645,519 research outputs found

    Pointwise Convergence in Probability of General Smoothing Splines

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    Establishing the convergence of splines can be cast as a variational problem which is amenable to a Γ\Gamma-convergence approach. We consider the case in which the regularization coefficient scales with the number of observations, nn, as λn=np\lambda_n=n^{-p}. Using standard theorems from the Γ\Gamma-convergence literature, we prove that the general spline model is consistent in that estimators converge in a sense slightly weaker than weak convergence in probability for p12p\leq \frac{1}{2}. Without further assumptions we show this rate is sharp. This differs from rates for strong convergence using Hilbert scales where one can often choose p>12p>\frac{1}{2}

    Weak convergence of particle swarm optimization

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    Particle swarm optimization algorithm is a stochastic meta-heuristic solving global optimization problems appreciated for its efficacity and simplicity. It consists in a swarm of particles interacting among themselves and searching the global optimum. The trajectory of the particles has been well-studied in a deterministic case and more recently in a stochastic context. Assuming the convergence of PSO, we proposed here two CLT for the particles corresponding to two kinds of convergence behavior. These results can lead to build confidence intervals around the local minimum found by the swarm or to the evaluation of the risk. A simulation study confirms these properties

    Weak Convergence of nn-Particle Systems Using Bilinear Forms

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    The paper is concerned with the weak convergence of nn-particle processes to deterministic stationary paths as nn\to\infty. A Mosco type convergence of a class of bilinear forms is introduced. The Mosco type convergence of bilinear forms results in a certain convergence of the resolvents of the nn-particle systems. Based on this convergence a criterion in order to verify weak convergence of invariant measures is established. Under additional conditions weak convergence of stationary nn-particle processes to stationary deterministic paths is proved. The method is applied to the particle approximation of a Ginzburg-Landau type diffusion. The present paper is in close relation to the paper L\"obus (2011/2012). Different definitions of bilinear forms and versions of Mosco type convergence are introduced. Both papers demonstrate that the choice of the form and the type of convergence relates to the particular particle system

    Discretizing the Heston Model: An Analysis of the Weak Convergence Rate

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    In this manuscript we analyze the weak convergence rate of a discretization scheme for the Heston model. Under mild assumptions on the smoothness of the payoff and on the Feller index of the volatility process, respectively, we establish a weak convergence rate of order one. Moreover, under almost minimal assumptions we obtain weak convergence without a rate. These results are accompanied by several numerical examples. Our error analysis relies on a classical technique from Talay & Tubaro, a recent regularity estimate for the Heston PDE by Feehan & Pop and Malliavin calculus
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