Timeline for Galactic rotation speed
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| Oct 26, 2023 at 14:00 | vote | accept | Rémy Galli | ||
| Oct 26, 2023 at 14:00 | |||||
| Oct 26, 2023 at 10:22 | history | edited | Ulrich Neumann | CC BY-SA 4.0 |
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| Oct 23, 2023 at 14:39 | comment | added | Rémy Galli | OK very good Thanks a lot | |
| Oct 23, 2023 at 14:36 | comment | added | Ulrich Neumann |
@RémyGalli From the fixpoint equation with R->0: rho[R]==v[R ] ^2/(4 Pi R^2 ) -Sqrt[1 - e^2]/e^3 NIntegrate[s^2 /Sqrt[1 - s^2] ,{s,0,e}] rho[R] /.R->0 it follows rho[0]=0.18
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| Oct 23, 2023 at 14:30 | comment | added | Ulrich Neumann |
@RémyGalli I took a grid which increases quadratically to get a finer mesh in the range 0,1 .
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| Oct 23, 2023 at 13:59 | comment | added | Rémy Galli | Thank you for your last solution using FEM. Naive question : how did you choose ri coefficients ? | |
| Oct 23, 2023 at 13:27 | comment | added | Rémy Galli | @Alex and Ulrich Ulrich solution modified by Alex is fine. It looks like Picard solution of Volterra integral of second kind. This gives an Interpolating function easy to manipulate. But, where does come the factor 0.18 from ??? | |
| Oct 23, 2023 at 13:23 | comment | added | Rémy Galli | @ Alex Thank you very muche for this great job. Why is there oscillations if I change Rma to 10 ? Because I need the solution between {0,10} ? | |
| Oct 23, 2023 at 13:15 | comment | added | Rémy Galli | @All I need a solution from R=0 to R=10 , and I observe some oscillations in Alex proposal when R>5. Alex solution is fast but this is a decomposition in wavelets not very easy to manipulate... | |
| Oct 23, 2023 at 13:13 | comment | added | Rémy Galli | @ All Sorry , I was away the last few days. Thanks for your answers , this is very useful. | |
| Oct 22, 2023 at 21:07 | history | edited | Ulrich Neumann | CC BY-SA 4.0 |
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| Oct 22, 2023 at 21:02 | history | answered | Ulrich Neumann | CC BY-SA 4.0 |