Representing |psi> with Continuous Eigenvectors: An Example

AI Thread Summary
A state vector |psi> in a space spanned by position eigenvectors |x> can be represented as a function of position, where the coefficients are given by C_n = <x_n | psi>. The discussion highlights that for continuous eigenvalues, the representation shifts from discrete column vectors to functions. The relationship between the position operator X and its eigenvectors is emphasized, with the equation X|x> = x|x> illustrating that x represents the spectral value or eigenvalue. The conversation reflects an attempt to connect these concepts with examples from Griffith's textbook, particularly in Chapter 3. Understanding the transition from discrete to continuous representations is crucial in quantum mechanics.
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Homework Statement


for discrete basis vectors {{e_n}}, a state vector |psi> is represented by a column vector, with elements being psi_n = <e_n|psi>. When basis vectors correspond to those with continuous eigenvalues, vectors are represented by functions. Give such an example of a state vector |psi> being represented in a space spanned by position eigenvectors {|x>}.


Homework Equations




The Attempt at a Solution



C_n = <x_n | psi>

I'm really taking a shot in the dark with this one. I'm using Griffith's, so I assume my solutions lies somewhere in chapter 3.
 
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So...|\psi\rangle is a ket which is part of the space spanned by eigenvectors of X, the latter being kets satisfying X|x\rangle = x |x\rangle, where the x is a real number, the spectral value of X.

Soo... |\psi\rangle = \mbox{(something)} ~ |x\rangle

What's (something) equal to ?
 


When you say spectral value, is that the same as the eigenvalue?
 


A generalization of eigenvalue. But you can think of it in a simplified way as an eigenvalue.
 
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