<p>We consider <i>L</i>-<InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation>-nonexpansive maps <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq4.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="87" /> </InlineMediaObject> <EquationSource Format="TEX">\(T:K\rightarrow K\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>T</mi> <mo>:</mo> <mi>K</mi> <mo stretchy="false">→</mo> <mi>K</mi> </mrow> </math></EquationSource> </InlineEquation> on a convex subset <i>K</i> of a Banach space <i>X</i>, i.e., maps in which <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq5.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="136" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega _T(\delta )\le L\delta +\omega (\delta )\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>ω</mi> <mi>T</mi> </msub> <mrow> <mo stretchy="false">(</mo> <mi>δ</mi> <mo stretchy="false">)</mo> </mrow> <mo>≤</mo> <mi>L</mi> <mi>δ</mi> <mo>+</mo> <mi>ω</mi> <mrow> <mo stretchy="false">(</mo> <mi>δ</mi> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation> with <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq6.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="66" /> </InlineMediaObject> <EquationSource Format="TEX">\(L\in [0,1]\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>L</mi> <mo>∈</mo> <mo stretchy="false">[</mo> <mn>0</mn> <mo>,</mo> <mn>1</mn> <mo stretchy="false">]</mo> </mrow> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation> being a modulus of continuity and <InlineEquation ID="IEq8"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq8.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="21" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega _T\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>ω</mi> <mi>T</mi> </msub> </math></EquationSource> </InlineEquation> is the minimal modulus of continuity of <i>T</i>. Both AFPP and FPP are studied. For moduli <InlineEquation ID="IEq9"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation> with <InlineEquation ID="IEq10"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq10.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="78" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega '(0)=\infty \)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msup> <mi>ω</mi> <mo>′</mo> </msup> <mrow> <mo stretchy="false">(</mo> <mn>0</mn> <mo stretchy="false">)</mo> </mrow> <mo>=</mo> <mi>∞</mi> </mrow> </math></EquationSource> </InlineEquation>, we show that if <i>X</i> contains an isomorphic copy of <InlineEquation ID="IEq11"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq11.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="15" /> </InlineMediaObject> <EquationSource Format="TEX">\(\textrm{c}_0\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>c</mtext> <mn>0</mn> </msub> </math></EquationSource> </InlineEquation> then it fails the FPP for 0-<InlineEquation ID="IEq12"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation>-nonexpansive maps with minimal displacement zero. In the affirmative direction, we prove for certain class of moduli <InlineEquation ID="IEq13"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation> that 0-<InlineEquation ID="IEq14"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation>-nonexpansive maps are constant on certain domains. Also, when <InlineEquation ID="IEq15"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq15.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="103" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega '(0)\le 1-L\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msup> <mi>ω</mi> <mo>′</mo> </msup> <mrow> <mo stretchy="false">(</mo> <mn>0</mn> <mo stretchy="false">)</mo> </mrow> <mo>≤</mo> <mn>1</mn> <mo>-</mo> <mi>L</mi> </mrow> </math></EquationSource> </InlineEquation> we show that AFPP works and FPP also works under monotonicity conditions on <InlineEquation ID="IEq16"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="25_2025_2475_Article_IEq1.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="14" /> </InlineMediaObject> <EquationSource Format="TEX">\(\omega \)</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation>. Further related results and examples are given.</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 L-\(\omega \)-Nonexpansive Maps

  • C. S. Barroso,
  • J. V. Bedoya,
  • C. S. R. da Silva

摘要

We consider L- \(\omega \) ω -nonexpansive maps \(T:K\rightarrow K\) T : K K on a convex subset K of a Banach space X, i.e., maps in which \(\omega _T(\delta )\le L\delta +\omega (\delta )\) ω T ( δ ) L δ + ω ( δ ) with \(L\in [0,1]\) L [ 0 , 1 ] , \(\omega \) ω being a modulus of continuity and \(\omega _T\) ω T is the minimal modulus of continuity of T. Both AFPP and FPP are studied. For moduli \(\omega \) ω with \(\omega '(0)=\infty \) ω ( 0 ) = , we show that if X contains an isomorphic copy of \(\textrm{c}_0\) c 0 then it fails the FPP for 0- \(\omega \) ω -nonexpansive maps with minimal displacement zero. In the affirmative direction, we prove for certain class of moduli \(\omega \) ω that 0- \(\omega \) ω -nonexpansive maps are constant on certain domains. Also, when \(\omega '(0)\le 1-L\) ω ( 0 ) 1 - L we show that AFPP works and FPP also works under monotonicity conditions on \(\omega \) ω . Further related results and examples are given.