Construction of action for heterotic string field theory including the Ramond sector

Understand

Extending the formulation for open superstring field theory given in arXiv:1508.00366, we attempt to construct a complete action for heterotic string field theory.

• The action is non-polynomial in the Ramond string field Psi, and we construct it order by order in Psi.
• Using a dual formulation in which the role of eta and Q is exchanged, the action is explicitly obtained at the quadratic and quartic order in Psi with the gauge transformations.