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arXiv 1604.05403math.RTmath.GN
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半双线性型的拓扑分类:归约到非奇异情形

Topological classification of sesquilinear forms: reduction to the nonsingular case

Carlos M. da Fonseca, Tetiana Rybalkina, Vladimir V. Sergeichuk

摘要:

两个半双线性型$Φ:\mathbb C^m\times\mathbb C^m\to \mathbb C$和$Ψ:\mathbb C^n\times\mathbb C^n\to \mathbb C$称为拓扑等价的,如果存在同胚$φ:\mathbb C^m\to \mathbb C^n$(即,连续双射,其逆也是连续双射),使得对于所有$x,y\in \mathbb C^m$都是$Φ(x,y)=Ψ(φ(x),φ(y))$。R.A.Horn和V.V.Sergeichuk在2006年构造了一个正方形复矩阵$A$的正则化分解,即一个直和$SAS^*=R\oplus J_{n_1}\oplus\dots\oplus J_{n_p}$,其中$S$和$R$是非奇异的,每个$J_{n_i}$是$n_i$乘$n_i$的奇异Jordan块。本文证明了$Φ$和$Ψ$是拓扑等价的当且仅当它们的矩阵的正则化分解在置换奇异和项$J_{n_i}$和用非奇异矩阵$R'\in\mathbb C^{r\times r}$替换$R\in\mathbb C^{r\times r}$时一致,使得$R$和$R'$是拓扑等价形式的矩阵.实和复双线性形式也得到类似的结果。

英文摘要:

Two sesquilinear forms $Φ:\mathbb C^m\times\mathbb C^m\to \mathbb C$ and $Ψ:\mathbb C^n\times\mathbb C^n\to \mathbb C$ are called topologically equivalent if there exists a homeomorphism $φ:\mathbb C^m\to \mathbb C^n$ (i.e., a continuous bijection whose inverse is also a continuous bijection) such that $Φ(x,y)=Ψ(φ(x),φ(y))$ for all $x,y\in \mathbb C^m$. R.A.Horn and V.V.Sergeichuk in 2006 constructed a regularizing decomposition of a square complex matrix $A$; that is, a direct sum $SAS^*=R\oplus J_{n_1}\oplus\dots\oplus J_{n_p}$, in which $S$ and $R$ are nonsingular and each $J_{n_i}$ is the $n_i$-by-$n_i$ singular Jordan block. In this paper, we prove that $Φ$ and $Ψ$ are topologically equivalent if and only if the regularizing decompositions of their matrices coincide up to permutation of the singular summands $J_{n_i}$ and replacement of $R\in\mathbb C^{r\times r}$ by a nonsingular matrix $R'\in\mathbb C^{r\times r}$ such that $R$ and $R'$ are the matrices of topologically equivalent forms. Analogous results for real and complex bilinear forms are also obtained.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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