TY - BOOK AU - Van de Geer,Sar TI - Estimation and testing under sparsity: ecole d'ete de probabilites de Saint-Flour xlv - 2015 T2 - Lecture notes in mathematics SN - 9783319327730 U1 - 000SA.09 23 PY - 2016/// CY - Switzerland PB - Springer KW - Estimation theory. KW - Inequalities (Mathematics) N1 - Includes bibliographical references and index; 1. Introduction -- 2. The Lasso -- 3. The square-root Lasso -- 4. The bias of the Lasso and worst possible sub-directions -- 5. Confidence intervals using the Lasso -- 6. Structured sparsity -- 7. General loss with norm-penalty -- 8. Empirical process theory for dual norms -- 9. Probability inequalities for matrices -- 10. Inequalities for the centred empirical risk and its derivative -- 11. The margin condition -- 12. Some worked-out examples -- 13. Brouwer's fixed point theorem and sparsity -- 14. Asymptotically linear estimators of the precision matrix -- 15. Lower bounds for sparse quadratic forms -- 16. Symmetrization, contraction and concentration -- 17. Chaining including concentration -- 18. Metric structure of convex hulls N2 - Taking the Lasso method as its starting point, this book describes the main ingredients needed to study general loss functions and sparsity-inducing regularizers. It also provides a semi-parametric approach to establishing confidence intervals and tests. Sparsity-inducing methods have proven to be very useful in the analysis of high-dimensional data. Examples include the Lasso and group Lasso methods, and the least squares method with other norm-penalties, such as the nuclear norm. The illustrations provided include generalized linear models, density estimation, matrix completion and sparse principal components. Each chapter ends with a problem section. The book can be used as a textbook for a graduate or PhD course ER -