Search results for "Analisi Matematica"
showing 10 items of 811 documents
Some new fixed point theorems in fuzzy metric spaces
2014
Motivated by Samet et al. [Nonlinear Anal., 75(4) (2012), 2154-2165], we introduce the notions of alpha-phi -fuzzy contractive mapping and beta-psi-fuzzy contractive mapping and prove two theorems which ensure the existence and uniqueness of a fixed point for these two types of mappings. The presented theorems extend, generalize and improve the corresponding results given in the literature.
Common fixed point theorems in fuzzy metric spaces employing CLR_{S} and JCLR_{ST} properties
2014
In this paper, we utilize the $CLR_{S}$ and $JCLR_{ST}$ properties to prove some existence theorems of common fixed point for contractive mappings in fuzzy metric spaces. Our results generalize and extend many known results from the literature. An example and some applications are given to show the usability of the presented results.
Common fixed point theorems for (ϕ, ψ)-weak contractions in fuzzy metric spaces
2010
Motivated by Rhoades (Nonlinear Anal., 47 (2001), 2683--2693), on the lines of Khan et al. (Bull. Aust. Math. Soc., 30 (1984), 1-9) employing the idea of altering distances, we extend the notion of (ϕ, ψ)-weak contraction to fuzzy metric spaces and utilize the same to prove common fixed point theorems for four mappings in fuzzy metric spaces.
Edelstein-Suzuki-type resuls for self-mappings in various abstract spaces with application to functional equations
2016
Abstract The fixed point theory provides a sound basis for studying many problems in pure and applied sciences. In this paper, we use the notions of sequential compactness and completeness to prove Eldeisten-Suzuki-type fixed point results for self-mappings in various abstract spaces. We apply our results to get a bounded solution of a functional equation arising in dynamic programming.
A fixed point theorem in G-metric spaces via alpha-series
2014
In the context of G-metric spaces we prove a common fixed point theorem for a sequence of self mappings using a new concept of alpha-series.
MR3136553 Reviewed Popa, Valeriu; Patriciu, Alina-Mihaela A general fixed point theorem for pairs of mappings satisfying implicit relations in two G-…
2014
In [Stud. Cercet. Ştiinţ. Ser. Mat. Univ. Bacău No. 7 (1997), 127–133 (1999); MR1721711], V. Popa initiated the study of fixed points for mappings satisfying implicit relations as a way to unify and generalize various contractive conditions. Later on, many papers were published extending this approach to different metric settings. In the paper under review, the authors prove a result of such type for two mappings defined on two generalized metric spaces, called G-metric spaces and introduced by Z. Mustafa and B. Sims [J. Nonlinear Convex Anal. 7 (2006), no. 2, 289–297; MR2254125 (2007f:54049)].
Fixed point results for $GP_(Λ,Θ)$-contractive mappings
2014
In this paper, we introduce new notions of GP-metric space and $GP_(Λ,Θ)$-contractive mapping and then prove some fixed point theorems for this class of mappings. Our results extend and generalized Banach contraction principle to GP-metric spaces. An example shows the usefulness of our results.
Anisotropic Navier Kirchhoff problems with convection and Laplacian dependence
2022
We consider the Navier problem-Delta(2)(k,p)u(x)=f(x,u(x), del u(x), Delta u(x)) in Omega, u vertical bar(partial derivative Omega) =Delta u vertical bar(partial derivative Omega) = 0,driven by the sign-changing (degenerate) Kirchhoff type p(x)-biharmonic operator, and involving a (del u, Delta u)-dependent nonlinearity f. We prove the existence of solutions, in weak sense, defining an appropriate Nemitsky map for the nonlinearity. Then, the Brouwer fixed point theorem assessed for a Galerkin basis of the Banach space W-2,W-p(x)(Omega)boolean AND W-0(1,p(x))(Omega) leads to the existence result. The case of nondegenerate Kirchhoff type p(x)-biharmonic operator is also considered with respec…
Moderately close Neumann inclusions for the Poisson equation
2016
We investigate the behavior of the solution of a mixed problem for the Poisson equation in a domain with two moderately close holes. If ϱ1 and ϱ2 are two positive parameters, we define a perforated domain Ω(ϱ1,ϱ2) by making two small perforations in an open set: the size of the perforations is ϱ1ϱ2, while the distance of the cavities is proportional to ϱ1. Then, if r∗ is small enough, we analyze the behavior of the solution for (ϱ1,ϱ2) close to the degenerate pair (0,r∗). Copyright © 2016 John Wiley & Sons, Ltd.
Solutions for parametric double phase Robin problems
2021
We consider a parametric double phase problem with Robin boundary condition. We prove two existence theorems. In the first the reaction is ( p − 1 )-superlinear and the solutions produced are asymptotically big as λ → 0 + . In the second the conditions on the reaction are essentially local at zero and the solutions produced are asymptotically small as λ → 0 + .