3,621 research outputs found

    Reply to ``Comment on `On the inconsistency of the Bohm-Gadella theory with quantum mechanics'''

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    In this reply, we show that when we apply standard distribution theory to the Lippmann-Schwinger equation, the resulting spaces of test functions would comply with the Hardy axiom only if classic results of Paley and Wiener, of Gelfand and Shilov, and of the theory of ultradistributions were wrong. As well, we point out several differences between the ``standard method'' of constructing rigged Hilbert spaces in quantum mechanics and the method used in Time Asymmetric Quantum Theory.Comment: 13 page

    The rigged Hilbert space approach to the Lippmann-Schwinger equation. Part I

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    We exemplify the way the rigged Hilbert space deals with the Lippmann-Schwinger equation by way of the spherical shell potential. We explicitly construct the Lippmann-Schwinger bras and kets along with their energy representation, their time evolution and the rigged Hilbert spaces to which they belong. It will be concluded that the natural setting for the solutions of the Lippmann-Schwinger equation--and therefore for scattering theory--is the rigged Hilbert space rather than just the Hilbert space.Comment: 34 pages, 1 figur

    Primers resultats de l'estudi de la ceràmica terra sigillata de Baetulo: circulació ceràmica i aportacions cronològiques a la ciutat

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    Les actuacions arqueologiques portades a terme des dels anys se tanta a la ciutat de Badalona, han permes posar al descobert una part important d'estructures corresponents a la ciutat romana de Baetulo. A partir d'aquestes excavacions, l' analisi especĂ­fica de la ceramica terra sigillata documentada en determinats contextos estratigrafics, on aquest tipus ceramic Ă©s l'element basic de dataciĂł, ens ha permes realitzar una revisiĂł de les cronologies proposades inicialment per a aquests estrats i per a les estructures associades. Aquesta revisiĂł, que afecta el perĂ­ode que va del regnat d' August fms a epoca flavia, ha suposat la clarificaciĂł del material de terra sigillata recuperat i, en alguns casos, la modificaciĂł de la interpretaciĂł de la seqĂĽencia estratigrafica i la se va dataciĂł

    F-transforms for the definition of contextual fuzzy partitions

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    Fuzzy partitions can be defined in many different ways, but usually, it is done taking into account the whole universe. In this paper, we present a method to define fuzzy partitions according to those elements in the universe holding certain fuzzy attribute. Specifically, we show how to define those fuzzy partitions by means of F-transforms.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech This work has been partially supported by the Spanish Ministry of Science by the projects TIN15-70266-C2-P-1 and TIN2016-76653-

    The Importance of Boundary Conditions in Quantum Mechanics

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    We discuss the role of boundary conditions in determining the physical content of the solutions of the Schrodinger equation. We study the standing-wave, the ``in,'' the ``out,'' and the purely outgoing boundary conditions. As well, we rephrase Feynman's +iϵ+i \epsilon prescription as a time-asymmetric, causal boundary condition, and discuss the connection of Feynman's +iϵ+i \epsilon prescription with the arrow of time of Quantum Electrodynamics. A parallel of this arrow of time with that of Classical Electrodynamics is made. We conclude that in general, the time evolution of a closed quantum system has indeed an arrow of time built into the propagators.Comment: Contribution to the proceedings of the ICTP conference "Irreversible Quantum Dynamics," Trieste, Italy, July 200

    The rigged Hilbert space approach to the Lippmann-Schwinger equation. Part II: The analytic continuation of the Lippmann-Schwinger bras and kets

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    The analytic continuation of the Lippmann-Schwinger bras and kets is obtained and characterized. It is shown that the natural mathematical setting for the analytic continuation of the solutions of the Lippmann-Schwinger equation is the rigged Hilbert space rather than just the Hilbert space. It is also argued that this analytic continuation entails the imposition of a time asymmetric boundary condition upon the group time evolution, resulting into a semigroup time evolution. Physically, the semigroup time evolution is simply a (retarded or advanced) propagator.Comment: 32 pages, 3 figure
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