Expectation value of Fourier conjugates

In summary, the expectation value of Fourier conjugates is the average value of a set of conjugate variables in a Fourier transform. It is closely related to the uncertainty principle and is used in quantum mechanics to predict the behavior of particles. It cannot be negative and can change over time due to the probabilistic nature of quantum systems.
  • #1
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I understand that the Uncertainty Principle relates the variances of Fourier conjugates. I am having trouble finding: 1) the mathematical relationship between the expectation values of Fourier conjugates generally; 2) and then specifically for a normalized Gaussian. Any suggestions or insights?
 
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  • #2
Work your way through a textbook on Fourier transforms :smile:
1) is there any ?
2) FT of Gaussian is Gaussian. Product of their ##\sigma## is constant. expectation values are not related :rolleyes: but I like to be shown wrong
 

1. What is the expectation value of Fourier conjugates?

The expectation value of Fourier conjugates refers to the average value of a physical quantity in a quantum mechanical system that is described by Fourier conjugate variables. These variables are related to each other through the Fourier transform.

2. How is the expectation value of Fourier conjugates calculated?

The expectation value of Fourier conjugates is calculated by taking the inner product of the quantum state vector with the operator corresponding to the physical quantity of interest. This is then multiplied by the complex conjugate of the Fourier transform of the state vector.

3. What is the significance of the expectation value of Fourier conjugates?

The expectation value of Fourier conjugates is significant because it provides a way to calculate the average value of a physical quantity in a quantum mechanical system. This value can be compared to experimental measurements to validate the predictions of quantum mechanics.

4. How does the uncertainty principle relate to the expectation value of Fourier conjugates?

The uncertainty principle states that the product of the uncertainties in two Fourier conjugate variables cannot be smaller than a certain value. This is related to the expectation value of Fourier conjugates because it provides a way to calculate these uncertainties and understand the limitations of measuring these variables simultaneously.

5. Can the expectation value of Fourier conjugates be negative?

Yes, the expectation value of Fourier conjugates can be negative. This can occur when the quantum state vector has a complex phase, which can lead to destructive interference and a negative expectation value. However, the physical interpretation of this negative value may depend on the specific system and physical quantity being measured.

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