摘要
Let be a real matrix with coherence . We present a simplified and improved study of the quasi-isometry property for most submatrices of obtained by uniform column sampling. Our results depend on , the operator norm and the dimensions with explicit constants, which improve the previously known values by a large factor. The analysis relies on a tail-decoupling argument, of independent interest, and a recent version of the Non-Commutative Chernoff inequality (NCCI).