Some remarks on topological 4d-gravity

TL;DR

This paper reinterprets Wu's method for topological 4d-gravity within a standard equivariant cohomology framework and uses it to generate observables for the theory.

Contribution

It provides a new understanding of Wu's approach by framing it in equivariant cohomology and applies this to derive observables in topological 4d-gravity.

Findings

Wu's method is compatible with equivariant cohomology

New observables for topological 4d-gravity are constructed

Framework unifies different approaches to topological gravity

Abstract

We show that the method of S. Wu to study topological 4d-gravity can be understood within a now standard method designed to produce equivariant cohomology classes. Next, this general framework is applied to produce some observables of the topological 4d-gravity.