<p>Let <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\({\mathcal {H}}_{n}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="script">H</mi> <mi>n</mi> </msub> </math></EquationSource> </InlineEquation> be the real space of <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(n\times n\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>n</mi> <mo>×</mo> <mi>n</mi> </mrow> </math></EquationSource> </InlineEquation> complex Hermitian matrices, and suppose <i>F</i> is a unitary similarity invariant function on <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\({\mathcal {H}}_{n}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="script">H</mi> <mi>n</mi> </msub> </math></EquationSource> </InlineEquation>. The structure is determined for maps <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\Phi \)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Φ</mi> </math></EquationSource> </InlineEquation> on <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\({\mathcal {H}}_{n}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="script">H</mi> <mi>n</mi> </msub> </math></EquationSource> </InlineEquation> satisfying <Equation ID="Equ11"> <EquationSource Format="TEX">\(\begin{aligned} F(\Phi (A)\circ \Phi (B)) = F(A\circ B) \qquad (A, B\in {\mathcal {H}}_{n}) \end{aligned}\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <mrow> <mtable> <mtr> <mtd columnalign="right"> <mrow> <mi>F</mi> <mrow> <mo stretchy="false">(</mo> <mi mathvariant="normal">Φ</mi> <mrow> <mo stretchy="false">(</mo> <mi>A</mi> <mo stretchy="false">)</mo> </mrow> <mo>∘</mo> <mi mathvariant="normal">Φ</mi> <mrow> <mo stretchy="false">(</mo> <mi>B</mi> <mo stretchy="false">)</mo> </mrow> <mo stretchy="false">)</mo> </mrow> <mo>=</mo> <mi>F</mi> <mrow> <mo stretchy="false">(</mo> <mi>A</mi> <mo>∘</mo> <mi>B</mi> <mo stretchy="false">)</mo> </mrow> <mspace width="2em" /> <mrow> <mo stretchy="false">(</mo> <mi>A</mi> <mo>,</mo> <mi>B</mi> <mo>∈</mo> <msub> <mi mathvariant="script">H</mi> <mi>n</mi> </msub> <mo stretchy="false">)</mo> </mrow> </mrow> </mtd> </mtr> </mtable> </mrow> </math></EquationSource> </Equation>with no surjectivity assumption on them, where the binary operation <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\circ \)</EquationSource> <EquationSource Format="MATHML"><math> <mo>∘</mo> </math></EquationSource> </InlineEquation> stands for the product or the Jordan triple product on matrices. To establish the proofs, we determine the structure of mappings on <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\({\mathcal {H}}_{n}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="script">H</mi> <mi>n</mi> </msub> </math></EquationSource> </InlineEquation> that are zero product preserving when restricted to the set of rank one Hermitian matrices. As an application, mappings on <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\({\mathcal {H}}_{n}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="script">H</mi> <mi>n</mi> </msub> </math></EquationSource> </InlineEquation> leaving invariant the pseudo spectra, the condition spectra, or the numerical spectra of the product or the Jordan triple product of matrices are also described.</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

Unitary similarity invariant function preservers of Hermitian matrix products

  • M. Bendaoud,
  • A. Benyouness,
  • M. Sarih,
  • A. Zine-dine

摘要

Let \({\mathcal {H}}_{n}\) H n be the real space of \(n\times n\) n × n complex Hermitian matrices, and suppose F is a unitary similarity invariant function on \({\mathcal {H}}_{n}\) H n . The structure is determined for maps \(\Phi \) Φ on \({\mathcal {H}}_{n}\) H n satisfying \(\begin{aligned} F(\Phi (A)\circ \Phi (B)) = F(A\circ B) \qquad (A, B\in {\mathcal {H}}_{n}) \end{aligned}\) F ( Φ ( A ) Φ ( B ) ) = F ( A B ) ( A , B H n ) with no surjectivity assumption on them, where the binary operation \(\circ \) stands for the product or the Jordan triple product on matrices. To establish the proofs, we determine the structure of mappings on \({\mathcal {H}}_{n}\) H n that are zero product preserving when restricted to the set of rank one Hermitian matrices. As an application, mappings on \({\mathcal {H}}_{n}\) H n leaving invariant the pseudo spectra, the condition spectra, or the numerical spectra of the product or the Jordan triple product of matrices are also described.