Pólya–Szegő capacity conjecture

For every compact set K⊂R2K\subset\mathbb{R}^{2}, let cap⁡log⁡(K)\operatorname{cap}_{\log}(K) denote its logarithmic capacity and let Cap⁡N(K)\operatorname{Cap}_{N}(K) denote the Newtonian (electrostatic) capacity of KK regarded as a subset of the plane in R3\mathbb{R}^{3}. If D⊂R2D\subset\mathbb{R}^{2} is a disk satisfying cap⁡log⁡(D)=cap⁡log⁡(K)\operatorname{cap}_{\log}(D)=\operatorname{cap}_{\log}(K), then Cap⁡N(K)≤Cap⁡N(D)\operatorname{Cap}_{N}(K)\leq\operatorname{Cap}_{N}(D), with equality only when KK is a disk, up to translation.

References

Primary source

arXiv

Additional references

Progress summary

Refreshed
Claimed progress

A September 2026 paper narrows the open capacity conjecture to a stronger analytic inequality but does not prove it.

The Pólya–Szegő capacity conjecture asserts that the disk minimizes the relevant planar capacity energy, with equality only for a disk. It remains open globally.

Known results

  • The conjecture is proved for several perturbation classes of the disk and along certain deformations, but these are local results rather than a global proof.
  • Within planar sets, the disk is the only minimizer for the established lower bound; the conjectured sharp inequality remains unresolved.

September 2026 conditional reduction

Carrie Clark and Richard S. Laugesen show that the conjecture would follow from ball-minimization of a transverse strip Dirichlet energy. They also prove related LpL^p extremality by symmetrization. This is a claimed reduction, not a proof of the required strip-energy inequality, so the main conjecture remains open.

Current status (as of September 2026): The planar capacity conjecture remains open; a new conditional reduction and related symmetrization results constitute claimed progress, not a verified solution.

Sources

Solutions 0

No solutions have been posted yet.