Banca de DEFESA: ZILMAR CANDIDO DE SANTANA JUNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ZILMAR CANDIDO DE SANTANA JUNIOR
DATE: 16/04/2026
TIME: 14:00
LOCAL: Google Meet
TITLE:

Tests of the ΛCDM Model with Gaussian Processes: Investigating the Dark Sector and Quasar Calibration

KEY WORDS:

Interaction, Dark energy, Dark matter, Cosmological models, Gaussian processes regression, Bayesian inference.

PAGES: 153
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

Although the standard model of cosmology possesses vast theoretical and observational support, it presents several inconsistencies, with some observations in strong tension with theoretical predictions. Therefore, it is imperative to seek modifications to the standard model in order to resolve these issues, while simultaneously striving to maintain its broad observational support. In this work, we investigate two main fronts. First, through two distinct approaches, we analyze a possible deviation in the energy density evolution law of dark matter, allowing for a non-gravitational interaction between the components of the dark sector. Additionally, we investigate alternative versions of a known relation between quasar luminosities. Regarding the dark sector investigation, our results indicate agreement with the standard model within 1σ to 2σ in all cases. However, the uncertainties are not precise enoughto rule out the hypotheses considered herein. In the study of quasars, the results pointed to moderate evidence indicating a preference for an evolution (e.g., of the relation’s parameters). This could explain why the Hubble diagram with quasars currently points to an inconsistency with the standard model.

COMMITTEE MEMBERS:
Interno - 1043096 - FARINALDO DA SILVA QUEIROZ
Externo à Instituição - JOAO RAFAEL LUCIO DOS SANTOS
Externo à Instituição - JOSE FERNANDES DE JESUS
Interno - 1674079 - LEO GOUVEA MEDEIROS
Presidente - 1390849 - RODRIGO FERNANDES LIRA DE HOLANDA