Self-closeness number and weak homotopy decomposition.

2021 ◽  
Author(s):  
Ho Won Choi ◽  
Kee Young Lee
2018 ◽  
Vol 62 (2) ◽  
pp. 553-558
Author(s):  
Jonathan Ariel Barmak

AbstractIt is well known that if X is a CW-complex, then for every weak homotopy equivalence f : A → B, the map f* : [X, A] → [X, B] induced in homotopy classes is a bijection. In fact, up to homotopy equivalence, only CW-complexes have that property. Now, for which spaces X is f* : [B, X] → [A, X] a bijection for every weak equivalence f? This question was considered by J. Strom and T. Goodwillie. In this note we prove that a non-empty space inverts weak equivalences if and only if it is contractible.


1970 ◽  
Vol 13 (2) ◽  
pp. 261-266
Author(s):  
Luc Demers
Keyword(s):  

In [3] D. B. Fuks defined a duality of functors in the category of weak homotopy types. In general this duality is more difficult to work with than the duality of functors of the category of pointed Kelley spaces [2]. It happens however that all so-called strong functors [2] F of induce functors of , and if we denote the duality operators of and by and D respectively, then there are many cases where .


Mathematics ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 981
Author(s):  
Antonio M. Cegarra

This paper deals with well-known weak homotopy equivalences that relate homotopy colimits of small categories and simplicial sets. We show that these weak homotopy equivalences have stronger cohomology-preserving properties than for local coefficients.


2003 ◽  
Vol 55 (1) ◽  
pp. 181-203 ◽  
Author(s):  
Stephen D. Theriault

AbstractJames gave an integral homotopy decomposition of ∑Ω∑X, Hilton-Milnor one for Ω(∑X ∨ ∑Y), and Cohen-Wu gave p-local decompositions of Ω∑X if X is a suspension. All are natural. Using idempotents and telescopes we show that the James andHilton-Milnor decompositions have analogues when the suspensions are replaced by coassociative co-H spaces, and the Cohen-Wu decomposition has an analogue when the (double) suspension is replaced by a coassociative, cocommutative co-H space.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Abdon Atangana ◽  
Adem Kılıçman

The homotopy decomposition method, a relatively new analytical method, is used to solve the 2D and 3D Poisson equations and biharmonic equations. The method is chosen because it does not require the linearization or assumptions of weak nonlinearity, the solutions are generated in the form of general solution, and it is more realistic compared to the method of simplifying the physical problems. The method does not require any corrected function or any Lagrange multiplier and it avoids repeated terms in the series solutions compared to the existing decomposition method including the variational iteration method, the Adomian decomposition method, and Homotopy perturbation method. The approximated solutions obtained converge to the exact solution as tends to infinity.


2016 ◽  
Vol 23 (1) ◽  
pp. 153-161 ◽  
Author(s):  
Suyoung Choi ◽  
Shizuo Kaji ◽  
Stephen Theriault

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