Timeline for Coordinate free computation of the second derivative of a functional
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 19, 2023 at 14:53 | vote | accept | Gauge | ||
| Jun 19, 2023 at 12:54 | comment | added | Michael Engelhardt | @LeoKovacic - of course I'm sure. The reason there isn't a Dirac $\delta $ in the first derivative is because the integral has taken care of it, as explicitly written. When taking another derivative, there's no integral anymore. Your functional doesn't care about how $f$ varies, so that variation doesn't have to be taken into account. We're really really stretching what type of question should be posted on this site. These are not things you should expect to be explained to you here. | |
| Jun 19, 2023 at 10:15 | comment | added | Gauge | So you're saying if the integrand doesn't depend on derivatives explicitly I can just find the first derivative by partial derivative and then make a functional out of the function I get with the Dirac function and then just take the derivative of that | |
| Jun 19, 2023 at 7:28 | comment | added | Gauge | The double nabla is just the divergence of the vector gradient , which you have to take into account in my opinion because you have to compute how the function f changes spatially | |
| Jun 19, 2023 at 7:26 | comment | added | Gauge | Though I knew the Dirac function should be used at some point so that is a good sign | |
| Jun 19, 2023 at 7:25 | comment | added | Gauge | Are you sure, I don't know how to check this , I don't think it's quite right , and why does first contain the delta and the other one not . | |
| Jun 18, 2023 at 23:45 | history | answered | Michael Engelhardt | CC BY-SA 4.0 |