Banca de DEFESA: WILLIAM JOUSE COSTA DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : WILLIAM JOUSE COSTA DA SILVA
DATA : 28/08/2019
HORA: 15:00
LOCAL: Auditório do CCET
TÍTULO:

OBSERVATIONAL CONSTRAINTS ON NONADDITIVE COSMOLOGICAL MODELS: FROM BULK VISCOSITY TO DYNAMICS

PALAVRAS-CHAVES:

Cosmology, Dark Sector, Nonadditivity, Bulk Viscosity, Bayesian Analysis

PÁGINAS: 162
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

From current cosmological observations, dark matter and dark energy are the energetic components that dominate the evolution and dynamics of the present universe, as baryonic matter and radiation have a share of less than 5% of total cosmic energy. Although necessary to describe some observational data the nature of the dark sector remains a mystery to cosmology. In this thesis, we study a cosmological models scenarios with bulk viscosity. Endowed with an alternative interpretation of the bulk viscosity and the dynamics of the Universe from the microscopic effects based in the nonadditive Statistical Mechanics we propose a extended ΛCDM model. This scenario take account nonadditive effects about the energy equipartition theorem as well as an interpretation of the viscous dark matter through nonextensive/dissipative correspondence (NexDC). In order to impose observational constraints on model parameters and compare models, we implement a Bayesian Analysis considering data from the type Ia supernovae, baryon acoustic oscillations and cosmic background radiation. The results obtained were that the non-extensive viscosity effect is discarded at 1σ confidence, but at 2σ we have a scenario with viscosity. From a model comparison point of view, the proposed models have unfavorable inconclusive evidence regarding the ΛCDM. In the second part of the thesis, we consider a description of viscous dark energy in the scope of universe dynamics modified by nonadditive theory as well as the standard. In order to impose observational limits, we performed a Bayesian Analysis using data from cosmic chronometers, type Ia supernova, baryonic acoustic oscillations, and cosmic background radiation. As a results of the analysis, we obtain that a bulk viscosity is discarded in 1σ in the dark energy context. In the comparison models, we can conclude that the viscous dark energy models are also discarded compared to the ΛCDM model.

MEMBROS DA BANCA:
Externo à Instituição - JAILSON SOUZA DE ALCANIZ - ON/MCT
Interno - 1674079 - LEO GOUVEA MEDEIROS
Interno - 6346140 - LUCIANO RODRIGUES DA SILVA
Presidente - 1672854 - RAIMUNDO SILVA JUNIOR
Interno - 1390849 - RODRIGO FERNANDES LIRA DE HOLANDA
Externo à Instituição - VALERIO MARRA - UFES