Banca de DEFESA: LEONARDO RIBEIRO COLAÇO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LEONARDO RIBEIRO COLAÇO
DATE: 11/12/2020
TIME: 09:00
LOCAL: Plataforma Google Meet
TITLE:

COSMOLOGICAL BOUNDS ON A POSSIBLE TIME VARIATION OF THE FINE STRUCTURE CONSTANT AND THE COSMIC DISTANCE DUALITY RELATION

KEY WORDS:

Invariant Couplings of Nature; Galaxy Clusters; Cosmological Bounds

PAGES: 158
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

In recent years, with the advent of increasingly robust and accurate astronomical observations, further investigations of the role of fundamental constants of nature has become a fascinating field of research, because any space-time variation of these constants would indicate the presence of a new physics and would put in check the relativistic cosmology itself, based on the Cosmological Principle.In this thesis, by using galaxy clusters observations, type Ia Supernovae measurements, and Strong Gravitational Lensing Systems we propose three methods to probe a possible time variation of the fine structure constant (). Such possible variation is investigated in the specific context of the Runaway Dilaton model, which was originated from string theories. We conclude that, although the observational bounds obtained on a possible variation of  () are not competitive with those from quasar spectroscopy (), our proposals provide completely independent bounds with different redshift intervals. Finally, a test to probe a possible deviation of the cosmic distance duality relation (CDDR) is also proposed, , by using scaling-relation measurements from galaxy clusters properties plus type Ia supernova. The cosmological bounds obtained on possible deviations from the relation are compatible with the limits present in the literature and point to the validity of the duality relation.

BANKING MEMBERS:
Externo à Instituição - FRANCISCO DE ASSIS DE BRITO - UFCG
Interno - 1674079 - LEO GOUVEA MEDEIROS
Interno - 1672854 - RAIMUNDO SILVA JUNIOR
Presidente - 1390849 - RODRIGO FERNANDES LIRA DE HOLANDA
Externo ao Programa - 1756325 - RONALDO CARLOTTO BATISTA
Externo à Instituição - SAULO HENRIQUE PEREIRA - UNESP