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arXiv 2008.03494math.ACmath.LOmath.RA
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赋值环与赋值域中的准二次模

Quasi-quadratic modules in valuation ring and valued field

Masato Fujita, Masaru Kageyama

AI总结:

本文在交换环中推广二次模定义准二次模,并证明在剩余类域特征不为二的2-亨塞尔赋值域子环中,准二次模与剩余域准二次模乘积的特定子集一一对应,同时显式构造了该对应及其对交与和运算的表达式。

摘要:

本文是前一版本的修订版,新增了一个附录,专门处理特征二的情形。我们在交换环中定义了准二次模,推广了二次模的概念。主要定理是关于一个2-亨塞尔赋值域$(K,{\bf val})$的子环$A$中准二次模的结构定理,其中剩余类域$F$的特征$\neq 2$。我们进一步假设赋值环$B$包含在$A$中。令$H={\bf val}(A^\times)$且$G_{\geq e}=\{g \in G\\;|\\; g \geq e\}$。记号$\mathfrak X_R$表示交换环$R$中所有准二次模的集合。我们的结构定理断言,$\mathfrak X_A$与$\prod_{g \in H \cup G_{\geq e}}\mathfrak X_F$的一个子集$\mathcal T_F^{ H \cup G_{\geq e}}$之间存在一一对应。我们显式构造了映射$Θ: \mathfrak X_A \rightarrow \mathcal T_F^{ H \cup G_{\geq e}}$及其逆映射。对于$\mathcal M, \mathcal N \in \mathfrak X_A$,我们还给出了$Θ(\mathcal M \cap \mathcal N)$和$Θ(\mathcal M+\mathcal N)$的显式表达式。此外,我们在附录中也简要考察了域$F$的特征为二的情形。

英文摘要:

This is a revised version of the previous version with a new appendix consisting of characteristic two case. We define quasi-quadratic modules in a commutative ring generalizing the notion of quadratic modules. The main theorem is a structure theorem of quasi-quadratic modules in a subring $A$ of a $2$-henselian valued field $(K,{\bf val})$ whose residue class field $F$ of characteristic $\neq 2$. We further assume that the valuation ring $B$ is contained in $A$. Set $H={\bf val}(A^\times)$ and $G_{\geq e}=\{g \in G\;|\; g \geq e\}$. The notation $\mathfrak X_R$ denotes the set of all the quasi-quadratic modules in a commutative ring $R$. Our structure theorem asserts that there exists a one-to-one correspondence between $\mathfrak X_A$ and a subset $\mathcal T_F^{ H \cup G_{\geq e}}$ of $\prod_{g \in H \cup G_{\geq e}}\mathfrak X_F$. We explicitly construct the map $Θ: \mathfrak X_A \rightarrow \mathcal T_F^{ H \cup G_{\geq e}}$ and its inverse. We also give explicit expressions of $Θ(\mathcal M \cap \mathcal N)$ and $Θ(\mathcal M+\mathcal N)$ for $\mathcal M, \mathcal N \in \mathfrak X_A$. In addition, we briefly investigate the case in which the field $F$ is of characteristic two in the appendix as well.

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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