What is the relationship between H, psi, and E in Quantum Mechanics?

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SUMMARY

The discussion centers on the relationship between the Hamiltonian operator (H), wave function (psi), and energy (E) in quantum mechanics, specifically in the context of the equation H*psi = E*psi. The user, Thomas, attempts to prove that the wave function can be expressed as N*exp(lambda*(1-cos(x))) when E equals zero. The solution involves manipulating the equation -D^2/Dx^2 + cos(x) + sin^2(x) = 0 and substituting the proposed form of psi. The key takeaway is that the substitution will only hold for a specific choice of the constant lambda.

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  • Basic calculus, including integration and exponentiation techniques.
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Homework Statement


I am currently doing undergraduate research and was assigned this as sort of an introduction. I am sure this is a very rudimentary problem and appreciate any help.

Basically, its your regular old H*psi = E*psi.

Well, knowing that H is psi(-D^2/Dx^2 + cosx + sin^2x = E*psi

and I want to prove that Ne^(lambda(1-cos)) is where E is equal to zero where N is the normalization constant and lambda is an arbitrary constant.

2. The attempt at a solution

The thing that I tried to do was divide by psi, and set E=0 to completely get rid of psi. I am not sure if I am allowed to do this but I did. This left me with

-D^2/Dx^2 + cosx + sin^2x = 0.

From there, I moved them to separate sides and doubly integrated. I got

ln|x| = cos^2(x)/4 - cos(x) +x^2/4

and exponentating I got

x = e^(Cos^2(x)/4 - cos(x) +x^2/4)

The problem is, without psi, I don't think that derivitave means anything and so I think I need to somehow keep the psi in there but I don't know what to do other than to divide out psi.

I would also rather a few hints instead of an explicit solution; I am sure that its just something that I am over looking and with a hint or two, I could do this.

I am very gracious of your help,

Thomas
 
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H operates on psi. So the equation is -psi(x)''+(cos(x)+sin^2(x))*psi(x)=0. And you don't have to solve it. Just substitute psi(x)=N*exp(lambda*(1-cos(x)). I think you'll find it works for only one choice of lambda.
 

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