The quantum relative entropy is well known to obey a monotonicity property (i.e., it does not increase under the action of a quantum channel). Here we present several refinements of this entropy inequality, some of which have a physical interpretation in terms of recovery from the action of the channel. The recovery channel given here is explicit and universal, depending only on the channel and one of the arguments to the relative entropy.
Publication Source (Journal or Book title)
IEEE International Symposium on Information Theory - Proceedings
Junge, M., Renner, R., Sutter, D., Wilde, M., & Winter, A. (2016). Universal recoverability in quantum information. IEEE International Symposium on Information Theory - Proceedings, 2016-August, 2494-2498. https://doi.org/10.1109/ISIT.2016.7541748