Two-dimensional gravity and intersection theory on moduli space.(English)Zbl 0757.53049

Proc. Conf., Cambridge/MA (USA) 1990, Surv. Differ. Geom., Suppl. J. Diff. Geom. 1, 243-310 (1991).
Summary: [For the entire collection see Zbl 0743.00053.]
These are notes based on two lectures given at the Conference on Geometry and Topology (Harvard University, April 1990). The first was mainly devoted to explaining a conjecture according to which stable intersection theory on moduli space of Riemann surfaces is governed by the KdV hierarchy of integrable equations. The second lecture was primarily an introduction to the “hermitian matrix model” of two-dimensional gravity, which is a crucial part of the background for the conjecture. Analogous but more general theories also exist and are sketched in these notes. The generalization in the first lecture involves considering intersection theory on the moduli space of pairs consisting of a Riemann surface $$\Sigma$$ and a holomorphic map of $$\Sigma$$ to a fixed Kähler manifold $$K$$. The simplest analogous generalization in the second lecture involves a chain of hermitian matrices.

MSC:

 32G15 Moduli of Riemann surfaces, Teichmüller theory (complex-analytic aspects in several variables) 81T40 Two-dimensional field theories, conformal field theories, etc. in quantum mechanics 14C17 Intersection theory, characteristic classes, intersection multiplicities in algebraic geometry 14H15 Families, moduli of curves (analytic) 32G81 Applications of deformations of analytic structures to the sciences 37J35 Completely integrable finite-dimensional Hamiltonian systems, integration methods, integrability tests 37K10 Completely integrable infinite-dimensional Hamiltonian and Lagrangian systems, integration methods, integrability tests, integrable hierarchies (KdV, KP, Toda, etc.) 81T30 String and superstring theories; other extended objects (e.g., branes) in quantum field theory 53C80 Applications of global differential geometry to the sciences

Zbl 0743.00053