On rate optimal local estimation in functional linear model

J. Johannes; R. Schenk

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arXiv · 0902.0645

On rate optimal local estimation in functional linear model

J. Johannes·R. Schenk

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Abstract

We consider the estimation of the value of a linear functional of the slope parameter in functional linear regression, where scalar responses are modeled in dependence of random functions. The theory in this paper covers in particular point-wise estimation as well as the estimation of weighted averages of the slope parameter. We propose a plug-in estimator which is based on a dimension reduction technique and additional thresholding. It is shown that this estimator is consistent under mild assumptions. We derive a lower bound for the maximal mean squared error of any estimator over a certain ellipsoid of slope parameters and a certain class of covariance operators associated with the regressor. It is shown that the proposed estimator attains this lower bound up to a constant and hence it is minimax optimal. Our results are appropriate to discuss a wide range of possible regressors, slope parameters and functionals. They are illustrated by considering the point-wise estimation of the slope parameter or its derivatives and its average value over a given interval.

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J. Johannes, R. Schenk. 2009-02-03. On rate optimal local estimation in functional linear model. https://arxiv.org/abs/0902.0645

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