Generic internal Hom over general complete Noetherian coefficient rings

Prove that, for a finitely presented morphism of quasi-compact quasi-separated schemes and constructible complexes with coefficients in an arbitrary complete Noetherian I-adic coefficient ring whose residue characteristic is invertible on the base, the internal mapping object exists and its formation commutes with arbitrary base change.

Background

The paper establishes generic base-change and generic universal-local-acyclicity results for complete Noetherian I-adic coefficient rings, but does not establish the corresponding general statement for constructible internal mapping objects. Specifically, the desired conclusions are the existence of an internal mapping object for two constructible complexes and compatibility of that object with arbitrary base change.

The unresolved issue concerns technical points in the proof for general complete Noetherian I-adic rings. The paper proves a more restricted theorem for complete Noetherian local rings and for the indicated l-adic coefficient field, leaving the broader coefficient-ring generality unresolved.

References

However, for items (4) and (5), we can not prove the above theorem in this generality. The reason is that there are certain technical points occuring during the proof we were unable to resolve.

— Spreading out perverse sheaves  (2610.06707 - Zurbuchen, 5 Oct 2026) in Introduction, subsection “Generic base change”