Multiplicity free covering of a graded manifold
Elizaveta Vishnyakova
TL;DR
The work constructs a multiplicity-free covering of graded manifolds corresponding to the homomorphism $\chi: \mathbb{Z}^n \to \mathbb{Z}$ and proves a universal lifting property with deck group $S_n$, linking graded geometry to symmetric $n$-fold vector bundles. It introduces multiplicity-free manifolds of type $\Delta$, establishes their equivalence with $n$-fold vector bundles, and shows that no such covering exists in the $n$-fold vector bundle category, thereby motivating the symmetric multiplicity-free framework. The authors prove an equivalence of categories between graded manifolds of type $L=\Delta/S_n$ and symmetric multiplicity-free manifolds of type $\Delta$ via the Cov functor, and they advance a Chevalley–Shephard–Todd–style description of $S_n$-invariants in this setting. The results provide a conceptual bridge between graded geometry and symmetric MF structures, with potential implications for loop-space viewpoints and categorical formulations in super- and graded-geometry.
Abstract
We define and study a multiplicity-free covering of a graded manifold. We compute its deck transformation group, which is isomorphic to the permutation group $S_n$. We show that it is not possible to construct a covering of a graded manifold in the category of $n$-fold vector bundles. As an application of our research, we give a new conceptual proof of the equivalence of the categories of graded manifolds and symmetric $n$-fold vector bundles.
