Papers by Alexandre LYRA DE OLIVEIRA
Interdisciplinaridade em Revista, Nov 28, 2019
Resumo: O Princípio da Máxima Entropia estabelecido em 1957 por E. Jaynes trata de generalizar pa... more Resumo: O Princípio da Máxima Entropia estabelecido em 1957 por E. Jaynes trata de generalizar para a Mecânica Estatística as leis de inferência estabelecidas a partir da Teoria das Comunicações de C. E. Shannon. Ao elaborar seu trabalho, Jaynes vinculou seu princípio ao denominado Princípio da Razão Insuficiente, o qual vinculou a Laplace. Nosso trabalho busca investigar epistemologicamente estes diferentes Princípios buscando, por exemplo, nos trabalhos de Bernoulli, Laplace, Keynes e outros, as raízes da Máxima Entropia.
Revista Scientiarum Historia, 2021
Neste trabalho, após um pequeno histórico do Princípio da Máxima Entropia (MaxEnt), discutiremos ... more Neste trabalho, após um pequeno histórico do Princípio da Máxima Entropia (MaxEnt), discutiremos de forma epistemológica sua generalização com a utilização da metodologia KKT em sistemas discretos. Para este objetivo faremos também um histórico resumido do método KKT e da sua utilização. Após esta exposição seguiremos para a utilização conjunta do MaxEnt com o KKT. Isto já foi feito em alguns trabalhos da literatura, mas no caso particular da Astrofísica é uma abordagem nova do nosso grupo, a qual acreditamos ser promissora.
Canadian Journal of Physics, 2008
We investigate the basic assumptions leading to Schwinger’s quantum action principle in quantum m... more We investigate the basic assumptions leading to Schwinger’s quantum action principle in quantum mechanics. We present this principle in a new way that clarifies some previous developments, for example, the derivation of the fundamental commutators among the canonical variables and the Heisenberg equation for operators. We define operators associated with the classical transformations of the Galilei group, i.e., translations, boosts, and rotations and show their commutators obey the Lie algebra of the Galilei group.PACS Nos.: 83.65.Ca, 11.10.Ef
Physics Research International, 2011
We investigate a nonlinear realization of the Lorentz transformation defined in 4-dimensional spa... more We investigate a nonlinear realization of the Lorentz transformation defined in 4-dimensional spacetime, and the corresponding invariant interval. This new interval is not a quadratic form in the standard Minkowski spacetime, then we search for a description where it becomes a quadratic form in an infinite dimensional vector space. In this extended space, we show how to generate two classes of nonlinear transformations, which form a group and interpret the non-linear transformation as compatible relations between atlas of a Lyra manifold.
INTRODUCAO Este e um projeto inovador no âmbito de inclusao social de estudantes com necessidades... more INTRODUCAO Este e um projeto inovador no âmbito de inclusao social de estudantes com necessidades especificas da Associacao de Pais e Amigos dos Excepcionais do Rio de Janeiro (APAE-RJ), desenvolvido por docentes da Universidade Federal do Rio de Janeiro (UFRJ) e do Colegio Pedro II - campus Sao Cristovao III. Alem dos docentes, sua equipe executora tambem conta com a participacao de dois alunos do curso de graduacao em Ciencias Matematicas e da Terra/ Universidade Federal do Rio de Janeiro (CCMN/UFRJ). OBJETIVOS Executar a sedimentacao e a possibilidade de ampliar a visao do estudante em relacao ao Universo. Pretende-se despertar o interesse na compreensao do Universo atraves dos modelos cientificos, particularmente da Astronomia. Pretende-se ainda que este conhecimento os conduza para o entendimento de que a modelagem cientifica do Universo nao e possivel sem a Fisica e a Matematica. PROCEDIMENTOS METODOLOGICOS Consta na exibicao de pequenos filmes, gincanas e palestras, onde cada...
viXra, 2015
Using the concept of absolute time introduced in a previous work \cite{carvalho} we define two co... more Using the concept of absolute time introduced in a previous work \cite{carvalho} we define two coordinate systems for spacetime, the Galilean and the Lorentzian systems. The relation between those systems allows us to develop a tensor calculus that transfer the Maxwell electrodynamics to the Galilean system. Then, by using a suitable Galilean limit, we show how this transformed Maxwell theory in the Galilei system results in the Galilei electrodynamics formulated by Levy Leblond and Le Bellac.
ISRN Mathematical Physics, 2013
We present two models combining some aspects of the Galilei and the Special relativities that lea... more We present two models combining some aspects of the Galilei and the Special relativities that lead to a unification of both relativities. This unification is founded on a reinterpretation of the absolute time of the Galilei relativity that is considered as a quantity in its own and not as mere reinterpretation of the time of the Special relativity in the limit of low velocity. In the first model, the Galilei relativity plays a prominent role in the sense that the basic kinematical laws of Special relativity, for example, the Lorentz transformation and the velocity law, follow from the corresponding Galilei transformations for the position and velocity. This first model also provides a new way of conceiving the nature of relativistic spacetime where the Lorentz transformation is induced by the Galilei transformation through an embedding of 3-dimensional Euclidean space into hyperplanes of 4-dimensional Euclidean space. This idea provides the starting point for the development of a se...
Anais da Academia Brasileira de Ciências, 2000
Proca's equations for two types of fields in a Dirac's aether with electric conductivity σ are so... more Proca's equations for two types of fields in a Dirac's aether with electric conductivity σ are solved exactly. The Proca electromagnetic fields are assumed with cylindrical symmetry. The background is a static, curved spacetime whose spatial section is homogeneous and has the topology of either the three-sphere S 3 or the projective three-space P 3. Simple relations between the range of Proca field λ, the Universe radius R, the limit of photon rest mass m γ and the conductivity σ are written down.
Anais da Academia Brasileira de Ciências, 2004
We search for an amplification mechanism of the seed cosmic magnetic induction by studying a new ... more We search for an amplification mechanism of the seed cosmic magnetic induction by studying a new version of the Dirac's æther in a curved cosmological background. We find that the variation of the scale factor R(t) with cosmic time brings to the magnetic field the desired effect of amplification, that we call geometric amplification.
We propose a new formulation for the AEther of Dirac based on a lagrangian approach. We analyse h... more We propose a new formulation for the AEther of Dirac based on a lagrangian approach. We analyse how the presence of a particular self-interaction term in the lagrangian lead us to a description of the aether as being a medium with conductivity which is governed by macroscopic Maxwell equations with a polarization tensor M αβ depending on the vector potential. These results are then applied to the analysis of the amplification of the primordial magnetic induction in a curved background of Friedmann's geometry.
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Papers by Alexandre LYRA DE OLIVEIRA