Computing Eigenfunctions for a One-Dimensional Operator

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Homework Help Overview

The discussion revolves around finding the eigenfunctions of a one-dimensional operator composed of the momentum operator and the position operator. Participants explore the implications of their equations and the normalization of the resulting eigenfunctions.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to derive the eigenfunction from the operator equation and expresses confusion about the constants involved. Other participants provide insights into the integration process and the nature of the eigenfunctions, questioning the handling of arbitrary constants and normalization.

Discussion Status

Participants are actively engaging with the problem, offering guidance on normalization and the properties of eigenfunctions. There is an ongoing exploration of how to evaluate the eigenvalues for both the position and momentum operators, with some participants seeking clarification on the mathematical steps involved.

Contextual Notes

There is a mention of normalization conditions and the potential for multiple interpretations of the eigenfunctions due to arbitrary constants. The discussion also touches on the expectations for evaluating eigenvalues over specified ranges.

  • #31
actually, this was written in the post

<br /> &lt; x &gt; = \int _{\text{All space}} \psi^*(x)x\psi(x) dx = \int x|\psi (x)|^2 dx <br />

So I have no clue why you asked. Maybe this is too difficult for you? I suggest you wait. You still don't seem to follow my advise that taking one small step a head =(
 
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  • #32
i just didnt know the notation. i know the complex conjugate. ok, so here's the question.
for yesterdays O(with hat) i got the eigenfunction(ѱ) after normalization to be,
ѱ=exp((x2 -x)/2ih') how would i go on about finding the expectation value of x, px and px2?
would you mind telling me the process step by step??
 
  • #33
I don't think you understand this thing with operators and eigenfunction...

It is a difference of FINDING the eigenfunctions to a given operator and finding the eigenvalues of a given operator on a given wavefunction.

The example was:

Given the wavefuction \psi(x) = (1/(\pi ^{1/4}\sqrt{d}))\exp (ikx - x^2/(2d^2))

Evaluate the expectation values of x, x^2, p and p^2

------

So for the first part, <x> is int ѱ* x ѱ dx

What you need to know here are two parts, first what the complex conjugate of ѱ is and then what integral of a Gaussian integral is.

http://en.wikipedia.org/wiki/Gaussian_integral

See " Generalizations "

This is too hard for you, I give up.
 

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