Wyniki wyszukiwania

1

Compactness and countable compactness in weak topologies

100%

Kirk W. A.

Studia Mathematica

|

1994-1995

|

tom 112

|

nr 3

243-250

EN

A bounded closed convex set K in a Banach space X is said to have quasi-normal structure if each bounded closed convex subset H of K for which diam(H) > 0 contains a point u for which ∥u-x∥ < diam(H) for each x ∈ H. It is shown that if the convex sets on the unit sphere in X satisfy this condition (which is much weaker than the assumption that convex sets on the unit sphere are separable), then relative to various weak topologies, the unit ball in X is compact whenever it is countably compact.

2

Hyperconvexity of ℝ-trees

100%

Kirk W. A.

Fundamenta Mathematicae

|

1998

|

tom 156

|

nr 1

67-72

EN

It is shown that for a metric space (M,d) the following are equivalent: (i) M is a complete ℝ-tree; (ii) M is hyperconvex and has unique metric segments.

3

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Approximate fixed points for nonexpansive mappings in uniformly convex spaces

63%

Kirk W. A., Martinez-Yanez C.

Annales Polonici Mathematici

|

1990

|

tom 51

|

nr 1

189-193

4

A fixed point theorem for transformations whose iterates have uniform Lipschitz constant

45%

Goebel K., Kirk W. A.

Studia Mathematica

|

1973

|

tom 47

|

nr 2

134-140

5

On local isometries and isometries in metric spaces

38%

Hu T., Kirk W. A.

Colloquium Mathematicum

|

1981

|

tom 44

|

nr 1

53-57

6

On conditions under which local isometries are motions

38%

Kirk W. A.

Colloquium Mathematicum

|

1970-1971

|

tom 22

|

nr 2

229-232

7

Caristi's fixed point theorem and metric convexity

38%

Kirk W. A.

Colloquium Mathematicum

|

1976

|

tom 36

|

nr 1

81-86

8

Fixed-point theorems for mapping defined on unbounded sets in Banach spaces

26%

Kirk W. A., Ray W. O.

Studia Mathematica

|

1979

|

tom 64

|

nr 2

127-138

Ograniczanie wyników

3 Colloquium Mathematicum

3 Studia Mathematica

1 Annales Polonici Mathematici

1 Fundamenta Mathematicae

8 Kirk W. A.

1 Goebel K.

1 Hu T.

1 Martinez-Yanez C.

1 Ray W. O.

1 1998

1 1995

1 1990

1 1981

1 1979

1 1976

1 1973

1 1971

Compactness and countable compactness in weak topologies

Hyperconvexity of ℝ-trees

Approximate fixed points for nonexpansive mappings in uniformly convex spaces

A fixed point theorem for transformations whose iterates have uniform Lipschitz constant

On local isometries and isometries in metric spaces

On conditions under which local isometries are motions

Caristi's fixed point theorem and metric convexity

Fixed-point theorems for mapping defined on unbounded sets in Banach spaces