{"title":"广义收缩的一个公共性质和不动点的存在性","authors":"S. Benahmed","doi":"10.24193/mathcluj.2022.1.06","DOIUrl":null,"url":null,"abstract":"The definitions of several types of generalized contractions for an application T from a complete metric space (X,d) in itself are recalled and reviewed. A common property [H] to all these concepts is put in light. We observe that assumption [H] is fulfilled in many cases and we prove that assumption [H] and lower semi-continuity of the function x maps to d(x,T(x)) ensure existence of a fixed point along with a sharp estimate for the distance to the fixed-points set.","PeriodicalId":39356,"journal":{"name":"Mathematica","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A common property to generalized contractions and existence of fixed points\",\"authors\":\"S. Benahmed\",\"doi\":\"10.24193/mathcluj.2022.1.06\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The definitions of several types of generalized contractions for an application T from a complete metric space (X,d) in itself are recalled and reviewed. A common property [H] to all these concepts is put in light. We observe that assumption [H] is fulfilled in many cases and we prove that assumption [H] and lower semi-continuity of the function x maps to d(x,T(x)) ensure existence of a fixed point along with a sharp estimate for the distance to the fixed-points set.\",\"PeriodicalId\":39356,\"journal\":{\"name\":\"Mathematica\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2022-04-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Mathematica\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.24193/mathcluj.2022.1.06\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"Mathematics\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematica","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.24193/mathcluj.2022.1.06","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Mathematics","Score":null,"Total":0}
A common property to generalized contractions and existence of fixed points
The definitions of several types of generalized contractions for an application T from a complete metric space (X,d) in itself are recalled and reviewed. A common property [H] to all these concepts is put in light. We observe that assumption [H] is fulfilled in many cases and we prove that assumption [H] and lower semi-continuity of the function x maps to d(x,T(x)) ensure existence of a fixed point along with a sharp estimate for the distance to the fixed-points set.