Mathematical methods are extensively used in dealing with simulation and approximation problems related to computer science, engineering, physics, and many others. Such problems can be often modelled in the abstract form of an equation (algebraic, functional, and differential) and then proving that its solutions exist and can be exactly determined or approximately obtained. Fixed-point theory is one of the most relevant and popular tools used over the last decades for approaching the above-mentioned equations. A large amount of results establishing the existence and multiplicity of solutions for suitable equations can be proved using fixed-point arguments. In fact, these equations can be associated to a general fixed-point equation of the form for a given mapping f; namely, we look for a point, x, with zero distance from its image, . Now, fixed-point theorems are not only confined to pure mathematics, but they also act as bridges beetween abstract theories and applications in sciences. Thus, the aim of this collection of papers is to cover some of the recent advancements in abstract research and in developing new useful applications. The specific topics mainly include both fixed-point theorems in generalized metric spaces and Banach spaces (see [1,2,3,4,5,6,7]) and fixed-point iterative schemes along with the convergence analysis of proposed solving algorithms (see [8,9,10,11,12,13,14]). In particular, we point the attention of the reader on the applications of fixed-point arguments to the context of various classes of differential equations (see [15,16,17,18]); for a similar approach to integral equations, see [19]. Finally, a complementary topic to that of fixed-point theories is the best proximity point theory. This theory arises naturally as a generalization of the concept of a fixed point and is relevant in the case where the mapping, f, under investigation is fixed-point-free; namely, we look for a point, , such that the distance between and reaches its minimum (see [7]).
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
Not applicable.
Conflicts of Interest
The author declares no conflict of interest.
References
- Işık, H.; Banaei, S.; Golkarmanesh, F.; Parvaneh, V.; Park, C.; Khorshidi, M. On New Extensions of Darbo’s Fixed Point Theorem with Application. Symmetry 2020, 12, 424. [Google Scholar] [CrossRef]
- Kanwal, T.; Hussain, A.; Baghani, H.; de la Sen, M. New Fixed Point Theorems in Orthogonal F-Metric Spaces with Application to Fractional Differential Equation. Symmetry 2020, 12, 832. [Google Scholar] [CrossRef]
- Popescu, O.; Stan, G. Some Fixed Point Theorems for (a-p)-Quasicontractions. Symmetry 2020, 12, 1973. [Google Scholar] [CrossRef]
- Vujaković, J.; Ljajko, E.; Radojević, S.; Radenović, S. On Some New Jungck–Fisher–Wardowski Type Fixed Point Results. Symmetry 2020, 12, 2048. [Google Scholar] [CrossRef]
- Pant, R.; Patel, P.; Shukla, R.; De la Sen, M. Fixed Point Theorems for Nonexpansive Type Mappings in Banach Spaces. Symmetry 2021, 13, 585. [Google Scholar] [CrossRef]
- Huang, H.; Singh, Y.M.; Khan, M.S.; Radenović, S. Rational Type Contractions in Extended b-Metric Spaces. Symmetry 2021, 13, 614. [Google Scholar] [CrossRef]
- Khan, A.A.; Ali, B. Completeness of b-Metric Spaces and Best Proximity Points of Nonself Quasi-Contractions. Symmetry 2021, 13, 2206. [Google Scholar] [CrossRef]
- Awwal, A.M.; Wang, L.; Kumam, P.; Mohammad, H. A Two-Step Spectral Gradient Projection Method for System of Nonlinear Monotone Equations and Image Deblurring Problems. Symmetry 2020, 12, 874. [Google Scholar] [CrossRef]
- Marcheva, P.I.; Ivanov, S.I. Convergence Analysis of a Modified Weierstrass Method for the Simultaneous Determination of Polynomial Zeros. Symmetry 2020, 12, 1408. [Google Scholar] [CrossRef]
- Wang, X. Fixed-Point Iterative Method with Eighth-Order Constructed by Undetermined Parameter Technique for Solving Nonlinear Systems. Symmetry 2021, 13, 863. [Google Scholar] [CrossRef]
- Berinde, V.; Ţicală, C. Enhancing Ant-Based Algorithms for Medical Image Edge Detection by Admissible Perturbations of Demicontractive Mappings. Symmetry 2021, 13, 885. [Google Scholar] [CrossRef]
- Ciobanescu, C.; Turcanu, T. On Iteration Sn for Operators with Condition (D). Symmetry 2020, 12, 1676. [Google Scholar] [CrossRef]
- Tang, Y.; Zhang, Y.; Gibali, A. New Self-Adaptive Inertial-like Proximal Point Methods for the Split Common Null Point Problem. Symmetry 2021, 13, 2316. [Google Scholar] [CrossRef]
- Chen, J.; Luo, X.; Tang, Y.; Dong, Q. Primal-Dual Splitting Algorithms for Solving Structured Monotone Inclusion with Applications. Symmetry 2021, 13, 2415. [Google Scholar] [CrossRef]
- Alsarori, N.; Ghadle, K.; Sessa, S.; Saleh, H.; Alabiad, S. New Study of the Existence and Dimension of the Set of Solutions for Nonlocal Impulsive Differential Inclusions with a Sectorial Operator. Symmetry 2021, 13, 491. [Google Scholar] [CrossRef]
- Jia, Z.; Liu, X.; Li, C. Fixed Point Theorems Applied in Uncertain Fractional Differential Equation with Jump. Symmetry 2020, 12, 765. [Google Scholar] [CrossRef]
- Guran, L.; Bota, M.-F. Existence of the Solutions of Nonlinear Fractional Differential Equations Using the Fixed Point Technique in Extended b-Metric Spaces. Symmetry 2021, 13, 158. [Google Scholar] [CrossRef]
- Baitiche, Z.; Derbazi, C.; Benchohra, M.; Zhou, Y. A New Class of Coupled Systems of Nonlinear Hyperbolic Partial Fractional Differential Equations in Generalized Banach Spaces Involving the Caputo Fractional Derivative. Symmetry 2021, 13, 2412. [Google Scholar] [CrossRef]
- Ilea, V.; Otrocol, D. Existence and Uniqueness of the Solution for an Integral Equation with Supremum, via w-Distances. Symmetry 2020, 12, 1554. [Google Scholar] [CrossRef]
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2022 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).