Existence of non-trivial Fourier–Mukai pairs among triangularizable spaces

Determine whether there exist non-homeomorphic locally compact triangularizable spaces X and Y whose derived categories of sheaves of abelian groups are equivalent, namely whether mathrm{Shv}(X)[mathrm{D}(mathbb{Z})]simeq mathrm{Shv}(Y)[mathrm{D}(mathbb{Z})].

Background

The paper defines a non-trivial Fourier–Mukai pair as a pair of non-homeomorphic topological spaces with equivalent derived infty-categories of sheaves of abelian groups. It proves that no such pair exists when the first space is second-countable, triangularizable, and either one-dimensional, a finite-type surface, or the 3-sphere.

The authors note that non-trivial examples arise from non-sober or Alexandrov spaces, which are regarded as point-set-topological pathologies, but report no example among triangularizable spaces. Thus the unresolved issue is whether non-trivial Fourier–Mukai partners exist in the broader class of “nice” triangularizable spaces outside the cases settled by the reconstruction theorem.

References

Among nice topological spaces (which for concreteness and convenience we take to mean triangularizable spaces), we do not know of a single non-trivial FM pair.

— Reconstruction of graphs and surfaces from derived categories  (2610.13488 - Harr, 9 Oct 2026) in Section 1, subsection “Statement of results”