Title: Positive extensions of Schur multipliers
Reporter: Prof. Yingfen Lin (Queen's University Belfast)
Time: 2017-12-11 ( Monday) 10:30
Abstract: The study of positive extensions of Schur multipliers can be traced to the matrices completion problem. In my talk, I will first introduce the study of matrices completions with some other motivations, then I will introduce partially defined Schur multipliers whose domains are operator systems. As a result, I will describe necessary and sufficient conditions for the existence of extensions to fully defined positive Schur multipliers. Application of this result to the extension problem for partially positive definite functions on locally compact groups will be given.