کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
842942 1470530 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The retractions onto the common fixed points of some families and semigroups of mappings
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی (عمومی)
پیش نمایش صفحه اول مقاله
The retractions onto the common fixed points of some families and semigroups of mappings
چکیده انگلیسی

Assume that CC is a closed convex subset of a reflexive Banach space EE and φ={Ti}i∈Iφ={Ti}i∈I is a family of self-mappings on CC of type (γ)(γ) such that F(φ)F(φ), the common fixed point set of φφ, is nonempty. From our results in this paper, it can be derived that: (a) If ∪i∈IF(Ti)∪i∈IF(Ti) is contained in a 3-dimensional subspace of EE then F(φ)F(φ) is a nonexpansive retract of CC; (b) If φφ is commutative, there exists a retraction RR of type (γ)(γ) from CC onto F(φ)F(φ), such that RTi=TiR=R(∀i)RTi=TiR=R(∀i), and every closed convex φφ-invariant subset of CC is RR-invariant; the same result holds for a non-commutative right amenable semigroup φφ, under some additional assumptions. Moreover, the existence of a (Ti)(Ti)-ergodic retraction RR of type (γ)(γ) from C˜={(xi)∈l∞(E):xi∈C,∀i∈I} onto F(φ)F(φ) in l∞(E)l∞(E) for the family φφ is discussed. We also apply some of our results to find ergodic retractions for nonexpansive affine mappings.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nonlinear Analysis: Theory, Methods & Applications - Volume 71, Issues 3–4, 1–15 August 2009, Pages 1171–1179
نویسندگان
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