Antonio Roldán
University of Jaén
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Antonio Roldán.
Abstract and Applied Analysis | 2013
Erdal Karapınar; Antonio Roldán; Juan Martínez-Moreno; C. Roldán
We study the existence and uniqueness of a fixed point of the multidimensional operators which satisfy Meir-Keeler type contraction condition. Our results extend, improve, and generalize the results mentioned above and the recent results on these topics in the literature.
Abstract and Applied Analysis | 2013
Antonio Roldán; Juan Martínez-Moreno; C. Roldán; Erdal Karapınar
We study the existence and uniqueness of coincidence point for nonlinear mappings of any number of arguments under a weak ( )-contractivity condition in partial metric spaces. The results we obtain generalize, extend, and unify several classical and very recent related results in the literature in metric spaces (see Aydi et al. (2011), Berinde and Borcut (2011), Gnana Bhaskar and Lakshmikantham (2006), Berzig and Samet (2012), Borcut and Berinde (2012), Choudhury et al. (2011), Karapinar and Luong (2012), Lakshmikantham and Ciric (2009), Luong and Thuan (2011), and Roldan et al. (2012)) and in partial metric spaces (see Shatanawi et al. (2012)).
Fixed Point Theory and Applications | 2013
Antonio Roldán; Erdal Karapınar
In this paper we present some (unidimensional and) multidimensional fixed point results under (ψ,φ)-contractivity conditions in the framework of G∗-metric spaces, which are spaces that result from G-metric spaces (in the sense of Mustafa and Sims) omitting one of their axioms. We prove that these spaces let us consider easily the product of G∗-metrics. Our result clarifies and improves some recent results on this topic because, among other different reasons, we will not need a partial order on the underlying space. Furthermore, the way in which several contractivity conditions are proposed imply that our theorems cannot be reduced to metric spaces.MSC: 46T99, 47H10, 47H09, 54H25.
Fuzzy Sets and Systems | 2014
Antonio Roldán; Juan Martínez-Moreno; Concepción Roldán; Yeol Je Cho
In recent times, coupled, tripled and quadruple fixed point theorems have been intensively studied by many authors in the context of partially ordered complete metric spaces using different contractivity conditions. Roldan et al. showed a unified version of these results for nonlinear mappings in any number of variables (which were not necessarily permuted or ordered) introducing the notion of multidimensional coincidence point. Very recently, Choudhury et al. proved coupled coincidence point results in the context of fuzzy metric spaces in the sense of George and Veeramani. In this paper, using the idea of coincidence point for nonlinear mappings in any number of variables, we study a fuzzy contractivity condition to ensure the existence of coincidence points in the framework of fuzzy metric spaces provided with Hadzic type t-norms. Then, we present an illustrative example in which our methodology leads to the existence of coincidence points but previous theorems cannot be applied.
Fixed Point Theory and Applications | 2014
Erdal Karapınar; Antonio Roldán; Naseer Shahzad; Wutiphol Sintunavarat
AbstractAfter the appearance of Ran and Reuring’s theorem and Nieto and Rodríguez-López’s theorem, the field of fixed point theory applied to partially ordered metric spaces has attracted much attention. Coupled, tripled, quadrupled and multidimensional fixed point results has been presented in recent times. One of the most important hypotheses of these theorems was the mixed monotone property. The notion of invariant set was introduced in order to avoid the condition of mixed monotone property, and many statements have been proved using these hypotheses. In this paper we show that the invariant condition, together with transitivity, lets us to prove in many occasions similar theorems to which were introduced using the mixed monotone property. MSC:46T99, 47H10, 47H09, 54H25.
Fixed Point Theory and Applications | 2013
Marwan Amin Kutbi; Antonio Roldán; Wutiphol Sintunavarat; Juan Martínez-Moreno; Concepción Roldán
In this paper we present the notion of F-closed set (which is weaker than the concept of F-invariant set introduced in Samet and Vetro (Ann. Funct. Anal. 1:46-56, 2010), and we prove some coupled fixed point theorems without the condition of mixed monotone property. Furthermore, we interpret the transitive property as a partial preorder and, then, some results in that paper and in Sintunavarat et al. (Fixed Point Theory Appl. 2012:170, 2012) can be reduced to the unidimensional case.MSC:46T99, 47H10, 47H09, 54H25.
soft computing | 2012
C. Roldán; Antonio Roldán; Juan Martínez-Moreno
Least-squares technique is well-known and widely used to determine the coefficients of a explanatory model from observations based on a concept of distance. Traditionally, the observations consist of pairs of numeric values. However, in many real-life problems, the independent or explanatory variable can be observed precisely (for instance, the time) and the dependent or response variable is usually described by approximate values, such as “about
Journal of Inequalities and Applications | 2013
Erdal Karapınar; Antonio Roldán
Journal of Computational and Applied Mathematics | 2015
Antonio Roldán; Juan Martínez-Moreno; Concepción Roldán; Yeol Je Cho
\pounds300
Fixed Point Theory and Applications | 2013
Erdal Karapınar; Antonio Roldán; Concepción Roldán; Juan Martínez-Moreno