25,100 research outputs found

    Toward a probability theory for product logic: states, integral representation and reasoning

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    The aim of this paper is to extend probability theory from the classical to the product t-norm fuzzy logic setting. More precisely, we axiomatize a generalized notion of finitely additive probability for product logic formulas, called state, and show that every state is the Lebesgue integral with respect to a unique regular Borel probability measure. Furthermore, the relation between states and measures is shown to be one-one. In addition, we study geometrical properties of the convex set of states and show that extremal states, i.e., the extremal points of the state space, are the same as the truth-value assignments of the logic. Finally, we axiomatize a two-tiered modal logic for probabilistic reasoning on product logic events and prove soundness and completeness with respect to probabilistic spaces, where the algebra is a free product algebra and the measure is a state in the above sense.Comment: 27 pages, 1 figur

    Minimal sufficient positive-operator valued measure on a separable Hilbert space

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    We introduce a concept of a minimal sufficient positive-operator valued measure (POVM), which is the least redundant POVM among the POVMs that have the equivalent information about the measured quantum system. Assuming the system Hilbert space to be separable, we show that for a given POVM a sufficient statistic called a Lehmann-Scheff\'{e}-Bahadur statistic induces a minimal sufficient POVM. We also show that every POVM has an equivalent minimal sufficient POVM and that such a minimal sufficient POVM is unique up to relabeling neglecting null sets. We apply these results to discrete POVMs and information conservation conditions proposed by the author.Comment: 25 pages. The main result is improved, and a new appendix is adde

    Noncommutative Chiral Anomaly and the Dirac-Ginsparg-Wilson Operator

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    It is shown that the local axial anomaly in 22-dimensions emerges naturally if one postulates an underlying noncommutative fuzzy structure of spacetime . In particular the Dirac-Ginsparg-Wilson relation on SF2{\bf S}^2_F is shown to contain an edge effect which corresponds precisely to the ``fuzzy'' U(1)AU(1)_A axial anomaly on the fuzzy sphere . We also derive a novel gauge-covariant expansion of the quark propagator in the form 1DAF=aΓ^L2+1DAa\frac{1}{{\cal D}_{AF}}=\frac{a\hat{\Gamma}^L}{2}+\frac{1}{{\cal D}_{Aa}} where a=22l+1a=\frac{2}{2l+1} is the lattice spacing on SF2{\bf S}^2_F, Γ^L\hat{\Gamma}^L is the covariant noncommutative chirality and DAa{\cal D}_{Aa} is an effective Dirac operator which has essentially the same IR spectrum as DAF{\cal D}_{AF} but differes from it on the UV modes. Most remarkably is the fact that both operators share the same limit and thus the above covariant expansion is not available in the continuum theory . The first bit in this expansion aΓ^L2\frac{a\hat{\Gamma}^L}{2} although it vanishes as it stands in the continuum limit, its contribution to the anomaly is exactly the canonical theta term. The contribution of the propagator 1DAa\frac{1}{{\cal D}_{Aa}} is on the other hand equal to the toplogical Chern-Simons action which in two dimensions vanishes identically .Comment: 26 pages, latex fil

    Generalized Coherent State Approach to Star Products and Applications to the Fuzzy Sphere

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    We construct a star product associated with an arbitrary two dimensional Poisson structure using generalized coherent states on the complex plane. From our approach one easily recovers the star product for the fuzzy torus, and also one for the fuzzy sphere. For the latter we need to define the `fuzzy' stereographic projection to the plane and the fuzzy sphere integration measure, which in the commutative limit reduce to the usual formulae for the sphere.Comment: 18 page
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