Generalize Eberhardt’s K-theory proof (Proposition 3.2) to the motives DM setting

Determine whether the proof of Proposition 3.2 in Jens Niklas Eberhardt’s “K-motives, Springer Theory and the Local Langlands Correspondence” (arXiv:2401.13052), which relies on explicit computations in K-theory, can be generalized to the triangulated category of motives DM, and, if so, construct an explicit DM-based proof or method establishing the corresponding result within the motivic framework.

Background

The paper proves an integral version of the motivic Springer correspondence using reduced motives and develops a formalism extending previous rational-coefficient results. In discussing related work, the author notes that Eberhardt claimed a stronger version via K-motives, relying on explicit K-theoretic computations.

The author’s approach replaces these K-theoretic inputs by two corollaries proved in the present paper to obtain the desired equivalence. However, the direct generalization of Eberhardt’s K-theory-based proof to the DM setting is explicitly stated as unclear, leaving open whether a DM-intrinsic proof analogous to Eberhardt’s exists.

References

Corollary \ref{prop:class_reduction} and Corollary \ref{cor:orth_linear_gp} are, together, analogues of Proposition 3.2 and at the time of writing it is not clear to the author how the proof of Proposition 3.2 in loc. cit., which uses explicit computations for K-theory, generalizes to DM.

An Integral Springer Correspondence  (2509.18280 - Landim, 22 Sep 2025) in Remark, Section 3.1 (The Springer setup)