A common fixed point theorem of Fisher in b-metric-like spaces
หน่วยงานเจ้าของโครงการ :
คณะวิทยาศาสตร์และเทคโนโลยี
ลักษณะโครงการวิจัย :
โครงการวิจัยเดี่ยว
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ไม่อยู่ภายใต้แผนงานวิจัย/ชุดโครงการวิจัย
ประเภทโครงการ :
โครงการวิจัยใหม่
วันเริ่มต้นโครงการ :
1 ตุลาคม 2563
วันสิ้นสุดโครงการ :
30 กันยายน 2564
ประเภทของการวิจัย :
งานวิจัยพื้นฐาน(ทฤษฎี)/บริสุทธิ์
ความสำคัญและที่มาของปัญหา :
The Banach fixed point theorem is a forceful tool in nonlinear analysis, has many applications and has been extended by a large number of authors. In recent years, several authors have obtained fixed and common fixed point results for various classes of mappings in the setting of many generalized metric spaces. In the papers of Bakhtin and Czerwik, the notion of b-metric space has been introduced and some fixed point theorems for single-valued and multi-valued mappings in b-metric spaces were proved. More recently, Hussain and Mitrovic proved fixed point results for multi-valued weak quasi-contractions in a b-metric space with the increased range of the Lipschitzian constants.
Definition 1. Let X be a nonempty set and let s ? 1 be a given real number. A function d : X ? X [0, ?) is said to be a b-metric if and only if for all x, y, z ? X the following conditions are satisfied:
(1) d(x,y) = 0 if and only if x = y;
(2) d(x,y) = d(y,x);?
(3) d(x,z) ? s[d(x,y)+d(y,z)].
A triplet (X, d, s), is called a b-metric space with coefficient s.?The classical spaces l p (R) and L p [0, 1], p ? (0, 1), are examples of b-metric spaces. The concept of convergence in such spaces is similar to that of the standard metric spaces.
In 2018, Nawab Hussain, Zoran D. Mitrovic and Stojan Radenovic formulate and prove our first new results with four mappings in the context of b-metric spaces.
Theorem 2. Let the pairs (S, I) and (T, J) be b-compatible defined on a complete b-metric space (X, d, s) and satisfying
d(Sx,Ty) ? ? max {d(Ix,Jy), d(Sx,Ix), d(Ty,Jy), 1/2s (d(Sx,Jy) + d(Ty,Ix))},
for all x, y ? X, where 0 ? ? < 1. If S(X) ?J(X), T(X) ? I(X) and if I, J, S and T are continuous, then S, T, I and J have a unique common fixed point.
From Theorem 2 obtain Fisher’s type result for four mappings in the context of b-metric spaces.
Theorem 3. Let the pairs (S, I) and (T, J) be b-compatible on a complete b-metric space (X, d, s) and satisfying
d(Sx, T y) ? ? d(Ix, Jy)
for all x, y ? X, where 0 ? ? < 1. If S(X) ? J(X) and T(X) ? I(X) and if I, J, S and T are continuous, then S, T, I and J have a unique common fixed point.?
Recently, Mitrovi ?c and Radenovi ?c introduced a bv(s)-metric space as a b-metric generalization of a v-generalized metric space, they also gave the Banach and Reich contractions variants in the new generalized space.
Definition 4. Let X be a nonempty set, bv : X ? X R+ and v ? N such that if for all x, y ? X and for all distinct points u1,u2,...,uv ? X\{x, y} the following hold:
(bv1) bv( x , y ) = 0 ?? x = y;?
(bv2) bv(x,y) = bv(y,x);?
(bv3) there is s?R with s ? 1 such that bv(x,y) ? s[bv(x,u1)+bv(u1,u2)+ ??? +bv(uv,y)]. Then bv is called a bv(s)-metric on X, and (X, bv ) is called a bv(s)-metric space with a coefficient s.?
Inspired by their work and that of Nawab Hussain, Zoran D. Mitrovic and Stojan Radenovic, we have given a proof for Fisher contraction principle in b-metric-like spaces with increased range of the Lipschitzian constants and without continuity of the b-metric-like function, to generalize some of the results proved in Jovanovic ? et al. and many others.
วัตถุประสงค์ของโครงการ :
To consider and analyze a common fixed point theorem of Fisher in b-metric-like spaces
and to prove the existence theorem of a such problem.
ขอบเขตของโครงการ :
Fixed points, Common fixed points, b-metric-like space
ผลที่คาดว่าจะได้รับ :
To obtain a common fixed point theorem of Fisher in b-metric-like spaces
and to prove the existence theorem of a such problem.