5 problems

Additivity conjecture. Quantum entanglement does not enhance the channel capacity, and the classical capacity of a quantum channel is additive.

Let $\Phi_1$ and $\Phi_2$ be quantum channels. For $p\geq 1$, define the maximal output $p$-norm by … and define the minimal output von Neumann entropy by … where the extrema range…

Let $\Phi_1,\ldots,\Phi_n$ be quantum channels, and let the quantities characterizing them include capacities for classical information and maximal output purity. Tensor products o…

Additivity conjecture. The above additivity holds for $\alpha\in[\frac{1}{2},1)$. If true, the regularized sandwiched Rényi mutual information in the strong converse exponent formu…

Let the Werner–Holevo channel be the unitarily covariant quantum channel considered in the paper, and let an operator convex function be a convex function satisfying the operator-c…