Aldous spectral-gap conjecture for interchange processes on weighted hypergraphs

Prove that the spectral gap of the interchange process on every arbitrary weighted hypergraph is attained by a one-particle eigenfunction, thereby resolving Caputo’s conjecture for weighted-hypergraph interchange processes.

Background

The paper places its results within the broader study of Aldous-type spectral-gap phenomena, in which the dominant relaxation mode is represented by a low-particle observable. The classical Aldous conjecture for interchange processes on weighted graphs is known, but its proposed extension to arbitrary weighted hypergraphs remains unresolved.

The authors distinguish this interchange-process problem from the stochastic exchange models treated in the paper: their degree-two reduction theorem does not establish the one-particle reduction conjectured for weighted-hypergraph interchange processes. The problem is therefore a genuinely unresolved extension of the graph case.

References

A prominent open problem in this direction is Caputo's conjecture for the interchange process on arbitrary weighted hypergraphs; see Remark~\ref{rem:IP}.

— Aldous' spectral gap phenomena in stochastic exchange models  (2609.10450 - Caputo et al., 9 Sep 2026) in Section 1, subsection "Open problems"; see also Remark 1.?? (Remark \ref{rem:IP})

Finding further occurrences of this phenomenon, and identifying a common mechanism behind them, remains an interesting open problem.

— Aldous' spectral gap phenomena in stochastic exchange models  (2609.10450 - Caputo et al., 9 Sep 2026) in Section 1, subsection "Open problems"