Search results for " Matematica"

On some parameters related to weak noncompactness in L1(μ,E)

2009

A measure of weak noncompactness γU is defined in a Banach space X in terms of convex compactness. We obtain relationships between the measure γU(A) of a bounded set A in the Bochner space L1(μ,E) and two parameters Π(A) and Λ1(A) related, respectively, to uniform integrability and weak-tightness. The criterion for relative weak compactness in L1(μ,E) is recovered.

Optimization Problems via Best Proximity Point Analysis

2014

Many problems arising in different areas of mathematics, such as optimization, variational analysis, and differential equations, can be modeled as equations of the form Tx=x, where T is a given mapping in the framework of a metric space. However, such equation does not necessarily possess a solution if T happens to be nonself-mapping. In such situations, one speculates to determine an approximate solution x (called a best proximity point) that is optimal in the sense that the distance between x and Tx is minimum. The aim of best proximity point analysis is to provide sufficient conditions that assure the existence and uniqueness of a best proximity point. This special issue is focused on th…

MR2851064 Daws, Matthew A bicommutant theorem for dual Banach algebras. Math. Proc. R. Ir. Acad. 111A (2011), no. 1, 21–28. (Reviewer: Camillo Trapan…

2012

MR2664252 Aziz, W.; Leiva, H.; Merentes, N.; Sánchez, J. L. Functions of two variables with bounded φ-variation in the sense of Riesz. J. Math. Appl.…

2011

The authors consider the space $BV_\varphi^R (I^b_a,\mathbb{R})$ of functions $f:I^b_a =[a,b]\times [a,b]\subset \mathbb{R}^2 \to \mathbb{R}$ with a $\varphi$-bounded variation in the sense of Riesz, where $\varphi: [0,+ \infty) \to [0,+ \infty)$ is nondecreasing and continuous with $\varphi(0)=0$ and $\varphi(t) \to +\infty$ as $t \to +\infty$. The authors show that $BV_\varphi^R (I^b_a,\mathbb{R})$ is a Banach algebra. Let $h: I^b_a \times \mathbb{R} \to \mathbb{R}$ and let $H: \mathbb{R}^{I^b_a} \to \mathbb{R}$ be the composition operator associated to $h$, that is the operator defined by $(Hf)(x)= h(x, f(x))$ for each $x \in I^b_a$. Then the authors consider the problem of characterizin…

Common Fixed Point of Generalized Contractive Type Mappings in Cone Metric Spaces

2011

We obtain common fixed points and points of coincidence of a pair of mappings satisfying a generalized contractive type condition in cone metric spaces. Our results generalize some well-known recent results in the literature.

Special Issue on Ciric type fixed point theorems

2015

Professor Ljubomir Ćirić was born on August 13, 1935 in Resnik, environmentof the Niš, in Serbia. Primary,secondary and university education Professor Ćirić received in Belgrade, where he completed his Mr Sci and his Dr Sci in 1969. His fields of specialization are Fixed point theory and Nonlinear analysis. He has been founder of different directions in the theory of fixed points, which and in today's time are in the full development. During the past 45 years, he has given significant contributions to these areas. We want point out that his works have been published and cited in prestigious international journals. Two of his work has been cited in the Web of Science over 560 times, each ove…

Relaxation result for differential inclusions with Stieltjes derivative

2023

The aim of this paper is to provide a Filippov-Wa\.{z}ewski Relaxation Theorem for the very general setting of Stieltjes differential inclusions. New relaxation results can be deduced for generalized differential problems, for impulsive differential inclusions with multivalued impulsive maps and possibly countable impulsive moments and also for dynamic inclusions on time scales.

MR3198857 Han, Deguang; Larson, David R.; Liu, Bei; Liu, Rui Dilations for systems of imprimitivity acting on Banach spaces. J. Funct. Anal. 266 (201…

2014

MR2849946 Subramanian, N.; Krishnamoorthy, S.; Balasubramanian, S. A new double $\chi$ sequence space defined by a modulus function. Selçuk J. Appl. …

2011

Equilibrium in a duopoly game with homogeneous adaptive expectations and isoelastic demand

2011

In this paper we consider a non linear discrete time Cournot duopoly game with isoelastic demand and where players have homogeneous adaptive expectations. The evolution of expected outputs over time is generated by the iteration of two-dimensional map and the long-run behavior is characterized by equilibrium points which are locally stable.