Debiased-Lasso asymptotic normality 2026-09-24
Under sparsity, compatibility, and inverse-Gram estimation conditions, the standardized coordinatewise error of the Debiased Lasso converges in distribution to a standard normal distribution.
Past exam of the mathematics course of the University of Cambridge 2024 iii Paper 205 4 b Solution Created 2026-09-24 Updated 2026-09-25
One standard construction uses the Debiased Lasso. Starting from the Square-root Lasso estimate , estimate a vector that approximately inverts the th column of the empirical Gram matrix , for example by a Nodewise Lasso. Defineand estimate by . The approximate two-sided level- test rejects whenwhere is a standard normal quantile.
Sufficient high-dimensional conditions include a Compatibility condition for the Lasso bounded away from zero, , , andtogether with the corresponding sparsity and consistency conditions for the nodewise inverse-Gram estimate. Under these assumptions the Debiased-Lasso asymptotic normality makes the rejection probability under tend to .