Phase factor in quantum mechanics

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SUMMARY

The discussion focuses on the properties of complex numbers, specifically the form ##e^{i\theta}##, which has an absolute value (modulus) of 1. Participants explain that the norm of a complex number can be derived using the complex conjugate, ##z^*=\bar{z}##, and that for any complex number expressed as ##re^{i\theta}##, the modulus ##r## equals 1 when ##r## is omitted. This property holds true for all real values of ##\theta##, confirming the fundamental nature of complex numbers in quantum mechanics.

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  • Understanding of complex numbers and their representations
  • Familiarity with complex conjugates and their properties
  • Basic knowledge of the polar form of complex numbers
  • Concept of modulus in complex analysis
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Shreya
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Homework Statement
I watched a lecture in which the professor called the circle expression as a pure phase and took its absolute value to be 1. I don't understand how it's absolute value is 1.
Please refer the image for the circled expression.
Relevant Equations
Wave function at x,t
Please be kind to help.I would be grateful
IMG_20211112_125534~2.jpg
 
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Any complex number of the form ##e^{i\theta}## has absolute value (modulus) ##1##.
 
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Can you please explain why is it so?
 
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Shreya said:
Can you please explain why is it so?
The norm of a complex number can be calculated using the number ##z## and ##z^*=\bar{z}## the complex conjugate.
So, given ##z=e^{i\theta}, \quad \theta \in \mathbb{R}##, you should be able to compute ##z^*## and its norm.
You will see that the norm is 1 independent on ##\theta##.
 
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Shreya said:
Can you please explain why is it so?
Any complex number can be written ##re^{i\theta}##, where ##r## is the modulus and ##\theta## is the angle in the complex plane. That's fairly elementary, I'm sorry to say!
 
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Thanks a lot 🙏 Pero K and Gaussian97! It helped a lot. 🙂
 

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