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Quantum $f$-divergence preserving maps on positive semidefinite operators acting on finite dimensional Hilbert spaces (1602.06942v4)
Published 22 Feb 2016 in math-ph, math.FA, math.MP, and quant-ph
Abstract: We determine the structure of all bijections on the cone of positive semidefinite operators which preserve the quantum $f$-divergence for an arbitrary strictly convex function $f$ defined on the positive halfline. It turns out that any such transformation is implemented by either a unitary or an antiunitary operator.