{"title":"2^n阶阿贝尔群的零和划分","authors":"Sylwia Cichacz-Przenioslo, Karol Suchan","doi":"10.46298/dmtcs.9914","DOIUrl":null,"url":null,"abstract":"The following problem has been known since the 80's. Let $\\Gamma$ be an\nAbelian group of order $m$ (denoted $|\\Gamma|=m$), and let $t$ and $m_i$, $1\n\\leq i \\leq t$, be positive integers such that $\\sum_{i=1}^t m_i=m-1$.\nDetermine when $\\Gamma^*=\\Gamma\\setminus\\{0\\}$, the set of non-zero elements of\n$\\Gamma$, can be partitioned into disjoint subsets $S_i$, $1 \\leq i \\leq t$,\nsuch that $|S_i|=m_i$ and $\\sum_{s\\in S_i}s=0$ for every $i$, $1 \\leq i \\leq\nt$. It is easy to check that $m_i\\geq 2$ (for every $i$, $1 \\leq i \\leq t$) and\n$|I(\\Gamma)|\\neq 1$ are necessary conditions for the existence of such\npartitions, where $I(\\Gamma)$ is the set of involutions of $\\Gamma$. It was\nproved that the condition $m_i\\geq 2$ is sufficient if and only if\n$|I(\\Gamma)|\\in\\{0,3\\}$. For other groups (i.e., for which $|I(\\Gamma)|\\neq 3$\nand $|I(\\Gamma)|>1$), only the case of any group $\\Gamma$ with\n$\\Gamma\\cong(Z_2)^n$ for some positive integer $n$ has been analyzed completely\nso far, and it was shown independently by several authors that $m_i\\geq 3$ is\nsufficient in this case. Moreover, recently Cichacz and Tuza proved that, if\n$|\\Gamma|$ is large enough and $|I(\\Gamma)|>1$, then $m_i\\geq 4$ is sufficient.\nIn this paper we generalize this result for every Abelian group of order $2^n$.\nNamely, we show that the condition $m_i\\geq 3$ is sufficient for $\\Gamma$ such\nthat $|I(\\Gamma)|>1$ and $|\\Gamma|=2^n$, for every positive integer $n$. We\nalso present some applications of this result to graph magic- and\nanti-magic-type labelings.","PeriodicalId":110830,"journal":{"name":"Discret. Math. Theor. Comput. Sci.","volume":"25 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2021-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Zero-sum partitions of Abelian groups of order $2^n$\",\"authors\":\"Sylwia Cichacz-Przenioslo, Karol Suchan\",\"doi\":\"10.46298/dmtcs.9914\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The following problem has been known since the 80's. Let $\\\\Gamma$ be an\\nAbelian group of order $m$ (denoted $|\\\\Gamma|=m$), and let $t$ and $m_i$, $1\\n\\\\leq i \\\\leq t$, be positive integers such that $\\\\sum_{i=1}^t m_i=m-1$.\\nDetermine when $\\\\Gamma^*=\\\\Gamma\\\\setminus\\\\{0\\\\}$, the set of non-zero elements of\\n$\\\\Gamma$, can be partitioned into disjoint subsets $S_i$, $1 \\\\leq i \\\\leq t$,\\nsuch that $|S_i|=m_i$ and $\\\\sum_{s\\\\in S_i}s=0$ for every $i$, $1 \\\\leq i \\\\leq\\nt$. It is easy to check that $m_i\\\\geq 2$ (for every $i$, $1 \\\\leq i \\\\leq t$) and\\n$|I(\\\\Gamma)|\\\\neq 1$ are necessary conditions for the existence of such\\npartitions, where $I(\\\\Gamma)$ is the set of involutions of $\\\\Gamma$. It was\\nproved that the condition $m_i\\\\geq 2$ is sufficient if and only if\\n$|I(\\\\Gamma)|\\\\in\\\\{0,3\\\\}$. For other groups (i.e., for which $|I(\\\\Gamma)|\\\\neq 3$\\nand $|I(\\\\Gamma)|>1$), only the case of any group $\\\\Gamma$ with\\n$\\\\Gamma\\\\cong(Z_2)^n$ for some positive integer $n$ has been analyzed completely\\nso far, and it was shown independently by several authors that $m_i\\\\geq 3$ is\\nsufficient in this case. Moreover, recently Cichacz and Tuza proved that, if\\n$|\\\\Gamma|$ is large enough and $|I(\\\\Gamma)|>1$, then $m_i\\\\geq 4$ is sufficient.\\nIn this paper we generalize this result for every Abelian group of order $2^n$.\\nNamely, we show that the condition $m_i\\\\geq 3$ is sufficient for $\\\\Gamma$ such\\nthat $|I(\\\\Gamma)|>1$ and $|\\\\Gamma|=2^n$, for every positive integer $n$. We\\nalso present some applications of this result to graph magic- and\\nanti-magic-type labelings.\",\"PeriodicalId\":110830,\"journal\":{\"name\":\"Discret. Math. Theor. Comput. Sci.\",\"volume\":\"25 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-11-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Discret. Math. Theor. Comput. Sci.\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.46298/dmtcs.9914\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Discret. Math. Theor. Comput. Sci.","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.46298/dmtcs.9914","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
摘要
下面这个问题从80年代就知道了。设$\Gamma$为顺序为$m$(记为$|\Gamma|=m$)的阿别群,设$t$、$m_i$、$1\leq i \leq t$为正整数,使得$\sum_{i=1}^t m_i=m-1$。确定$\Gamma$的非零元素集合$\Gamma^*=\Gamma\setminus\{0\}$何时可以划分为不相交的子集$S_i$、$1 \leq i \leq t$,使得$|S_i|=m_i$、$\sum_{s\in S_i}s=0$对于每一个$i$、$1 \leq i \leqt$。很容易检查$m_i\geq 2$(对于每个$i$、$1 \leq i \leq t$)和$|I(\Gamma)|\neq 1$是存在这样的分区的必要条件,其中$I(\Gamma)$是$\Gamma$的对合集。证明了条件$m_i\geq 2$当且仅当$|I(\Gamma)|\in\{0,3\}$是充分的。对于其他组(即$|I(\Gamma)|\neq 3$和$|I(\Gamma)|>1$),到目前为止,只有任何组$\Gamma$对于某些正整数$n$具有$\Gamma\cong(Z_2)^n$的情况才被完全分析过,并且有几位作者独立地表明$m_i\geq 3$在这种情况下是有效的。此外,最近Cichacz和Tuza证明,如果$|\Gamma|$足够大,$|I(\Gamma)|>1$,那么$m_i\geq 4$是充分的。本文将这一结果推广到所有阶为$2^n$的阿贝尔群,即证明了条件$m_i\geq 3$对于$\Gamma$是充分的,使得对于每一个正整数$n$$|I(\Gamma)|>1$和$|\Gamma|=2^n$。我们还给出了这一结果在图示幻型和反幻型标记中的一些应用。
Zero-sum partitions of Abelian groups of order $2^n$
The following problem has been known since the 80's. Let $\Gamma$ be an
Abelian group of order $m$ (denoted $|\Gamma|=m$), and let $t$ and $m_i$, $1
\leq i \leq t$, be positive integers such that $\sum_{i=1}^t m_i=m-1$.
Determine when $\Gamma^*=\Gamma\setminus\{0\}$, the set of non-zero elements of
$\Gamma$, can be partitioned into disjoint subsets $S_i$, $1 \leq i \leq t$,
such that $|S_i|=m_i$ and $\sum_{s\in S_i}s=0$ for every $i$, $1 \leq i \leq
t$. It is easy to check that $m_i\geq 2$ (for every $i$, $1 \leq i \leq t$) and
$|I(\Gamma)|\neq 1$ are necessary conditions for the existence of such
partitions, where $I(\Gamma)$ is the set of involutions of $\Gamma$. It was
proved that the condition $m_i\geq 2$ is sufficient if and only if
$|I(\Gamma)|\in\{0,3\}$. For other groups (i.e., for which $|I(\Gamma)|\neq 3$
and $|I(\Gamma)|>1$), only the case of any group $\Gamma$ with
$\Gamma\cong(Z_2)^n$ for some positive integer $n$ has been analyzed completely
so far, and it was shown independently by several authors that $m_i\geq 3$ is
sufficient in this case. Moreover, recently Cichacz and Tuza proved that, if
$|\Gamma|$ is large enough and $|I(\Gamma)|>1$, then $m_i\geq 4$ is sufficient.
In this paper we generalize this result for every Abelian group of order $2^n$.
Namely, we show that the condition $m_i\geq 3$ is sufficient for $\Gamma$ such
that $|I(\Gamma)|>1$ and $|\Gamma|=2^n$, for every positive integer $n$. We
also present some applications of this result to graph magic- and
anti-magic-type labelings.