发表机构
Dipartimento di Matematica, Università di Cagliari(卡利亚里大学数学系)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
本文提出 kernel--wreath 构造,从单斜括号生成无限族有限单斜括号,保持可解性,并应用于阶 12 及 Byott 族。
AI 中文摘要
我们为有限斜括号引入了一种 kernel--wreath 构造。设 $C$ 为有限斜括号,记 $(C,+)=A$ 且 $(C,\circ)=R$,并令 $\chi:R\twoheadrightarrow T$ 为到非平凡有限阿贝尔群 $T$ 的满同态。我们证明,在置换圈积 $R\wr T$ 中,一个自然指标为 $|T|$ 的核在 $A^T$ 上正则作用,从而定义了一个新的斜括号 $\KT_T(C,\chi)$,其加法群为 $A^{|T|}$。该构造保持乘法群的每个有限阿贝尔商,以及可解性,并将种子括号 $C$ 作为对角子括号包含。因此,它可以无限迭代。更精确地,若 $Q$ 是 $R$ 的非平凡有限阿贝尔商且 $p\in\pi(Q)$,则得到无限塔 \\[ C=C_0\hookrightarrow C_1\hookrightarrow C_2\hookrightarrow\cdots \\] 其中对每个 $m\geq0$,有 $(C_m,+)\cong A^{p^m}$。我们的主要永久性结果表明,若 $C$ 是单的且不是平凡斜括号,则 $\KT_T(C,\chi)$ 也是单的。因此,一个乘法群具有非平凡有限阿贝尔商的单种子可产生有限单斜括号的无限族。特别地,从有限非阿贝尔单群 $S$ 的 holomorph 的合适可解正则子群出发,我们得到加法群为 $S^{p^m}$ 且乘法群可解的无限族单斜括号。此外,我们还给出了阶为 $12$ 的单斜括号以及 Byott 族的进一步应用。
英文摘要
We introduce a kernel--wreath construction for finite skew braces. Let $C$ be a finite skew brace, write $(C,+)=A$ and $(C,\circ)=R$, and let $χ:R\twoheadrightarrow T$ be an epimorphism onto a non-trivial finite abelian group. We show that a natural index-$|T|$ kernel in the permutational wreath product $R\wr T$ acts regularly on $A^T$, and hence defines a new skew brace $\KT_T(C,χ)$ with additive group $A^{|T|}$. The construction preserves every finite abelian quotient of the multiplicative group, as well as solvability, and contains the seed brace $C$ as a diagonal subbrace. It can therefore be iterated indefinitely. More precisely, if $Q$ is a non-trivial finite abelian quotient of $R$ and $p\inπ(Q)$, then one obtains an infinite tower \[ C=C_0\hookrightarrow C_1\hookrightarrow C_2\hookrightarrow\cdots \] with $(C_m,+)\cong A^{p^m}$ for every $m\geq0$. Our main permanence result shows that if $C$ is simple and is not a trivial skew brace, then $\KT_T(C,χ)$ is again simple. Consequently, a single simple seed whose multiplicative group has a non-trivial finite abelian quotient gives rise to infinite families of finite simple skew braces. In particular, starting from suitable solvable regular subgroups of the holomorph of a finite non-abelian simple group $S$, we obtain infinite families of simple skew braces with additive groups $S^{p^m}$ and solvable multiplicative groups. Further applications are given to the simple skew braces of order $12$ and to Byott's family.
Comments13 pages