Citation: Lin, Ting-Chun, Isaac H. Kim, and Min-Hsiu Hsieh. "A new operator extension of strong subadditivity of quantum entropy." Letters in Mathematical Physics 113.3 (2023): 68.
Web: https://arxiv.org/abs/2211.13372
Tags: Information-theory
The strong subadditivity of von Neumann entropy is a foundational results, whose proof is famously difficult and was first due to Lieb and Ruskai:
> Lieb, Elliott H., and Mary Beth Ruskai. "Proof of the strong subadditivity of quantum-mechanical entropy." Les rencontres physiciens-mathématiciens de Strasbourg-RCP25 19 (1973): 36-55.
this paper gives a new proof of the result, and a new operator-theoretic extension of the result, as well as proving a key lemma which seems quite interesting in its own right.
This is relevant to me because strong subadditivity is used all over the place in the study of topological entanglement entropy, especially from information-convex perspective. The source of strong subadditivity in this context is a good thing to know.