What is the name of the theory Sheldon and Amy developed for the Nobel Prize?

The theory Sheldon and Amy developed for the Nobel Prize was super asymmetry.

In the final season of The Big Bang Theory, Sheldon Cooper and Amy Farrah Fowler propose super asymmetry, a theoretical idea suggesting that particles and their supersymmetric partners may display an asymmetrical relationship. Their work attracts major scientific attention and ultimately earns them the Nobel Prize in Physics.

The idea begins when Sheldon notices a potentially important pattern while preparing for his wedding to Amy. Instead of treating the discovery as a private triumph, the couple develops it into a research program, publishes their findings, and faces intense scrutiny from the scientific community. The storyline gives the series a long-running scientific arc that culminates in the finale.

Super asymmetry is fictional within the show's story, although it draws on real concepts such as supersymmetry and particle physics. It should not be confused with string theory, M-theory, or loop quantum gravity, which are separate theoretical frameworks.