Post

Henrik Wilming
@arrr.de

This clarifies the mathematical structure behind the inequality and immediately generalizes it to inclusions of arbitrary von Neumann algebras. The proof is essentially just as short as in the finite-dimensional case and boils down to APA* ≤ AA* for any projector P.

Henrik Wilming
@arrr.de

I should also add that the result by Lin et al. has been published in Lett. Math. Phys., 113, 68 (2023) doi.org/10.1007/s110... I inserted the arxiv reference above because of the character limit.

doi.orgA new operator extension of strong subadditivity of quantum entropy - Letters in Mathematical PhysicsLet $$S(\rho )$$ S ( ρ ) be the von Neumann entropy of a density matrix $$\rho $$ ρ . Weak monotonicity asserts that $$S(\rho _{AB}) - S(\rho _A) + S(\rho _{BC}) - S(\rho _C)\ge 0$$ S ( ρ AB ) - S ( ρ...