We use the first author's idea on "constructing virtual fundamental cycles without gluing ' to define the quantum correction term between the gauged linear sigma model and the nonlinear sigma model.
Cite
@article{arxiv.2110.15379,
title = {Counting pointlike instantons virtually without gluing},
author = {Gang Tian and Guangbo Xu},
journal= {arXiv preprint arXiv:2110.15379},
year = {2021}
}