{"title":"有理纤维立方四面体","authors":"Hanine Awada","doi":"10.1007/s00229-024-01585-9","DOIUrl":null,"url":null,"abstract":"<p>Some classes of cubic fourfolds are birational to fibrations over <span>\\({\\mathbb {P}}^2\\)</span>, where the fibers are rational surfaces. This is the case for cubics containing a plane (resp. an elliptic ruled surface), where the fibers are quadric surfaces (resp. del Pezzo sextic surfaces). It is known that the rationality of these cubic hypersurfaces is related to the rationality of these surfaces over the function field of <span>\\({\\mathbb {P}}^2\\)</span> and to the existence of rational (multi)sections of the fibrations. We study, in the moduli space of cubic fourfolds, the intersection of the divisor <span>\\({\\mathcal {C}}_{8}\\)</span> (resp. <span>\\({\\mathcal {C}}_{18}\\)</span>) with <span>\\({\\mathcal {C}}_{14}\\)</span>, <span>\\({\\mathcal {C}}_{26}\\)</span> and <span>\\({\\mathcal {C}}_{38}\\)</span>, whose elements are known to be rational cubic fourfolds. We provide descriptions of the irreducible components of these intersections and give new explicit examples of rational cubics fibered in (quartic, quintic) del Pezzo surfaces or in quadric surfaces over <span>\\({\\mathbb {P}}^2\\)</span>. We also investigate the existence of rational sections for these fibrations. Under some mild assumptions on the singularities of the fibers, these properties can be translated in terms of Brauer classes on certain surfaces.</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"17 1","pages":""},"PeriodicalIF":0.5000,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Rational fibered cubic fourfolds\",\"authors\":\"Hanine Awada\",\"doi\":\"10.1007/s00229-024-01585-9\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Some classes of cubic fourfolds are birational to fibrations over <span>\\\\({\\\\mathbb {P}}^2\\\\)</span>, where the fibers are rational surfaces. This is the case for cubics containing a plane (resp. an elliptic ruled surface), where the fibers are quadric surfaces (resp. del Pezzo sextic surfaces). It is known that the rationality of these cubic hypersurfaces is related to the rationality of these surfaces over the function field of <span>\\\\({\\\\mathbb {P}}^2\\\\)</span> and to the existence of rational (multi)sections of the fibrations. We study, in the moduli space of cubic fourfolds, the intersection of the divisor <span>\\\\({\\\\mathcal {C}}_{8}\\\\)</span> (resp. <span>\\\\({\\\\mathcal {C}}_{18}\\\\)</span>) with <span>\\\\({\\\\mathcal {C}}_{14}\\\\)</span>, <span>\\\\({\\\\mathcal {C}}_{26}\\\\)</span> and <span>\\\\({\\\\mathcal {C}}_{38}\\\\)</span>, whose elements are known to be rational cubic fourfolds. We provide descriptions of the irreducible components of these intersections and give new explicit examples of rational cubics fibered in (quartic, quintic) del Pezzo surfaces or in quadric surfaces over <span>\\\\({\\\\mathbb {P}}^2\\\\)</span>. We also investigate the existence of rational sections for these fibrations. Under some mild assumptions on the singularities of the fibers, these properties can be translated in terms of Brauer classes on certain surfaces.</p>\",\"PeriodicalId\":49887,\"journal\":{\"name\":\"Manuscripta Mathematica\",\"volume\":\"17 1\",\"pages\":\"\"},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2024-07-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Manuscripta Mathematica\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1007/s00229-024-01585-9\",\"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":"Manuscripta Mathematica","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00229-024-01585-9","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
Some classes of cubic fourfolds are birational to fibrations over \({\mathbb {P}}^2\), where the fibers are rational surfaces. This is the case for cubics containing a plane (resp. an elliptic ruled surface), where the fibers are quadric surfaces (resp. del Pezzo sextic surfaces). It is known that the rationality of these cubic hypersurfaces is related to the rationality of these surfaces over the function field of \({\mathbb {P}}^2\) and to the existence of rational (multi)sections of the fibrations. We study, in the moduli space of cubic fourfolds, the intersection of the divisor \({\mathcal {C}}_{8}\) (resp. \({\mathcal {C}}_{18}\)) with \({\mathcal {C}}_{14}\), \({\mathcal {C}}_{26}\) and \({\mathcal {C}}_{38}\), whose elements are known to be rational cubic fourfolds. We provide descriptions of the irreducible components of these intersections and give new explicit examples of rational cubics fibered in (quartic, quintic) del Pezzo surfaces or in quadric surfaces over \({\mathbb {P}}^2\). We also investigate the existence of rational sections for these fibrations. Under some mild assumptions on the singularities of the fibers, these properties can be translated in terms of Brauer classes on certain surfaces.
期刊介绍:
manuscripta mathematica was founded in 1969 to provide a forum for the rapid communication of advances in mathematical research. Edited by an international board whose members represent a wide spectrum of research interests, manuscripta mathematica is now recognized as a leading source of information on the latest mathematical results.