What is the Interpretation of the Inverse Property of a Delta Function in QM?

Click For Summary
The discussion centers on the interpretation of the inverse property of the delta function in quantum mechanics, specifically the equation x δ^{-1}(x) = -δ(x). The original poster finds this expression confusing and questions its validity, suggesting it may be a typo. They propose that the correct relationship might be x δ' = -δ, which is a recognized identity. After further investigation, it is confirmed that the notation was indeed a typo in the text. The conversation highlights the importance of accuracy in mathematical expressions within quantum mechanics literature.
Peeter
Messages
303
Reaction score
3
In a book on QM are listed a few properties of the delta function, one of which is:

x \delta^{-1}(x) = - \delta(x)

I can't figure out how to interpret that? Putting the statement in integral form isn't particularily enlightening looking:

<br /> f(x) = \int f(x-x&#039;) \delta(x&#039;) dx&#039; = <br /> \int -x&#039; \delta^{-1}(x&#039;) f(x - x&#039;) dx&#039; <br />

any hint what this property is about or how one would show it?
 
Physics news on Phys.org
I'm not aware of any meaningful operation corresponding to the "inverse of the delta function" in regular distribution theory and even intuitively speaking, it doesn't seem to be meaningful. Are you sure it's not actually:

x\delta^\prime = -\delta,

which is a meaningful and true identity?
 
Last edited:
Thanks Preno. Your statement makes sense (ie: can show it with integration by parts).

I'm pretty sure it was listed as ^{-1}, but will have to wait til I'm home to verify. It's probably another typo in the text.

Confirmed. Just another typo in the text.
 
Last edited:
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA

Similar threads

  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 0 ·
Replies
0
Views
1K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 31 ·
2
Replies
31
Views
5K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 25 ·
Replies
25
Views
4K
  • · Replies 31 ·
2
Replies
31
Views
4K
  • · Replies 33 ·
2
Replies
33
Views
6K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K