The Born Rule: Difference between revisions

From Physics Book
Jump to navigation Jump to search
No edit summary
No edit summary
Line 3: Line 3:
The Born Rule is an important result of quantum mechanics that describes the probability density of a measured quantum system. In particular, it states that the square of the wavefunction is proportional to the probability density function. This result is a continuous form of the norm squared of the inner product being the probability that a known state takes the value of another. <br>
The Born Rule is an important result of quantum mechanics that describes the probability density of a measured quantum system. In particular, it states that the square of the wavefunction is proportional to the probability density function. This result is a continuous form of the norm squared of the inner product being the probability that a known state takes the value of another. <br>
Discrete Probability<math> P_{\psi}(A = a) = |\bra{\phi_{a}}\ket{\psi}|^2 </math> <br>
Discrete Probability<math> P_{\psi}(A = a) = |\bra{\phi_{a}}\ket{\psi}|^2 </math> <br>
Continuous Probability Density Function <math> P = \left | \Psi(x,t)^2 \right |</math>
Continuous Probability Density Function <math> P = \left | \Psi(x,t) \right |^2 </math>


==Normalizing the Wavefunction==
==Normalizing the Wavefunction==
As the physical meaning of complex numbers is nonsense, we must normalize the wavefunction to conduct a meaningful analysis of quantum systems. At the position <math>x</math> and time <math>t</math>, <math> \left | \Psi(x,t)^2 \right |</math> is the probability density (the physical importance is found in the square of <math>\Psi</math>). By definition, an entire probability density function must have an area equal to one. Hence it follows that <br>
As the physical meaning of complex numbers is nonsense, we must normalize the wavefunction to conduct a meaningful analysis of quantum systems. At the position <math>x</math> and time <math>t</math>, <math> \left | \Psi(x,t) \right |^2 </math> is the probability density (the physical importance is found in the square of <math>\Psi</math>). By definition, an entire probability density function must have an area equal to one. Hence it follows that <br>
<math>\int_{-\infty}^{\infty}{ \left | \Psi(x,t)^2 \right |dx}=1 </math>,
<math>\int_{-\infty}^{\infty}{ \left | \Psi(x,t) \right |^2 dx}=1 </math>,
<br>as a given particle in question must be located somewhere between <math> -\infty < x <\infty  </math> <br>
<br>as a given particle in question must be located somewhere between <math> -\infty < x <\infty  </math> <br>
Or more formally:
Or more formally:
<math>P_{x\in[-\infty,\infty]}=1 </math>
<math>P_{x\in[-\infty,\infty]}=1 </math>

Revision as of 21:00, 27 November 2022

Claimed - Rehaan Naik 11/27/2022

The Born Rule is an important result of quantum mechanics that describes the probability density of a measured quantum system. In particular, it states that the square of the wavefunction is proportional to the probability density function. This result is a continuous form of the norm squared of the inner product being the probability that a known state takes the value of another.
Discrete Probability[math]\displaystyle{ P_{\psi}(A = a) = |\bra{\phi_{a}}\ket{\psi}|^2 }[/math]
Continuous Probability Density Function [math]\displaystyle{ P = \left | \Psi(x,t) \right |^2 }[/math]

Normalizing the Wavefunction

As the physical meaning of complex numbers is nonsense, we must normalize the wavefunction to conduct a meaningful analysis of quantum systems. At the position [math]\displaystyle{ x }[/math] and time [math]\displaystyle{ t }[/math], [math]\displaystyle{ \left | \Psi(x,t) \right |^2 }[/math] is the probability density (the physical importance is found in the square of [math]\displaystyle{ \Psi }[/math]). By definition, an entire probability density function must have an area equal to one. Hence it follows that
[math]\displaystyle{ \int_{-\infty}^{\infty}{ \left | \Psi(x,t) \right |^2 dx}=1 }[/math],
as a given particle in question must be located somewhere between [math]\displaystyle{ -\infty \lt x \lt \infty }[/math]
Or more formally: [math]\displaystyle{ P_{x\in[-\infty,\infty]}=1 }[/math]