Skip to main content

and
  1. No Access

    Chapter

    Gödel Incompleteness and the Empirical Sciences

    We show how widespread are metamathematical phenomena in mathematics and in the sciences which rely on mathematics. We will consider specific examples of undecidable sentences in mathematics, physics and econo...

    N. C. A. da Costa, F. A. Doria in Space, Time and the Limits of Human Understanding (2017)

  2. No Access

    Article

    Non-reflexive Logical Foundation for Quantum Mechanics

    On the one hand, non-reflexive logics are logics in which the principle of identity does not hold in general. On the other hand, quantum mechanics has difficulties regarding the interpretation of ‘particles’ a...

    N. C. A. da Costa, C. de Ronde in Foundations of Physics (2014)

  3. No Access

    Article

    Definability and Invariance

    In his thesis Para uma Teoria Geral dos Homomorfismos (1944), the Portuguese mathematician José Sebastião e Silva constructed an abstract or generalized Galois theory, that is intimately linked to F. Klein’s Erla...

    N. C. A. da Costa, A. A. M. Rodrigues in Studia Logica (2007)

  4. No Access

    Chapter

    On Some Recent Undecidability and Incompleteness Results in the Axiomatized Sciences

    We summarize in an intuitive vein a few recent results by the authors on the incompleteness of elementary real analysis and its consequences to the axiomatized sciences, from chaos theory to the dynamics of po...

    N. C. A. Da Costa, F. A. Doria in Philosophy of Latin America (2003)

  5. No Access

    Chapter and Conference Paper

    H-computation

    N. C. A. da Costa, F. A. Doria in Advances in Artificial Intelligence (1996)

  6. No Access

    Chapter

    Structures, Suppes Predicates, and Boolean-Valued Models in Physics

    An old and important question concerning physical theories has to do with their axiomatization [47]. The sixth problem in Hilbert’s celebrated list of mathematical problems deals with its desirable (or ideal) ...

    N. C. A. da Costa, F. A. Doria in Philosophical Logic and Logical Philosophy (1996)

  7. No Access

    Article

    Undecidable hopf bifurcation with undecidable fixed point

    We exhibit a polynomial dynamical system where one cannot decide whether a Hopf bifurcation occurs. Therefore one cannot decide whether there will be parameter values such that a stable fixed point becomes an ...

    N. C. A. da Costa, F. A. Doria in International Journal of Theoretical Physics (1994)

  8. No Access

    Article

    Two questions on the geometry of gauge fields

    We first show that a theorem by Cartan that generalizes the Frobenius integrability theorem allows us (given certain conditions) to obtain noncurvature solutions for the differential Bianchi conditions and for.....

    N. C. A. da Costa, F. A. Doria, A. F. Furtado-do-Amaral in Foundations of Physics (1994)

  9. No Access

    Article

    Dynamical system where proving chaos is equivalent to proving Fermat's conjecture

    We prove that we can explicitly construct the expression for a low-dimensional Hamiltonian system where proving the existence of a Smale horseshoe is equivalent to proving that Fermat's Conjecture is true. We ...

    N. C. A. da Costa, F. A. Doria in International Journal of Theoretical Physi… (1993)

  10. No Access

    Chapter and Conference Paper

    On Arnol'd's Hilbert symposium problems

    We prove that stability is undecidable for dynamical systems whose right-hand side is explicitly written in the language of elementary analysis.

    N. C. A. da Costa, F. A. Doria in Computational Logic and Proof Theory (1993)

  11. No Access

    Article

    Classical physics and Penrose's thesis

    We expose and discussPenrose's thesis: “Nature produces harnessable noncomputable processes, but none at the classical level.” We then suggest a partial counterexample to it, based on aGedanken experiment about a...

    N. C. A. da Costa, F. A. Doria in Foundations of Physics Letters (1991)

  12. No Access

    Article

    Undecidability and incompleteness in classical mechanics

    We describe Richardson's functor from the Diophantine equations and Diophantine problems into elementary real-valued functions and problems. We then derive a general undecidability and incompleteness result fo...

    N. C. A. da Costa, F. A. Doria in International Journal of Theoretical Physics (1991)

  13. Book Series

  14. No Access

    Book

    Vagueness

    An Investigation into Natural Languages and the Sorites Paradox

    Linda Claire Burns in Reason and Argument (1991)

  15. No Access

    Article

    A Suppes predicate for general relativity and set-theoretically generic spacetimes

    We summarize ideas from Zermelo-Fraenkel set theory up to an axiomatic treatment for general relativity based on a Suppes predicate. We then examine the meaning of set-theoretic genericity for manifolds that u...

    N. C. A. da Costa, F. A. Doria in International Journal of Theoretical Physi… (1990)

  16. No Access

    Article

    Book reviews

    N. C. A. da Costa, David Harrah, Michael Tye, D. S. Clarke Jr., Jeffrey Olen in Philosophia (1985)

  17. No Access

    Article

    A new formulation of discussive logic

    S. Jaśkowski introduced the discussive prepositional calculus D 2as a basis for a logic which could be used as underlying logic of inconsistent but nontrivial theories (see, for example, N. C. A. da Costa and L. ...

    Jerzy Kotas, N. C. A. da Costa in Studia Logica (1979)