Estimation of sparse linear regression coefficients under L-subexponential covariates
摘要
We tackle estimating sparse coefficients in a linear regression when the covariates are sampled from an L-subexponential random vector. Such vectors follow a class of distributions that exhibit heavier tails than Gaussian random vectors. Previous studies have established error bounds similar to those derived for Gaussian random vectors. However, these methods require stronger conditions than those used for Gaussian random vectors to derive the error bounds. In the present study, we present an error bound identical to the one obtained for Gaussian random vectors up to constant factors without imposing stronger conditions, for covariates drawn from an L-subexponential random vector. Of special interest, we employ an