<p>We prove that for the functions of the form <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41_2024_10141_Article_IEq1.gif" Format="GIF" Height="24" Rendition="HTML" Resolution="72" Type="Linedraw" Width="130" /> </InlineMediaObject> <EquationSource Format="TEX">\(g(x) = h(x) + \frac{C}{x+i}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>g</mi> <mrow> <mo stretchy="false">(</mo> <mi>x</mi> <mo stretchy="false">)</mo> </mrow> <mo>=</mo> <mi>h</mi> <mrow> <mo stretchy="false">(</mo> <mi>x</mi> <mo stretchy="false">)</mo> </mrow> <mo>+</mo> <mfrac> <mi>C</mi> <mrow> <mi>x</mi> <mo>+</mo> <mi>i</mi> </mrow> </mfrac> </mrow> </math></EquationSource> </InlineEquation>, where <i>h</i> belongs to the continuous Wiener algebra <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41_2024_10141_Article_IEq2.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="23" /> </InlineMediaObject> <EquationSource Format="TEX">\(W_0\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>W</mi> <mn>0</mn> </msub> </math></EquationSource> </InlineEquation>, the intersection of the Gabor frame set <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41_2024_10141_Article_IEq3.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="21" /> </InlineMediaObject> <EquationSource Format="TEX">\(\mathcal {F}_g\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="script">F</mi> <mi>g</mi> </msub> </math></EquationSource> </InlineEquation> with every hyperbola <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41_2024_10141_Article_IEq4.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="147" /> </InlineMediaObject> <EquationSource Format="TEX">\(\{\alpha , \beta &gt; 0 \mid \alpha \beta = c\}\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">{</mo> <mi>α</mi> <mo>,</mo> <mi>β</mi> <mo>&gt;</mo> <mn>0</mn> <mo>∣</mo> <mi>α</mi> <mi>β</mi> <mo>=</mo> <mi>c</mi> <mo stretchy="false">}</mo> </mrow> </math></EquationSource> </InlineEquation> is open in the relative topology. In particular, this applies to all rational functions <i>g</i>. We also show that the same phenomenon occurs for the functions from the Wiener algebra <i>W</i> which are discontinuous at one point.</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

Relative Openness of the Gabor Frame Set on the Hyperbolas

  • Aleksei Kulikov

摘要

We prove that for the functions of the form \(g(x) = h(x) + \frac{C}{x+i}\) g ( x ) = h ( x ) + C x + i , where h belongs to the continuous Wiener algebra \(W_0\) W 0 , the intersection of the Gabor frame set \(\mathcal {F}_g\) F g with every hyperbola \(\{\alpha , \beta > 0 \mid \alpha \beta = c\}\) { α , β > 0 α β = c } is open in the relative topology. In particular, this applies to all rational functions g. We also show that the same phenomenon occurs for the functions from the Wiener algebra W which are discontinuous at one point.