{"title":"Spin(7) 和 Spin(8) 列群同调类的几何表示","authors":"Eiolf Kaspersen, Gereon Quick","doi":"arxiv-2409.06491","DOIUrl":null,"url":null,"abstract":"By constructing concrete complex-oriented maps we show that the eight-fold of\nthe generator of the third integral cohomology of the spin groups Spin(7) and\nSpin(8) is in the image of the Thom morphism from complex cobordism to singular\ncohomology, while the generator itself is not in the image. We thereby give a\ngeometric construction for a nontrivial class in the kernel of the differential\nThom morphism of Hopkins and Singer for the Lie groups Spin(7) and Spin(8). The\nconstruction exploits the special symmetries of the octonions.","PeriodicalId":501119,"journal":{"name":"arXiv - MATH - Algebraic Topology","volume":"178 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Geometric representation of cohomology classes for the Lie groups Spin(7) and Spin(8)\",\"authors\":\"Eiolf Kaspersen, Gereon Quick\",\"doi\":\"arxiv-2409.06491\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"By constructing concrete complex-oriented maps we show that the eight-fold of\\nthe generator of the third integral cohomology of the spin groups Spin(7) and\\nSpin(8) is in the image of the Thom morphism from complex cobordism to singular\\ncohomology, while the generator itself is not in the image. We thereby give a\\ngeometric construction for a nontrivial class in the kernel of the differential\\nThom morphism of Hopkins and Singer for the Lie groups Spin(7) and Spin(8). The\\nconstruction exploits the special symmetries of the octonions.\",\"PeriodicalId\":501119,\"journal\":{\"name\":\"arXiv - MATH - Algebraic Topology\",\"volume\":\"178 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - Algebraic Topology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.06491\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - Algebraic Topology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.06491","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Geometric representation of cohomology classes for the Lie groups Spin(7) and Spin(8)
By constructing concrete complex-oriented maps we show that the eight-fold of
the generator of the third integral cohomology of the spin groups Spin(7) and
Spin(8) is in the image of the Thom morphism from complex cobordism to singular
cohomology, while the generator itself is not in the image. We thereby give a
geometric construction for a nontrivial class in the kernel of the differential
Thom morphism of Hopkins and Singer for the Lie groups Spin(7) and Spin(8). The
construction exploits the special symmetries of the octonions.