Invariants for $\mathbb G_{(r)}$-modules

Eric M. Friedlander

Published 2025-05-12Version 1

Following earlier work of C. Bendel, J. Petvsova, P. Sobaje, A. Suslin, and the author, we further investigate refined invariants for finite dimensional representations $M$ of infinitesimal group schemes $\mathbb G$ over a field $k$ of characteristic $p>0$. In particular, we explore invariants of modules for Frobenius kernels $\mathbb G_{(r)}$ of linear algebraic groups $\mathbb G$ of exponential type. Such finite group schemes admit a refinement of support theory, including Jordan type functions and constructions of vector bundles for special classes of $\mathbb G_{(r)}$-modules. We reformulate earlier results for $\mathbb G_{(r)}$-modules in terms which are both more explicit and more accessible to computation, yet preserve the usual support theory for $\mathbb G_{(r)}$-modules.