Multi-Particle QM Homework: Equations & Attempt at Solution

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The discussion focuses on a homework problem related to multi-particle quantum mechanics, specifically involving the commutation relation ##[a(x),a^+(x')]=\delta(x-x')##. The user has attempted to express their solution using integrals of creation operators and the Hamiltonian operator applied to the wave function ##\Psi(x_1,x_2)##. The main issue raised is the need for clarification on how to justify the solution without the integral form, indicating a potential misunderstanding in the application of the Hamiltonian to the wave function.

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Students and researchers in quantum mechanics, particularly those working on multi-particle systems and seeking to deepen their understanding of operator algebra and commutation relations.

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Homework Statement



Question attached:

multi-particle qm.png


Homework Equations



below

The Attempt at a Solution



I have completed this question and the needed commutator relation is that ##[a(x),a^+(x')]=\delta(x-x')##

However I have it all with the integral i.e.

##\int dx_1 dx_2 a^+(x_1)a^+(x_2) \Psi (x_1,x_2) | 0> ##

and

##\int dx_1 dx_2 a^+(x_1)a^+(x_2) \frac{-h^2}{2m}(\frac{\partial^2}{\partial x_1^2}+\frac{\partial^2}{\partial x_2^2} ) \Psi (x_1,x_2) |0> ## such terms etc

and am unsure of the final argument needed to explain why it holds without the integral.

Many thanks for your help.
 

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binbagsss said:

Homework Statement



Question attached:

View attachment 224316

Homework Equations



below

The Attempt at a Solution



I have completed this question and the needed commutator relation is that ##[a(x),a^+(x')]=\delta(x-x')##

However I have it all with the integral i.e.

##\int dx_1 dx_2 a^+(x_1)a^+(x_2) \Psi (x_1,x_2) | 0> ##

and

##\int dx_1 dx_2 a^+(x_1)a^+(x_2) \frac{-h^2}{2m}(\frac{\partial^2}{\partial x_1^2}+\frac{\partial^2}{\partial x_2^2} ) \Psi (x_1,x_2) |0> ## such terms etc

and am unsure of the final argument needed to explain why it holds without the integral.

Many thanks for your help.
It is hard to help without any details about your steps or the precise result of your final expression. I have the gut feeling that you applied H to Psi but that maybe you used the same coordinates in both H and Psi, which can lead to a problem. But again, more details would be helpful.
 

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