3 papers
hep-th2026
Closed String Field Theory in 25.99 Dimensions
Amr Ahmadain, Alexander Frenkel, Xi Yin
We return to and refine Zwiebach's formulation of closed string field theory (CSFT) built around non-critical backgrounds [1,2], restricting our attention to genus zero. The struct…
hep-th2025
A Background-Independent Closed String Action at Tree Level
Amr Ahmadain, Alexander Frenkel, Aron C. Wall
We propose an off-shell bosonic string action that removes the renormalization window constraint of [1]. To all orders in conformal perturbation theory, this action allows for defo…
hep-th2025
Non-linear sigma model in string field theory
Alexander Frenkel, Manki Kim
We revisit the non-linear sigma model approach to string theory with the closed superstring field theory. We construct the string field theory around the non-linear sigma model bac…