2025/05/29 by Murai, Satoshi, Rhoades, Brendon, Wilson, Andy
#Combinatorics (math.CO) #FOS: Mathematics #Representation Theory (math.RT)
paper · doi:10.48550/arxiv.2505.24027
The \em superspace ring of rank n is the algebra Ωn of differential forms on affine n-space. The algebra Ωn is bigraded with respect to polynomial and exterior degree and carries a natural action of the symmetric group \mathfrakSn. Modding out by \mathfrakSn-invariants with vanishing constant term yields the \em superspace coinvariant ring SRn. We prove that, as an ungraded \mathfrakSn-module, the space SRn is isomorphic to the sign-twisted permutation action of \mathfrakSn on ordered set partitions of \1,…,n\. We refine this result by calculating the bigraded \mathfrakSn-isomorphism type of SRn. This proves the Fields Conjectures of N. Bergeron, L. Colmenarejo, S.-X. Li, J. Machacek, R. Sulzgruber, and M. Zabrocki as well as a related conjecture of V. Reiner.