Moyal Formulation of Witten's Star Product in the Fermionic Ghost Sector

TL;DR

This paper reformulates the fermionic ghost sector of Witten's open string field theory using noncommutative field theory, revealing new algebraic structures and addressing singularities in the Moyal formulation.

Contribution

It introduces a Moyal product approach to the fermionic ghost sector, connecting it to Clifford Algebras and exploring alternative operator representations.

Findings

Witten's star product corresponds to a continuous tensor product of Clifford Algebras in Siegel gauge.

The BRST operator is found to be singular in this formulation.

Alternative Moyal representations and regularization methods for singularities are discussed.

Abstract

In this paper, we recast the fermionic ghost sector of Witten's open bosonic string field theory in the language of noncommutative field theory. In particular, following the methods of hep-th/0202087, we find that in Siegel gauge Witten's star product roughly corresponds to a continuous tensor product of Clifford Algebras, and we formulate important operators of the theory in this language, notably the kinetic operator of vacuum string field theory and the BRST operator describing the vacuum of the unstable D-25 brane. We find that the BRST operator is singular in this formulation. We explore alternative operator/Moyal representations of the star product analogous to the split string description and the discrete Moyal basis developed extensively in recent work by Bars and Matsuo (hep-th/0204260). Finally, we discuss some interesting singularities in the formalism and how they may be regulated.