Operads and moduli spaces of genus 00 Riemann surfaces

We study a pair of dual operads which arise in the study of moduli spaces of pointed genus 0 curves (this duality is similar to that between commutative and Lie algebras). These operads are both quadratic, and even Koszul, and arise in the theory of quantum cohomology.Comment: 26 pages, latex2e with amslatex 1.2beta (available from e-math.ams.com by anonymous ftp), no figure