Gromov’s linear isoperimetric filling conjecture for Hadamard spaces

Let XX be a Hadamard space and let r=asrk⁡(X)r=\operatorname{asrk}(X) be its asymptotic rank. For every integer k≥rk\ge r, there exists a constant C=C(X,k)>0C=C(X,k)>0 such that every integral kk-cycle T∈Ik(X)T\in\mathbf{I}_k(X) admits an integral (k+1)(k+1)-current V∈Ik+1(X)V\in\mathbf{I}_{k+1}(X) with ∂V=T\partial V=T and M(V)≤C M(T)\mathbf{M}(V)\le C\,\mathbf{M}(T), where M\mathbf{M} denotes mass.

References

Progress summary

Refreshed
Claimed solved

An unrefereed August 2026 preprint claims to prove the conjecture in all finite-rank cases covered by its assumptions, but the result has not been independently verified.

Gromov’s conjecture predicts linear filling bounds for integral cycles in dimensions at least the asymptotic rank of a Hadamard space. The latest claim concerns spaces with finite asymptotic Nagata dimension and finite asymptotic rank.

Known results

  • Asymptotic rank at most 22: near-linear bounds M(V)≤CM(T)1+δ\mathbf{M}(V)\leq C\mathbf{M}(T)^{1+\delta}, not linear, under finite asymptotic Nagata dimension (Lang, Stadler, and Urech, 2025).
  • Homogeneous Hadamard manifolds: linear bounds for r≤k<nr\leq k<n (2022 preprint).

August 2026 claimed proof

A preprint reported on August 26, 2026 claims linear filling bounds for integral cycles in every dimension kk at least the asymptotic rank, under finite asymptotic Nagata dimension and rank. If correct, this extends the rank-one and rank-two theory to arbitrary finite asymptotic ranks; the claim is unrefereed and unverified.

Current status (as of August 2026): the conjecture is claimed solved under finite asymptotic Nagata-dimension and rank assumptions, but the new theorem remains unverified.

Sources

Solutions 0

No solutions have been posted yet.