What is a probability amplitude?

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    Amplitude Probability
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Discussion Overview

The discussion revolves around the concept of probability amplitude, particularly in the context of quantum mechanics. Participants explore its definition, mathematical formulation, and interpretation, with references to the wave equation and the Schrödinger equation.

Discussion Character

  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant seeks clarification on the concept of probability amplitude after reading existing literature.
  • Another participant states that probability amplitude is a solution to an equation, such as the wave equation, and its absolute value squared is interpreted as a probability.
  • A further elaboration suggests that the probability amplitude function is specifically a solution to the Schrödinger equation, providing different probability amplitudes for various eigenstates, such as position eigenstates.
  • This participant explains that each position is assigned a complex number as its probability amplitude, and the probability of finding a particle at that position is derived from the square of this amplitude, involving the complex conjugate.
  • There is mention of uncertainty regarding the underlying reasons for the mathematical procedures used to derive probabilities from probability amplitudes.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and clarity regarding the concept, but there is no explicit consensus on a singular interpretation or deeper meaning of probability amplitude.

Contextual Notes

The discussion includes assumptions about the mathematical framework of quantum mechanics and does not resolve the reasons behind the procedures for calculating probabilities from probability amplitudes.

Carnot
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Hi

What is a probability amplitude - I have read the article on wikipedia and I still don't get it.
Hope someone out there can explain it to me..

Thanks
 
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The probability amplitude is the solution of some equation, such as the wave equation. When it is squared (absolute value) it is interpreted as a probability. Don't try to look for a deeper meaning.
 
mathman said:
The probability amplitude is the solution of some equation, such as the wave equation. When it is squared (absolute value) it is interpreted as a probability. Don't try to look for a deeper meaning.
Would be a bit more accurate to say the probability amplitude function is a solution to the Schrödinger equation (the probability amplitude function is the system's "quantum state"), but this function gives a set of different probability amplitudes for different possible eigenstates of some observable quantity, like different position eigenstates. For each possible position (or set of positions for a collection of multiple particles), the function would assign a complex number (say, 2 + 3i) to that position(s) which would be the "probability amplitude" for that particular position(s). And if you make a position measurement, the square of the probability amplitude for any particular position eigenstate (really the complex conjugate of the probability amplitude, like [2 + 3i]*[2 - 3i]) gives the probability the particle (or collection of particles) will be found in that position(s). No one knows why you have to go through this arcane procedure of finding the time evolution of the probability amplitude and taking the complex conjugate at the moment of measurement to get the probabilities of different measurement results, it's just that this procedure seems to be the correct way to predict real-world probabilities.
 
That made it a bit clearer :-)

Thanks a lot both of you
 

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