Multiplicativity of Maximal p-Norms in Werner-Holevo channels for $1 \le   p \le 2$
  Recently, King and Ruskai [1] conjectured that the maximal p-norm of the Werner--Holevo channel is multiplicative for all $1\le p \le 2$. In this paper we prove this conjecture. Our proof relies on certain convexity and monotonicity properties of the p--norm. 
Nilanjana Datta