Results 21 to 30 of about 342 (67)

Topological Transversality Principles and General Coincidence Theory

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2017
This paper presents general topological coincidence principles for multivalued maps defined on subsets of completely regular topological spaces.
O’Regan Donal
doaj   +1 more source

Some fixed point theorems for set valued directional contraction mappings

International Journal of Mathematics and Mathematical Sciences, Volume 3, Issue 3, Page 455-460, 1980., 1980
Let S be a subset of a metric space X and let B(X) be the class of all nonempty bounded subsets of X with the Hausdorff pseudometric H. A mapping F : S → B(X) is a directional contraction iff there exists a real α ∈ [0, 1) such that for each x ∈ S and y ∈ F(x), H(F(x), F(z)) ≤ αd(x, z) for each z ∈ [x, y]∩S, where [x, y] = {z ∈ X : d(x, z) + d(z, y ...
V. M. Sehgal
wiley   +1 more source

A pointwise contraction criteria for the existence of fixed points

International Journal of Mathematics and Mathematical Sciences, Volume 2, Issue 3, Page 473-480, 1979., 1979
Let S be a subset of a metric space (X, d) and T : S → X be a mapping. In this paper, we define the notion of lower directional increment QT(x, y] of T at x ∈ S in the direction of y ∈ X and give sufficient conditions for T to have a fixed point when QT(x, Tx] < 1 for each x ∈ S. The results herein generalize the recent theorems of Clarke (Caned. Math.
V. M. Sehgal
wiley   +1 more source

Revisiting of some outstanding metric fixed point theorems via E-contraction

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2018
In this paper, we introduce the notion of α-ψ-contractive mapping of type E, to remedy of the weakness of the existing contraction mappings. We investigate the existence and uniqueness of a fixed point of such mappings.
Fulga Andreea, Karapınar Erdal
doaj   +1 more source

Abstract Leray–Schauder Type Alternatives and Extensions

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2019
We present a Leray–Schauder type alternative for a general class of maps. This enables us to obtain some Birkhoff–Kellogg type results and a Furi–Pera result.
O’Regan Donal
doaj   +1 more source

Leray–Schauder Alternatives for Maps Satisfying Countable Compactness Conditions

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2019
In this paper we present Leray–Schauder alternatives for a general class of Mönch type maps.
O’Regan Donal
doaj   +1 more source

Some Fixed Point Theorems for Kannan Mappings [PDF]

, 2010
2000 Mathematics Subject Classification: Primary: 47H10; Secondary: 54H25.Some results on the existence and uniqueness of fixed points for Kannan mappings on admissible subsets of bounded metric spaces and on bounded closed convex subsets of complete ...
Narang, T. D., Tejpal, Shavetambry
core  

Approximating fixed points of nonexpansive and generalized nonexpansive mappings

, 1991
International Journal of Mathematics and Mathematical Sciences, Volume 16, Issue 1, Page 81-86, 1993.
M. Maiti, B. Saha
wiley   +1 more source

CONTINUITY OF THE TYCHONOFF FUNCTOR τ [PDF]

, 1990
Let C be a class of the inverse systems X = {Xλ, fαβ,A}. We say that a functor F is C-continuous if F(limX) is homeomorphic with lim F(X). In the present paper the continuity of Tychonoff functor τ is investigated.
Ivan Lončar
core   +1 more source

Equivariant Nielsen invariants for discrete groups

, 2006
For discrete groups G, we introduce equivariant Nielsen invariants. They are equivariant analogs of the Nielsen number and give lower bounds for the number of fixed point orbits in the G-homotopy class of an equivariant endomorphism f:X->X.
Weber, Julia
core   +2 more sources