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Some Common Fixed Point Theorems in Menger Spaces

Sunny Chauhan, B. D. Pant (2013)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

In this paper, we prove some common fixed point theorems for occasionally weakly compatible mappings in Menger spaces. An example is also given to illustrate the main result. As applications to our results, we obtain the corresponding fixed point theorems in metric spaces. Our results improve and extend many known results existing in the literature.

Some common fixed point theorems in normed linear spaces

Alfred Olufemi Bosede (2010)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

In this paper, we establish some generalizations to approximate common fixed points for selfmappings in a normed linear space using the modified Ishikawa iteration process with errors in the sense of Liu [10] and Rafiq [14]. We use a more general contractive condition than those of Rafiq [14] to establish our results. Our results, therefore, not only improve a multitude of common fixed point results in literature but also generalize some of the results of Berinde [3], Rhoades [15] and recent results...

Some convergence, stability and data dependency results for a Picard-S iteration method of quasi-strictly contractive operators

Müzeyyen Ertürk, Faik Gürsoy (2019)

Mathematica Bohemica

We study some qualitative features like convergence, stability and data dependency for Picard-S iteration method of a quasi-strictly contractive operator under weaker conditions imposed on parametric sequences in the mentioned method. We compare the rate of convergence among the Mann, Ishikawa, Noor, normal-S, and Picard-S iteration methods for the quasi-strictly contractive operators. Results reveal that the Picard-S iteration method converges fastest to the fixed point of quasi-strictly contractive...

Some duality results on bounded approximation properties of pairs

Eve Oja, Silja Treialt (2013)

Studia Mathematica

The main result is as follows. Let X be a Banach space and let Y be a closed subspace of X. Assume that the pair ( X * , Y ) has the λ-bounded approximation property. Then there exists a net ( S α ) of finite-rank operators on X such that S α ( Y ) Y and | | S α | | λ for all α, and ( S α ) and ( S * α ) converge pointwise to the identity operators on X and X*, respectively. This means that the pair (X,Y) has the λ-bounded duality approximation property.

Some eigenvalue estimates for wavelet related Toeplitz operators

Krzysztof Nowak (1993)

Colloquium Mathematicae

By a straightforward computation we obtain eigenvalue estimates for Toeplitz operators related to the two standard reproducing formulas of the wavelet theory. Our result extends the estimates for Calderón-Toeplitz operators obtained by Rochberg in [R2]. In the first section we recall two standard reproducing formulas of the wavelet theory, we define Toeplitz operators and discuss some of their properties. The second section contains precise statements of our results and their proofs. At the end...

Some equivalent metrics for bounded normal operators

Mohammad Reza Jabbarzadeh, Rana Hajipouri (2018)

Mathematica Bohemica

Some stronger and equivalent metrics are defined on , the set of all bounded normal operators on a Hilbert space H and then some topological properties of are investigated.

Some examples concerning applicability of the Fredholm-Radon method in potential theory

Josef Král, Wolfgang L. Wendland (1986)

Aplikace matematiky

Simple examples of bounded domains D 𝐑 3 are considered for which the presence of peculiar corners and edges in the boundary δ D causes that the double layer potential operator acting on the space 𝒮 ( δ D ) of all continuous functions on δ D can for no value of the parameter α be approximated (in the sub-norm) by means of operators of the form α I + T (where I is the identity operator and T is a compact linear operator) with a deviation less then | α | ; on the other hand, such approximability turns out to be possible for...

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