Generalizing the Weil–Cartan equivalence to Lie groupoids and Lie n-groupoids
Determine whether the equivalence between the Weil and Cartan models of equivariant cohomology for a compact connected Lie group—implemented by the automorphism Φ = exp(ξ^α \widehat{\iota}_α) on T[1]g[1] × T[1]M that identifies the basic complex with (S(g^*) ⊗ Ω^•(M))^G and its Cartan differential—extends to the setting of Lie groupoids and Lie n-groupoids; specifically, develop appropriate Weil and Cartan models for equivariant cohomology in these higher contexts and construct an analogue of Φ that intertwines them.
References
As far as we know, the generalization of this result for Lie groupoids or Lie n-groups is still an open problem.
                — Lecture notes on the symplectic geometry of graded manifolds and higher Lie groupoids
                
                (2510.09448 - Cueca et al., 10 Oct 2025) in Section 3.5, T[1]g[1] and equivariant cohomology (after the Kalkman–Mathai–Quillen theorem)