scholarly journals Sifat-Sifat Morfisma di dalam Kategori Ruang Penutup Ruang Topologis yang Terhubung Lintasan (On the Morphisms of the Category of Path Connected Covering Spaces )

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Valentino Risali ◽  
Indah Emilia Wijayanti

Untuk sebarang ruang topologis $X$ dapat dibentuk $Cov_X$ yaitu kategori \linebreak ruang penutup $X$ yang terhubung lintasan. Pada tulisan ini akan dibahas syarat perlu dan cukup eksistensi morfisma antara dua ruang penutup yang terhubung lintasan lokal. Untuk sebarang $x_0 \in X$ dan grup fundamental $G=\pi_1(X,x_0)$, dapat dibentuk kategori $SetG$, yaitu kategori semua himpunan yang dilengkapi aksi kanan oleh $G$. Selanjutnya dibentuk fungtor $F$ dari $Cov_X$ ke  $SetG$. Dalam tulisan dibuktikan bahwa $F$ bersifat \textit{fully faithful} jika $X$ terhubung lintasan dan terhubung lintasan lokal. Akibatnya untuk mengidentifikasi morfisma-morfisma antara dua obyek $A$ dan $B$ di $Cov_X$ dapat dilakukan dengan cara melihat sifat morfisma-morfisma antara $F(A)$ dan $F(B)$. (For any topological space $X$, we can construct the category of path \linebreak connected covering spaces of $X$, denoted by $Cov_X$. In this paper we study a sufficient and necesarry condition for the existence of morphism between two locally path \linebreak connected covering spaces. For every $x_0 \in X$ and fundamental group $G=\pi_1(X,x_0)$, we can construct the category of sets with right action of $G$, denoted by $SetG$. \linebreak Furthermore, we can define a functor $F$ from $Cov_X$ to $SetG$. We proof that the functor $F$ is fully faithul if $X$ is path connected and locally path connected. From this result, we can identify morphisms between $A$ and $B$ in $Cov_X$ by using the properties of morphisms between $F(A)$ and $F(B)$. )


1975 ◽  
Vol 19 (3) ◽  
pp. 237-244 ◽  
Author(s):  
R. Brown ◽  
G. Danesh-Naruie

Let X be a topological space. Then we may define the fundamental groupoid πX and also the quotient groupoid (πX)/N for N any wide, totally disconnected, normal subgroupoid N of πX (1). The purpose of this note is to show that if X is locally path-connected and semi-locally 1-connected, then the topology of X determines a “lifted topology” on (πX)/N so that it becomes a topological groupoid over X. With this topology the subspace which is the fibre of the initial point map ∂′: (πX)/N→X over x in X, is the usual covering space of X determined by the normal subgroup N{x} of the fundamental group π(X, x).





1960 ◽  
Vol 3 (2) ◽  
pp. 186-187
Author(s):  
J. Lipman

The point of this note is to get a lemma which is useful in treating homotopy between paths in a topological space [1].As explained in the reference, two paths joining a given pair of points in a space E are homotopic if there exists a mapping F: I x I →E (I being the closed interval [0,1] ) which deforms one path continuously into the other. In practice, when two paths are homotopic and the mapping F is constructed, then the verification of all its required properties, with the possible exception of continuity, is trivial. The snag occurs when F is a combination of two or three functions on different subsets of I x I. Then the boundary lines between these subsets have to be given special consideration, and although the problems resulting are routine their disposal can involve some tedious calculation and repetition. In the development [l] of the fundamental group of a space, for example, this sort of situation comes up four or five times.



2015 ◽  
Vol 92 (1) ◽  
pp. 145-148
Author(s):  
ADAM J. PRZEŹDZIECKI

For every countable group $G$ we construct a compact path connected subspace $K$ of $\mathbb{R}^{4}$ such that ${\it\pi}_{1}(K)\cong G$. Our construction is much simpler than the one found recently by Virk.



2020 ◽  
pp. 422-427
Author(s):  
Hiyam Hassan Kadhem ◽  
Noor Abdul Moneem Jawad

      In this paper, we show that each soft topological group is a strong small soft loop transfer space at the identity element. This indicates that the soft quasitopological fundamental group of a soft connected and locally soft path connected space, is a soft topological group.



2015 ◽  
Vol 25 (01n02) ◽  
pp. 301-323 ◽  
Author(s):  
John Meakin ◽  
Nóra Szakács

It is well known that under mild conditions on a connected topological space 𝒳, connected covers of 𝒳 may be classified via conjugacy classes of subgroups of the fundamental group of 𝒳. In this paper, we extend these results to the study of immersions into two-dimensional CW-complexes. An immersion f : 𝒟 → 𝒞 between CW-complexes is a cellular map such that each point y ∈ 𝒟 has a neighborhood U that is mapped homeomorphically onto f(U) by f. In order to classify immersions into a two-dimensional CW-complex 𝒞, we need to replace the fundamental group of 𝒞 by an appropriate inverse monoid. We show how conjugacy classes of the closed inverse submonoids of this inverse monoid may be used to classify connected immersions into the complex.



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