Timeline for Friedmann-Robertson-Walker (FRW) metric and scale factor confusion
Current License: CC BY-SA 4.0
18 events
| when toggle format | what | by | license | comment | |
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| S Jul 6, 2018 at 11:24 | history | bounty ended | Peter4075 | ||
| S Jul 6, 2018 at 11:24 | history | notice removed | Peter4075 | ||
| Jul 5, 2018 at 14:49 | history | tweeted | twitter.com/StackPhysics/status/1014884065672130561 | ||
| Jul 3, 2018 at 5:37 | vote | accept | Peter4075 | ||
| Jul 1, 2018 at 10:31 | history | edited | Qmechanic♦ | CC BY-SA 4.0 |
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| Jul 1, 2018 at 10:24 | answer | added | knzhou | timeline score: 5 | |
| S Jul 1, 2018 at 9:14 | history | bounty started | Peter4075 | ||
| S Jul 1, 2018 at 9:14 | history | notice added | Peter4075 | Improve details | |
| Jun 30, 2018 at 9:15 | history | edited | Peter4075 | CC BY-SA 4.0 |
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| Jun 30, 2018 at 9:09 | history | edited | Peter4075 | CC BY-SA 4.0 |
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| Jun 29, 2018 at 19:34 | comment | added | Javier | It really depends. You can't tell just from the form of the metric, because there is still some coordinate freedom. If you want $k \in \{-1,0,1\}$, then $r$ must be adimensional and hence rescaled, and $a$ will be a length. But you can have $k$ be just any real number, and $r$ will be a length. | |
| Jun 29, 2018 at 19:17 | comment | added | Peter4075 | @Javier - OK, thanks for that. So are you saying that in order for the third metric I give to be correct we need to rescale the radial coordinate $r$? | |
| Jun 29, 2018 at 18:50 | comment | added | Javier | You might be interested in this answer of mine: physics.stackexchange.com/questions/397279/…. What matters is the form of the equations, not the names of the variables. | |
| Jun 29, 2018 at 17:10 | comment | added | Peter4075 | @Javier - how can they be the same if they're different equations, and if they are the same how can the third equation be true? | |
| Jun 29, 2018 at 15:10 | history | edited | Peter4075 | CC BY-SA 4.0 |
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| Jun 29, 2018 at 13:44 | comment | added | Javier | The $a$ in the second form is the same as the $R$ before. Don't pay too much attention to the names of things. | |
| Jun 29, 2018 at 11:58 | history | edited | Kyle Kanos | CC BY-SA 4.0 |
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| Jun 29, 2018 at 8:17 | history | asked | Peter4075 | CC BY-SA 4.0 |