Visualizing the Lie Bracket in ๐๐(2)
Jan 22, 2025
ยท
1 min read
An interactive 3D notebook for visualizing the Lie bracket structure of ๐๐(2) using a geometric cross-product analogy. Developed as a demonstration for Lecture 3 (Matrix Lie Algebras) in the Lie Groups with Applications course at Quantum Formalism.
Key Goals
- Compute the Lie bracket $[X, Y] = XY - YX$ for elements in ๐๐(2)
- Map each element of ๐๐(2) to a vector in $\mathbb{R}^3$ using the Pauli basis
- Visualize $X$, $Y$, and $[X, Y]$ as 3D vectors on the unit sphere
- Demonstrate that the Lie bracket corresponds to the cross product in this representation
Tools & Concepts
- Basis derived from scaled Pauli matrices: $i\sigma_x/2, i\sigma_y/2, i\sigma_z/2$
- Lie algebra computations with NumPy
- 3D visualization via
matplotlib
andmplot3d
- Interactive control with
ipywidgets
This notebook illustrates deep algebraic structure through concrete geometric visuals โ an ideal companion to coursework on Lie algebras, cross products, and matrix groups.
Note: Repository will be made public soon.