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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Running vacuum cosmological models: linear scalar perturbations

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Author(s):
Perico, E. L. D. ; Tamayo, D. A.
Total Authors: 2
Document type: Journal article
Source: Journal of Cosmology and Astroparticle Physics; n. 8 AUG 2017.
Web of Science Citations: 2
Abstract

In cosmology, phenomenologically motivated expressions for running vacuum are commonly parameterized as linear functions typically denoted by Lambda (H-2) or Lambda (R). Such models assume an equation of state for the vacuum given by (P) over bar Lambda =- (rho) over bar Lambda relating its background pressure (P) over bar Lambda with its mean energy density (rho) over bar Lambda equivalent to Lambda/8 pi G. This equation of state suggests that the vacuum dynamics is due to an interaction with the matter content of the universe. Most of the approaches studying the observational impact of these models only consider the interaction between the vacuum and the transient dominant matter component of the universe. We extend such models by assuming that the running vacuum is the sum of independent contributions, namely (rho) over bar Lambda = Sigma(i) (rho) over bar Lambda i.Each Lambda i vacuum component is associated and interacting with one of the i matter components in both the background and perturbation levels. We derive the evolution equations for the linear scalar vacuum and matter perturbations in those two scenarios, and identify the running vacuum imprints on the cosmic microwave background anisotropies as well as on the matter power spectrum. In the Lambda(H-2) scenario the vacuum is coupled with every matter component, whereas the Lambda(R) description only leads to a coupling between vacuum and non-relativistic matter, producing different effects on the matter power spectrum. (AU)

FAPESP's process: 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center
Grantee:Elisabete Maria de Gouveia Dal Pino
Support type: Multi-user Equipment Program
FAPESP's process: 15/01721-9 - Voids and halo cosmology within modified gravity
Grantee:Eder Leonardo Duarte Perico
Support type: Scholarships in Brazil - Post-Doctorate