paper

Sandwiched Rényi Divergence Satisfies Data Processing Inequality

arXiv:1306.5920 · doi:10.1063/1.4838855

Abstract

Sandwiched (quantum) -Rényi divergence has been recently defined in the independent works of Wilde et al. (arXiv:1306.1586) and Müller-Lennert et al (arXiv:1306.3142v1). This new quantum divergence has already found applications in quantum information theory. Here we further investigate properties of this new quantum divergence. In particular we show that sandwiched -Rényi divergence satisfies the data processing inequality for all values of . Moreover we prove that -Holevo information, a variant of Holevo information defined in terms of sandwiched -Rényi divergence, is super-additive. Our results are based on Hölder's inequality, the Riesz-Thorin theorem and ideas from the theory of complex interpolation. We also employ Sion's minimax theorem.

13 pages, title changed, fixed typos, results unchanged, to appear in J. Math. Phys

References in corpus (7)

Cited by in corpus (152)