Renormalization schemes for SFT solutions
  In this paper, we examine the space of renormalization schemes compatible with the Kiermaier and Okawa [arXiv:0707.4472] framework for constructing Open String Field Theory solutions based on marginal operators with singular self-OPEs. We show that, due to freedom in defining the renormalization scheme which tames these singular OPEs, the solutions obtained from the KO framework are not necessarily unique. We identify a multidimensional space of SFT solutions corresponding to a single given marginal operator. 
Joanna L. Karczmarek and Matheson Longton
hep-th