Adjoint representation vs the adjoint of a matrix

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SUMMARY

The discussion centers on the distinction between the adjoint representation of a Lie group and the adjoint of a matrix. The adjoint representation, denoted as ##Ad: G \to GL(\mathfrak{g})##, is defined via the conjugation map ##C_g(h) = ghg^{-1}##, specifically as the pushforward ##C_{g*}|_{g=e}: \mathfrak{g} \to \mathfrak{g}##. In contrast, the adjoint of a matrix involves transposing and taking the complex conjugate, which does not relate to the adjoint representation in the context of groups. The speaker concludes that these concepts are fundamentally different, particularly when considering finite-dimensional vector spaces.

PREREQUISITES
  • Understanding of Lie groups and Lie algebras
  • Familiarity with the concept of conjugation in group theory
  • Knowledge of matrix operations, specifically transposition and complex conjugation
  • Basic understanding of linear transformations and the general linear group, GL(V)
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  • Study the properties of the adjoint representation in detail
  • Explore the relationship between Lie groups and their corresponding Lie algebras
  • Learn about the implications of the adjoint operation in linear algebra
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Mathematicians, physicists, and students studying abstract algebra, particularly those interested in the structure and representation of Lie groups and algebras.

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In my limited study of abstract Lie groups, I have come across the adjoint representation ##Ad: G \to GL(\mathfrak{g})## on the lie algebra ##\matfrak{g}##. It is defined through the conjugation map ##C_g(h) = ghg^{-1}## as the pushforward ##C_{g*}|_{g=e}: \mathfrak{g} \to \mathfrak{g}##.

Does this bear any relation to that one would call the adjoint of a matrix? I.e. the operation where one transposes and takes the complex conjugate?
 
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I a not sure, but I would think the answer is no, at least not in the case of groups since when A a V (finite-dim. since we are using matrices)in the target space , i.e., A is in GL(V) , then A^T is a map in End(V*) , not in GL(V).
 
I am studying the mathematical formalism behind non-commutative geometry approach to quantum gravity. I was reading about Hopf algebras and their Drinfeld twist with a specific example of the Moyal-Weyl twist defined as F=exp(-iλ/2θ^(μν)∂_μ⊗∂_ν) where λ is a constant parametar and θ antisymmetric constant tensor. {∂_μ} is the basis of the tangent vector space over the underlying spacetime Now, from my understanding the enveloping algebra which appears in the definition of the Hopf algebra...

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