Timeline for One Point Compactification
Current License: CC BY-SA 2.5
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 27, 2009 at 10:53 | comment | added | Pete L. Clark | I think the good old inversion z |-> 1/z makes this easier to see: i.e., just take the closed unit disk in the plane with the origin removed. | |
| Oct 27, 2009 at 17:16 | comment | added | David E Speyer | You are right. I have edited to fix the error. | |
| Oct 27, 2009 at 17:16 | history | edited | David E Speyer | CC BY-SA 2.5 |
deleted 1 characters in body
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| Oct 27, 2009 at 17:09 | comment | added | Chris Schommer-Pries | I think you mean { (x,y) : x^2 + y^2 < 1}. i.e. you want to leave the boundary circle there. Then Y is contractible. Otherwise Y is a pinched torus and also has fundamental group the integers (although the induced map is zero). | |
| Oct 27, 2009 at 17:03 | history | answered | David E Speyer | CC BY-SA 2.5 |