Minkovskii-type inequality for arbitrary density matrix of composite and   noncomposite systems
  New kind of matrix inequality known for bipartite system density matrix is obtained for arbitrary density matrix of composite or noncomposite qudit systems including the single qudit state. The examples of two qubit system and qudit with j=3/2 are discussed. 
V. N. Chernega, O. V. Man'ko, V. I. Man'ko
quant-ph