We give two proofs of a conjecture of Hori and Vafa which expresses the J-function—a generating function for 1-point descendant Gromov-Witten invariants—of a Grassmannian in terms of the J-function of a product of projective spaces. Similar relations are obtained for 2-point descendants and 3-point primary Gromov-Witten invariants. As an application, we prove Givental's R-conjecture, and hence the Virasoro conjecture, for Grassmannians.
"Two proofs of a conjecture of Hori and Vafa." Duke Math. J. 126 (1) 101 - 136, 15 January 2005. https://doi.org/10.1215/S0012-7094-04-12613-2