Banca de DEFESA: JOÃO GUILHERME RODRIGUES VALANGELIS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: JOÃO GUILHERME RODRIGUES VALANGELIS
DATA: 03/08/2026
HORA: 09:00
LOCAL: Remota
TÍTULO: Estudo Analítico sobre o Espalhamento de Ondas Escalares em um Buraco Negro de Schwarzschild com Violação da Simetria de Lorentz
PALAVRAS-CHAVES: Spontaneous Lorentz symmetry breaking; Kalb-Ramond field; Confluent Heun functions; Hawking radiation; Scattering; Quasinormal modes.
PÁGINAS: 48
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

In this work, we study the propagation of a massless scalar field in a
Schwarzschild spacetime modified by a background Kalb-Ramond field, which induces
spontaneous Lorentz symmetry breaking via a non-minimal coupling to gravity. The
Klein-Gordon equation is solved analytically by mapping its radial equation onto the
confluent Heun equation. Near the event horizon, we analyze the thermal spectrum and
the Hawking temperature perceived by stationary observers, examining how geometric
modifications influence the emission flux. In the asymptotic region, the radial equation
reduces to a Coulomb-like form in the low-frequency limit, allowing us to obtain
analytical expressions for the phase shifts and scattering cross sections. Furthermore, we
discuss the conditions for the polynomial truncation of confluent Heun solutions and
their relation to the numerical quasinormal mode spectrum computed via Leaver’smethod and the WKB approximation. Finally, the analysis of the effective potentialallows us to verify the modal stability of the scalar field. The results indicate thatspontaneous Lorentz symmetry breaking alters the geometrical, thermodynamical, andwave properties of the black hole while preserving overall linear spacetime stability.

MEMBROS DA BANCA:
Externo ao Programa - 1391774 - AILTON CAMPOS DO NASCIMENTO
Externo ao Programa - 00.000.004/8234-83 - GIANDOMENICO PALUMBO - UC
Presidente - 3331689 - HELDER ALEXANDER SANTOS E COSTA
Externo ao Programa - 3430956 - JORGIVAN MORAIS DIAS
Interno - 1650556 - TAYRONI FRANCISCO DE ALENCAR ALVES