2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/77005Eguchi-Hori-Xiong and S. Katz proposed a conjecture that the partition function of topological sigma model coupled to gravity is annihilated by infinitely many differential operators which form half branch of the Virasoro algebra. In this paper, we give a proof to this conjecture for the genus 0 part.LaTex, 38 pages. Corrected some typos and minor mistakes in the first version of this paper posted on June 7, 1998Algebraic GeometryHigh Energy Physics - TheoryMathematical PhysicsDifferential Geometrytext