0000000000299496

AUTHOR

Cristina Di Bari

COMMON FIXED POINTS FOR psi-CONTRACTIONS ON PARTIAL METRIC SPACES

We prove some generalized versions of an interesting result of Matthews using conditions of different type in 0-complete partial metric spaces. We give, also, a homotopy result for operators on partial metric spaces.

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Fixed point, attractors and weak fuzzy contractive mappings in a fuzzy metric space

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Nonlinear quasi-contractions of Ciric type

In this paper we obtain points of coincidence and common fixed points for two self mappings satisfying a nonlinear contractive condition of Ciric type. As application, using the scalarization method of Du, we deduce a result of common fixed point in cone metric spaces.

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Some fixed point results for multi-valued mappings in partial metric spaces

Abstract In this paper, we obtain some fixed point results for multi-valued mappings in partial metric spaces. Our results unify, generalize and complement various known comparable results from the current literature. An example is also included to illustrate the main result in the paper. MSC:46S40, 47H10, 54H25.

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A remark on differentiable functions with partial derivatives in Lp

AbstractWe consider a definition of p,δ-variation for real functions of several variables which gives information on the differentiability almost everywhere and the absolute integrability of its partial derivatives on a measurable set. This definition of p,δ-variation extends the definition of n-variation of Malý and the definition of p-variation of Bongiorno. We conclude with a result of change of variables based on coarea formula.

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Common fixed points for self mappings on compact metric spaces

In this paper we obtain a result of existence of points of coincidence and of common fixed points for two self mappings on compact metric spaces satisfying a contractive condition of Suzuki type. We also present some examples to illustrate our results. Moreover, using the scalarization method of Du, we deduce a result of common fixed point in compact cone metric spaces.

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Common fixed points in cone metric spaces for $MK$-pairs and $L$-pairs

In this paper we introduce some contractive conditions of Meir-Keeler type for a pair of mappings, called $MK$-$pair$ and $L\textrm{-}pair$, in the framework of cone metric spaces and we prove theorems which assure existence and uniqueness of common fixed points for $MK$-$pairs$ and $L \textrm{-}pairs$. As an application we obtain a result of common fixed point of a $p$-$MK$-pair, a mapping and a multifunction, in complete cone metric spaces. These results extend and generalize well-known comparable results in the literature.

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Common fixed points in generalized metric spaces

Abstract We establish some common fixed point theorems for mappings satisfying a ( ψ , φ ) -weakly contractive condition in generalized metric spaces. Presented theorems extend and generalize many existing results in the literature.

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Common fixed points for locally lipschitz mappings

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Common Fixed Point Theorems for Weakly Compatible Maps Satisfying a General Contractive Condition

We introduce a new generalized contractive condition for four mappings in the framework of metric space. We give some common fixed point results for these mappings and we deduce a fixed point result for weakly compatible mappings satisfying a contractive condition of integral type.

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Absolute continuity for Banach space valued mappings

We consider the notion of p,λ,δ-absolute continuity for Banach space valued mappings introduced in [2] for real valued functions and for λ = 1. We investigate the validity of some basic properties that are shared by n, λ-absolutely continuous functions in the sense of Maly and Hencl. We introduce the class $δ-BV^p_{λ,loc}$ and we give a characterization of the functions belonging to this class.

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$varphi$-pairs and common fixed points in cone metric spaces

In this paper we introduce a contractive condition, called $\varphi \textrm{-}pair$, for two mappings in the framework of cone metric spaces and we prove a theorem which assures existence and uniqueness of common fixed points for $\varphi \textrm{-}pairs$. Also we obtain a result on points of coincidence. These results extend and generalize well-known comparable results in the literature.

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Primitive rispetto all’ oscillazione

We study the real valued functions having a primitive with respect to the oscillation or a primitive with respect to the oscillation up to anegligible set.

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Weakly \varphi-pairs and common fixed points in cone metric spaces

In this paper we introduce a weak contractive condition, called weakly \varphi-pair, for two mappings in the framework of cone metric spaces and we prove a theorem which ensures existence and uniqueness of common fixed points for such mappings. Also we obtain a result on points of coincidence. These results extend and generalize well-known comparable results in the literature.

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Common fixed points of g-quasicontractions and related mappings in 0-complete partial metric spaces

Abstract Common fixed point results are obtained in 0-complete partial metric spaces under various contractive conditions, including g-quasicontractions and mappings with a contractive iterate. In this way, several results obtained recently are generalized. Examples are provided when these results can be applied and neither corresponding metric results nor the results with the standard completeness assumption of the underlying partial metric space can. MSC:47H10, 54H25.

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Best proximity points for cyclic Meir–Keeler contractions

Abstract We introduce a notion of cyclic Meir–Keeler contractions and prove a theorem which assures the existence and uniqueness of a best proximity point for cyclic Meir–Keeler contractions. This theorem is a generalization of a recent result due to Eldred and Veeramani.

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A remark on absolutely continuous functions in ℝ n

We introduce the notion ofα, λ-absolute continuity for functions of several variables and we compare it with the Hencl’s definition. We obtain that eachα, λ-absolutely continuous function isn, λ-absolutely continuous in the sense of Hencl and hence is continuous, differentiable almost everywhere and satisfies change of variables results based on a coarea formula and an area formula.

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Some Common Coupled Fixed Point Results for Generalized Contraction in Complex-Valued Metric Spaces

We introduce and study the notion of common coupled fixed points for a pair of mappings in complex valued metric space and demonstrate the existence and uniqueness of the common coupled fixed points in a complete complex-valued metric space in view of diverse contractive conditions. In addition, our investigations are well supported by nontrivial examples.

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Matematica

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Common fixed points in cone metric spaces for CJM-pairs

Abstract In this paper we introduce some contractive conditions of Meir–Keeler type for two mappings, called f - M K -pair mappings and f - C J M -pair (from Ciric, Jachymski, and Matkowski) mappings, in the framework of regular cone metric spaces and we prove theorems which guarantee the existence and uniqueness of common fixed points. We give also a fixed point result for a multivalued mapping that satisfies a contractive condition of Meir–Keeler type. These results extend and generalize some recent results from the literature. To conclude the paper, we extend our main result to non-regular cone metric spaces by using the scalarization method of Du.

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Common fixed points for self-mappings on partial metric spaces

Abstract In this paper, we prove some results of a common fixed point for two self-mappings on partial metric spaces. Our results generalize some interesting results of Ilić et al. (Appl. Math. Lett. 24:1326-1330, 2011). We conclude with a result of the existence of a fixed point for set-valued mappings in the context of 0-complete partial metric spaces. MSC:54H25, 47H10.

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A local notion of absolute continuity in IR^n

We consider the notion of p, δ-absolute continuity for functions of several variables introduced in [2] and we investigate the validity of some basic properties that are shared by absolutely continuous functions in the sense of Maly. We introduce the class $δ−BV^p_loc(\Omega,IR^m)$ and we give a characterization of the functions belonging to this class.

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A remark on absolutely continuous functions in IR^n

We introduce the notion of α, λ-absolute continuity for functions of several variables and we compare it with the Hencl’s definition. We obtain that each α,λ-absolutely continuous function is n, λ-absolutely continuous in the sense of Hencl and hence is continuous, differentiable almost everywhere and satisfies change of variables results based on a coarea formula and an area formula.

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Fixed points for weak $\varphi$-contractions on partial metric spaces

In this paper, following [W.A. Kirk, P.S. Srinivasan, P. Veeramani, Fixed points for mappings satisfying cyclical contractive conditions, Fixed Point Theory, 4 (2003) 79-89], we give a fixed point result for cyclic weak $\varphi$-contractions on partial metric space. A Maia type fixed point theorem for cyclic weak $\varphi$-contractions is also given.

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