Cohomological field theories with non-tautological classes
arXiv:1802.08981
Abstract
A method of constructing Cohomological Field Theories (CohFTs) with unit using minimal classes on the moduli spaces of curves is developed. As a simple consequence, CohFTs with unit are found which take values outside of the tautological cohomology of the moduli spaces of curves. A study of minimal classes in low genus is presented in the Appendix by D. Petersen.
21 pages including a 5 page Appendix by D. Petersen, "Minimal cohomology classes on \bar{M}_{g,n} in low genus", final version