常慧杰,桑彦彬
对称空间中满足弱压缩条件及公共极限值域性质的4个非自映射不动点定理
常慧杰[1],桑彦彬
(中北大学 理学院,山西 太原 030051)
利用公共极限值域性质,在映射满足弱压缩条件情况下,建立了一类在对称空间中2对非自映射公共不动点的存在定理.
弱压缩;公共不动点;公共极限值域性质
1引言及预备知识
近年来,4个映射的公共不动点定理受到了广泛的关注,文献[1]研究了对称空间中4个自映射的公共不动点定理,此映射满足性质和弱相容条件,并举出相应的例子.进一步,文献在对称空间中,将性质改为公共极限值域性质,4个自映射变成4个非自映射,并得到相应的不动点定理.
定义1[3]若满足条件:
定义2[4-5]设是对称空间,那么
定义3[6]令和是定义在具有对称距离的非空集合上的2个自映射,若对于任意,当时,恒有,则称为弱相容.
定义4[7]设是任意的集合,是定义在上的2个非自映射,若在中存在序列,使得,其中:,则称在上具有公共极限值域性质(记作).
定义5[8]设是任意的集合,和是定义在上的4个非自映射.若在中存在2个序列,,使得,其中:,则称映射对和在上具有公共极限值域性质(记作).
引理[9]令,则,且时,.
本文利用公共极限值域性质,借助度量空间中Cauchy列的收敛性及弱压缩算子的概念及其性质,将文献[2]中的算子进行变换,得到4个非自映射公共不动点定理的相应结论.关于4个非自映射不动点定理更一般结论的进一步讨论可参见文献[10];关于对称空间中一些更一般的结论可参见文献[11].
2主要结果及证明
假定下列条件成立:
生姜皮 生姜皮为生姜的外皮,辛凉力缓,和脾利水,善治水肿、小便不利,常配茯苓皮、桑白皮、大腹皮等治各种水肿,起利水消肿作用。
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Fixed point theorems for four non-self mappings in symmetric spaces satisfyingweakly contractive conditions and common limit range property
CHANG Hui-jie,SANG Yan-bin
(School of Science,North University of China,Taiyuan 030051,China)
Utilizing the common limit range property,the existence results of common fixed points for two pairs of non-self weakly compatible mappings satisfyingweakly contractive conditions are established .
weakly contractive;common fixed points;common limit range property
O177.91
A
10.3969/j.issn.1007-9831.2016.03.003
2016-01-14
中北大学校基金项目
常慧杰(1989-),男,山西太原人,在读硕士研究生,从事非线性泛函研究.E-mail:852740174@qq.com
桑彦彬(1979-),男,山西泽州人,副教授,博士,从事非线性泛函分析研究.E-mail:sangyanbin@126.com