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Type: Tese
Title: Análise termoestatística dos potenciais de Yukawa e Lee–Wick em espaços de fase não comutativos
Author: Sousa, Maria Girlandia de
First Advisor: Mendes, Albert Carlo Rodrigues
Co-Advisor: Abreu, Everton Murilo Carvalho de
Referee Member: Pinto, Clifford Neves
Referee Member: Neves, Mario Junior de Oliveira
Referee Member: Ananias Neto, Jorge
Referee Member: Oliveira Neto, Gil de
Resumo: Nos últimos anos, modelos físicos baseados em álgebras não comutativas têm atraído considerável interesse, pois fornecem uma estrutura para investigar teorias envolvendo um parâmetro fundamental na escala de Planck, frequentemente associado a aspectos semiclássicos da gravidade quântica. A geometria não comutativa modifica a estrutura subjacente do espaço de fase, podendo conduzir a novos entendimentos sobre problemas ainda em aberto na física teórica. Nesta tese, adotamos uma abordagem clássica para realizar uma análise termoestatística dos potenciais de interação de Yukawa e Lee – Wick em espaços de fase não comutativos. Utilizando a álgebra não comutativa, obtemos as equações de movimento associadas a esses potenciais e investigamos grandezas termodinâmicas, como a densidade de estados, a função de partição, a energia média e a capacidade térmica. Empregamos os formalismos dos ensembles microcanônico e canônico no contexto da mecânica estatística de Boltzmann – Gibbs. Nossos resultados mostram que a introdução do parâmetro de não comutatividade Θ induz modificações não triviais nas quantidades termodinâmicas, incluindo mudanças qualitativas na capacidade térmica. Em particular, podem emergir regiões com capacidade térmica negativa, as quais interpretamos como assinaturas das limitações do tratamento semiclássico e perturbativo, e não como efeitos físicos definitivos. A análise é realizada sob as hipóteses de não comutatividade fraca e |βV (r)| ≪ 1, o que restringe o regime de validade dos resultados. Dentro desse domínio, nossos achados destacam o papel da geometria do espaço de fase na determinação do comportamento termodinâmico.
Abstract: In recent years, physical models based on noncommutative algebras have attracted considerable interest, since they provide a framework for investigating theories involving a fundamental parameter at the Planck scale, often associated with semiclassical aspects of quantum gravity. Noncommutative geometry modifies the underlying phase-space structure, potentially leading to new insights into unresolved problems in theoretical physics. In this thesis, we adopt a classical approach to perform a thermostatistical analysis of the well-established Yukawa and Lee – Wick interaction potentials in a noncommutative phase space. Using the noncommutative algebra, we derive the equations of motion associated with these potentials and investigate the corresponding thermodynamic quantities, including the density of states, partition function, mean energy, and heat capacity. Both the microcanonical and canonical ensemble formalisms are considered within the framework of Boltzmann – Gibbs statistical mechanics. Our results show that the introduction of the noncommutative parameter Θ induces nontrivial modifications in thermodynamic quantities, including qualitative changes in the heat capacity. In particular, regions with negative heat capacity may emerge, which we interpret as signatures of the limitations of the semiclassical and perturbative treatment rather than definitive physical effects. The analysis is carried out under the assumptions of weak noncommutativity and |βV (r)| ≪ 1, which constrain the regime of validity of the results. Within this domain, our findings highlight the role of phase-space geometry in shaping thermodynamic behavior. In recent years, physical models based on noncommutative algebras have attracted considerable interest, since they provide a framework for investigating theories involving a fundamental parameter at the Planck scale, often associated with semiclassical aspects of quantum gravity. Noncommutative geometry modifies the underlying phase-space structure, potentially leading to new insights into unresolved problems in theoretical physics. In this thesis, we adopt a classical approach to perform a thermostatistical analysis of the well-established Yukawa and Lee – Wick interaction potentials in a noncommutative phase space. Using the noncommutative algebra, we derive the equations of motion associated with these potentials and investigate the corresponding thermodynamic quantities, including the density of states, partition function, mean energy, and heat capacity. Both the microcanonical and canonical ensemble formalisms are considered within the framework of Boltzmann – Gibbs statistical mechanics. Our results show that the introduction of the noncommutative parameter Θ induces nontrivial modifications in thermodynamic quantities, including qualitative changes in the heat capacity. In particular, regions with negative heat capacity may emerge, which we interpret as signatures of the limitations of the semiclassical and perturbative treatment rather than definitive physical effects. The analysis is carried out under the assumptions of weak noncommutativity and |βV (r)| ≪ 1, which constrain the regime of validity of the results. Within this domain, our findings highlight the role of phase-space geometry in shaping thermodynamic behavior.
Keywords: Potencial de Yukawa
Potencial de Lee–Wick
Não comutatividade
Análise termoestatística
Yukawa potential
Lee–Wick potential
Noncommutativity
Thermostatistical analysis
CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
Language: por
Country: Brasil
Publisher: Universidade Federal de Juiz de Fora (UFJF)
Institution Initials: UFJF
Department: ICE – Instituto de Ciências Exatas
Program: Programa de Pós-graduação em Física
Access Type: Acesso Aberto
Attribution-NonCommercial-NoDerivs 3.0 Brazil
Creative Commons License: http://creativecommons.org/licenses/by-nc-nd/3.0/br/
URI: https://repositorio.ufjf.br/jspui/handle/ufjf/20711
Issue Date: 24-Jun-2026
Appears in Collections:Doutorado em Física (Teses)



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