9 citations · 48 across the 15 of their papers we have counts for
15 papers
A fixed point theorem in
Andrzej Wiśnicki
We show that if is a complete metric space with uniform relative normal structure and is a subgroup of the isometry group of with bounded orbits, then there is a point…
Amenable semigroups and nonexpansive dynamical systems
Andrzej Wiśnicki
We characterize amenability of subspaces of , where is a semitopological semigroup, in terms of fixed point properties of nonexpansive actions. In particular, we give a c…
Around the nonlinear Ryll-Nardzewski theorem
Andrzej Wiśnicki
Suppose that is a weak compact convex subset of a dual Banach space with the Radon-Nikodým property. We show that if is a nonexpansive and norm-distal dynamic…
The Knaster-Tarski theorem versus monotone nonexpansive mappings
Rafael Espínola, Andrzej Wiśnicki
Let be a partially ordered set with the property that each family of order intervals of the form with the finite intersection property has a nonempty i…
Amenable semigroups of nonexpansive mappings on weakly compact convex sets
Andrzej Wiśnicki
We show a few fixed point theorems for semigroups acting on weakly compact convex subsets of Banach spaces when or have a left invariant…
On some results on the stability of Markov operators
Stanisław Wȩdrychowicz, Andrzej Wiśnicki
We formulate a criterion for the existence of an invariant measure for a Feller semigroup defined on a metric space with the e-property for bounded continuous functions and use it…
Uniformly Lipschitzian group actions on hyperconvex spaces
Andrzej Wiśnicki, Jacek Wośko
Suppose that is a group of uniformly -Lipschitzian mappings with bounded orbits acting on a hyperconvex metric space . We sh…
A common fixed point theorem for a commuting family of weak continuous nonexpansive mappings
Sławomir Borzdyński, Andrzej Wiśnicki
It is shown that if is a commuting family of weak continuous nonexpansive mappings acting on a weak compact convex subset of the dual Banach space ,…
The minimal displacement and extremal spaces
Krzysztof Bolibok, Andrzej Wiśnicki, Jacek Wośko
We show that both separable preduals of and non-type I -algebras are strictly extremal with respect to the minimal displacement of -Lipschitz mappings acting on the…
The fixed point property in direct sums and modulus R(a,X)
Andrzej Wiśnicki
We show that the direct sum of Banach spaces with a strictly monotone norm has the weak fixed point property for nonexpansive mappings whenever for…
On the Suzuki nonexpansive-type mappings
Anna Betiuk-Pilarska, Andrzej Wiśnicki
It is shown that if is a nonempty convex and weakly compact subset of a Banach space with and satisfies condition or is continuous and sat…
The super fixed point property for asymptotically nonexpansive mappings
Andrzej Wiśnicki
We show that the super fixed point property for nonexpansive mappings and for asymptotically nonexpansive mappings in the intermediate sense are equivalent. As a consequence, we ob…
On the structure of fixed-point sets of asymptotically regular semigroups
Andrzej Wiśnicki
We extend a few recent results of Górnicki (2011) asserting that the set of fixed points of an asymptotically regular mapping is a retract of its domain. In particular, we prove th…
On the fixed points of nonexpansive mappings in direct sums of Banach spaces
Andrzej Wiśnicki
We show that if a Banach space X has the weak fixed point property for nonexpansive mappings and Y has the generalized Gossez-Lami Dozo property or is uniformly convex in every dir…
On the fixed point property in direct sums of Banach spaces with strictly monotone norms
Stanisław Prus, Andrzej Wiśnicki
It is shown that if a Banach space X has the weak Banach-Saks property and the weak fixed point property for nonexpansive mappings and Y satisfies property asymptotic (P) (which is…