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991.
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994.
We study the ultraviolet behavior of two dimensional supersymmetric non-linear -models with target space an arbitrary Kähler manifoldM, so that the models areN=2 supersymmetric. We point out that these models have an additional fermionic axial symmetry if and only if the metric onM is Ricci flat. We show that the preservation of this symmetry in perturbation theory implies that both bare and renormalized metrics onM are Ricci flat. Combining this result with the constraint ofN=2 supersymmetry requiring that all counter-terms to the metric beyond one-loop order be cohomologically trivial, we argue thatN=2 models defined on Ricci flat Kähler manifolds are on-shell ultraviolet finite to all orders of perturbation theory. 相似文献
995.
996.
Michael Scheutzow 《Probability Theory and Related Fields》1986,72(3):425-462
Summary We prove a propagation of chaos result for the mean-field limit of a model for a trimolecular chemical reaction called Brusselator. Then we show that the pair of nonlinear (i.e. law-dependent) stochastic differential equations describing the evolution of the concentration of the molecules at a given site in the mean field limit has a solution with a periodic law (in t). Finally we identify the limit and establish a central limit theorem for the periodic law in the case where the noise tends to zero.Part of this work was performed while on leave at the Department of Mathematics and Statistics, Carleton University, Ottawa, Canada and supported by NSERC operating grants of M. Csörgö and D. Dawson 相似文献
997.
A bound is given for the average length of a lexicographic path, a definition that is motivated by degeneracies encountered when using the randomized simplex method. 相似文献
998.
In this paper we prove selection theorems for everywhere and almost everywhere convergent subsequences, based on the notion of uniformly limited oscillation, ofA, Λ-oscillation and ofA, Λ-variation, whereA is a system of intervals and Λ a sequence of reals. By this, we generalize and strengthen the selection theorems of Schrader (for oscillation) and of Waterman (for Λ-variation). 相似文献
999.
L. N. Nikol'skaya 《Journal of Mathematical Sciences》1986,32(5):513-519
In the paper one finds necessary and sufficient conditions for the existence of nontrivial solutions of the equation (A+C)f=f for all compact (or small in norm) perturbations C; for the unperturbed operators A one considers the operators of dual and conjugate to dual integral equations with kernels depending on the difference of arguments, Wiener-Hopf operators, and singular integral operators. The answer is given in terms of the symbol S (A) of the operator A.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Maternaticheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 138, pp. 127–136, 1984. 相似文献
1000.
In the present paper we introduce the generalized alternatingpolynomials , the coefficients of which are defined together with the parameter Wn by the linear system
where Tn(x) = cos (n arc cos x), is a set of n+2 distinct points in the interval [1, 1], and fis a continuous function on [1, 1], For the set of nodesxk = cos [k/(n+1)] the wn-polynomials coincide with the polynomialsof equiamplitude alternation introduced by de La Vall?e-Poussinand discussed in the literature earlier (Eterman, Malozemov,Meinardus, Cheney & Rivlin, Phillips & Taylor, Brutman,and others). It is shown that the generalized alternating polynomials arerelated to the polynomials of interpolation through the Lanczoseconomization process. Some approximation properties of wn -polynomialsand Wn -parameters are studied. The application of wn -polynomialsto function approximation and to the estimate of remainder termsfor quadrature formulas is discussed. 相似文献