Timeline for Fundamental group of the line with the double origin.
Current License: CC BY-SA 2.5
14 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 21, 2010 at 13:31 | comment | added | Tyler Lawson | @Noah: Corrected. The set notation was wrong and I had a sign error. My apologies. | |
| May 21, 2010 at 13:30 | history | edited | Tyler Lawson | CC BY-SA 2.5 |
more corrections because I am an idiot
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| May 21, 2010 at 13:15 | comment | added | Noah Stein | Apparently I can't edit my own comments. By "instead" I meant "instead of $\{y<0\}$". | |
| May 21, 2010 at 13:14 | comment | added | S. Carnahan♦ | Yes, it is a bit like real points of $y^2 = x^2(x+a)$ for $a$ very very small. | |
| May 21, 2010 at 13:13 | comment | added | Noah Stein | I'm confused about this set $R^2\setminus\{y<0\}$. If it is to be homeomorphic to $R\times (0,\infty)$ it should be open. Do you mean $\{y\leq 0,x=0\}$ instead? Also, I'm not sure about that $g$ being an inverse, because as written $g(0,u)=(0,0)$ for all $u$. | |
| May 21, 2010 at 13:07 | comment | added | Pete L. Clark | In fact, this is is somewhat reminiscent of the universal cover of the nodal cubic that we were talking about some months ago, no? | |
| May 21, 2010 at 13:05 | comment | added | Pete L. Clark | Never mind -- I see it now. Thanks. | |
| May 21, 2010 at 12:58 | comment | added | Pete L. Clark | @Scott: I can't quite see it yet. Could you be a little more more explicit? | |
| May 21, 2010 at 12:45 | comment | added | S. Carnahan♦ | @Pete: No, it is not Hausdorff. You glue a bunch of real lines along open rays. | |
| May 21, 2010 at 12:43 | comment | added | Tyler Lawson | @Chris: The "usual" coordinate charts make it look like a quasifibration. I've added some details about a change of coordinates that makes it look more like an actual fibration. | |
| May 21, 2010 at 12:42 | history | edited | Tyler Lawson | CC BY-SA 2.5 |
added details
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| May 21, 2010 at 12:39 | comment | added | Pete L. Clark | Weird. Is the universal cover just the usual real line? | |
| May 21, 2010 at 12:32 | comment | added | Chris Schommer-Pries | Is this a fibration or only a quasi-fibtration? (a quasi-fibration is still good enough for your argument). | |
| May 21, 2010 at 12:20 | history | answered | Tyler Lawson | CC BY-SA 2.5 |