Banca de DEFESA: HENRIQUE LEONHARD GIEG

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : HENRIQUE LEONHARD GIEG
DATA : 27/03/2023
HORA: 14:00
LOCAL: Auditório 801 no 8º andar do Bloco B do Campus Santo André da Universidade Federal do ABC
TÍTULO:

Neutrinos in Generic Binary Neutron Stars Configurations

PÁGINAS: 168
RESUMO:

In this work we implement improvements in the BAM code for simulations of astrophysical systems in the context of Numerical Relativity. Such improvements consist in the introduction of the necessary computational infrastructure to the use of equations of state (EoSs) derived from microscopic theories to realistically describe the stellar matter in regimes of high densities and finite temperature. Furthermore, weak-force reactions governed by neutrinos are considered through the so-called Neutrinos Leakage Scheme (NLS) and the M1 formalism for the radiation transport equations.

With the new implementations, we performed test simulations with TOV stars employing the NLS and successfully reproduced neutrino-induced gravitational collapse.

We also carried out, for the first time in BAM, simulations of the late stages of the merger of a binary neutron star (BNS) using the new numerical tooling implemented in this work in order to validate our methods by comparison with reported results. Our results are published in Ref. [1].

Next, we performed simulations exploring the BNS parameter space with different mass-ratios and initial spins, obtaining good agreement with the results reported in the literature in terms of the final states of the systems and properties of the ejected matter.

Finally, we performed test simulations of BNSs with the more realistic M1 scheme, which dynamically evolves moments of the distribution function modeling the neutrinos. With this, we demonstrated the robustness of our methods, obtaining stable numerical evolutions, despite the substantial increase in the complexity of the simulations, and whose predicted properties in the post-merger stages are quite convincing. In the near future we will carry out higher resolution simulations with the M1 scheme in order to study generic BNS mergers in detail.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1545398 - MAXIMILIANO UJEVIC TONINO
Membro Titular - Examinador(a) Interno ao Programa - 1574260 - ROLDAO DA ROCHA JUNIOR
Membro Titular - Examinador(a) Interno ao Programa - 1549709 - GERMAN LUGONES
Membro Titular - Examinador(a) Externo à Instituição - CÉSAR HENRIQUE LENZI - ITA
Membro Titular - Examinador(a) Externo à Instituição - GEORGE EMANUEL AVRAAM MATSAS - UNESP
Membro Suplente - Examinador(a) Interno ao Programa - 382324 - VILSON TONIN ZANCHIN
Membro Suplente - Examinador(a) Interno ao Programa - 1677691 - CECILIA BERTONI MARTHA HADLER CHIRENTI
Membro Suplente - Examinador(a) Externo à Instituição - RICCARDO STURANI - UNESP
Membro Suplente - Examinador(a) Externo à Instituição - ALBERTO VAZQUEZ SAA - UNICAMP