16,132 research outputs found

    Translocality and a Duality Principle in Generally Covariant Quantum Field Theory

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    It is argued that the formal rules of correspondence between local observation procedures and observables do not exhaust the entire physical content of generally covariant quantum field theory. This result is obtained by expressing the distinguishing features of the local kinematical structure of quantum field theory in the generally covariant context in terms of a translocal structure which carries the totality of the nonlocal kinematical informations in a local region. This gives rise to a duality principle at the dynamical level which emphasizes the significance of the underlying translocal structure for modelling a minimal algebra around a given point. We discuss the emergence of classical properties from this point of view.Comment: 12 pages. To appear in Classical Quantum Gravit

    Godel's Incompleteness Phenomenon - Computationally

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    We argue that Godel's completeness theorem is equivalent to completability of consistent theories, and Godel's incompleteness theorem is equivalent to the fact that this completion is not constructive, in the sense that there are some consistent and recursively enumerable theories which cannot be extended to any complete and consistent and recursively enumerable theory. Though any consistent and decidable theory can be extended to a complete and consistent and decidable theory. Thus deduction and consistency are not decidable in logic, and an analogue of Rice's Theorem holds for recursively enumerable theories: all the non-trivial properties of such theories are undecidable

    A New Method for Obtaining the Baryons Mass under the Killingbeck Plus Isotonic Oscillator Potentials

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    In this work, the spectrum of ground state and excited baryons (N, {\Delta}, , , and {\Omega} particles) has been investigated by using a non-relativistic quantum mechanics under the Killingbeck plus isotonic oscillator potentials. Using the Jacobi-coordinates, anzast method and generalized G\"ursey Radicati (GR) mass formula the three body wave equation is solved to calculate the different states of the considered baryons. A comparison between our calculations and the available experimental data shows that the position of the Roper resonances of the nucleon, the ground states and the excited multiplets up to three GeV are in general well reproduced. Also one can conclude that; the interaction between the quark constituents of baryon resonances could be described adequately by using the combination of Killingbeck and isotonic oscillator potentials form.Comment: arXiv admin note: text overlap with arXiv:nucl-th/0506032 by other author

    Separating Bounded Arithmetics by Herbrand Consistency

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    The problem of Π1−\Pi_1-separating the hierarchy of bounded arithmetic has been studied in the paper. It is shown that the notion of Herbrand Consistency, in its full generality, cannot Π1−\Pi_1-separate the theory IΔ0+⋀jΩj{\rm I\Delta_0+\bigwedge_j\Omega_j} from IΔ0{\rm I\Delta_0}; though it can Π1−\Pi_1-separate IΔ0+Exp{\rm I\Delta_0+Exp} from IΔ0{\rm I\Delta_0}. This extends a result of L. A. Ko{\l}odziejczyk (2006), by showing the unprovability of the Herbrand Consistency of IΔ0{\rm I\Delta_0} in the theory IΔ0+⋀jΩj{\rm I\Delta_0+\bigwedge_j\Omega_j}.Comment: Published by Oxford University Press. arXiv admin note: text overlap with arXiv:1005.265

    Herbrand Consistency of Some Arithmetical Theories

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    G\"odel's second incompleteness theorem is proved for Herbrand consistency of some arithmetical theories with bounded induction, by using a technique of logarithmic shrinking the witnesses of bounded formulas, due to Z. Adamowicz [Herbrand consistency and bounded arithmetic, \textit{Fundamenta Mathematicae} 171 (2002) 279--292]. In that paper, it was shown that one cannot always shrink the witness of a bounded formula logarithmically, but in the presence of Herbrand consistency, for theories IΔ0+Ωm{\rm I\Delta_0+\Omega_m} with m⩾2m\geqslant 2, any witness for any bounded formula can be shortened logarithmically. This immediately implies the unprovability of Herbrand consistency of a theory T⊇IΔ0+Ω2T\supseteq {\rm I\Delta_0+\Omega_2} in TT itself. In this paper, the above results are generalized for IΔ0+Ω1{\rm I\Delta_0+\Omega_1}. Also after tailoring the definition of Herbrand consistency for IΔ0{\rm I\Delta_0} we prove the corresponding theorems for IΔ0{\rm I\Delta_0}. Thus the Herbrand version of G\"odel's second incompleteness theorem follows for the theories IΔ0+Ω1{\rm I\Delta_0+\Omega_1} and IΔ0{\rm I\Delta_0}

    Russian foreign policy: The return of great power politics

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    In Russian Foreign Policy: The Return of Great Power Politics, Jeffrey Mankoff examines the course of Russian foreign policy since the dissolution of the Soviet Union in 1991. He provides a comprehensive over-view of both the continuity and the changes in Russian foreign policy from the end of the Cold War to the Putin era, and analyses Russia’s interactions with major global powers. Throughout the book, the author makes use of various theoretical approaches, including theories of international relations, classical geopolitical theory and Russian geopolitical tradition
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