The equivariant A-twist and gauged linear sigma models on the two-sphere

摘要: We study two-dimensional $$ \mathcal{N}=\left(2,\;2\right) $$ supersymmetric gauged linear sigma models (GLSM) on the Ω-deformed sphere, S 2 , which is a one-parameter deformation of A-twisted sphere. provide an exact formula for correlation functions using localization. The contribution each instanton sector given in terms Jeffrey-Kirwan residue Coulomb branch. In limit vanishing Ω-deformation, localization greatly simplifies computation functions, and leads to new results non-abelian theories. discuss number examples comment ϵ Ω-deformation quantum cohomology relations. Finally, we present complementary Higgs branch scheme special case abelian gauge groups.