- #1
Ted123
- 446
- 0
• [itex]\mathfrak{g}[/itex] is the Lie algebra with basis vectors [itex]E,F,G[/itex] such that the following relations for Lie brackets are satisfied:
[itex][E,F]=G,\;\;[E,G]=0,\;\;[F,G]=0.[/itex]
• [itex]\mathfrak{h}[/itex] is the Lie algebra consisting of 3x3 matrices of the form
[itex]\begin{bmatrix} 0 & a & c \\ 0 & 0 & b \\ 0 & 0 & 0 \end{bmatrix}[/itex] where [itex]a,b,c[/itex] are any complex numbers. The vector addition and scalar multiplication on [itex]\mathfrak{h}[/itex] are the usual operations on matrices.
The Lie bracket on [itex]\mathfrak{h}[/itex] is defined as the matrix commutator: [itex][X,Y] = XY - YX[/itex] for any [itex]X,Y \in \mathfrak{h}.[/itex]
If we wanted to show [itex]\mathfrak{g} \cong \mathfrak{h}[/itex] then is it necessary to show that a basis for [itex]\mathfrak{h}[/itex]:
[itex]\left\{ E=\begin{bmatrix} 0 & 1 & 0 \\ 0 & 0 & 0 \\ 0 & 0 & 0 \end{bmatrix} , F=\begin{bmatrix} 0 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 0 & 0 \end{bmatrix} , G=\begin{bmatrix} 0 & 0 & 1 \\ 0 & 0 & 0 \\ 0 & 0 & 0 \end{bmatrix} \right\}[/itex]
satisfies [itex][E,F]=G,\;[E,G]=0,\;[F,G]=0[/itex] (i.e. the lie bracket relations in [itex]\mathfrak{g}[/itex]) or is it enough to find a map [itex]\varphi : \mathfrak{g} \to\mathfrak{h}[/itex] and show it is a homomorphism, linear and bijective? (which I have)
[itex][E,F]=G,\;\;[E,G]=0,\;\;[F,G]=0.[/itex]
• [itex]\mathfrak{h}[/itex] is the Lie algebra consisting of 3x3 matrices of the form
[itex]\begin{bmatrix} 0 & a & c \\ 0 & 0 & b \\ 0 & 0 & 0 \end{bmatrix}[/itex] where [itex]a,b,c[/itex] are any complex numbers. The vector addition and scalar multiplication on [itex]\mathfrak{h}[/itex] are the usual operations on matrices.
The Lie bracket on [itex]\mathfrak{h}[/itex] is defined as the matrix commutator: [itex][X,Y] = XY - YX[/itex] for any [itex]X,Y \in \mathfrak{h}.[/itex]
If we wanted to show [itex]\mathfrak{g} \cong \mathfrak{h}[/itex] then is it necessary to show that a basis for [itex]\mathfrak{h}[/itex]:
[itex]\left\{ E=\begin{bmatrix} 0 & 1 & 0 \\ 0 & 0 & 0 \\ 0 & 0 & 0 \end{bmatrix} , F=\begin{bmatrix} 0 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 0 & 0 \end{bmatrix} , G=\begin{bmatrix} 0 & 0 & 1 \\ 0 & 0 & 0 \\ 0 & 0 & 0 \end{bmatrix} \right\}[/itex]
satisfies [itex][E,F]=G,\;[E,G]=0,\;[F,G]=0[/itex] (i.e. the lie bracket relations in [itex]\mathfrak{g}[/itex]) or is it enough to find a map [itex]\varphi : \mathfrak{g} \to\mathfrak{h}[/itex] and show it is a homomorphism, linear and bijective? (which I have)