Search results for "Matematica"

Recensione: MR2817284 Dhompongsa, S.; Nanan, N. Fixed point theorems by ways of ultra-asymptotic centers. Abstr. Appl. Anal. 2011, Art. ID 826851, 21…

2012

Paper review

Recensione: MR2739903 Haddadi, Mohammad Reza; Mazaheri, Hamid; Labbaf Ghasemi, Mohammad Hussein Relation between fixed point and asymptotical center …

2011

Paper review

MR2524371 (2010g:47114) Domínguez Benavides, T.; García Falset, J.; Llorens-Fuster, E.; Lorenzo Ramírez, P. Fixed point properties and proximinality …

2010

In the paper under review the authors mainly investigate the existence of a fixed point for nonexpansive mappings in the general setting of strictly $L(\tau)$ Banach spaces. They consider a linear topology $\tau$ on a Banach space $(X, \|\cdot \|)$, weaker than the norm topology, then the Banach space $X$ is a strictly $L(\tau)$ space if there exists a continuous function $\delta:[0, \infty[ \times [0, \infty[ \to [0, \infty[$ such that $\delta(\cdot,s)$ and $\delta(r, \cdot)$ are strictly increasing; $\delta(0,s)=s$, for every $s \in [0, \infty[$; and $\phi_{(x_n)}(y)= \delta (\phi_{(x_n)}(0), \|y\|)$, for every $y \in X$ and for every bounded and $\tau$-null sequence $(x_n)$, where $\phi_…

MR2449047 (2009j:47108) Chermisi, Milena; Martellotti, Anna Fixed point theorems for middle point linear operators in $L^1$. Fixed Point Theory Appl.…

2009

In the paper under review the notion of middle point operator is introduced. The authors prove that for a given nonempty, bounded, $\rho$-closed, convex subset K of L1(μ), where $\rho$ is the metric of the convergence locally in measure, if T from (K, $\rho$) to(K, $\rho$) is a continuous, $\rho$-nonexpansive, middle point linear operator, then T has at least one fixed point in K. To prove the theorem they use results of A. V. Bukhvalov [in Operator theory in function spaces and Banach lattices, 95–112, Birkh¨auser, Basel, 1995; MR1322501 (95m:46123)] and M. Furi and A. Vignoli [Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. (8) 48 (1970), 195–198; MR0279792 (43 #5513)]. Then they …

Fixed point results for weak contractive mappings in ordered K-metric spaces

2012

In this paper, we derive new coincidence and common fixed point theorems for self-maps satisfying a weak contractive condition in an ordered K-metric space. As application, the obtained results are used to prove an existence theorem of solutions of a nonlinear integral equation.

PPF dependent fixed point results for triangular $alpha_c$-admissible mappings

2014

We introduce the concept of triangular $alpha_c$-admissible mappings (pair of mappings) with respect to $η_c$ nonself-mappings and establish the existence of PPF dependent fixed (coincidence) point theorems for contraction mappings involving triangular $alpha_c$-admissible mappings (pair of mappings) with respect to $η_c$ nonself-mappings in Razumikhin class. Several interesting consequences of our theorems are also given.

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

2011

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.

MR2805472 Tsagareishvili, V. Fourier-Haar coefficients of continuous functions. 132 (2011), no. 1-2, 1--14.

2011

MR3050566 Calcagni, Gianluca; Nardelli, Giuseppe; Scalisi, Marco Quantum mechanics in fractional and other anomalous spacetimes. J. Math. Phys. 53 (2…

2013

L'insostenibile leggerezza della matematica

2018

Frattali e bolle di sapone (Piano lauree scientifiche - matematica)