12/12/2007 – 14h – Auditório Principal, Bloco G – IAG/USP

João Vital Cunha

Depto. de Astronomia, IAG/USP

Título/Title: Energia escura: origem, candidatos e vínculos observacionais

Resumo/Abstract:

Recent observational advances of the Astronomy transform the Cosmology in a discipline precise and with status equivalent to the other areas of Science.

In the context of general relativity, the theoretical development was stimulated by the possible existence of the dark energy, a new field which was not predicted by the standard model of particle physics, and whose main effect is to generate the present accelerated stage of the Universe as suggested by the Supernovae type Ia observations. The nature of this energetic component remains a mystery until the present thereby giving origin to an intense debate leading to several candidates in the literature whose more important examples are: a cosmological constant, a scalar field (or quintessence), a Lambda(t)-term, X-matter and the Chaplygin gas.

In this seminar, we confront these different models of Dark Energy with with distinct observational data. We analyze the constraints from the ages of globular clusters, existence old high redshifts objects, angular diameter of compact sources and supernovas observations. We determine also new limits on the cosmological parameters by using the X-ray spectrum the of galaxy clusters.

 

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