Conceções éticas de estudantes universitários portugueses sobre as sentenças penais: reabilitar ou retribuir?

A presente investigação tem como objetivo analisar as perceções dos estudantes universitários portugueses sobre as finalidades das sentenças penais tendo subjacentes as Teorias Absolutas e das Teorias Relativas. Pretendeu-se avaliar que objetivos de sentença são mais apoiados entre os estudantes e perceber se existem outras variáveis como preditores significativos, tais como, género, orientação politica, religião, curso e experiência prévia de vitimação. Uma amostra de 344 estudantes universitários, a frequentar os cursos de Ciências Sociais (40,8%), Engenharia (34,9%) e Direito (24,3%), com idades compreendidas entre os 17 e os 48 anos, selecionada por conveniência, preencheu o instrumento de 20 itens adaptado de Cullen, Cullen, e Wozniak. Os resultados apontam para a estabilidade da estrutura dimensional do instrumento adaptado, definido por 2 fatores e 16 itens: o fator punição e o fator reabilitação. O fator mais apoiado entre os participantes foi o de reabilitação o que contraria que a opinião pública a respeito da sentença é mais influenciada pelo retribucionismo. Os participantes apoiam várias finalidades da sentença. Não foram encontradas diferenças estatisticamente significativas em função da orientação política, da religião e da experiência de vitimização. Contudo, diferenças estatisticamente significativas foram encontradas para o sexo dos participantes e para o curso.

Quantum field theory approach to the optical conductivity of strained and deformed graphene

The computation of the optical conductivity of strained and deformed graphene is discussed within the framework of quantum field theory in curved spaces. The analytical solutions of the Dirac equation in an arbitrary static background geometry for one dimensional periodic deformations are computed, together with the corresponding Dirac propagator. Analytical expressions are given for the optical conductivity of strained and deformed graphene associated with both intra and interbrand transitions. The special case of small deformations is discussed and the result compared to the prediction of the tight-binding model.

Pseudofermion dynamical theory for the spin dynamical correlation functions of the half-filled 1D Hubbard model

A modified version of the metallic-phase pseudofermion dynamical theory (PDT) of the 1D Hubbard model is introduced for the spin dynamical correlation functions of the half-filled 1D Hubbard model Mott– Hubbard phase. The Mott–Hubbard insulator phase PDT is applied to the study of the model longitudinal and transverse spin dynamical structure factors at finite magnetic field h, focusing in particular on the sin- gularities at excitation energies in the vicinity of the lower thresholds. The relation of our theoretical results to both condensed-matter and ultra-cold atom systems is discussed.

On the temperature dependence of the absorption cross section for black holes in string theory

We study the low frequency absorption cross section of spherically symmetric nonextremal d-dimensional black holes. In the presence of α′ corrections, this quantity must have an explicit dependence on the Hawking temperature of the form 1/TH. This property of the low frequency absorption cross section is shared by the D1-D5 system from type IIB superstring theory already at the classical level, without α′ corrections. We apply our formula to the simplest example, the classical d-dimensional Reissner-Nordstr¨om solution, checking that the obtained formula for the cross section has a smooth extremal limit. We also apply it for a d-dimensional Tangherlini-like solution with α′3 corrections.

Absorption of scalars by nonextremal charged black holes in string theory

We analyze the low frequency absorption cross section of minimally coupled massless scalar fields by different kinds of charged static black holes in string theory, namely the D1–D5 system in d=5 and a four dimensional dyonic four-charged black hole. In each case we show that this cross section always has the form of some parameter of the solution divided by the black hole Hawking temperature. We also verify in each case that, despite its explicit temperature dependence, such quotient is finite in the extremal limit, giving a well defined cross section. We show that this precise explicit temperature dependence also arises in the same cross section for black holes with string \alpha' corrections: it is actually induced by them.