Operator Inequalities for J–contractions

نویسندگان

  • N. BEBIANO
  • R. LEMOS
  • G. SOARES
چکیده

A selfadjoint involutive matrix J endows Cn with an indefinite inner product [·, ·] given by [x,y] = 〈Jx,y〉 , x,y ∈ Cn. Characterizations of the J -chaotic order Log(A) J Log(B) are presented for J -selfadjoint matrices A,B with positive eigenvalues, in terms of operator functions involving the α -power mean and the J -relative entropy. An indefinite complete form of the Furuta inequality and some exponential operator inequalities for J -selfadjoint matrices are also obtained. The parallelism between the inequalities in Hilbert spaces and the corresponding indefinite versions in Krein spaces is pointed out. Mathematics subject classification (2010): 47B50, 47A63, 15A45.

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تاریخ انتشار 2012