Topology, Geometry and Quantum Field Theory

Part I. Contributions: 1. A variant of K-theory Michael Atiyah and Michael Hopkins; 2. Two-vector bundles and forms of elliptic cohomology Nils Baas, Bjorn Dundas and John Rognes; 3. Geometric realisation of the Segal-Sugawara construction David Ben-Zvi and Edward Frenkel; 4. Differential isomorphism and equivalence of algebraic varieties Yuri Berest and George Wilson; 5. A polarized view of string topology Ralph Cohen and Veronique Godin; 6. Random matrices and Calabi-Yau geometry Robbert Dijkgraaf; 7. A survey of the topological properties of symplectomorphism groups Dusa McDuff; 8. K-theory from a physical perspective Gregory Moore; 9. Heisenberg groups and algebraic topology Jack Morava; 10. What is an elliptic object? Stephan Stolz and Peter Teichner; 11. Open and closed string field theory interpreted in classical algebraic topology Dennis Sullivan; 12. K-theory of the moduli of principal bundles on a surface and deformations of the Verlinde algebra Constantin Teleman; 13. Cohomology of the stable mapping class group Michael S. Weiss; 14. Conformal field theory in four and six dimensions Edward Witten; Part II. The Definition of Conformal Field Theory by Graeme Segal: 15. Definition of a conformal field theory Graeme Segal.