Mathematical Sciences ( IF 2 ) Pub Date : 2021-04-18 , DOI: 10.1007/s40096-021-00400-w Alberto Sánchez-Alzola , Francisco Javier García-Pacheco , Enrique Naranjo-Guerra , Soledad Moreno-Pulido
A supporting vector of a matrix A for a certain norm \(\Vert \cdot \Vert \) on \(\mathbb {R}^n\) is a vector x such that \(\Vert x\Vert =1\) and \(\Vert Ax\Vert =\Vert A\Vert =\displaystyle \max _{\Vert y\Vert =1}\Vert Ay\Vert \). In this manuscript, we characterize the existence of supporting vectors in the infinite-dimensional case for both the \(\ell _1\)-norm and the \(\ell _{\infty }\)-norm. Besides this characterization, our theorems provide a description of the set of supporting vectors for operators on \(\ell _{\infty }\) and \(\ell _1\). As an application of our results in the finite-dimensional case for both the \(\ell _1\)-norm and the \(\ell _{\infty }\)-norm, we study meteorological data from stations located on the province of Cádiz (Spain). For it, we consider a matrix database with the highest temperature deviations of these stations.
中文翻译:
$$ \ ell _1 $$ℓ1-范数和$$ \ ell _ {\ infty} $$ℓ∞-范数的支持向量和一个应用
一矩阵的支撑矢量甲一定范数\(\ Vert的\ CDOT \ Vert的\)上\(\ mathbb {R} ^ N \)是一个矢量X,使得\(\ Vert的X \韦尔= 1 \)和\(\ Vert Ax \ Vert = \ Vert A \ Vert = \ displaystyle \ max _ {\ Vert y \ Vert = 1} \ Vert Ay \ Vert \)。在此手稿中,我们描述了\(\ ell _1 \)-范数和\(\ ell _ {\ infty} \)-范数在无限维情况下支持向量的存在。除了这种表征之外,我们的定理还为\(\ ell _ {\ infty} \)和\(\ ell _1 \)上的运算符提供了一组支持向量的描述。。作为\(\ ell _1 \)-范数和\(\ ell _ {\ infty} \)-范数在有限维情况下的结果的应用,我们研究了来自省内各站点的气象数据加的斯(西班牙)的地图。为此,我们考虑具有这些站最高温度偏差的矩阵数据库。