Visualizing Representations of ๐”ฐ๐”ฉ(2,โ„‚)

Feb 22, 2025 ยท 1 min read

An interactive notebook that illustrates representations of the Lie algebra sl(2,C)\mathfrak{sl}(2, \mathbb{C}) by implementing the action of its generators on homogeneous polynomials. Designed for Lecture 4 (Representation Theory) of the Lie Groups with Applications course at Quantum Formalism.

Goal

To explore the action of the sl(2,C)\mathfrak{sl}(2, \mathbb{C}) generators โ€” the weight operator HH, raising operator EE, and lowering operator FF โ€” on the space of homogeneous polynomials VmV_m in two variables (z1,z2)(z_1, z_2), and to visualize the ladder structure of irreducible representations.

Key Activities

  • Defined the representation space VmV_m, consisting of degree-mm homogeneous polynomials in two variables
  • Implemented H,EH, E, and F F as differential operators acting on symbolic expressions in sympy
  • Built an interactive interface for applying these operators to a given polynomial using ipywidgets
  • Demonstrated weight shifts and the full ladder structure for each irreducible VmV_m

Technologies & Concepts

  • Python, SymPy (symbolic differentiation & polynomial manipulation)
  • ipywidgets for interactivity
  • Representation theory of sl(2,C)\mathfrak{sl}(2, \mathbb{C})
  • Differential operators on polynomial spaces

Note: This project is currently in development โ€” the code repository will be made public soon.