Is there such an identity about SO(3)?

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Discussion Overview

The discussion revolves around the identity involving the generators of the Lie algebra of SO(3) and their relationship with elements of SO(3). Participants explore whether there is a universal formula applicable to all Lie groups and seek to validate the proposed identity.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant presents the identity T^i K_{ij} = K T^j K^{-1} and seeks to prove its validity, suggesting a universal formula for all Lie groups.
  • Another participant argues that the elements mentioned do not generate SO(3), stating that SO(3) is uncountable and cannot have a finite set of generators.
  • A further response reiterates the claim that the elements do not generate SO(3) and questions the nature of the K elements in the context of physicists' understanding of Lie groups and algebras.
  • One participant claims to have clarified their understanding and checked a special case, asserting the identity holds true but expresses uncertainty about proving it without brute-force calculations.

Areas of Agreement / Disagreement

Participants express disagreement regarding the nature of the generators of SO(3) and the validity of the proposed identity. The discussion remains unresolved with competing views on the topic.

Contextual Notes

There are limitations in the discussion regarding the definitions of the elements involved and the assumptions about the nature of generators in the context of Lie groups.

kakarukeys
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[tex]T^i K_{ij} = K T^j K^{-1}[/tex]
repeated indices imply summation.
[tex]T^i[/tex] are the generators (Lie algebra elements) of SO(3).
i.e.[tex]T^i_{jk} = - \epsilon_{ijk}[/tex]
[tex]T^i \in so(3)[/tex]
[tex]K \in SO(3)[/tex]

How to show it's true?
Is there a universal formula for all Lie group?
 
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Those elements do not generate SO(3). SO(3) is uncountable, it cannot have a finte set of generators.
 
matt grime said:
Those elements do not generate SO(3). SO(3) is uncountable, it cannot have a finte set of generators.

For physicists, generators of a Lie group are elements of the corresponding Lie algebra, or maybe such elements multiplied by i. I don't know what the K's are.
 
Yes. I have just clarified!
I also checked a special case, and it's true.
I don't know how to prove this identity besides brute-force calculation which gives no insight at all.
 

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