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High dimensional errors-in-variables models with dependent measurements

Abstract

Suppose that we observe yRfy \in \mathbb{R}^f and XRf×mX \in \mathbb{R}^{f \times m} in the following errors-in-variables model: \begin{eqnarray*} y & = & X_0 \beta^* + \epsilon \\ X & = & X_0 + W \end{eqnarray*} where X0X_0 is a f×mf \times m design matrix with independent subgaussian row vectors, ϵRf\epsilon \in \mathbb{R}^f is a noise vector and WW is a mean zero f×mf \times m random noise matrix with independent subgaussian column vectors, independent of X0X_0 and ϵ\epsilon. This model is significantly different from those analyzed in the literature in the sense that we allow the measurement error for each covariate to be a dependent vector across its ff observations. Such error structures appear in the science literature when modeling the trial-to-trial fluctuations in response strength shared across a set of neurons. Under sparsity and restrictive eigenvalue type of conditions, we show that one is able to recover a sparse vector βRm\beta^* \in \mathbb{R}^m from the model given a single observation matrix XX and the response vector yy. We establish consistency in estimating β\beta^* and obtain the rates of convergence in the q\ell_q norm, where q=1,2q = 1, 2 for the Lasso-type estimator, and for q[1,2]q \in [1, 2] for a Dantzig-type conic programming estimator. We show error bounds which approach that of the regular Lasso and the Dantzig selector in case the errors in WW are tending to 0.

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