Modification to the simple harmonic oscillator

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The discussion centers on the implications of modifying the simple harmonic oscillator Hamiltonian and whether perturbation theory is needed. It is argued that the eigenstates of the original harmonic oscillator remain unchanged, implying that the matrix elements of position operators are unaffected by the modification. However, there is skepticism regarding the assertion that the modification does not alter the size of the Hilbert space. The completeness of the eigenstates is emphasized, but the potential impact of modifications on the Hilbert space remains a point of contention. The conversation highlights the need for clarity on how modifications influence the underlying mathematical structure.
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Homework Statement
The simple harmonic oscillator Hamiltonian is altered such that the p' = p + 2mcx. How does this affect the condition necessary for the matrix elements <m|x|n> and <m, x^2| n> to be nonzero, given |n> is an eigenstate of the original harmonic oscillator.
Relevant Equations
x = Sqrt(h/2mw)(a + adagger)
I was assuming there could be something via perturbation theory? I am unsure.
 
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At first glance, I don't think that perturbation theory is necessary. The ##\ket{n}## form a complete basis, even for the modified Hamiltonian.

However, I do not understand the question. "Given ##\ket{n}## is an eigenstate of the original harmonic oscillator," then ##\braket{m|\hat{x}|n}## and ##\braket{m|\hat{x}^2|n}## are unchanged, whatever the Hamiltonian is.
 
DrClaude said:
At first glance, I don't think that perturbation theory is necessary. The ##\ket{n}## form a complete basis, even for the modified Hamiltonian.
I would like to question this statement. How do you know such modification doesn't change the size of the Hilbert's space?
 
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