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Canadian Mathematical Bulletin

Indecomposable Positive Maps in Matrix Algebras

Kôtarô Tanahashi, Jun Tomiyama

Published Sep 1, 1988• 77 citations
Publisher

Abstract

Abstract We prove that Choi's map in M3 cannot be written as the sum of a 2-positive map and a 2-copositive map. We also provide other examples of positive maps in Mn which cannot be written as the sum of an n-positive map and a 2-copositive map.
DOI
10.4153/cmb-1988-044-4

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