•  52
    Kinematics of a Spacetime with an Infinite Cosmological Constant
    with R. Aldrovandi, M. Calçada, and J. G. Pereira
    Foundations of Physics 33 (4): 613-624. 2003.
    A solution of the sourceless Einstein's equation with an infinite value for the cosmological constant Λ is discussed by using Inönü–Wigner contractions of the de Sitter groups and spaces. When Λ→∞, spacetime becomes a four-dimensional cone, dual to Minkowski space by a spacetime inversion. This inversion relates the four-cone vertex to the infinity of Minkowski space, and the four-cone infinity to the Minkowski light-cone. The non-relativistic limit c→∞ is further considered, the kinematical gro…Read more
  •  23
    This article assesses the similarity and difference between the Western European style of doing bioethics and the Scandinavian one. First, it reviews the introductory article by the editor, C. Delkeskamp-Hayes in the first issue of Christian Bioethics (2008), devoted to the possibility of a specifically Christian bioethics in Europe. Second, it analyses bioethics debates in Scandinavian today. In light of Delkeskamp-Hayes' article, the main similarity is that both regions are facing secularizati…Read more