Statistical Properties of Lasso
摘要
In this chapter, we return to the noisy linear regression. Recall the sparse linear model \(Y = \mathbb {X} \beta ^* + \varepsilon \) , where \(\mathbb {X} \in \mathbb {R}^{n\times d}\) and \(\|\beta ^*\|_0 \le s\) . We estimate the high-dimensional linear model via the Lasso estimator \(\displaystyle \widehat \beta = \operatorname *{\text{arg min}}_{\beta }\frac {1}{2n} \|Y-\mathbb {X}\beta \|_2^2 + \lambda \|\beta \|_1. \) In this chapter, we will study the statistical properties of the Lasso estimator. Like the RIP condition for the basis pursuit, we also need conditions for Lasso.