Conserved quantity due to invariance under temporal rotations

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Discussion Overview

The discussion revolves around the implications of invariance under temporal rotations in the context of the so(3,3) Lie algebra and its relation to conserved quantities as described by Noether's Theorem. Participants explore the potential similarities between conserved quantities arising from temporal and spatial rotations, particularly focusing on the units of energy multiplied by time and their relation to angular momentum.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that the integrand derived from invariance under temporal rotations resembles that of spatial rotations, suggesting both lead to conserved quantities with units of Planck's constant.
  • Another participant questions the implications of this observation, asking why it might be an issue.
  • A further contribution proposes that if the initial claim is correct, it could indicate the existence of a second type of "spinor" representation involving temporal rotation generators, potentially offering new insights into the mathematical description of spin 1/2 particles.

Areas of Agreement / Disagreement

The discussion features multiple competing views regarding the implications of the findings, and no consensus is reached on the correctness or significance of the claims made.

Contextual Notes

Participants express uncertainty about the validity of their calculations and the implications of their observations, indicating a reliance on informal reasoning rather than rigorous proofs or established literature.

Who May Find This Useful

This discussion may be of interest to those studying advanced topics in theoretical physics, particularly in the areas of Lie algebras, Noether's Theorem, and representations related to quantum mechanics.

Marty4691
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Hi,

I was looking at the so(3,3) Lie algebra which has 3 temporal rotation generators as well as the normal 3 spatial rotation generators. When I try to use Noether's Theorem to determine what the conserved quantity is, due to invariance under temporal rotations, I seem to get an integral where the integrand is of the form

[(energy)*(time) - (energy)*(time)]

The equivalent integrand corresponding to spatial rotations is

[(momentum)*(distance) - (momentum)*(distance)]

which is normal because the conserved quantity turns out to be angular momentum. But (energy)*(time) has the same units as angular momentum which seems to imply that invariance under temporal rotations and invariance under spatial rotations both lead to conserved quantities with the units of Planck's constant. I'm not sure if this can be right.

My calculations are on the back of an envelope so I was hoping that someone might know if this is correct or if there is a paper that deals more rigorously with this question.

Thanks.
 
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Marty4691 said:
But (energy)*(time) has the same units as angular momentum which seems to imply that invariance under temporal rotations and invariance under spatial rotations both lead to conserved quantities with the units of Planck's constant. I'm not sure if this can be right.
Why would this be an issue?
 
In the context of so(3,3), if the above is correct then there might be a second type of "spinor" representation. The normal spinor representation has the form

{(J+iK), (J+iK), (J+iK)}

where the Js are spatial rotation generators and the Ks are boost generators. The second type of representation would have the form

{(T+iK), (T+iK), (T+iK)}

where the Ts are temporal rotation generators.

It might open the door to an additional mathematical description for a spin 1/2 particle.
 

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