English

Mapping between Witten and Lightcone String Field Theories

High Energy Physics - Theory 2021-12-14 v2

Abstract

We propose a transformation between the off-shell field variables of Witten's open bosonic string field theory and the traditional lightcone string field theory of Kaku and Kikkawa, based on Mandelstam's interacting string picture. This is accomplished by deforming the Witten vertex into lightcone cubic and quartic vertices, followed by integrating out the ghost and lightcone oscillator excitations from the string field. Surprisingly, the last step does not alter the cubic and quartic interactions and does not generate effective vertices, and leads precisely to Kaku and Kikkawa's lightcone string field theory.

Keywords

Cite

@article{arxiv.2012.09521,
  title  = {Mapping between Witten and Lightcone String Field Theories},
  author = {Theodore Erler and Hiroaki Matsunaga},
  journal= {arXiv preprint arXiv:2012.09521},
  year   = {2021}
}

Comments

74 pages, 23 figures. Added appendix on the lightcone SFT action. Simplified discussion of the field transformation and the singular nature of lightcone gauge in generic SFTs, which has been called the "soft string problem."

R2 v1 2026-06-23T21:02:40.780Z