Dark energy and the accelerating Universe: conceptual aspects and observational tests

• Grant number: 10/05416-2
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): July 01, 2010
• Effective date (End): June 30, 2012
• Field of knowledge: Physical Sciences and Mathematics - Astronomy
• Principal researcher: Jose Ademir Sales de Lima
• Grantee: José Fernando de Jesus
• Home Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In the context of the current Cosmology, the flat $\Lambda$CDM model has been successful in conciliating different observations, like the cosmic expansion acceleration (suggested by Supernova Ia observations), the Cosmic Microwave Background Power Spectrum, Structure Formation, the Matter Power Spectrum, Baryon Acoustic Oscillations and the Total Age of the Universe. However, such model suffers of minor observational issues, like age of some old objects at high redshifts, preference of a closed Universe by SNs Ia and, most important, a big theoretical problem, the so called Cosmological Constant Problem. Such a problem, allied to the cosmic coincidence mystery, has stimulated cosmologists and astronomers to propose alternative scenarios to the cosmic concordance model ($\Lambda$CDM).In this project, we are going to perform a comparative study (of statistical character) among $\Lambda$CDM and several alternative cosmologies existing on literature. In the context of general relativity, the central objective is to establish which is the best candidate for dark energy, i.e., which of the components that accelerates the Universe will have the best agreement with the available observational data (XCDM, scalar fields, etc.). In another line of development, we will discuss also the possibility of reduction of the dark sector of the Universe, considering accelerating models (within general relativity or in alternative gravitation theories), containing only dark matter and baryons as dominant components. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DEL POPOLO, A.; PACE, F.; MAYDANYUK, S. P.; LIMA, J. A. S.; JESUS, J. F. Shear and rotation in Chaplygin cosmology. Physical Review D, v. 87, n. 4 FEB 21 2013. Web of Science Citations: 36.

LIMA, J. A. S.; JESUS, J. F.; OLIVEIRA, F. A. CDM accelerating cosmology as an alternative to Lambda CDM model. Journal of Cosmology and Astroparticle Physics, n. 11 NOV 2010. Web of Science Citations: 49.