<p>In this article we study the difference between orthogonality induced by norm derivatives (known as <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10_2025_1154_Article_IEq1.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="13" /> </InlineMediaObject> <EquationSource Format="TEX">\(\rho \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ρ</mi> </math></EquationSource> </InlineEquation>-orthogonality) and Birkhoff-James orthogonality in a normed linear space <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10_2025_1154_Article_IEq2.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="13" /> </InlineMediaObject> <EquationSource Format="TEX">\(\mathbb {X}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="double-struck">X</mi> </math></EquationSource> </InlineEquation> by introducing a new geometric constant, denoted by <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10_2025_1154_Article_IEq3.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="40" /> </InlineMediaObject> <EquationSource Format="TEX">\(\Gamma (\mathbb {X}).\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Γ</mi> <mo stretchy="false">(</mo> <mi mathvariant="double-struck">X</mi> <mo stretchy="false">)</mo> <mo>.</mo> </mrow> </math></EquationSource> </InlineEquation> We explore the relation between various geometric properties of the space and the constant <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10_2025_1154_Article_IEq3.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="40" /> </InlineMediaObject> <EquationSource Format="TEX">\(\Gamma (\mathbb {X}).\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Γ</mi> <mo stretchy="false">(</mo> <mi mathvariant="double-struck">X</mi> <mo stretchy="false">)</mo> <mo>.</mo> </mrow> </math></EquationSource> </InlineEquation> We also investigate the left symmetric and right symmetric elements of a normed linear space with respect to <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10_2025_1154_Article_IEq1.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="13" /> </InlineMediaObject> <EquationSource Format="TEX">\(\rho \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ρ</mi> </math></EquationSource> </InlineEquation>-orthogonality and obtain a characterization of the same. We characterize inner product spaces among normed linear spaces using the symmetricity of <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10_2025_1154_Article_IEq1.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="13" /> </InlineMediaObject> <EquationSource Format="TEX">\(\rho \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ρ</mi> </math></EquationSource> </InlineEquation>-orthogonality. Finally, we provide a complete description of both left symmetric and right symmetric elements with respect to <InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10_2025_1154_Article_IEq1.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="13" /> </InlineMediaObject> <EquationSource Format="TEX">\(\rho \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ρ</mi> </math></EquationSource> </InlineEquation>-orthogonality for some particular Banach spaces.</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

Orthogonality induced by norm derivatives: a new geometric constant and symmetry

  • Souvik Ghosh,
  • Kallol Paul,
  • Debmalya Sain

摘要

In this article we study the difference between orthogonality induced by norm derivatives (known as \(\rho \) ρ -orthogonality) and Birkhoff-James orthogonality in a normed linear space \(\mathbb {X}\) X by introducing a new geometric constant, denoted by \(\Gamma (\mathbb {X}).\) Γ ( X ) . We explore the relation between various geometric properties of the space and the constant \(\Gamma (\mathbb {X}).\) Γ ( X ) . We also investigate the left symmetric and right symmetric elements of a normed linear space with respect to \(\rho \) ρ -orthogonality and obtain a characterization of the same. We characterize inner product spaces among normed linear spaces using the symmetricity of \(\rho \) ρ -orthogonality. Finally, we provide a complete description of both left symmetric and right symmetric elements with respect to \(\rho \) ρ -orthogonality for some particular Banach spaces.