Banca de DEFESA: HEBERTT LEANDRO SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : HEBERTT LEANDRO SILVA
DATE: 26/08/2021
TIME: 09:00
LOCAL: Plataforma Google Meet
TITLE:

Gravitational Waves Fundamental: Applications in Astrophysics and Cosmology

KEY WORDS:

Hubble-Lemaitre constant, Longitudinal Modes, Gravitational Waves.

PAGES: 91
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

The detection of gravitational waves, predicted by General Relativity, opened up possibilities to study physics previously unexplored. Based on affirmation, the present work is divided into two parts. First, we analyze an effect derived from geodesic deviation equation, called memory effects. We propose a model, representing a simplified description of astrophysical source emitting radiation and analyse its effect on detector a far away from the source after the radiation has passed. The particular memory effect we investigate is due to the change in longitudinal modes, rather than the well-study memory effect in radiative modes. The toy model proposed assumes spherical symmetry in which the entire source initially at rest is converted into radiation. Both longitudinal and transverse(radiative) modes contribute to the Riemann tensor and interact with the detector and the possibility of detecting time varying longitudinal modes is studied. In the second part of the  thesis, we propose a way to measure the Hubble constant,which enters the relationship between the redshift z and luminosity distance $d_L$, and it is a crucial parameter in Cosmology that provides a measure of the Universe expansion rate. The application consists of measuring $ H_0 $ using the gravitational wave detections from binary black hole coalescences whose amplitude depends inversely on the luminosity distance $d_L$ without electromagnetic counterparts enabling a measure of the {\it{redshift}}. The method consists of breaking the degeneracy between $H_0$ and the redshift by using the statistical information on the astrophysical binary black hole population using the source distribution as a function of redshift.

BANKING MEMBERS:
Externo à Instituição - JAILSON SOUZA DE ALCANIZ - ON/MCT
Interno - 1674079 - LEO GOUVEA MEDEIROS
Interno - 1672854 - RAIMUNDO SILVA JUNIOR
Presidente - 236.141.018-43 - RICCARDO STURANI - UFRN
Externo à Instituição - VALERIO MARRA - UFES