Lie Groups and Lie Algebras: Winter-2023
Practice Exercises 8 : Due Friday 3/10

  1. Octonionic rotations S0 4617S
    1. Choose two elements \(x,y\in\mathbb{O}\) such that \(xy\ne yx\) and \(x,y\not\in\mathbb{H}\subset\mathbb{O}\).
      (The notation is such that \(\mathbb{H}=\langle 1,i,j,k \rangle\) and \(\mathbb{O}=\mathbb{H}\oplus\mathbb{H}\ell\).)
      1. Compute the following quantities: \begin{align*} a &= \bar{\imath}\bigl(\bar{\jmath}(\bar{k}x)\bigr) \\ b &= \bigl((xk)j\bigr)i \\ c &= \bar\imath\bigl(\bar\jmath(\bar{k}xk)j\bigr)i \\ p &= \bar{\imath}\bigl(\bar{\jmath}(\bar{k}y)\bigr) \\ q &= \bigl((yk)j\bigr)i \\ r &= \bar\imath\bigl(\bar\jmath(\bar{k}yk)j\bigr)i \end{align*} What do you notice about your results?
      2. Compute the following quantities: \begin{align*} s &= xy \\ t &= \bigl((sk)j\bigr)i \\ u &= ap \end{align*} What do you notice about your results?