<p>Given Hilbert space operators <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq1.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="96" /> </InlineMediaObject> <EquationSource Format="TEX">\(A, B\in \mathcal {L}(H)\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>A</mi> <mo>,</mo> <mi>B</mi> <mo>∈</mo> <mi mathvariant="script">L</mi> <mo stretchy="false">(</mo> <mi>H</mi> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation>. The pair (<i>A</i>,&#xa0;<i>B</i>) satisfies the Fuglede–Putnam–Aluthge property if <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq2.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="77" /> </InlineMediaObject> <EquationSource Format="TEX">\(AT=TB\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>A</mi> <mi>T</mi> <mo>=</mo> <mi>T</mi> <mi>B</mi> </mrow> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq3.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="74" /> </InlineMediaObject> <EquationSource Format="TEX">\(T\in \mathcal {L}(H)\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>T</mi> <mo>∈</mo> <mi mathvariant="script">L</mi> <mo stretchy="false">(</mo> <mi>H</mi> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation> implies <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq4.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="77" /> </InlineMediaObject> <EquationSource Format="TEX">\({\tilde{A}}T=T{\tilde{B}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mover accent="true"> <mi>A</mi> <mo stretchy="false">~</mo> </mover> <mi>T</mi> <mo>=</mo> <mi>T</mi> <mover accent="true"> <mi>B</mi> <mo stretchy="false">~</mo> </mover> </mrow> </math></EquationSource> </InlineEquation>, where <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq5.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">\({\tilde{A}}\)</EquationSource> <EquationSource Format="MATHML"><math> <mover accent="true"> <mi>A</mi> <mo stretchy="false">~</mo> </mover> </math></EquationSource> </InlineEquation> is the Aluthge transform of <i>A</i>. We prove that the class of pairs (<i>A</i>,&#xa0;<i>B</i>) that possess the Fuglede–Putnam–Aluthge property includes pairs of quasinormal operators, pairs of partial isometries with a normal square, the class of pairs (<i>A</i>,&#xa0;<i>B</i>) such that <i>A</i> and <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq6.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="23" /> </InlineMediaObject> <EquationSource Format="TEX">\(B^*\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>B</mi> <mo>∗</mo> </msup> </math></EquationSource> </InlineEquation> are <i>p</i>-hyponormal or <i>log</i>-hyponormal, pairs (<i>A</i>,&#xa0;<i>B</i>) where <i>A</i> is a dominant operator and <InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq6.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="23" /> </InlineMediaObject> <EquationSource Format="TEX">\(B^*\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>B</mi> <mo>∗</mo> </msup> </math></EquationSource> </InlineEquation> is <i>p</i>-hyponormal or <i>log</i>-hyponormal, the class of pairs (<i>A</i>,&#xa0;<i>B</i>) for which <i>A</i> and <InlineEquation ID="IEq8"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq6.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="23" /> </InlineMediaObject> <EquationSource Format="TEX">\(B^*\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>B</mi> <mo>∗</mo> </msup> </math></EquationSource> </InlineEquation> are <InlineEquation ID="IEq9"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq9.gif" Format="GIF" Height="11" Rendition="HTML" Resolution="72" Type="Linedraw" Width="21" /> </InlineMediaObject> <EquationSource Format="TEX">\(w_*\)</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mi>w</mi> <mrow> <mrow /> <mo>∗</mo> </mrow> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>-hyponormal and all pairs of operators satisfying the Fuglede–Putnam property (FP-property). We also show that, (1) If <i>A</i> is invertible, then (<i>A</i>,&#xa0;<i>B</i>) has the FP-property implies that <InlineEquation ID="IEq10"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq10.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="48" /> </InlineMediaObject> <EquationSource Format="TEX">\(({\tilde{A}}, {\tilde{B}})\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mover accent="true"> <mi>A</mi> <mo stretchy="false">~</mo> </mover> <mo>,</mo> <mover accent="true"> <mi>B</mi> <mo stretchy="false">~</mo> </mover> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation> has the FP-property. (2) If <i>A</i> and <i>B</i> are <i>iw</i>-hyponormal, then (<i>A</i>,&#xa0;<i>B</i>) has the FP-property if and only if <InlineEquation ID="IEq11"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq10.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="48" /> </InlineMediaObject> <EquationSource Format="TEX">\(({\tilde{A}}, {\tilde{B}})\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mover accent="true"> <mi>A</mi> <mo stretchy="false">~</mo> </mover> <mo>,</mo> <mover accent="true"> <mi>B</mi> <mo stretchy="false">~</mo> </mover> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation> has it too. We give some classes of operators <i>A</i> and <i>B</i> for which <InlineEquation ID="IEq12"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41478_2025_903_Article_IEq10.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="48" /> </InlineMediaObject> <EquationSource Format="TEX">\(({\tilde{A}}, {\tilde{B}})\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <mover accent="true"> <mi>A</mi> <mo stretchy="false">~</mo> </mover> <mo>,</mo> <mover accent="true"> <mi>B</mi> <mo stretchy="false">~</mo> </mover> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation> has the FP-property.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

On the Fuglede–Putnam–Aluthge property

  • Mohamed Morjane,
  • Karim Azhoum,
  • Mohamed Ech-Chad,
  • Youssef Bouhafsi

摘要

Given Hilbert space operators \(A, B\in \mathcal {L}(H)\) A , B L ( H ) . The pair (AB) satisfies the Fuglede–Putnam–Aluthge property if \(AT=TB\) A T = T B and \(T\in \mathcal {L}(H)\) T L ( H ) implies \({\tilde{A}}T=T{\tilde{B}}\) A ~ T = T B ~ , where \({\tilde{A}}\) A ~ is the Aluthge transform of A. We prove that the class of pairs (AB) that possess the Fuglede–Putnam–Aluthge property includes pairs of quasinormal operators, pairs of partial isometries with a normal square, the class of pairs (AB) such that A and \(B^*\) B are p-hyponormal or log-hyponormal, pairs (AB) where A is a dominant operator and \(B^*\) B is p-hyponormal or log-hyponormal, the class of pairs (AB) for which A and \(B^*\) B are \(w_*\) w -hyponormal and all pairs of operators satisfying the Fuglede–Putnam property (FP-property). We also show that, (1) If A is invertible, then (AB) has the FP-property implies that \(({\tilde{A}}, {\tilde{B}})\) ( A ~ , B ~ ) has the FP-property. (2) If A and B are iw-hyponormal, then (AB) has the FP-property if and only if \(({\tilde{A}}, {\tilde{B}})\) ( A ~ , B ~ ) has it too. We give some classes of operators A and B for which \(({\tilde{A}}, {\tilde{B}})\) ( A ~ , B ~ ) has the FP-property.