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Existence and uniqueness of strong coupled fixed points for different classes of Perov type couplings in the setup of cone metric spaces equipped with c-distances are obtained. Some examples are presented to support the results proved herein. We also study the well-posedness of strong coupled fixed point problem. Our results generalize and extend various comparable results in the existing literature.

We introduce a large class of contractive mappings, called Suzuki–Berinde type contraction. We show that any Suzuki–Berinde type contraction has a fixed point and characterizes the completeness of the underlying normed space. A fixed point theorem for multivalued mappings is also obtained. These results unify, generalize and complement various known comparable results in the literature.

The purpose of this paper is to introduce the class of multi-valued operators by the technique of interpolation of operators. Our results extend and generalize several results from the existing literature. Moreover, we also study the data dependence problem of the fixed point set and Ulam–Hyers stability of the fixed point problem for the operators introduced herein. Moreover, as an application, we obtain a homotopy result.

Several mathematical models have been developed to investigate the dynamics SARS-CoV-2 and its different variants. Most of the multi-strain SARS-CoV-2 models do not capture an important and more realistic feature of such models known as randomness. As the dynamical behavior of most epidemics, especially SARS-CoV-2, is unarguably influenced by several random factors, it is appropriate to consider a stochastic vaccination co-infection model for two strains of SARS-CoV-2. In this work, a new stochastic model for two variants of SARS-CoV-2 is presented. The conditions of existence and the uniqueness of a unique global solution of the stochastic model are derived. Constructing an appropriate Lyapunov function, the conditions for the stochastic system to fluctuate around endemic equilibrium of the deterministic system are derived. Stationary distribution and ergodicity for the new co-infection model are also studied. Numerical simulations are carried out to validate theoretical results. It is observed that when the white noise intensities are larger than certain thresholds and the associated stochastic reproduction numbers are less than unity, both strains die out and go into extinction with unit probability. More-over, it is observed that, for weak white noise intensities, the solution of the stochastic system fluctuates around the endemic equilibrium (EE) of the deterministic model. Frequency distributions are also studied to show random fluctuations due to stochastic white noise intensities. The results presented herein also reveal the impact of vaccination in reducing the co-circulation of SARS-CoV-2 variants within a given population. • A new stochastic model for dual variants of SARS-CoV-2 is presented. • Boundary and co-existence endemic equilibria are established for the deterministic version of the model. • The conditions for the extinction of both variants are also derived. • Stationary distribution and ergodicity for the new model are established. • Numerical simulations are carried out to validate theoretical results. [ABSTRACT FROM AUTHOR]

The aim of this paper is first to introduce generalizations of quantum integrals and derivatives which are called (ϕ-h)integrals and (ϕ-h)derivatives, respectively. Then we investigate some implicit integral inequalities for (ϕ-h)integrals. Different classes of convex functions are used to prove these inequalities for symmetric functions. Under certain assumptions, Hermite–Hadamard-type inequalities for q-integrals are deduced. The results presented herein are applicable to convex, m-convex, and ħ-convex functions defined on the non-negative part of the real line.

The aim of this paper is to study the sufficient conditions for the existence of fixed points of Perov type T-contractive mappings in the setup of complete cone b-metric space associated with generalized c-distance. Some examples are presented to support our main results and concepts defined herein. The results proved in the paper extend and generalize various well known results in the existing literature.

The aim of this paper is to prove some common fixed point theorems for certain nonlinear mappings satisfying rational contractive conditions in modular metric spaces. Our results extend, generalize and includes many known results as special cases in the framework of modular metric spaces. Furthermore, we apply our results in finding solutions of nonlinear integral equation of Urysohn type.

We introduce a new algorithm to approximate a solution of split variational inclusion problems of multivalued maximal monotone operators in uniformly convex and uniformly smooth Banach spaces under the Bregman distance. A strong convergence theorem for the above problem is established and several important known results are deduced as corollaries to it. As application, we solve a split minimization problem and provide a numerical example to support better findings of our result.

The aim of this paper is to introduce the concept of polytopic fuzzy sets as an extension of spherical fuzzy sets, picture fuzzy sets, and q-rung orthopair fuzzy sets. We define some basic operations and aggregation operators on polytopic fuzzy sets. Based on these operators, we present three new methods to deal with the multiple-attribute decision-making problem which cannot be solved with the help of existing aggregation operators. Finally, a numerical example is given to illustrate the validity of the proposed approach.

The objective of this paper is to introduce the notion of a D∗-cone metric space and then to establish the existence of common fixed points of mappings satisfying Perov type contraction conditions in the framework of such spaces. Also some convergence properties of sequences in D∗-cone metric space are studied without imposing the condition of normality on a cone. Our result complement, extend and generalize a number of comparable results in the existing literature.

The aim of this paper is to introduce generalized Suzuki type F-contraction fuzzy mappings and to prove the existence of fixed fuzzy points for such mappings in the setup of complete ordered metric spaces. An example is provided to show the validity of our results, followed by couple of remarks about the comparison of obtained results with the existing results in the literature. An application of our result to the domain of words is also presented.

The purpose of this paper is to obtain the existence of common fixed points of family of multivalued mappings satisfying generalized F-contraction conditions in ordered metric spaces. Some examples are presented to support the results proved herein. Our results generalize and extend various comparable results in the existing literature.

This paper aims to study the impacts of COVID-19 and dengue vaccinations on the dynamics of zika transmission by developing a vaccination model with the incorporation of saturated incidence rates. Analyses are performed to assess the qualitative behavior of the model. Carrying out bifurcation analysis of the model, it was concluded that co-infection, super-infection and also re-infection with same or different disease could trigger backward bifurcation. Employing well-formulated Lyapunov functions, the model’s equilibria are shown to be globally stable for a certain scenario. Moreover, global sensitivity analyses are performed out to assess the impact of dominant parameters that drive each disease’s dynamics and its co-infection. Model fitting is performed on the actual data for the state of Amazonas in Brazil. The fittings reveal that our model behaves very well with the data. The significance of saturated incidence rates on the dynamics of three diseases is also highlighted. Based on the numerical investigation of the model, it was observed that increased vaccination efforts against COVID-19 and dengue could positively impact zika dynamics and the co-spread of triple infections.

We prove strong convergence of the sequence generated by implicit viscosity approximation method involving a multivalued nonexpansive mapping in framework of CAT(0) space. Under certain appropriate conditions on parameters, we show that such a sequence converges strongly to a fixed point of the mapping which solves a variational inequality. We also present some convergence results for the implicit viscosity approximation method in complete ℝ-trees without the endpoint condition.

The aim of this paper is to present common fixed point results of set-valued graphic F-contraction mappings on a family of sets endowed with a graph. Some examples are presented to support the results proved herein. Our results unify, generalize and extend various results in the existing literature.

The aim of this paper is to introduce a class of generalized Suzuki type $$ (\alpha _{*},\psi _{\varphi })$$ (α∗,ψφ) -contractive multivalued operators and to prove the existence of fixed point and common fixed point of such operators in the setup of b-metric spaces. Some examples are presented to support the results proved herein. Our results generalize and extend various results in the existing literature. An estimate of Hausdorff distance between the fixed point sets of two generalized Suzuki type $$(\alpha _{*},\psi _{\varphi })$$ (α∗,ψφ) -contractive multivalued operators is obtained. We further investigate the Ulam–Hyers stability of fixed point problem of operators considered herein in the framework of b-metric spaces.

The aim of this paper is to introduce the new concept of ordered complete dislocated quasi G-metric space. The notion of dominated mappings is applied to approximate the unique solution of non linear functional equations. In this paper, we find the fixed point results for mappings satisfying the locally contractive conditions on a closed ball in an ordered complete dislocated quasi G-metric space. Our results improve several well known classical results.

The purpose of this paper is to introduce Picard–Krasnoselskii hybrid iterative process which is a hybrid of Picard and Krasnoselskii iterative processes. In case of contractive nonlinear operators, our iterative scheme converges faster than all of Picard, Mann, Krasnoselskii and Ishikawa iterative processes in the sense of Berinde (Iterative approximation of fixed points, 2002). We support our analytic proofs with a numerical example. Using this iterative process, we also find the solution of delay differential equation.

In this paper, we introduce new concepts of α-type F-contractive mappings which are essentially weaker than the class of F-contractive mappings given in [21, 22] and different from α-GF-contractions given in [8]. Then, sufficient conditions for the existence and uniqueness of fixed point are established for these new types of contractive mappings, in the setting of complete metric space. Consequently, the obtained results encompass various generalizations of the Banach contraction principle. Moreover, some examples and an application to nonlinear fractional differential equation are given to illustrate the usability of the new theory.

A new non-integer order mathematical model for SARS-CoV-2, Dengue and HIV co-dynamics is designed and studied. The impact of SARS-CoV-2 infection on the dynamics of dengue and HIV is analyzed using the tools of fractional calculus. The existence and uniqueness of solution of the proposed model are established employing well known Banach contraction principle. The Ulam-Hyers and generalized Ulam-Hyers stability of the model is also presented. We have applied the Laplace Adomian decomposition method to investigate the model with the help of three different fractional derivatives, namely: Caputo, Caputo-Fabrizio and Atangana-Baleanu derivatives. Stability analyses of the iterative schemes are also performed. The model fitting using the three fractional derivatives was carried out using real data from Argentina. Simulations were performed with each non-integer derivative and the results thus obtained are compared. Furthermore, it was concluded that efforts to keep the spread of SARS-CoV-2 low will have a significant impact in reducing the co-infections of SARS-CoV-2 and dengue or SARS-COV-2 and HIV. We also highlighted the impact of three different fractional derivatives in analyzing complex models dealing with the co-dynamics of different diseases. [ABSTRACT FROM AUTHOR]

In this paper, a similarity measure between intuitionistic fuzzy soft sets based on Hausdorff distance is defined and a possible application of this measure in medical diagnosis is presented. Also, Hamming and Euclidean distances are defined for interval-valued fuzzy soft and interval-valued intuitionistic fuzzy soft sets.

The aim of this paper is to introduce a new type of generalized multivalued contraction mappings and to present some results regarding fixed points of new class of multivalued contractions. As applications we obtain some basic results in fixed point theory like characterization of metric completeness, data dependence of fixed points and homotopy result. We prove the existence and uniqueness of bounded solution of functional equation arising in dynamic programming. Our results generalize, extend and unify various comparable results in the existing literature.

No single gastrojejunostomy anastomosis technique (GJA) in Laparoscopic Roux-en-Y gastric bypass (LRYGB) is currently preferred over another. Bendewald et al. confirmed that there was no difference in anastomotic stricture rates when comparing hand-sewn (HS), linear-stapled (LS), and circular-stapled (CS) GJA techniques. We present and analyze our own institutional data to readdress stricture rates. From January 2010 to January 2013, 860 consecutive patients underwent LRYGB using HS, LS, and CS anastomotic techniques at a single institution. All patients in this study were followed to see if they had a complication of a stricture within this time period. Hospital records were retrospectively reviewed and those who had stricture complications shown on endoscopy requiring intervention were compiled and compared using univariate analysis. Patient demographics did not differ substantially between the three groups. The most common technique employed was LS (n= 429, 49.8 %), followed by CS (n= 254, 29.5 %) and HS (n= 177, 20.6 %), respectively. Using multivariate analysis, there was a significant difference in the rate of strictures between the anastomotic techniques (LS 4.42 %, HS 2.82 %, CS 1.18 %, p= 0.0163). Our data show that the discussion of which anastomotic technique is superior should be reopened given the statistically significant low rate of strictures in patients who underwent LRYGB with a CS anastomosis in comparison with LS and HS anastomoses.

In this paper, we obtain some unique common fixed point results for generalized cyclic contraction pair of mappings. These results establish some of the more general common fixed point theorems for two maps in metric spaces.

Azam et al. (Numer Funct Anal Optim, 32(3):243–253, 2011) introduced a notion of complex valued metric space and obtained common fixed point result for mappings in such spaces. In this paper, introducing the concept of complex valued generalized metric spaces, some fixed and common fixed point results are obtained. As an application, periodic point property of common fixed point problem for two rational type contractive mappings involved therein is established.

In this paper, we introduce common approximate $$f$$-endpoint property for multi-valued mapping $$T:X\rightarrow P_{cl,bd}(X)$$to obtain a necessary and sufficient condition for existence of a unique common $$f$$-endpoint for such multi-valued mappings. Our results extend and unify comparable results in existing literature (see for example, Kamran in Nonlinear Anal (TMA) 67:2289–2296, 2007; Sintunavarat and Kumam in Appl Math Lett 25:52–57, 2012 and references mentioned therein). We also provide an example to support our results.

We establish some common fixed point results for multivalued mappings satisfying generalized contractive conditions on a complete partial metric space. The presented theorems extend some known results to partial metric spaces. We motivate our results by some given examples and an application for finding the solution of a functional equation arising in dynamic programming.

We prove some common fixed point results for four mappings satisfying generalized weak contractive condition in partially ordered complete b-metric spaces. Our results extend and improve several comparable results in the existing literature

In this paper, common fixed point for four maps using an implicit contractive condition in a complete metric space is proved. Some periodic point results for such mappings are also obtained. These results extend and generalize several comparable results in the current literature.

In this paper, the study of necessary conditions for the existence of unique fixed point of $$T$$-Hardy–Rogers type contractions mappings in the setting of ordered generalized metric spaces is initiated. These results unify and extend various comparable results from literature. We also provide example in support of results presented herein.

Abstract.In [Numer. Funct. Anal. Optim. 32 (2011), 243–253], Azam, Fisher, and Khan introduced a notion of complex-valued metric spaces and obtained common fixed point results for mappings satisfying rational inequalities. In the present paper, employing the concept of asymptotically regular mappings, the existence of a fixed point is obtained in a complex-valued metric space.

Abstract.The aim of this paper is to study the existence of fixed points of T-Ciric type mappings in the setup of partially ordered spaces. Moreover, the T-generalized weakly contractive mappings are introduced and also sufficient conditions for obtaining fixed points of such mappings in ordered spaces are studied. As an application of our results, periodic points of T-Banach operators are obtained. Finally, we provide some examples to illustrate the results presented herein.

Abstract: We prove the existence of coincidence points and common fixed points for multivalued f-weak contraction mappings which assume closed values only. As an application, related common fixed point, invariant approximation, random coincidence point and random invariant approximation results are also obtained. Our results provide extensions as well as substantial improvements of several well known results in the existing literature.

Abstract: Sufficient conditions for a random solution of random operator inclusions involving random multivalued operators satisfying a general contractive condition are obtained. A simultaneous random solution of the system of two random operator inclusions is also derived.

• The purpose of this article is to initiate a new type of cyclic contraction mapping and establish a fixed point theorem in Banach space. • To approximate the fixed point of such a mapping, a convergence theorem for the Krasnoselskij iteration is presented for which a priori and a posterior error estimates are also determined. • As an application, we investigate the iterated function systems (IFS) comprised of generalized cyclic contraction mappings. • Some examples are also presented to validate the results. The purpose of this article is to initiate a new class of cyclic contraction mappings and establish a related fixed point theorem in the framework of a Banach space. To approximate the fixed point, a convergence theorem employing the Krasnoselskij iteration is presented for which a priori and a posterior error estimates are also determined. These results modify and extend several comparable results in the existing literature. As an application, we investigate the iterated function system (IFS) comprised of generalized cyclic contraction mappings. Some examples are also presented to validate the results. [ABSTRACT FROM AUTHOR]

A discrete-time Michaelis-Menten-type prey harvesting is discussed in this paper, in the modified Leslie-Gower predator-prey model. Detailed analysis of the topology of nonnegative interior fixed points is given, including their existence and stability dynamics. Also, the conditions for the existence of flip and Neimark-Sacker bifurcations are derived by using the center manifold theorem and bifurcation theory. The numerical simulations are provided, using a computer package, to illustrate the consistency of theoretical results.

The aim of this paper is to introduce the concept of friendly mappings with the help of commutative diagram. It is shown that a nonempty set has the fixed point property relative to the collection of friendly mappings. Some examples are presented to support the results proved herein.

Abstract: The aim of this paper is to prove some random fixed point theorems for asymptotically nonexpansive random operator defined on an unbounded closed and starshaped subset of a Banach space.

This paper proposes a generalized modified iterative scheme where the composed self-mapping driving can have distinct step-dependent composition order in both the auxiliary iterative equation and the main one integrated in Ishikawa’s scheme. The self-mapping which drives the iterative scheme is a perturbed 2-cyclic one on the union of two sequences of nonempty closed subsets Ann=0∞ and Bnn=0∞ of a uniformly convex Banach space. As a consequence of the perturbation, such a driving self-mapping can lose its cyclic contractive nature along the transients of the iterative process. These sequences can be, in general, distinct of the initial subsets due to either computational or unmodeled perturbations associated with the self-mapping calculations through the iterative process. It is assumed that the set-theoretic limits below of the sequences of sets Ann=0∞ and Bnn=0∞ exist. The existence of fixed best proximity points in the set-theoretic limits of the sequences to which the iterated sequences converge is investigated in the case that the cyclic disposal exists under the asymptotic removal of the perturbations or under its convergence of the driving self-mapping to a limit contractive cyclic structure.

We present the notion of set valued (α,η)-(θ,ϝ) rational contraction mappings and then some common fixed point results of such mappings in the setting of metric spaces are established. Some examples are presented to support the concepts introduced and the results proved in this paper. These results unify, extend, and refine various results in the literature. Some fixed point results for both single and multivalued (θ,ϝ) rational contractions are also obtained in the framework of a space endowed with partial order. As application, we establish the existence of solutions of nonlinear elastic beam equations and first-order periodic problem.

In this paper, we will introduce the concept of Suzuki type multivalued (θ,R)-contraction and we will prove some fixed point results in the setting of a metric space equipped with a binary relation. Our results generalize and extend various comparable results in the existing literature. Examples are provided to support the results proved here. As an application of our results, we obtain a homotopy result, proving the existence of a solution for a second-order differential equation and for a first-order fractional differential equation.

We construct a random iteration scheme and study necessary conditions for its convergence to a common random fixed point of two pairs of compatible random operators satisfying Meir-Keeler type conditions in Polish spaces. Some random fixed point theorems for weakly compatible random operators under generalized contractive conditions in the framework of symmetric spaces are also proved.

We prove the existence of a common random fixed point of two asymptotically nonexpansive random operators through strong and weak convergences of an iterative process. The necessary and sufficient condition for the convergence of sequence of measurable functions to a random fixed point of asymptotically quasi-nonexpansive random operators in uniformly convex Banach spaces is also established.

We generate a sequence of measurable mappings iteratively and study necessary conditions for its strong convergence to a random fixed point of strongly pseudocontractive random operator. We establish the weak convergence of an implicit random iterative procedure to common random fixed point of a finite family of nonexpansive random operators in Hilbert spaces. We prove the equivalence between the convergence of random Ishikawa and random Mann iterative schemes for contraction random operator and strongly pseudocontractive random operator. We also examine the stability of random fixed point iterative procedures for the random operators satisfying certain contractive conditions in the context of metric spaces.

In this paper, we study the discrete time-fractional glycolysis model using the Caputo fractional derivative. The discrete time-fractional glycolysis model is obtained using El-Sayed and Salman's method. The existence and uniqueness of this system are proved. The stability and bifurcation analysis of the fixed points of the discrete system is carried out with details. The theoretical results are then complemented with numerical examples. [ABSTRACT FROM AUTHOR]