Fixed point theorems for maps with various local contraction - - PowerPoint PPT Presentation

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Fixed point theorems for maps with various local contraction - - PowerPoint PPT Presentation

Background Main Results Open Problems Fixed point theorems for maps with various local contraction properties Krzysztof Chris Ciesielski 1 and Jakub Jasinski 2 1 West Virginia University Morgantown, WV and University of Pennsylvania


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Background Main Results Open Problems

Fixed point theorems for maps with various local contraction properties

Krzysztof Chris Ciesielski1 and Jakub Jasinski2

1West Virginia University

Morgantown, WV and University of Pennsylvania Philadelphia, PA

2University of Scranton,

Scranton, PA

Twelfth Symposium on General Topology Prague, July 25-29, 2016

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

Abstract

Let X, d be a metric space. We compare ten classes of continuous self-maps f : X → X. All of these self-maps are proved to have fixed or periodic points for spaces X with certain topological properties. We will assume X to be

  • 1. complete
  • 2. complete and connected
  • 3. complete and rectifiably path connected
  • 4. complete and d-convex
  • 5. compact
  • 6. compact and connected
  • 7. compact and rectifiably path connected
  • 8. compact and d-convex

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 3

Background Main Results Open Problems

Abstract

Let X, d be a metric space. We compare ten classes of continuous self-maps f : X → X. All of these self-maps are proved to have fixed or periodic points for spaces X with certain topological properties. We will assume X to be

  • 1. complete
  • 2. complete and connected
  • 3. complete and rectifiably path connected
  • 4. complete and d-convex
  • 5. compact
  • 6. compact and connected
  • 7. compact and rectifiably path connected
  • 8. compact and d-convex

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 4

Background Main Results Open Problems

Abstract

Let X, d be a metric space. We compare ten classes of continuous self-maps f : X → X. All of these self-maps are proved to have fixed or periodic points for spaces X with certain topological properties. We will assume X to be

  • 1. complete
  • 2. complete and connected
  • 3. complete and rectifiably path connected
  • 4. complete and d-convex
  • 5. compact
  • 6. compact and connected
  • 7. compact and rectifiably path connected
  • 8. compact and d-convex

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 5

Background Main Results Open Problems

Abstract

Let X, d be a metric space. We compare ten classes of continuous self-maps f : X → X. All of these self-maps are proved to have fixed or periodic points for spaces X with certain topological properties. We will assume X to be

  • 1. complete
  • 2. complete and connected
  • 3. complete and rectifiably path connected
  • 4. complete and d-convex
  • 5. compact
  • 6. compact and connected
  • 7. compact and rectifiably path connected
  • 8. compact and d-convex

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 6

Background Main Results Open Problems

Abstract

Let X, d be a metric space. We compare ten classes of continuous self-maps f : X → X. All of these self-maps are proved to have fixed or periodic points for spaces X with certain topological properties. We will assume X to be

  • 1. complete
  • 2. complete and connected
  • 3. complete and rectifiably path connected
  • 4. complete and d-convex
  • 5. compact
  • 6. compact and connected
  • 7. compact and rectifiably path connected
  • 8. compact and d-convex

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 7

Background Main Results Open Problems

The Classics

Definition (#1) A function f : X → X is called Contractive, (C), if there exists a constant 0 ≤ λ < 1 such that for any two elements x, y ∈ X we have d(f(x), f(y)) ≤ λd(x, y). Theorem (Banach, 1922) If (X, d) is a complete metric space and f : X → X is (C), then f has a unique fixed point, that is, there exists a unique ξ ∈ X such that f(ξ) = ξ.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 8

Background Main Results Open Problems

The Classics

Definition (#1) A function f : X → X is called Contractive, (C), if there exists a constant 0 ≤ λ < 1 such that for any two elements x, y ∈ X we have d(f(x), f(y)) ≤ λd(x, y). Theorem (Banach, 1922) If (X, d) is a complete metric space and f : X → X is (C), then f has a unique fixed point, that is, there exists a unique ξ ∈ X such that f(ξ) = ξ.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 9

Background Main Results Open Problems

The Classics

Definition (#2) A function f : X → X is called Shrinking, (S), if for any two elements x, y ∈ X, x = y we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) If X, d is compact and f : X → X is (S), then it has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 10

Background Main Results Open Problems

The Classics

Definition (#2) A function f : X → X is called Shrinking, (S), if for any two elements x, y ∈ X, x = y we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) If X, d is compact and f : X → X is (S), then it has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

The Classics

Definition (#2) A function f : X → X is called Shrinking, (S), if for any two elements x, y ∈ X, x = y we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) If X, d is compact and f : X → X is (S), then it has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 12

Background Main Results Open Problems

The Classics

Definition (#3) A function f : X → X is called Locally Shrinking, (LS), if for any element z ∈ X there exists an εz > 0 such that f | `B(z, ε) is shrinking, i.e. for any two x = y ∈ B(z, εz) we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) Let X, d be compact and let f : X → X. (i) If f is (LS), then f has a periodic point. ♠ (ii) If f is (LS) and X is connected, then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 13

Background Main Results Open Problems

The Classics

Definition (#3) A function f : X → X is called Locally Shrinking, (LS), if for any element z ∈ X there exists an εz > 0 such that f | `B(z, ε) is shrinking, i.e. for any two x = y ∈ B(z, εz) we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) Let X, d be compact and let f : X → X. (i) If f is (LS), then f has a periodic point. ♠ (ii) If f is (LS) and X is connected, then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 14

Background Main Results Open Problems

The Classics

Definition (#3) A function f : X → X is called Locally Shrinking, (LS), if for any element z ∈ X there exists an εz > 0 such that f | `B(z, ε) is shrinking, i.e. for any two x = y ∈ B(z, εz) we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) Let X, d be compact and let f : X → X. (i) If f is (LS), then f has a periodic point. ♠ (ii) If f is (LS) and X is connected, then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 15

Background Main Results Open Problems

The Classics

Definition (#3) A function f : X → X is called Locally Shrinking, (LS), if for any element z ∈ X there exists an εz > 0 such that f | `B(z, ε) is shrinking, i.e. for any two x = y ∈ B(z, εz) we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) Let X, d be compact and let f : X → X. (i) If f is (LS), then f has a periodic point. ♠ (ii) If f is (LS) and X is connected, then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 16

Background Main Results Open Problems

The Classics

Definition (#3) A function f : X → X is called Locally Shrinking, (LS), if for any element z ∈ X there exists an εz > 0 such that f | `B(z, ε) is shrinking, i.e. for any two x = y ∈ B(z, εz) we have d(f(x), f(y)) < d(x, y). Theorem (Edelstein, 1962) Let X, d be compact and let f : X → X. (i) If f is (LS), then f has a periodic point. ♠ (ii) If f is (LS) and X is connected, then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

The Classics

Definition (#4) A function f : X → X is called Pointwise Contracting, (PC), if for every z ∈ X there exists a λz ∈ [0, 1) and an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λzd(x, z). Definition (#5) A function f : X → X is called uniformly Pointwise Contracting, (uPC), if there exists a λ ∈ [0, 1) such that for every z ∈ X there exists an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λd(x, z). Theorem (Hu and Kirk, 1978; proof corrected by Jungck, 1982) If X, d is a rectifiably path connected complete metric space and a map f : X → X is (uPC), then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 18

Background Main Results Open Problems

The Classics

Definition (#4) A function f : X → X is called Pointwise Contracting, (PC), if for every z ∈ X there exists a λz ∈ [0, 1) and an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λzd(x, z). Definition (#5) A function f : X → X is called uniformly Pointwise Contracting, (uPC), if there exists a λ ∈ [0, 1) such that for every z ∈ X there exists an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λd(x, z). Theorem (Hu and Kirk, 1978; proof corrected by Jungck, 1982) If X, d is a rectifiably path connected complete metric space and a map f : X → X is (uPC), then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 19

Background Main Results Open Problems

The Classics

Definition (#4) A function f : X → X is called Pointwise Contracting, (PC), if for every z ∈ X there exists a λz ∈ [0, 1) and an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λzd(x, z). Definition (#5) A function f : X → X is called uniformly Pointwise Contracting, (uPC), if there exists a λ ∈ [0, 1) such that for every z ∈ X there exists an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λd(x, z). Theorem (Hu and Kirk, 1978; proof corrected by Jungck, 1982) If X, d is a rectifiably path connected complete metric space and a map f : X → X is (uPC), then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

The Classics

Definition (#4) A function f : X → X is called Pointwise Contracting, (PC), if for every z ∈ X there exists a λz ∈ [0, 1) and an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λzd(x, z). Definition (#5) A function f : X → X is called uniformly Pointwise Contracting, (uPC), if there exists a λ ∈ [0, 1) such that for every z ∈ X there exists an εz > 0 such that for any element x ∈ B(z, εz) we have d(f(x), f(z)) ≤ λd(x, z). Theorem (Hu and Kirk, 1978; proof corrected by Jungck, 1982) If X, d is a rectifiably path connected complete metric space and a map f : X → X is (uPC), then f has a unique fixed point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

Classics/Recent

Definition (#6) A function f : X → X is called Uniformly Locally Contracting, (ULC), if there exist a λ ∈ [0, 1) and an ε > 0 such that for every z ∈ X the restriction f | `B(z, ε) is contractive with the same λz = λ. Theorem Assume that X, d is complete and that f : X → X is (ULC) (i) (Edelstein, 1961) If X is connected, then f has a unique fixed point. (ii) (C & J, 2016) If X has a finite number of components , then f has a periodic point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

Classics/Recent

Definition (#6) A function f : X → X is called Uniformly Locally Contracting, (ULC), if there exist a λ ∈ [0, 1) and an ε > 0 such that for every z ∈ X the restriction f | `B(z, ε) is contractive with the same λz = λ. Theorem Assume that X, d is complete and that f : X → X is (ULC) (i) (Edelstein, 1961) If X is connected, then f has a unique fixed point. (ii) (C & J, 2016) If X has a finite number of components , then f has a periodic point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

Classics/Recent

Definition (#6) A function f : X → X is called Uniformly Locally Contracting, (ULC), if there exist a λ ∈ [0, 1) and an ε > 0 such that for every z ∈ X the restriction f | `B(z, ε) is contractive with the same λz = λ. Theorem Assume that X, d is complete and that f : X → X is (ULC) (i) (Edelstein, 1961) If X is connected, then f has a unique fixed point. (ii) (C & J, 2016) If X has a finite number of components , then f has a periodic point.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 24

Background Main Results Open Problems

Recent

Recall, Definition (#4) A function f : X → X is called Pointwise Contractive, (PC), if for every z ∈ X there exist λz ∈ [0, 1) and an εz > 0 such that d(f(x), f(z)) ≤ λzd(x, z) whenever x ∈ B(z, εz). Theorem (C & J, Top. and its App. 204 2016 70-78) Assume that X, d is compact and rectifiably path connected. If f : X → X is (PC), then f has a unique fixed point. Example (C & J, J. Math. Anal. Appl. 434 2016 1267 - 1280 ) There exists a Cantor set X ⊂ R and a (PC) self-map f : X → X without periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

Recent

Recall, Definition (#4) A function f : X → X is called Pointwise Contractive, (PC), if for every z ∈ X there exist λz ∈ [0, 1) and an εz > 0 such that d(f(x), f(z)) ≤ λzd(x, z) whenever x ∈ B(z, εz). Theorem (C & J, Top. and its App. 204 2016 70-78) Assume that X, d is compact and rectifiably path connected. If f : X → X is (PC), then f has a unique fixed point. Example (C & J, J. Math. Anal. Appl. 434 2016 1267 - 1280 ) There exists a Cantor set X ⊂ R and a (PC) self-map f : X → X without periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

Recent

Recall, Definition (#4) A function f : X → X is called Pointwise Contractive, (PC), if for every z ∈ X there exist λz ∈ [0, 1) and an εz > 0 such that d(f(x), f(z)) ≤ λzd(x, z) whenever x ∈ B(z, εz). Theorem (C & J, Top. and its App. 204 2016 70-78) Assume that X, d is compact and rectifiably path connected. If f : X → X is (PC), then f has a unique fixed point. Example (C & J, J. Math. Anal. Appl. 434 2016 1267 - 1280 ) There exists a Cantor set X ⊂ R and a (PC) self-map f : X → X without periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Global Properties. f : X → X is (C) contractive if ∃λ ∈ [0, 1)∀x, y ∈ X (d(f(x), f(y)) ≤ λd(x, y)) , (S) shrinking if ∀x = y ∈ X (d(f(x), f(y)) < d(x, y)) . Clearly (C) = ⇒ (S). Each global property gives rise to two kinds of local properties, named local and pointwise, as follows:

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Global Properties. f : X → X is (C) contractive if ∃λ ∈ [0, 1)∀x, y ∈ X (d(f(x), f(y)) ≤ λd(x, y)) , (S) shrinking if ∀x = y ∈ X (d(f(x), f(y)) < d(x, y)) . Clearly (C) = ⇒ (S). Each global property gives rise to two kinds of local properties, named local and pointwise, as follows:

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 29

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Global Properties. f : X → X is (C) contractive if ∃λ ∈ [0, 1)∀x, y ∈ X (d(f(x), f(y)) ≤ λd(x, y)) , (S) shrinking if ∀x = y ∈ X (d(f(x), f(y)) < d(x, y)) . Clearly (C) = ⇒ (S). Each global property gives rise to two kinds of local properties, named local and pointwise, as follows:

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 30

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Global Properties. f : X → X is (C) contractive if ∃λ ∈ [0, 1)∀x, y ∈ X (d(f(x), f(y)) ≤ λd(x, y)) , (S) shrinking if ∀x = y ∈ X (d(f(x), f(y)) < d(x, y)) . Clearly (C) = ⇒ (S). Each global property gives rise to two kinds of local properties, named local and pointwise, as follows:

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 31

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x = y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), Pointwise Properties (we fix y=z): (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), Pointwise properties are also known as radial. Clearly (Locally) = ⇒ (Pointwise).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x = y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), Pointwise Properties (we fix y=z): (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), Pointwise properties are also known as radial. Clearly (Locally) = ⇒ (Pointwise).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 33

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x = y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), Pointwise Properties (we fix y=z): (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), Pointwise properties are also known as radial. Clearly (Locally) = ⇒ (Pointwise).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 34

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x = y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), Pointwise Properties (we fix y=z): (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), Pointwise properties are also known as radial. Clearly (Locally) = ⇒ (Pointwise).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 35

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

The following implications follow from the definitions: (C) (LC) (S) (LS) (PC) (PS)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 36

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 work for all z ∈ X. Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (uLC) f is (weakly) uniformly locally contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λd(x, y)), (ULC) f is (strongly) Uniformly locally contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) ≤ λd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), (ULS) f is Uniformly locally shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 work for all z ∈ X. Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (uLC) f is (weakly) uniformly locally contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λd(x, y)), (ULC) f is (strongly) Uniformly locally contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) ≤ λd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), (ULS) f is Uniformly locally shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-38
SLIDE 38

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 work for all z ∈ X. Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (uLC) f is (weakly) uniformly locally contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λd(x, y)), (ULC) f is (strongly) Uniformly locally contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) ≤ λd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), (ULS) f is Uniformly locally shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-39
SLIDE 39

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 work for all z ∈ X. Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (uLC) f is (weakly) uniformly locally contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λd(x, y)), (ULC) f is (strongly) Uniformly locally contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) ≤ λd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), (ULS) f is Uniformly locally shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-40
SLIDE 40

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Local properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 work for all z ∈ X. Local Properties: (LC) f is locally contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λzd(x, y)), (uLC) f is (weakly) uniformly locally contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) ≤ λd(x, y)), (ULC) f is (strongly) Uniformly locally contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) ≤ λd(x, y)), (LS) f is locally shrinking if ∀z ∈ X∃εz > 0∀x, y ∈ B(z, εz) (d(f(x), f(y)) < d(x, y)), (ULS) f is Uniformly locally shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-41
SLIDE 41

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Similarly, pointwise properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 works for all z ∈ X. Pointwise Properties: (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (uPC) f is (weakly) uniformly pointwise contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λd(x, z)), (UPC) f is Uniformly pointwise contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x ∈ B(z, ε) (d(f(x), f(z)) ≤ λd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), (UPS) f is Uniformly pointwise shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-42
SLIDE 42

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Similarly, pointwise properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 works for all z ∈ X. Pointwise Properties: (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (uPC) f is (weakly) uniformly pointwise contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λd(x, z)), (UPC) f is Uniformly pointwise contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x ∈ B(z, ε) (d(f(x), f(z)) ≤ λd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), (UPS) f is Uniformly pointwise shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-43
SLIDE 43

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Similarly, pointwise properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 works for all z ∈ X. Pointwise Properties: (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (uPC) f is (weakly) uniformly pointwise contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λd(x, z)), (UPC) f is Uniformly pointwise contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x ∈ B(z, ε) (d(f(x), f(z)) ≤ λd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), (UPS) f is Uniformly pointwise shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-44
SLIDE 44

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

Similarly, pointwise properties can be made stronger by requiring uniformity, i.e. that the same λ ∈ [0, 1) and/or the same ε > 0 works for all z ∈ X. Pointwise Properties: (PC) f is pointwise contractive if ∀z ∈ X∃λz ∈ [0, 1)∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λzd(x, z)), (uPC) f is (weakly) uniformly pointwise contractive if ∃λ ∈ [0, 1)∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) ≤ λd(x, z)), (UPC) f is Uniformly pointwise contractive if ∃λ ∈ [0, 1)∃ε > 0∀z ∈ X∀x ∈ B(z, ε) (d(f(x), f(z)) ≤ λd(x, z)), (PS) f is pointwise shrinking if ∀z ∈ X∃εz > 0∀x ∈ B(z, εz) (d(f(x), f(z)) < d(x, z)), (UPS) f is Uniformly pointwise shrinking if ∃ε > 0∀z ∈ X∀x, y ∈ B(z, ε) (d(f(x), f(y)) < d(x, y)).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-45
SLIDE 45

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties or is it 12?

The following implications follow from the definitions: (C) (ULC) (uLC) (LC) (S) (ULS) (LS) (UPC) (uPC) (PC) (UPS) (PS) Remark: (ULS)=(UPS) and (ULC)=(UPC). Any (λ, ε)-(UPC) function is (λ, ε

2)-(ULC) and (ε)-(UPS) is

ε

2

  • (ULS).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-46
SLIDE 46

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties or is it 12?

The following implications follow from the definitions: (C) (ULC) (uLC) (LC) (S) (ULS) (LS) (UPC) (uPC) (PC) (UPS) (PS) Remark: (ULS)=(UPS) and (ULC)=(UPC). Any (λ, ε)-(UPC) function is (λ, ε

2)-(ULC) and (ε)-(UPS) is

ε

2

  • (ULS).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-47
SLIDE 47

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties or is it 12?

The following implications follow from the definitions: (C) (ULC) (uLC) (LC) (S) (ULS) (LS) (UPC) (uPC) (PC) (UPS) (PS) Remark: (ULS)=(UPS) and (ULC)=(UPC). Any (λ, ε)-(UPC) function is (λ, ε

2)-(ULC) and (ε)-(UPS) is

ε

2

  • (ULS).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-48
SLIDE 48

Background Main Results Open Problems

The Ten Contracting/Shrinking Properties

The following diagram (C) (ULC) (uLC) (LC) (S) (ULS) (LS) (uPC) (PC) (PS) shows the essential classes and implications.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-49
SLIDE 49

Background Main Results Open Problems

Fixed and Periodic Points

Theorem (Complete Spaces) Assume X is complete. No combination of any of the properties shown imply any other property, unless the graph forces such

  • implication. Neither does any combination of them imply the

existence of a periodic point unless it contains (C). (C)F

B

(ULC) (uLC) (LC) (S) (ULS) (LS) (uPC) (PC) (PS)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

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SLIDE 50

Background Main Results Open Problems

Fixed and Periodic Points

Theorem (Complete Spaces cont.) Specifically, there exist 9 complete spaces X with self-maps f : X → X without periodic points witnessing the following: (PC): (PC) (S) (uPC): (uPC) (S)&(LC) (LS): (LS) (uPC) (ULS): (ULS) (uLC) (S): (S) (ULC) (LC): (LC) (S)&(uPC) (uLC): (uLC) (S)&(LC)&(uPC) (ULC): (ULC) (S)&(uLC) (C): (C) (S)&(ULC)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-51
SLIDE 51

Background Main Results Open Problems

Fixed and Periodic Points

Theorem (Complete Spaces cont.) Specifically, there exist 9 complete spaces X with self-maps f : X → X without periodic points witnessing the following: (PC): (PC) (S) (uPC): (uPC) (S)&(LC) (LS): (LS) (uPC) (ULS): (ULS) (uLC) (S): (S) (ULC) (LC): (LC) (S)&(uPC) (uLC): (uLC) (S)&(LC)&(uPC) (ULC): (ULC) (S)&(uLC) (C): (C) (S)&(ULC)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-52
SLIDE 52

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-53
SLIDE 53

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-54
SLIDE 54

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-55
SLIDE 55

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-56
SLIDE 56

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-57
SLIDE 57

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-58
SLIDE 58

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-59
SLIDE 59

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-60
SLIDE 60

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-61
SLIDE 61

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-62
SLIDE 62

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (PC) (S). Remark: f is (PC) iff limsupx→z

d(f(x),f(z)) d(x,z)

< 1 for all z ∈ X. Take X = [0, ∞) and f(x) = x + e−x2 so f ′(x) = 1 − 2xe−x2. We have f ′(0) = 1 so not-(PC) at z = 0. Also f ′[(0, ∞)] ⊆ (0, 1) so f is (S) by the MVT. For all x ∈ [0, ∞),f(x) > x so no periodic points.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-63
SLIDE 63

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-64
SLIDE 64

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-65
SLIDE 65

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-66
SLIDE 66

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-67
SLIDE 67

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-68
SLIDE 68

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-69
SLIDE 69

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-70
SLIDE 70

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uPC) (S)&(LC). Take X = R and f(x) = 1

2

  • x +

√ x2 + 1

  • .

Then f ′(x) = 1

2

  • 1 +

x

x2+1

  • so for any a ∈ R, f ′[(−∞, a]] = (0, c] for

some c < 1 so MVT gives (S)&(LC). limx→∞ f ′(x) = 1 so ¬(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-71
SLIDE 71

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (LS) (uPC) There exists a compact perfect set X ⊆ R and an autohomeomorphism f : X → X with f′ ≡ 0. So f is (uPC) with any λ ∈ (0, 1) and f has no periodic points, [C & J, 2015] so it is not (LS) by the Edelstein’s Theorem ♠.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-72
SLIDE 72

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (LS) (uPC) There exists a compact perfect set X ⊆ R and an autohomeomorphism f : X → X with f′ ≡ 0. So f is (uPC) with any λ ∈ (0, 1) and f has no periodic points, [C & J, 2015] so it is not (LS) by the Edelstein’s Theorem ♠.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-73
SLIDE 73

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (LS) (uPC) There exists a compact perfect set X ⊆ R and an autohomeomorphism f : X → X with f′ ≡ 0. So f is (uPC) with any λ ∈ (0, 1) and f has no periodic points, [C & J, 2015] so it is not (LS) by the Edelstein’s Theorem ♠.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-74
SLIDE 74

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (LS) (uPC) There exists a compact perfect set X ⊆ R and an autohomeomorphism f : X → X with f′ ≡ 0. So f is (uPC) with any λ ∈ (0, 1) and f has no periodic points, [C & J, 2015] so it is not (LS) by the Edelstein’s Theorem ♠.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-75
SLIDE 75

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (LS) (uPC) There exists a compact perfect set X ⊆ R and an autohomeomorphism f : X → X with f′ ≡ 0. So f is (uPC) with any λ ∈ (0, 1) and f has no periodic points, [C & J, 2015] so it is not (LS) by the Edelstein’s Theorem ♠.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-76
SLIDE 76

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (ULS) (uLC) Take two increasing sequences: 0 < βn ր 1 and 0 = a0 < a1 < ... ր ∞, In = [an, an+1], such that |I2n| = |I2n+1| =

1 n+1. Define metrics ρn(x, y) = |In|

  • |x−y|

|In|

βn

  • n In and

"make" a metric ρ on X =

n<ω In so that f : X → X, mapping linearly

and increasingly In onto In+1 has needed properties. For x ≤ y, n < m ρ(x, y) =

  • ρn(x, y)

if x, y ∈ In ρn(x, an+1) + |am − an+1| + ρm(am, y) if x ∈ In,y ∈ Im

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-77
SLIDE 77

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (ULS) (uLC) Take two increasing sequences: 0 < βn ր 1 and 0 = a0 < a1 < ... ր ∞, In = [an, an+1], such that |I2n| = |I2n+1| =

1 n+1. Define metrics ρn(x, y) = |In|

  • |x−y|

|In|

βn

  • n In and

"make" a metric ρ on X =

n<ω In so that f : X → X, mapping linearly

and increasingly In onto In+1 has needed properties. For x ≤ y, n < m ρ(x, y) =

  • ρn(x, y)

if x, y ∈ In ρn(x, an+1) + |am − an+1| + ρm(am, y) if x ∈ In,y ∈ Im

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-78
SLIDE 78

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (ULS) (uLC) Take two increasing sequences: 0 < βn ր 1 and 0 = a0 < a1 < ... ր ∞, In = [an, an+1], such that |I2n| = |I2n+1| =

1 n+1. Define metrics ρn(x, y) = |In|

  • |x−y|

|In|

βn

  • n In and

"make" a metric ρ on X =

n<ω In so that f : X → X, mapping linearly

and increasingly In onto In+1 has needed properties. For x ≤ y, n < m ρ(x, y) =

  • ρn(x, y)

if x, y ∈ In ρn(x, an+1) + |am − an+1| + ρm(am, y) if x ∈ In,y ∈ Im

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-79
SLIDE 79

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (S) (ULC) Remetrization.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-80
SLIDE 80

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (LC) (S)&(uPC) Remetrization.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-81
SLIDE 81

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (uLC) (S)&(LC)&(uPC) Remetrization.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-82
SLIDE 82

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (ULC) (S)&(uLC) Remetrization.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-83
SLIDE 83

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Figure: (C) (S)&(ULC) We have the following ...

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-84
SLIDE 84

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Example (A (S)&(ULC)&not(C) map f without periodic points) Define sequences cn and dn: c0 = 0, dn = cn + 2−(n+3) and cn+1 = dn + 1

2 + 2−(n+1). Set X = n<ω[cn, dn] and let

f : X → X, f(x) = cn+1 for x ∈ [cn, dn]. We have

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-85
SLIDE 85

Background Main Results Open Problems

Fixed and Periodic Points, Blue does not imply yellow

Example (A (S)&(ULC)&not(C) map f without periodic points) Define sequences cn and dn: c0 = 0, dn = cn + 2−(n+3) and cn+1 = dn + 1

2 + 2−(n+1). Set X = n<ω[cn, dn] and let

f : X → X, f(x) = cn+1 for x ∈ [cn, dn]. We have

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-86
SLIDE 86

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (Connected Spaces) Assume X is complete and connected. No combination of any

  • f the properties shown imply any other property, unless the

graph forces such implication. Neither does any combination imply the exitance of a periodic point unless it contains (C) or (ULC). (C)F

B

(ULC)F

E

(uLC) (LC) (S) (ULS) (LS) (uPC) (PC) (PS)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-87
SLIDE 87

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (Connected Spaces) Assume X is complete and connected. No combination of any

  • f the properties shown imply any other property, unless the

graph forces such implication. Neither does any combination imply the exitance of a periodic point unless it contains (C) or (ULC). (C)F

B

(ULC)F

E

(uLC) (LC) (S) (ULS) (LS) (uPC) (PC) (PS)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-88
SLIDE 88

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-89
SLIDE 89

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-90
SLIDE 90

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-91
SLIDE 91

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-92
SLIDE 92

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-93
SLIDE 93

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-94
SLIDE 94

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-95
SLIDE 95

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

A sequence s = x0, x1, ..., xn ∈ X n+1 is an ε-chain between x0 and xn if d(xi, xi+1) ≤ ε. Let l(s) =

i<n d(xi, xi+1). Define

ˆ D : X 2 → [0, ∞), ˆ D(x, y) = inf{l(s): s is an ε-chain between x and y}. Theorem ( <- - - - - - - ) Assume X, d is connected. For any ε > 0 there is an ε-chain between any two points. ˆ D is a metric topologically equivalent to d. If X, d is complete, than so is X, ˆ D. If f : X, d → X, d is (ULC), then f : X, ˆ D → X, ˆ D is (C). If X, d is also compact and f : X, d → X, d is (ULS), then f : X, ˆ D → X, ˆ D is (S).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-96
SLIDE 96

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (Rectifiably Path Connected Spaces) Assume X is complete and rectifiably path connected. No combination of any of the properties shown imply any other property, unless the graph forces such implication. Neither does any combination imply the exitance of a periodic point unless it contains (C), (ULC), (uLC) or (uPC). (C)F

B

(ULC)F

E

(uLC)F

HKJ

(LC) (S) (ULS) (LS) (uPC)F

HKJ

(PC) (PS)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-97
SLIDE 97

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Definition A metric space X, d is d-convex provided for any distinct points x, y ∈ X there exists a path p: [0, 1] → X from x to y such that d(p(t1), p(t3)) = d(p(t1), p(t2)) + d(p(t2), p(t3)) whenever 0 ≤ t1 < t2 < t3 ≤ 1.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-98
SLIDE 98

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (d-convex Spaces) Assume X is complete and d-convex. Jungck (1982) showed (uPC) ⇒ (C) with the same λ. A modified argument shows that (PS) ⇒ (S). (C)F

B

(ULC)F

B

(uLC)F

B

(LC) (S) (ULS) (LS) (uPC)F

B

(PC) (PS) No combination of any of the properties shown imply any other property, unless the graph forces such implication. Neither does any combination imply the existence of a periodic point unless it contains (C)=(ULC)=(uLC)=(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-99
SLIDE 99

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (d-convex Spaces) Assume X is complete and d-convex. Jungck (1982) showed (uPC) ⇒ (C) with the same λ. A modified argument shows that (PS) ⇒ (S). (C)F

B

(ULC)F

B

(uLC)F

B

(LC) (S) (ULS) (LS) (uPC)F

B

(PC) (PS) No combination of any of the properties shown imply any other property, unless the graph forces such implication. Neither does any combination imply the existence of a periodic point unless it contains (C)=(ULC)=(uLC)=(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-100
SLIDE 100

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (d-convex Spaces) Assume X is complete and d-convex. Jungck (1982) showed (uPC) ⇒ (C) with the same λ. A modified argument shows that (PS) ⇒ (S). (C)F

B

(ULC)F

B

(uLC)F

B

(LC) (S) (ULS) (LS) (uPC)F

B

(PC) (PS) No combination of any of the properties shown imply any other property, unless the graph forces such implication. Neither does any combination imply the existence of a periodic point unless it contains (C)=(ULC)=(uLC)=(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-101
SLIDE 101

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (d-convex Spaces) Assume X is complete and d-convex. Jungck (1982) showed (uPC) ⇒ (C) with the same λ. A modified argument shows that (PS) ⇒ (S). (C)F

B

(ULC)F

B

(uLC)F

B

(LC) (S) (ULS) (LS) (uPC)F

B

(PC) (PS) No combination of any of the properties shown imply any other property, unless the graph forces such implication. Neither does any combination imply the existence of a periodic point unless it contains (C)=(ULC)=(uLC)=(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-102
SLIDE 102

Background Main Results Open Problems

Fixed and Periodic Points - Connected Spaces

Theorem (d-convex Spaces) Assume X is complete and d-convex. Jungck (1982) showed (uPC) ⇒ (C) with the same λ. A modified argument shows that (PS) ⇒ (S). (C)F

B

(ULC)F

B

(uLC)F

B

(LC) (S) (ULS) (LS) (uPC)F

B

(PC) (PS) No combination of any of the properties shown imply any other property, unless the graph forces such implication. Neither does any combination imply the existence of a periodic point unless it contains (C)=(ULC)=(uLC)=(uPC).

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-103
SLIDE 103

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact Spaces) Assume X, d is compact. Ding and Nadler (2002) and C&J 2015 showed (LC) ⇒ (ULC) and (LS) ⇒ (ULS). (C)F

B

(ULC)P

E

(uLC)P

E

(LC)P

E

(S)F

E

(ULS)P

E

(LS)P

E

(uPC) (PC) (PS) No combination of any of the properties shown imply any other property, unless the diagram forces such implication. Neither does any combination imply the existence of a fixed or periodic unless indicated on the diagram.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-104
SLIDE 104

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact Spaces) Assume X, d is compact. Ding and Nadler (2002) and C&J 2015 showed (LC) ⇒ (ULC) and (LS) ⇒ (ULS). (C)F

B

(ULC)P

E

(uLC)P

E

(LC)P

E

(S)F

E

(ULS)P

E

(LS)P

E

(uPC) (PC) (PS) No combination of any of the properties shown imply any other property, unless the diagram forces such implication. Neither does any combination imply the existence of a fixed or periodic unless indicated on the diagram.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-105
SLIDE 105

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact Spaces) Assume X, d is compact. Ding and Nadler (2002) and C&J 2015 showed (LC) ⇒ (ULC) and (LS) ⇒ (ULS). (C)F

B

(ULC)P

E

(uLC)P

E

(LC)P

E

(S)F

E

(ULS)P

E

(LS)P

E

(uPC) (PC) (PS) No combination of any of the properties shown imply any other property, unless the diagram forces such implication. Neither does any combination imply the existence of a fixed or periodic unless indicated on the diagram.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-106
SLIDE 106

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact Spaces) Assume X, d is compact. Ding and Nadler (2002) and C&J 2015 showed (LC) ⇒ (ULC) and (LS) ⇒ (ULS). (C)F

B

(ULC)P

E

(uLC)P

E

(LC)P

E

(S)F

E

(ULS)P

E

(LS)P

E

(uPC) (PC) (PS) No combination of any of the properties shown imply any other property, unless the diagram forces such implication. Neither does any combination imply the existence of a fixed or periodic unless indicated on the diagram.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-107
SLIDE 107

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact Connected Spaces) Assume X is compact and connected. (C)F

B

(ULC)F

E

(uLC)F

E

(LC)F

E

(S)F

E

(ULS)F

E

(LS)F

E

(uPC)?

CJ

(PC)?

CJ

(PS)?

CJ

No combination of any of the properties shown imply any other property, unless the diagram forces such implication.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-108
SLIDE 108

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact Connected Spaces) Assume X is compact and connected. (C)F

B

(ULC)F

E

(uLC)F

E

(LC)F

E

(S)F

E

(ULS)F

E

(LS)F

E

(uPC)?

CJ

(PC)?

CJ

(PS)?

CJ

No combination of any of the properties shown imply any other property, unless the diagram forces such implication.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-109
SLIDE 109

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact Rectifiably Path Connected Spaces) Assume X is compact and rectifiably path connected. (C)F

B

(ULC)F

E

(uLC)F

E

(LC)F

E

(S)F

E

(ULS)F

E

(LS)F

E

(uPC)F

HKJ

(PC)F

CJ

(PS)?

CJ

No combination of any of the properties shown imply any other property, unless the diagram forces such implication.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-110
SLIDE 110

Background Main Results Open Problems

Fixed and Periodic Points - Compact Spaces

Theorem (Compact d-Convex Spaces) Assume X is compact and d-convex. (C)F

B

(ULC)F

B

(uLC)F

B

(LC)F

B

(S)F

E

(ULS)F

E

(LS)F

E

(uPC)F

B

(PC)F

CJ

(PS)F

E

No combination of any of the properties shown imply any other property, unless the diagram forces such implication.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-111
SLIDE 111

Background Main Results Open Problems

Open Problems

  • 1. Assume that X, d is compact and either connected or

path connected. If the map f : X, d → X, d is (PS), must f have either fix or periodic point? What if f is (PC)?

  • r (uPC)?
  • 2. Assume that X, d is compact and rectifiably path
  • connected. If the map f : X, d → X, d is (PS), does it

imply that f has a fixed or periodic point?

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-112
SLIDE 112

Background Main Results Open Problems

Open Problems

  • 1. Assume that X, d is compact and either connected or

path connected. If the map f : X, d → X, d is (PS), must f have either fix or periodic point? What if f is (PC)?

  • r (uPC)?
  • 2. Assume that X, d is compact and rectifiably path
  • connected. If the map f : X, d → X, d is (PS), does it

imply that f has a fixed or periodic point?

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-113
SLIDE 113

Background Main Results Open Problems

Open Problems

  • 1. Assume that X, d is compact and either connected or

path connected. If the map f : X, d → X, d is (PS), must f have either fix or periodic point? What if f is (PC)?

  • r (uPC)?
  • 2. Assume that X, d is compact and rectifiably path
  • connected. If the map f : X, d → X, d is (PS), does it

imply that f has a fixed or periodic point?

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-114
SLIDE 114

Background Main Results Open Problems

Thank you for your attention.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-115
SLIDE 115

Background Main Results Open Problems

Open Problems

  • 3. Let X ⊂ R be compact perfect and let g be a function from

X onto X 2. Can g be differentiable? If a differentiable g = f, h as in Problem 3 existed then f : X → X would be a surjection with f ′(x) = 0 except for a meager subset of X, [C&J, 2014].

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-116
SLIDE 116

Background Main Results Open Problems

Open Problems

  • 3. Let X ⊂ R be compact perfect and let g be a function from

X onto X 2. Can g be differentiable? If a differentiable g = f, h as in Problem 3 existed then f : X → X would be a surjection with f ′(x) = 0 except for a meager subset of X, [C&J, 2014].

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-117
SLIDE 117

Background Main Results Open Problems

Open Problems

Theorem (C & J, 2015) There exists a perfect compact set X ⊆ R and autohomeomorphism f: X → X with f′(x) = 0 for all x ∈ X.It follows that f is λ − (uPC) with any λ ∈ [0, 1). Moreover, X, f is a minimal dynamical system so f has no periodic points.

Figure: Action of f2 = f, f on X2.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-118
SLIDE 118

Background Main Results Open Problems

Open Problems

Theorem (C & J, 2015) There exists a perfect compact set X ⊆ R and autohomeomorphism f: X → X with f′(x) = 0 for all x ∈ X.It follows that f is λ − (uPC) with any λ ∈ [0, 1). Moreover, X, f is a minimal dynamical system so f has no periodic points.

Figure: Action of f2 = f, f on X2.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-119
SLIDE 119

Background Main Results Open Problems

Open Problems

Theorem (C & J, 2015) There exists a perfect compact set X ⊆ R and autohomeomorphism f: X → X with f′(x) = 0 for all x ∈ X.It follows that f is λ − (uPC) with any λ ∈ [0, 1). Moreover, X, f is a minimal dynamical system so f has no periodic points.

Figure: Action of f2 = f, f on X2.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-120
SLIDE 120

Background Main Results Open Problems

Open Problems

Theorem (C & J, 2015) There exists a perfect compact set X ⊆ R and autohomeomorphism f: X → X with f′(x) = 0 for all x ∈ X.It follows that f is λ − (uPC) with any λ ∈ [0, 1). Moreover, X, f is a minimal dynamical system so f has no periodic points.

Figure: Action of f2 = f, f on X2.

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper

slide-121
SLIDE 121

Background Main Results Open Problems

(C)F

B

(ULC)P

E

(uLC)P

E

(LC)P

E

(S)F

E

(ULS)P

E

(LS)P

E

(uPC) (PC) (PS)

Krzysztof Chris Ciesielski and Jakub Jasinski Fixed point theorems for maps with various local contraction proper