The combinatorial derivation
Let $G$ be a group, $\mathcal{P}_G$ be the family of all subsets of $G$. For a subset $A\subseteq G$, we put $\Delta(A)=\{g\in G:|gA\cap A|=\infty\}$. The mapping $\Delta:\mathcal{P}_G\rightarrow\mathcal{P}_G$, $A\mapsto\Delta(A)$, is called a combinatorial derivation and can be considered as an ana...
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Format: | Article |
Language: | English |
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Universitat Politècnica de València
2013-09-01
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Series: | Applied General Topology |
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Online Access: | http://polipapers.upv.es/index.php/AGT/article/view/1587 |
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author | Igor V. Protasov |
author_facet | Igor V. Protasov |
author_sort | Igor V. Protasov |
collection | DOAJ |
description | Let $G$ be a group, $\mathcal{P}_G$ be the family of all subsets of $G$. For a subset $A\subseteq G$, we put
$\Delta(A)=\{g\in G:|gA\cap A|=\infty\}$. The mapping $\Delta:\mathcal{P}_G\rightarrow\mathcal{P}_G$, $A\mapsto\Delta(A)$, is called a combinatorial derivation and can be considered as an analogue of the topological derivation $d:\mathcal{P}_X\rightarrow\mathcal{P}_X$, $A\mapsto A^d$, where $X$ is a topological space and $A^d$ is the set of all limit points of $A$. Content: elementary properties, thin and almost thin subsets, partitions, inverse construction and $\Delta$-trajectories, $\Delta$ and $d$. |
first_indexed | 2024-12-12T03:08:04Z |
format | Article |
id | doaj.art-0688cae4196a4204923a5d7fd6bc91ba |
institution | Directory Open Access Journal |
issn | 1576-9402 1989-4147 |
language | English |
last_indexed | 2024-12-12T03:08:04Z |
publishDate | 2013-09-01 |
publisher | Universitat Politècnica de València |
record_format | Article |
series | Applied General Topology |
spelling | doaj.art-0688cae4196a4204923a5d7fd6bc91ba2022-12-22T00:40:28ZengUniversitat Politècnica de ValènciaApplied General Topology1576-94021989-41472013-09-0114217117810.4995/agt.2013.15871371The combinatorial derivationIgor V. Protasov0Kyiv UniversityLet $G$ be a group, $\mathcal{P}_G$ be the family of all subsets of $G$. For a subset $A\subseteq G$, we put $\Delta(A)=\{g\in G:|gA\cap A|=\infty\}$. The mapping $\Delta:\mathcal{P}_G\rightarrow\mathcal{P}_G$, $A\mapsto\Delta(A)$, is called a combinatorial derivation and can be considered as an analogue of the topological derivation $d:\mathcal{P}_X\rightarrow\mathcal{P}_X$, $A\mapsto A^d$, where $X$ is a topological space and $A^d$ is the set of all limit points of $A$. Content: elementary properties, thin and almost thin subsets, partitions, inverse construction and $\Delta$-trajectories, $\Delta$ and $d$.http://polipapers.upv.es/index.php/AGT/article/view/1587Combinatorial derivation$\Delta$-trajectorieslarge, small and thin subsets of groupspartitions of groupsStone-\v{C}ech compactification of a group |
spellingShingle | Igor V. Protasov The combinatorial derivation Applied General Topology Combinatorial derivation $\Delta$-trajectories large, small and thin subsets of groups partitions of groups Stone-\v{C}ech compactification of a group |
title | The combinatorial derivation |
title_full | The combinatorial derivation |
title_fullStr | The combinatorial derivation |
title_full_unstemmed | The combinatorial derivation |
title_short | The combinatorial derivation |
title_sort | combinatorial derivation |
topic | Combinatorial derivation $\Delta$-trajectories large, small and thin subsets of groups partitions of groups Stone-\v{C}ech compactification of a group |
url | http://polipapers.upv.es/index.php/AGT/article/view/1587 |
work_keys_str_mv | AT igorvprotasov thecombinatorialderivation AT igorvprotasov combinatorialderivation |