I Three Plus Anti-symmetric Particles

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Fermions exhibit anti-symmetry under exchange, which applies to any pair of particles within a group of three or more. The total wavefunction for indistinguishable fermions must change sign when any two particles are exchanged, ensuring that the overall wavefunction remains anti-symmetric. This principle holds regardless of whether the particles are described by individual wavefunctions or a collective one. Each pair of particles within the group contributes to the anti-symmetry, reinforcing the systematic nature of the wavefunction. Understanding this concept is crucial for grasping the behavior of fermions in quantum mechanics.
JohnH
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So I understand that fermions are anti-symmetric under exchange, but in the contexts I've seen this explained they were always talking about two particles, or at least two wavefunctions. I'm curious how this works when there are three or more particles. Is any two given pairs of those 3+ particles anti-symmetric under exchange or is it more systematic? Or is it that there's essentially one wavefunction for all the particles (quanta of energy) in one spin and another wavefunction for all the quanta of energy in the other spin such that it's just those two wavefunctions that are anti-symmetric under exchange?
 
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JohnH said:
So I understand that fermions are anti-symmetric under exchange, but in the contexts I've seen this explained they were always talking about two particles, or at least two wavefunctions. I'm curious how this works when there are three or more particles.
The wave function for three electrons is covered here:

https://galileo.phys.virginia.edu/classes/752.mf1i.spring03/IdenticalParticlesRevisited.htm

The total wavefunction must reverse sign under the exchange of any two particles.
JohnH said:
Is any two given pairs of those 3+ particles anti-symmetric under exchange or is it more systematic? Or is it that there's essentially one wavefunction for all the particles (quanta of energy) in one spin and another wavefunction for all the quanta of energy in the other spin such that it's just those two wavefunctions that are anti-symmetric under exchange?
I can't make any sense of this part of your question.
 
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PeroK said:
I can't make any sense of this part of your question.
Yeah, just trying to answer my own question last minute. Probably better off waiting for an answer. Anyway, thank you for it.
 
The wave functions of indistinguishable fermions must be antisymmetric under exchange of any pair of arguments, ##(\vec{x}_j,\sigma_j##, where ##\vec{x}_j## is the postition and ##\sigma_j## the spin-##z##-component (##\sigma_j\in \{-s,-s+1,\ldots,s-1,s \}##, where ##s## is a half-integer positive number, ##s \in \{1/2,3/2,\ldots \}##), i.e., if ##\psi(t,\vec{x}_1,\sigma_1;\vec{x}_2,\sigma_2;\ldots; \vec{x}_N,\sigma_N)## is an ##N##-particle fermionic wave function, then it's antisymmetric by exchanging any pair ##(\vec{x}_i,\sigma_i)## and ##(\vec{x}_j,\sigma_j)##.
 
For the quantum state ##|l,m\rangle= |2,0\rangle## the z-component of angular momentum is zero and ##|L^2|=6 \hbar^2##. According to uncertainty it is impossible to determine the values of ##L_x, L_y, L_z## simultaneously. However, we know that ##L_x## and ## L_y##, like ##L_z##, get the values ##(-2,-1,0,1,2) \hbar##. In other words, for the state ##|2,0\rangle## we have ##\vec{L}=(L_x, L_y,0)## with ##L_x## and ## L_y## one of the values ##(-2,-1,0,1,2) \hbar##. But none of these...

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