(0,2) Elephants

Understand

We enumerate massless E6 singlets for (0,2)-compactifications of the heterotic string on a Calabi-Yau threefold with the "standard embedding" in three distinct ways.

• In the large radius limit of the threefold, these singlets count deformations of the Calabi-Yau together with its tangent bundle.
• In the "small-radius" limit we apply Landau-Ginzburg methods.
• In the orbifold limit we use a combination of geometry and free field methods.