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Exponentials of de Branges–Rovnyak kernels

Published online by Cambridge University Press:  03 June 2021

Shuhei Kuwahara
Affiliation:
Sapporo Seishu High School, Sapporo, Japan e-mail: s.kuwahara@sapporoseishu.ed.jp
Michio Seto*
Affiliation:
Department of Mathematics, National Defense Academy, Yokosuka, Japan
*

Abstract

In this note, we give a new property of de Branges–Rovnyak kernels. As the main theorem, it is shown that the exponential of de Branges–Rovnyak kernel is strictly positive definite if the corresponding Schur class function is nontrivial.

Type
Article
Copyright
© Canadian Mathematical Society 2021

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