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Convergence of Ishikawa iterates for a multi-valued mapping with a fixed point

K. P. R. Sastry, G. V. R. Babu (2005)

Czechoslovak Mathematical Journal

Existence of fixed points of multivalued mappings that satisfy a certain contractive condition was proved by N. Mizoguchi and W. Takahashi. An alternative proof of this theorem was given by Peter Z. Daffer and H. Kaneko. In the present paper, we give a simple proof of that theorem. Also, we define Mann and Ishikawa iterates for a multivalued map T with a fixed point p and prove that these iterates converge to a fixed point q of T under certain conditions. This fixed point q may be different from...

Covering dimension and differential inclusions

Giovanni Anello (2000)

Commentationes Mathematicae Universitatis Carolinae

In this paper we shall establish a result concerning the covering dimension of a set of the type { x X : Φ ( x ) Ψ ( x ) } , where Φ , Ψ are two multifunctions from X into Y and X , Y are real Banach spaces. Moreover, some applications to the differential inclusions will be given.

Decomposable hulls of multifunctions

Andrzej Nowak, Celina Rom (2002)

Discussiones Mathematicae, Differential Inclusions, Control and Optimization

Let F be a multifunction with values in Lₚ(Ω, X). In this note, we study which regularity properties of F are preserved when we consider the decomposable hull of F.

Equilibria and strict equilibria of multivalued maps on noninvariant sets

Pierre Cardaliaguet, Grzegorz Gabor, Marc Quincampoix (2003)

Annales Polonici Mathematici

This paper is concerned with existence of equilibrium of a set-valued map in a given compact subset of a finite-dimensional space. Previously known conditions ensuring existence of equilibrium imply that the set is either invariant or viable for the differential inclusion generated by the set-valued map. We obtain some equilibrium existence results with conditions which imply neither invariance nor viability of the given set. The problem of existence of strict equilibria is also discussed.

Existence and density results for retarded subdifferential evolution inclusions

Tiziana Cardinali, Simona Pieri (1996)

Discussiones Mathematicae, Differential Inclusions, Control and Optimization

In this paper we study Cauchy problems for retarded evolution inclusions, where the Fréchet subdifferential of a function F:Ω→R∪{+∞} (Ω is an open subset of a real separable Hilbert space) having a φ-monotone subdifferential of oder two is present. First we establish the existence of extremal trajectories and we show that the set of these trajectories is dense in the solution set of the original convex problem for the norm topology of the Banach space C([-r, T₀], Ω) ("strong relaxation theorem")....

Existence Theorems for the Dirichlet Elliptic Inclusion Involving Exponential-Growth-Type Multivalued Right-Hand Side

Hôǹg Thái Nguyêñ, Dariusz Pączka (2005)

Bulletin of the Polish Academy of Sciences. Mathematics

We present two existence results for the Dirichlet elliptic inclusion with an upper semicontinuous multivalued right-hand side in exponential-type Orlicz spaces involving a vector Laplacian, subject to Dirichlet boundary conditions on a domain Ω⊂ ℝ². The first result is obtained via the multivalued version of the Leray-Schauder principle together with the Nakano-Dieudonné sequential weak compactness criterion. The second result is obtained by using the nonsmooth variational technique together with...

Fixed point and continuation results for contractions in metric and gauge spaces

M. Frigon (2007)

Banach Center Publications

We present an overview of generalizations of Banach's fixed point theorem and continuation results for contractions, i.e., results establishing that the existence of a fixed point is preserved by suitable homotopies. We will consider single-valued and multi-valued contractions in metric and in gauge spaces.

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