: Renormalization-group flow of the effective action of cosmological large-scale structures
• Verf.angabe: Stefan Floerchinger, Mathias Garny, Nikolaos Tetradis and Urs Achim Wiedemann
• E-Jahr: 2017
• Jahr: 24 January 2017
• Umfang: 41 S.
• Fussnoten: Gesehen am 24.11.2017
• Titel Quelle: Enthalten in: Journal of cosmology and astroparticle physics
• Ort Quelle: London : IOP, 2003
• Jahr Quelle: 2017
• Band/Heft Quelle: (2017), 1, Artikel-ID 048, Seite 1-41
• ISSN Quelle: 1475-7516
• DOI: doi:10.1088/1475-7516/2017/01/048
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1565709683

Abstract

Following an approach of Matarrese and Pietroni, we derive the functional renormalization group (RG) flow of the effective action of cosmological large-scale structures. Perturbative solutions of this RG flow equation are shown to be consistent with standard cosmological perturbation theory. Non-perturbative approximate solutions can be obtained by truncating the a priori infinite set of possible effective actions to a finite subspace. Using for the truncated effective action a form dictated by dissipative fluid dynamics, we derive RG flow equations for the scale dependence of the effective viscosity and sound velocity of non-interacting dark matter, and we solve them numerically. Physically, the effective viscosity and sound velocity account for the interactions of long-wavelength fluctuations with the spectrum of smaller-scale perturbations. We find that the RG flow exhibits an attractor behaviour in the IR that significantly reduces the dependence of the effective viscosity and sound velocity on the input values at the UV scale. This allows for a self-contained computation of matter and velocity power spectra for which the sensitivity to UV modes is under control.