2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140752In the approach to Gromov-Witten theory developed by Givental, genus-zero Gromov-Witten invariants of a manifold X are encoded by a Lagrangian cone in a certain infinite-dimensional symplectic vector space. We give a construction of this cone, in the spirit of S^1-equivariant Floer theory, in terms of S^1-equivariant Gromov-Witten theory of the product X \times P^1. This gives a conceptual understanding of the "dilaton shift": a change-of-variables which plays an essential role in Givental's theory.17 pages, LaTeX, uses Paul Taylor's diagrams package diagrams.sty Version 2: exposition streamlined, references added. Final version; to appear in Mathematical Research LettersAlgebraic GeometryMathematical PhysicsSymplectic Geometry14N35 (Primary); 53D45, 57R58 (Secondary)text