Extensions of a theorem of Fuglede and Putnam
Extensions of a theorem of Fuglede and Putnam
The operator equation <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper A upper X equals upper X upper B"> <mml:semantics> <mml:mrow> <mml:mi>A</mml:mi> <mml:mi>X</mml:mi> <mml:mo>=</mml:mo> <mml:mi>X</mml:mi> <mml:mi>B</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">AX = XB</mml:annotation> </mml:semantics> </mml:math> </inline-formula> implies <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper A Superscript asterisk Baseline upper X equals upper X upper B Superscript asterisk"> …