On the expectation of operator norms of random matrices

We prove estimates for the expected value of operator norms of Gaussian random matrices with independent and mean-zero entries, acting as operators from ${\mathrm{\ell }}_{p^{\ast }}^m$ to ${\mathrm{\ell }}_q^n$, $1\le p^{\ast }\le 2\le q\le \mathrm{\infty }$.