Timeline for To what extent can we use the informal version of the Dirac delta function in Physics?
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Sep 12, 2022 at 15:20 | comment | added | Filippo | I was thaught this stuff in my first semester, but unfortunately I didn't ask if this has any applications to theoretical physics... | |
| Sep 12, 2022 at 15:17 | comment | added | Filippo | @AndrewSteane Indeed the comment resulted from a discussion whether expressions of the form$$\int_D\delta(f(x))dx$$should be regarded as being defined or not. As I have show in my first comment, they are not defined in the context of distrubution theory, because the limit depends on the chosen nascent dirac delta. However, we can rigorously evaluate such integrals if we consider a list of "suitable" representations. | |
| Sep 12, 2022 at 14:41 | comment | added | Andrew Steane | @Filippo Your comment is a useful reminder, but I note that the integral considered in the question you refer to goes from 0, i.e. the very place where the function has its peak. Clearly that is a special case. | |
| Sep 12, 2022 at 14:19 | comment | added | John Doty | @Filippo Can you give a reference for a case in which this issue caused disagreement between calculation and an experimental result? | |
| Sep 12, 2022 at 13:59 | comment | added | Filippo | Warning: One may think that all nascent dirac deltas are "suitable" representations, but it turns out that such limits have different values depending on the chosen sequence. | |
| Sep 12, 2022 at 13:47 | history | answered | Andrew Steane | CC BY-SA 4.0 |