{"title":"埃塔尔度图和 0 循环","authors":"Iván Rosas-Soto","doi":"10.1016/j.jalgebra.2024.10.036","DOIUrl":null,"url":null,"abstract":"<div><div>Using the triangulated category of étale motives over a field <em>k</em>, for a smooth projective variety <em>X</em> over <em>k</em>, we define the group <span><math><msubsup><mrow><mtext>CH</mtext></mrow><mrow><mn>0</mn></mrow><mrow><mtext>ét</mtext></mrow></msubsup><mo>(</mo><mi>X</mi><mo>)</mo></math></span> as an étale analogue of 0-cycles. We study the properties of <span><math><msubsup><mrow><mtext>CH</mtext></mrow><mrow><mn>0</mn></mrow><mrow><mtext>ét</mtext></mrow></msubsup><mo>(</mo><mi>X</mi><mo>)</mo></math></span> and give a description of the birational invariance of such a group. We define and present the étale degree map using Gysin morphisms in étale motivic cohomology and the étale index as an analogue to the classical case. We give examples of smooth projective varieties over a field <em>k</em> without zero cycles of degree one but with étale zero cycles of degree one, but this property is not always true as we give examples where the étale degree map is not surjective.</div></div>","PeriodicalId":14888,"journal":{"name":"Journal of Algebra","volume":"665 ","pages":"Pages 384-414"},"PeriodicalIF":0.8000,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Étale degree map and 0-cycles\",\"authors\":\"Iván Rosas-Soto\",\"doi\":\"10.1016/j.jalgebra.2024.10.036\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Using the triangulated category of étale motives over a field <em>k</em>, for a smooth projective variety <em>X</em> over <em>k</em>, we define the group <span><math><msubsup><mrow><mtext>CH</mtext></mrow><mrow><mn>0</mn></mrow><mrow><mtext>ét</mtext></mrow></msubsup><mo>(</mo><mi>X</mi><mo>)</mo></math></span> as an étale analogue of 0-cycles. We study the properties of <span><math><msubsup><mrow><mtext>CH</mtext></mrow><mrow><mn>0</mn></mrow><mrow><mtext>ét</mtext></mrow></msubsup><mo>(</mo><mi>X</mi><mo>)</mo></math></span> and give a description of the birational invariance of such a group. We define and present the étale degree map using Gysin morphisms in étale motivic cohomology and the étale index as an analogue to the classical case. We give examples of smooth projective varieties over a field <em>k</em> without zero cycles of degree one but with étale zero cycles of degree one, but this property is not always true as we give examples where the étale degree map is not surjective.</div></div>\",\"PeriodicalId\":14888,\"journal\":{\"name\":\"Journal of Algebra\",\"volume\":\"665 \",\"pages\":\"Pages 384-414\"},\"PeriodicalIF\":0.8000,\"publicationDate\":\"2024-11-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Algebra\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0021869324005957\",\"RegionNum\":2,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Algebra","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0021869324005957","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
Using the triangulated category of étale motives over a field k, for a smooth projective variety X over k, we define the group as an étale analogue of 0-cycles. We study the properties of and give a description of the birational invariance of such a group. We define and present the étale degree map using Gysin morphisms in étale motivic cohomology and the étale index as an analogue to the classical case. We give examples of smooth projective varieties over a field k without zero cycles of degree one but with étale zero cycles of degree one, but this property is not always true as we give examples where the étale degree map is not surjective.
期刊介绍:
The Journal of Algebra is a leading international journal and publishes papers that demonstrate high quality research results in algebra and related computational aspects. Only the very best and most interesting papers are to be considered for publication in the journal. With this in mind, it is important that the contribution offer a substantial result that will have a lasting effect upon the field. The journal also seeks work that presents innovative techniques that offer promising results for future research.