From Clarkson-McCarthy inequality to Ball-Carlen-Lieb inequality

In this paper, we give two new generalizations of Clarkson-McCarthy with several operators, which depends on the unitary orbit technique developed by Bourin, Hadamard Three-lines Theorem and the duality argument developed by Ball, Carlen and Lieb. Moreover, we complete the optimal 2-uniform convexity inequality established by Ball, Carlen and Lieb in [Invent. Math. 115 (1994) 463-482.]. Some open problems are presented.