Timeline for To prove that an operator commutes with any function of it
Current License: CC BY-SA 3.0
20 events
| when toggle format | what | by | license | comment | |
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| S Aug 19, 2016 at 10:53 | history | suggested | Vishnu JK | CC BY-SA 3.0 |
better formatting and new tag
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| Aug 19, 2016 at 8:36 | review | Suggested edits | |||
| S Aug 19, 2016 at 10:53 | |||||
| Aug 18, 2016 at 6:09 | comment | added | garyF | @Qmechanic …If that theorem involves differential calculus, then Valter Moretti pointed out below that this may not hold for non-analytic functions. | |
| Aug 18, 2016 at 5:42 | comment | added | garyF | @Qmechanic What is that theorem/postulate called? If i can use $[\hat A, \hat A] = 0 \implies [\hat A, f(\hat A)] = 0$, the proof will be done in one step; but i'd need to state theorem/postulate. | |
| Aug 18, 2016 at 5:38 | comment | added | garyF | @AndreaBecker i was doubting that i made a mistake in this very step after i took the Kronecker-delta :P If you could please post your answer below, i'd be happy to accept that!~ | |
| Aug 17, 2016 at 23:19 | comment | added | Qmechanic♦ | Possible duplicates: physics.stackexchange.com/q/194436/2451 and links therein. | |
| Aug 17, 2016 at 18:40 | comment | added | Andrea Becker | @garyF You've almost did it yourself but made a mistake. When you sum over $j$, due to Kronecker delta $\delta_{ij}$ only the terms with $j=i$ are picked up, and hence, in both lhs and rhs you end up with $\sum_{i} a_i f(a_{i})|a_{i}\rangle\langle a_{i}|$. | |
| Aug 17, 2016 at 17:46 | review | Suggested edits | |||
| Aug 17, 2016 at 17:54 | |||||
| Aug 17, 2016 at 17:45 | comment | added | user36790 |
Related meta post: meta.physics.stackexchange.com/a/6952 in reminder of using \newcommand.
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| Aug 17, 2016 at 17:38 | vote | accept | garyF | ||
| Aug 17, 2016 at 17:03 | comment | added | garyF | @count_to_10 pardon me, i am used to having this package imported by default in my TeX. MathJax problems aside… 😅 | |
| Aug 17, 2016 at 17:00 | history | edited | garyF | CC BY-SA 3.0 |
clarification on the question i want
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| Aug 17, 2016 at 16:56 | review | Close votes | |||
| Aug 18, 2016 at 6:59 | |||||
| Aug 17, 2016 at 16:55 | comment | added | zeldredge | @count_to_10 You can use \newcommand on Stack Exchange to define \bra and \ket. | |
| Aug 17, 2016 at 16:55 | history | edited | zeldredge | CC BY-SA 3.0 |
added 100 characters in body
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| Aug 17, 2016 at 16:51 | comment | added | user108787 | Hi gary, I'm happy to edit your post, because its not rendering properly, at least on my machine. I am used to rangle and langle for bras and kets, I would prefer your way of writing Dirac notation but I don't know how to do it. | |
| Aug 17, 2016 at 16:43 | answer | added | Dave Williams | timeline score: 4 | |
| Aug 17, 2016 at 16:37 | history | edited | Qmechanic♦ | CC BY-SA 3.0 |
added 2 characters in body; edited tags
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| Aug 17, 2016 at 16:37 | review | First posts | |||
| Aug 17, 2016 at 17:47 | |||||
| Aug 17, 2016 at 16:34 | history | asked | garyF | CC BY-SA 3.0 |