Matrix convexity and unitary power dilations of Toeplitz-contractive operator tuples [0.03%]
Toeplitz-压缩型算子组的矩阵凸性和酉幂扩张
Douglas Farenick
Douglas Farenick
Using works of T. Ando and L. Gurvits, the well-known theorem of P.R. Halmos concerning the existence of unitary dilations for contractive linear operators acting on Hilbert spaces is recast as a result for d-tuples of contractive Hilbert s...
Dániel Virosztek
Dániel Virosztek
The seminal work of Kubo and Ando (Math Ann 246:205-224, 1979/80) provided us with an axiomatic approach to means of positive operators. As most of their axioms are algebraic in nature, this approach has a clear algebraic flavour. On the ot...