A fully Gaussian quantum Stein's lemma
This paper investigates how Gaussian restrictions affect hypothesis testing for multimode bosonic states using quantum Stein's lemma. It shows that the asymptotic error exponent, or Gaussian Stein exponent, can be simplified into a single-letter formula by separating the contribution of first moments from covariance terms. Under specific conditions, collective Gaussian measurements offer no asymptotic advantage over independent single-copy measurements.