From joint convexity of quantum relative entropy to a concavity theorem of Lieb

This paper provides a succinct proof of a 1973 theorem of Lieb that establishes the concavity of a certain trace function. The development relies on a deep result from quantum information theory, the joint convexity of quantum relative entropy, as well as a recent argument due to Carlen and Lieb.

• Type: Journal
• Year: 2011
• Where: CORR
• Authors: Joel A. Tropp
• Keywords: Carlen, CORR 2011, Education, Quantum Information Theory, Relative Entropy