Namespaces
Variants
Actions

Difference between revisions of "Differential group"

From Encyclopedia of Mathematics
Jump to: navigation, search
(Importing text file)
 
(details)
 
(2 intermediate revisions by one other user not shown)
Line 1: Line 1:
An Abelian group <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/d/d032/d032190/d0321901.png" /> with a given endomorphism <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/d/d032/d032190/d0321902.png" /> such that <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/d/d032/d032190/d0321903.png" />. This endomorphism is called a differential. The elements of a differential group are known as chains; the elements of the kernel <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/d/d032/d032190/d0321904.png" /> are known as cycles; and the elements of the image <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/d/d032/d032190/d0321905.png" /> are called boundaries.
+
An [[Abelian group]] $C$ with a given endomorphism $d : C \rightarrow C$ such that $d^2 = 0$. This endomorphism is called a ''differential''. The elements of a differential group are known as chains; the elements of the kernel $\ker d$ are known as ''cycles''; and the elements of the image $\mathrm{im}\, d$ are called ''boundaries''.  The ''homology'' of $C$ is the quotient $\ker d / \mathrm{im}\,d$.
  
 +
====References====
 +
* {{Ref|a1}} E.H. Spanier, "Algebraic topology", McGraw-Hill (1966) pp. 156
  
 
+
{{TEX|done}}
====Comments====
 
 
 
 
 
====References====
 
<table><TR><TD valign="top">[a1]</TD> <TD valign="top">  E.H. Spanier,  "Algebraic topology" , McGraw-Hill  (1966)  pp. 156</TD></TR></table>
 

Latest revision as of 14:52, 8 April 2023

An Abelian group $C$ with a given endomorphism $d : C \rightarrow C$ such that $d^2 = 0$. This endomorphism is called a differential. The elements of a differential group are known as chains; the elements of the kernel $\ker d$ are known as cycles; and the elements of the image $\mathrm{im}\, d$ are called boundaries. The homology of $C$ is the quotient $\ker d / \mathrm{im}\,d$.

References

  • [a1] E.H. Spanier, "Algebraic topology", McGraw-Hill (1966) pp. 156
How to Cite This Entry:
Differential group. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Differential_group&oldid=13399
This article was adapted from an original article by A.V. Mikhalev (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article