{"title":"奥伯沃尔法赫的恩爱夫妻问题","authors":"Gloria Rinaldi","doi":"10.1002/jcd.21946","DOIUrl":null,"url":null,"abstract":"<p>We generalize the well-known Oberwolfach problem posed by Ringel in 1967. We suppose to have <span></span><math>\n <semantics>\n <mrow>\n <mfrac>\n <mi>v</mi>\n \n <mn>2</mn>\n </mfrac>\n </mrow>\n <annotation> $\\frac{v}{2}$</annotation>\n </semantics></math> couples (here <span></span><math>\n <semantics>\n <mrow>\n <mi>v</mi>\n \n <mo>≥</mo>\n \n <mn>4</mn>\n </mrow>\n <annotation> $v\\ge 4$</annotation>\n </semantics></math> is an even integer) and suppose that they have to be seated for several nights at <span></span><math>\n <semantics>\n <mrow>\n <mi>t</mi>\n </mrow>\n <annotation> $t$</annotation>\n </semantics></math> round tables in such a way that each person seats next to his partner exactly <span></span><math>\n <semantics>\n <mrow>\n <mi>r</mi>\n \n <mo>≥</mo>\n \n <mn>0</mn>\n </mrow>\n <annotation> $r\\ge 0$</annotation>\n </semantics></math> times and next to every other person exactly once. We call this problem the Oberwolfach problem with loving couples. When <span></span><math>\n <semantics>\n <mrow>\n <mi>r</mi>\n \n <mo>=</mo>\n \n <mn>0</mn>\n </mrow>\n <annotation> $r=0$</annotation>\n </semantics></math>, the problem coincides with the so-called spouse-avoiding variant, which was introduced by Huang, Kotzig, and Rosa in 1979. While if either <span></span><math>\n <semantics>\n <mrow>\n <mi>r</mi>\n \n <mo>=</mo>\n \n <mn>2</mn>\n </mrow>\n <annotation> $r=2$</annotation>\n </semantics></math> or <span></span><math>\n <semantics>\n <mrow>\n <mi>r</mi>\n </mrow>\n <annotation> $r$</annotation>\n </semantics></math> equals the number of nights, it corresponds to the spouse-loving variant or to the Honeymoon variant, which was recently studied by Bolohan et al. and by Lepine and Sajna, respectively. In this paper, for each possible choice of <span></span><math>\n <semantics>\n <mrow>\n <mi>r</mi>\n </mrow>\n <annotation> $r$</annotation>\n </semantics></math>, we construct many classes of solutions to the Oberwolfach problem with loving couples. We also obtain new solutions to the Honeymoon variant.</p>","PeriodicalId":15389,"journal":{"name":"Journal of Combinatorial Designs","volume":"32 9","pages":"532-545"},"PeriodicalIF":0.5000,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The Oberwolfach problem with loving couples\",\"authors\":\"Gloria Rinaldi\",\"doi\":\"10.1002/jcd.21946\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We generalize the well-known Oberwolfach problem posed by Ringel in 1967. We suppose to have <span></span><math>\\n <semantics>\\n <mrow>\\n <mfrac>\\n <mi>v</mi>\\n \\n <mn>2</mn>\\n </mfrac>\\n </mrow>\\n <annotation> $\\\\frac{v}{2}$</annotation>\\n </semantics></math> couples (here <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>v</mi>\\n \\n <mo>≥</mo>\\n \\n <mn>4</mn>\\n </mrow>\\n <annotation> $v\\\\ge 4$</annotation>\\n </semantics></math> is an even integer) and suppose that they have to be seated for several nights at <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>t</mi>\\n </mrow>\\n <annotation> $t$</annotation>\\n </semantics></math> round tables in such a way that each person seats next to his partner exactly <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>r</mi>\\n \\n <mo>≥</mo>\\n \\n <mn>0</mn>\\n </mrow>\\n <annotation> $r\\\\ge 0$</annotation>\\n </semantics></math> times and next to every other person exactly once. We call this problem the Oberwolfach problem with loving couples. When <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>r</mi>\\n \\n <mo>=</mo>\\n \\n <mn>0</mn>\\n </mrow>\\n <annotation> $r=0$</annotation>\\n </semantics></math>, the problem coincides with the so-called spouse-avoiding variant, which was introduced by Huang, Kotzig, and Rosa in 1979. While if either <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>r</mi>\\n \\n <mo>=</mo>\\n \\n <mn>2</mn>\\n </mrow>\\n <annotation> $r=2$</annotation>\\n </semantics></math> or <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>r</mi>\\n </mrow>\\n <annotation> $r$</annotation>\\n </semantics></math> equals the number of nights, it corresponds to the spouse-loving variant or to the Honeymoon variant, which was recently studied by Bolohan et al. and by Lepine and Sajna, respectively. In this paper, for each possible choice of <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>r</mi>\\n </mrow>\\n <annotation> $r$</annotation>\\n </semantics></math>, we construct many classes of solutions to the Oberwolfach problem with loving couples. We also obtain new solutions to the Honeymoon variant.</p>\",\"PeriodicalId\":15389,\"journal\":{\"name\":\"Journal of Combinatorial Designs\",\"volume\":\"32 9\",\"pages\":\"532-545\"},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2024-05-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Combinatorial Designs\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/jcd.21946\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Combinatorial Designs","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jcd.21946","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
We generalize the well-known Oberwolfach problem posed by Ringel in 1967. We suppose to have couples (here is an even integer) and suppose that they have to be seated for several nights at round tables in such a way that each person seats next to his partner exactly times and next to every other person exactly once. We call this problem the Oberwolfach problem with loving couples. When , the problem coincides with the so-called spouse-avoiding variant, which was introduced by Huang, Kotzig, and Rosa in 1979. While if either or equals the number of nights, it corresponds to the spouse-loving variant or to the Honeymoon variant, which was recently studied by Bolohan et al. and by Lepine and Sajna, respectively. In this paper, for each possible choice of , we construct many classes of solutions to the Oberwolfach problem with loving couples. We also obtain new solutions to the Honeymoon variant.
期刊介绍:
The Journal of Combinatorial Designs is an international journal devoted to the timely publication of the most influential papers in the area of combinatorial design theory. All topics in design theory, and in which design theory has important applications, are covered, including:
block designs, t-designs, pairwise balanced designs and group divisible designs
Latin squares, quasigroups, and related algebras
computational methods in design theory
construction methods
applications in computer science, experimental design theory, and coding theory
graph decompositions, factorizations, and design-theoretic techniques in graph theory and extremal combinatorics
finite geometry and its relation with design theory.
algebraic aspects of design theory.
Researchers and scientists can depend on the Journal of Combinatorial Designs for the most recent developments in this rapidly growing field, and to provide a forum for both theoretical research and applications. All papers appearing in the Journal of Combinatorial Designs are carefully peer refereed.