An extension of the Fuglede commutativity theorem modulo the Hilbert-Schmidt class to operators of the form โ๐_{๐}๐๐_{๐}
An extension of the Fuglede commutativity theorem modulo the Hilbert-Schmidt class to operators of the form โ๐_{๐}๐๐_{๐}
We study the operators <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="normal upper Delta left-parenthesis upper X right-parenthesis equals sigma-summation Underscript 1 Overscript n Endscripts upper M Subscript n Baseline upper X upper N Subscript n"> <mml:semantics> <mml:mrow> <mml:mi mathvariant="normal">ฮ<!-- ฮ --></mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>X</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mo movablelimits="false">โ<!-- โ --></mml:mo> โฆ