Constrained BV Description of String Field Theory

Understand

In the conventional BV description of string field theory, the string field Phi is split as Phi = Psi+Psi* where Psi includes all states with ghost number less than or equal to G and describes the spacetime fields, and Psi* includes all states with ghost number >G and describes the spacetime antifields.

• A new approach is proposed here in which separate string fields Psi and Psi* of unrestricted ghost number describe the spacetime fields and antifields.
• The string antifield Psi* is constrained to satisfy Psi* = {\partial L}/{\partial(Q Psi)} where L is the BV Lagrangian and Q is the worldsheet BRST operator.
• Dirac antibrackets are defined using this constraint, and the resulting description is equivalent to the conventional BV description for open and closed bosonic string field theory.