【第4章】Frobenius群 \(F_{20}\)
【4-10】 \(F_{20}\) の既約表現のまとめ
Frobenius群 \(F_{20}\) の正則表現を、前節で求めた \(T\) によって既約表現に 分解したときの、最終的な分割された表現に(10.1)の様に \( \rho_{i,j} \) と名前を付けます。\begin{align} & \widetilde{L_i}=T^{-1} \times L_i \times T= \begin{pmatrix} \boxed{\rho_1}&0&0&0&0&0&0&0\\ 0 & \boxed{\rho_2 }& 0 & 0 & 0 &0&0&0 \\ 0 &0& \boxed{\rho_3 }& 0 & 0 & 0 &0&0 \\ 0 &0&0& \boxed{\rho_4 }& 0 & 0 & 0 &0 \\ 0&0&0&0& \boxed{ \begin{matrix} & & \\ & \rho_{5,1} & \\ & 4 \times 4 & \end{matrix}} & 0 & 0 &0\\ 0&0&0&0&0& \boxed{ \begin{matrix} & & \\ & \rho_{5,2} & \\ & 4 \times 4 & \end{matrix}} & 0 & 0\\ 0&0&0&0&0&0&\boxed{ \begin{matrix} & & \\ & \rho_{5,3} & \\ & 4 \times 4 & \end{matrix}} & 0\\ 0&0&0&0&0&0&0& \boxed{ \begin{matrix} & & \\ & \rho_{5,4} & \\ & 4 \times 4 & \end{matrix}}\\ \end{pmatrix} \\ \end{align}
冗長になるかもしれませんが、既約表現に分解された(20x20)の大きな行列 \(\widetilde{L_i}\) 全てを記述することは 出来ません。しかし、既約表現から8種類の小ブロックを抽出した行列ならば、全てを表示できます。そこで、(10.1)の表示 \(\rho_{i,j}\) と 対応付けて整理したのが下記の表となります。何かの参考になれば幸いです。
| \(F_{20}\) の元 | \(\sigma_{1}\) | \(\sigma_{2}\) | \(\sigma_{3}\) | \(\sigma_{4}\) | \(\sigma_{5}\) |
|---|---|---|---|---|---|
| 巡回置換 | \(e\) | \((12345)\) | \((13524)\) | \((14253)\) | \((15432)\) |
| \(\rho_{1}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{2}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{3}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{4}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{5,1}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,2}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,3}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,4}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 1 & 0\\0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\-1 & -1 & -1 & -1\\1 & 0 & 0 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) |
| \(F_{20}\) の元 | \(\sigma_{6}\) | \(\sigma_{7}\) | \(\sigma_{8}\) | \(\sigma_{9}\) | \(\sigma_{10}\) |
|---|---|---|---|---|---|
| 巡回置換 | \((2354)\) | \((1243)\) | \((1325)\) | \((1452)\) | \((1534)\) |
| \(\rho_{1}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{2}\) | \(i\) | \(i\) | \(i\) | \(i\) | \(i\) |
| \(\rho_{3}\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) |
| \(\rho_{4}\) | \(-i\) | \(-i\) | \(-i\) | \(-i\) | \(-i\) |
| \(\rho_{5,1}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\end{bmatrix}\) |
| \(\rho_{5,2}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,3}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,4}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 1 & 0\\1 & 0 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 0 & 1\\0 & 1 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) |
| \(F_{20}\) の元 | \(\sigma_{11}\) | \(\sigma_{12}\) | \(\sigma_{13}\) | \(\sigma_{14}\) | \(\sigma_{15}\) |
|---|---|---|---|---|---|
| 巡回置換 | \((25)(34)\) | \((14)(23)\) | \((12)(35)\) | \((15)(24)\) | \((13)(45)\) |
| \(\rho_{1}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{2}\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) |
| \(\rho_{3}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{4}\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) |
| \(\rho_{5,1}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) |
| \(\rho_{5,2}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,3}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,4}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\-1 & -1 & -1 & -1\\0 & 0 & 0 & 1\\0 & 0 & 1 & 0\end{bmatrix}\) |
| \(F_{20}\) の元 | \(\sigma_{16}\) | \(\sigma_{17}\) | \(\sigma_{18}\) | \(\sigma_{19}\) | \(\sigma_{20}\) |
|---|---|---|---|---|---|
| 巡回置換 | \((2453)\) | \((1342)\) | \((1523)\) | \((1254)\) | \((1435)\) |
| \(\rho_{1}\) | \(1\) | \(1\) | \(1\) | \(1\) | \(1\) |
| \(\rho_{2}\) | \(-i\) | \(-i\) | \(-i\) | \(-i\) | \(-i\) |
| \(\rho_{3}\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) | \(-1\) |
| \(\rho_{4}\) | \(i\) | \(i\) | \(i\) | \(i\) | \(i\) |
| \(\rho_{5,1}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\end{bmatrix}\) |
| \(\rho_{5,2}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) |
| \(\rho_{5,3}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) |
| \(\rho_{5,4}\) | \(\begin{bmatrix}0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\end{bmatrix}\) | \(\begin{bmatrix}0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\\0 & 0 & 1 & 0\end{bmatrix}\) | \(\begin{bmatrix}-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\\1 & 0 & 0 & 0\end{bmatrix}\) | \(\begin{bmatrix}0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\\0 & 0 & 0 & 1\end{bmatrix}\) | \(\begin{bmatrix}1 & 0 & 0 & 0\\0 & 0 & 1 & 0\\-1 & -1 & -1 & -1\\0 & 1 & 0 & 0\end{bmatrix}\) |