Timeline for Kernel and cokernel
Current License: CC BY-SA 2.5
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 8, 2010 at 10:39 | answer | added | Roman Fedorov | timeline score: 5 | |
| Aug 8, 2010 at 10:37 | comment | added | Sasha | You should remember, that the kernel (as well as the cokernel) is a morphism --- not just an object. Namely, a kernel of $f:X \to Y$ is a morphism $g:K \to X$ such that $f\circ g = 0$ and a universal property is satisfied. So, $Coker(Ker(f))$ is $Coker(g)$. | |
| Aug 8, 2010 at 9:02 | comment | added | fosco | A typical feature of the categorical properties is to define objects only up to isomorphism. THe various ker(f), coker(f) can't be distingished from any point of view, because every assertion made about a particular choice of ker(f) is valid, in the same form, for any other choice. | |
| Aug 8, 2010 at 8:51 | comment | added | user2035 | see Mac Lane VIII.1 (or presumably any other standard source) | |
| Aug 8, 2010 at 7:44 | history | asked | Amadeus | CC BY-SA 2.5 |